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	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:3221:_Landscape_Features&amp;diff=408462</id>
		<title>Talk:3221: Landscape Features</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:3221:_Landscape_Features&amp;diff=408462"/>
				<updated>2026-03-19T08:29:33Z</updated>
		
		<summary type="html">&lt;p&gt;2603:800C:1200:596A:7154:D390:7A60:3197: I like these kinds of maps&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;&amp;lt;!-- Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom. --&amp;gt;&lt;br /&gt;
F1rst P0st!!! [[User:R128|R128]] ([[User talk:R128|talk]]) 17:27, 18 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
The ???? in New York is probably the [https://en.wikipedia.org/wiki/Adirondack_Mountains Adirondack Mountains]:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;blockquote&amp;gt;About 10 million years ago, the region began to be uplifted. It has been lifted about 7,000 feet (2,000 m) and is continuing at about 0.08 inches (2 mm) per year, which is greater than the rate of denudation. The cause of the uplift is unknown, but geologists theorize that it is caused by a hot spot in the Earth's crust.[18] A recent study has revealed a column of seismically slow materials about 30 to 50 miles (50 to 80 km) deep beneath the Adirondack Mountains,[20] which was interpreted to be the upwelling asthenosphere contributing to the uplift of the mountains.&amp;lt;/blockquote&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[User:Zzzt|Zzzt]] ([[User talk:Zzzt|talk]]) 17:58, 18 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
Geology being the cause of geological events is a tautology.--[[User:Henke37|Henke37]] ([[User talk:Henke37|talk]]) 18:26, 18 March 2026 (UTC)&lt;br /&gt;
:It's only a tautology where the plates are separating. It's a &amp;quot;compressology&amp;quot; where they're colliding, etc. ;) [[Special:Contributions/81.179.199.253|81.179.199.253]] 21:36, 18 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
conterguous* [[Special:Contributions/137.25.230.78|137.25.230.78]] 20:34, 18 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
I wonder if we should have a category for {{w|Isogloss}}. (Whether isoseme or some other variation.) I added in the two others 'of this basic illustrative nature' that I remembered off the top of my head, but I think there might be more. [[Special:Contributions/81.179.199.253|81.179.199.253]] 21:33, 18 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
;Sections to explain&lt;br /&gt;
&lt;br /&gt;
I'm not a geologist, so I don't know how to answer these questions, but I will leave this template here to eventually be copied into the article:&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Location&lt;br /&gt;
! Description&lt;br /&gt;
! Explanation&lt;br /&gt;
|-&lt;br /&gt;
| Adirondack Mountains&lt;br /&gt;
| ???&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Most of northern U.S. border&lt;br /&gt;
| Glaciers&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Appalachian Mountains&lt;br /&gt;
| Continents colliding&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Mississippi river basin&lt;br /&gt;
| Rivers&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| SE U.S.&lt;br /&gt;
| Farming&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Southern Florida&lt;br /&gt;
| Ongoing disputes between limestone and water&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Southern Missouri/Northern Arkansas&lt;br /&gt;
| ...geology&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Central column of U.S.&lt;br /&gt;
| Farming&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Central Idaho/Yellowstone&lt;br /&gt;
| A supervolcano&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Eastern Washington&lt;br /&gt;
| A megaflood&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| West Coast&lt;br /&gt;
| ...a plate tectonic speedrun.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| SW&lt;br /&gt;
| Water and time&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Northern Alaska&lt;br /&gt;
| ...geology&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Aleutians&lt;br /&gt;
| Volcanoes&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Hawaiian island chain&lt;br /&gt;
| Volcanoes&lt;br /&gt;
| &lt;br /&gt;
|}&lt;br /&gt;
[[User:Fephisto|Fephisto]] ([[User talk:Fephisto|talk]]) 18:59, 18 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
:...uh, why don't I just copy it into the article blank for now, actually?[[User:Fephisto|Fephisto]] ([[User talk:Fephisto|talk]]) 19:00, 18 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
This page should be in Category: Comics with color [[Special:Contributions/50.47.110.240|50.47.110.240]] 21:05, 18 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
New here, and don't know the formatting, but the table is currently missing the Cascade and Sierra Nevada &amp;quot;Vocanoes&amp;quot; region, though it's pretty self-explanatory. {{unsigned ip|136.56.99.85|21:29, 18 March 2026 (UTC)}}&lt;br /&gt;
&lt;br /&gt;
:Got it. [[User:Fephisto|Fephisto]] ([[User talk:Fephisto|talk]]) 00:12, 19 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
Also missing the “…geology” section surrounding the supervolcano. {{unsigned ip|146.115.160.214|21:58, 18 March 2026}}&lt;br /&gt;
&lt;br /&gt;
:Got it.[[User:Fephisto|Fephisto]] ([[User talk:Fephisto|talk]]) 00:11, 19 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
I feel like comic [[3141]] is worth a mention here, but I'm not sure where to put it. [[User:MrCandela|MrCandela]] ([[User talk:MrCandela|talk]]) 22:49, 18 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
:Added to the Adirondock row. [[User:Fephisto|Fephisto]] ([[User talk:Fephisto|talk]]) 00:12, 19 March 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
This explanation, and working on it, absolutely taught me more about US geology than I learned in school. [[Special:Contributions/2603:800C:1200:596A:7154:D390:7A60:3197|2603:800C:1200:596A:7154:D390:7A60:3197]] 08:29, 19 March 2026 (UTC)&lt;/div&gt;</summary>
		<author><name>2603:800C:1200:596A:7154:D390:7A60:3197</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408461</id>
		<title>3221: Landscape Features</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408461"/>
				<updated>2026-03-19T08:07:00Z</updated>
		
		<summary type="html">&lt;p&gt;2603:800C:1200:596A:7154:D390:7A60:3197: /* Explanation */ Mississippi&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3221&lt;br /&gt;
| date      = March 18, 2026&lt;br /&gt;
| title     = Landscape Features&lt;br /&gt;
| image     = landscape_features_2x.png&lt;br /&gt;
| imagesize = 537x454px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = 'Well, there's speculation that it's due to a mantle hotspot.' --a geologist who's trying to cover up the fact that they didn't hear your question&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|This page was created by a MANTLE HOTSPOT. Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a map of the United States, purporting to explain some of the most significant geologic/human activity in each region. For each area it names one major mechanism (plate tectonics, erosion, volcanism, etc.) which it claims is responsible for the majority of interesting formations and features.&lt;br /&gt;
&lt;br /&gt;
Many of these causes are summarized in a single word answer, which doesn't do much to explain a complex landscape. A few phrases are longer but still don't actually explain much. And some areas are just labeled &amp;quot;geology&amp;quot;. &lt;br /&gt;
&lt;br /&gt;
The title text plays off the fact that a large part of geology is concerned with activity in the mantle, so explaining some geologic feature by saying &amp;quot;there's speculation that it's due to a mantle hotspot&amp;quot; does not give much information. Saying this would let a distracted geologist buy time while responding to a missed question. Many of Earth's seemingly out-of-place features (e.g., {{w|Hawaii hotspot}}, {{w|Iceland}}, the {{w|Snake River Plain}} in Idaho, etc.) form from such mantle hotspots. Thus, it's an easy go-to explanation for many of the geological features people are often most curious about.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Location&lt;br /&gt;
! Description&lt;br /&gt;
! Explanation&lt;br /&gt;
|-&lt;br /&gt;
| Adirondack Mountains&lt;br /&gt;
| ???&lt;br /&gt;
| The Adirondack Mountains are made of billion-year-old rock but were uplifted relatively recently, within the last 5–10 million years. They’re still rising today despite being far from any plate boundary, forming a dome with no clear tectonic cause, [[3141|thus the &amp;quot;???&amp;quot; due to an ongoing mystery as to their formation]]. &lt;br /&gt;
|-&lt;br /&gt;
| Most of northern conterminous U.S.&lt;br /&gt;
| glaciers&lt;br /&gt;
| During the {{w|Last Glacial Period}}, this area was covered by {{w|Laurentide Ice Sheet|an ice sheet}} that left its marks on the landscape, in the form of {{w|moraines}}, {{w|eskers}}, {{w|glacial erratics}}, etc.&lt;br /&gt;
|-&lt;br /&gt;
| Appalachian Mountains&lt;br /&gt;
| continents colliding&lt;br /&gt;
| {{w|Geology of the Appalachians|The Appalachian Mountains formed roughly 480 to 300 million years ago}} through a series of continent-continent collisions, culminating in the assembly of the supercontinent Pangaea. The primary collision involved ancestral North America (Laurentia) crashing into Gondwana (Africa/South America), resulting in a Himalayan-scale mountain range.&lt;br /&gt;
|-&lt;br /&gt;
| Mississippi and Ohio River Basins&lt;br /&gt;
| rivers&lt;br /&gt;
| The {{w|Mississippi River}}'s geology has a complex, 70 million year history involving massive sediment deposition, glacial activity, and tectonic shifting. Formed mostly by melting glaciers ~12,000 years ago, it drains a vast, shifting basin, depositing millions of tons of sediment in a massive delta and creating a vast, shifting alluvial plain. The {{w|Ohio_River#Geology|Ohio River's geology}} is similar.&lt;br /&gt;
|-&lt;br /&gt;
| Southeastern U.S.&lt;br /&gt;
| farming&lt;br /&gt;
| Landscape changes from {{w|cotton production in the United States}}, due to the presence of the {{w|Black Belt (geological formation)}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Florida&lt;br /&gt;
| ongoing disputes between limestone and water&lt;br /&gt;
| Florida is a vast {{w|karst}} landscape formed by the dissolution of underground limestone and dolostone bedrock by acidic rainwater, resulting in a terrain characterized by sinkholes, springs, caverns, and disappearing streams. This soluble bedrock, formed from ancient marine deposits, covers much of the state, directly connecting surface water to the Floridian aquifer system.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Missouri/Northern Arkansas&lt;br /&gt;
| geology&lt;br /&gt;
| The {{w|Ozark Mountains}}, which are composed primarily of ancient limestone and {{w|dolomite}}, form a rugged landscape characterized by hills, caves, and springs. Prolonged erosion of these soluble rocks has produced extensive karst features, including sinkholes and underground rivers.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Great Plains}}&lt;br /&gt;
| farming&lt;br /&gt;
| The lack of other major events left the terrain relatively level, and areas were historically shaped by either herds of bison or indigenous agriculture, both limiting the growth of forests. &amp;quot;Farming&amp;quot; is likely a reference to the more recent mix of large-scale crop farming (especially staples like wheat and corn) and herding (bison replaced by cattle).&lt;br /&gt;
|-&lt;br /&gt;
| Central Idaho/Yellowstone&lt;br /&gt;
| a supervolcano&lt;br /&gt;
| The {{w|Snake River Plain}} is an area of high-elevation flat plain in the otherwise contiguous Rocky Mountains. It was formed by the movement of the continental plate over the {{w|Yellowstone Hotspot}}.&lt;br /&gt;
|-&lt;br /&gt;
| American West surrounding Idaho/Yellowstone&lt;br /&gt;
| geology&lt;br /&gt;
| [[3162: Heart Mountain]]&lt;br /&gt;
|-&lt;br /&gt;
| Immediately off of West coast up to the Four Corners&lt;br /&gt;
| volcanoes&lt;br /&gt;
| A combination of various {{w|volcanic field}}s of different origins, including {{w|Cascade Volcanoes}} in the Pacific Northwest, {{w|Albuquerque volcanic field}} in New Mexico, {{w|San Francisco volcanic field}} in Arizona, and {{w|San Juan volcanic field}} in Colorado.&lt;br /&gt;
|-&lt;br /&gt;
| Eastern Washington&lt;br /&gt;
| megafloods&lt;br /&gt;
| Most likely a reference to the {{w|Missoula floods}} and the {{w|Bonneville flood}}, a series of floods caused by glacial ice dam failures causing massive lakes to flood large regions of present-day eastern Washington. These floods actually continued all the way to the Pacific Ocean, altering the shape of the {{w|Columbia River Gorge}} and flooding much of the {{w|Willamette River}} in western Oregon. The comic may have simplified these to avoid bisecting the adjacent zones along the coast.&lt;br /&gt;
|-&lt;br /&gt;
| West Coast&lt;br /&gt;
| a plate tectonic speedrun&lt;br /&gt;
| Most likely a reference to the significant tectonic activity on the western coast of the US, caused by the collisions of the {{w|Juan de Fuca plate}}, {{w|Pacific plate}}, and the {{w|North American plate}}, as part of the {{w|Ring of Fire}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southwest Desert&lt;br /&gt;
| water and time&lt;br /&gt;
| The nearly 40 major sedimentary rock layers exposed in the {{w|geology of the Grand Canyon area}} range in age from about 200 million to nearly 2 billion years old. Uplift of the region started about 75 million years ago during the mountain-building event largely responsible for creating the Rocky Mountains. The opening of the Gulf of California around 6 million years ago enabled a large river to cut its way northeast from the gulf. The new river captured the older drainage to form the ancestral Colorado River, which in turn started to form the Grand Canyon. Wetter climates brought upon by ice ages starting 2 million years ago greatly increased excavation of the Grand Canyon, which was nearly as deep 1.2 million years ago as it is now.  &lt;br /&gt;
|-&lt;br /&gt;
| Northern Alaska&lt;br /&gt;
| geology&lt;br /&gt;
| Northern {{w|Geology of Alaska|Alaska geology}} is dominated by the Brooks Range (a major Paleozoic mountain belt) and the Arctic Slope sedimentary basin, containing rich Paleozoic-Mesozoic rock sequences. The region is part of the Arctic Alaska–Chukotka Microplate, shaped by Mesozoic tectonic shifts, including the Arctic Ocean opening and the Brooks Range uplift.&lt;br /&gt;
|-&lt;br /&gt;
| Aleutian Islands&lt;br /&gt;
| volcanoes&lt;br /&gt;
| The Aleutian Islands are a continuation of the Alaskan {{w|Aleutian Range}}, and form part of the {{w|Ring of Fire}}. Most of the islands in the chain bear signs of being formed by volcanoes, and many volcanic cones still exist on the islands today.&lt;br /&gt;
|-&lt;br /&gt;
| Southeast Alaska&lt;br /&gt;
| glaciers&lt;br /&gt;
| This part of Alaska (including {{w|Glacier National Park (U.S.)|Glacier National Park}}) and western Canada has many glaciers that are still carving the landscape.&lt;br /&gt;
|-&lt;br /&gt;
| Hawaiian island chain&lt;br /&gt;
| volcanoes&lt;br /&gt;
| Hawaii, including the {{w|Northwest Hawaiian Islands}}, and seamounts northwest of it were formed by a tectonic plate moving over a hotspot, with volcanoes erupting and forming land as it went. The entire chain can be seen [https://www.google.com/maps/@34.0555574,-176.5939317,4904085m/data=!3m1!1e3?entry=ttu&amp;amp;g_ep=EgoyMDI2MDMxNS4wIKXMDSoASAFQAw%3D%3D here]. Volcanic fog from the {{w|List of volcanoes in the Hawaiian–Emperor seamount chain|three active volcanoes on the Big Island}} can often be seen on neighboring islands.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;h1&amp;gt;Feature of Each State&amp;lt;/h1&amp;gt;&lt;br /&gt;
Washington: Mega floods, a plates tectonics speedrun&lt;br /&gt;
&lt;br /&gt;
Idaho: a super volcano, geology&lt;br /&gt;
&lt;br /&gt;
Montana: geology, glaciers&lt;br /&gt;
&lt;br /&gt;
North Dakota: glaciers, farming&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
This map with subdivisions follows up on a number of prior (non-[[:Category:Bad Map Projections|cursed]]) maps representing (supposed) geographical splits of some conversational outcome or other, such as [[1407: Worst Hurricane]] and [[2108: Carbonated Beverage Language Map]].&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[A small panel showing Cueball pointing toward the left and Ponytail standing to his right overlaps the top of a much larger panel containing a map.]&lt;br /&gt;
:Cueball: What's up with this weird landscape?&lt;br /&gt;
:Ponytail: Oh, it was caused by ...&lt;br /&gt;
&lt;br /&gt;
:[The larger panel shows a map of the United States, with southern Canada, northern Mexico, and most of Cuba and the Bahamas visible as well. An inset at lower left shows Alaska along with part of northwest Canada, with a smaller inset showing Hawaii. International borders and coastlines are indicated in black, and state borders are indicated in gray. Red lines divide the United States into irregularly shaped zones (the red lines indicating zones do not cross into the neighboring countries, except in the Alaska inset), with each zone being labeled with red text. Each text label begins with &amp;quot;...&amp;quot; to indicate that it is the conclusion of Ponytail's sentence. The following are the labels used:]&lt;br /&gt;
:[Main map:]&lt;br /&gt;
:... a plate tectonics speedrun&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... megafloods&lt;br /&gt;
:... a supervolcano&lt;br /&gt;
:... geology&lt;br /&gt;
:... water and time&lt;br /&gt;
:... glaciers&lt;br /&gt;
:... rivers&lt;br /&gt;
:... continents colliding&lt;br /&gt;
:... ???&lt;br /&gt;
:... ongoing disputes between limestone and water&lt;br /&gt;
:[On the main map, the label &amp;quot;... glaciers&amp;quot; appears three times in various places in the same contiguous zone that runs from Washington state to Maine. The label &amp;quot;... farming&amp;quot; appears twice, representing two separate zones, one that runs from Montana to Louisiana and the other that runs from New Jersey to Mississippi. The label &amp;quot;... geology&amp;quot; appears twice on the main map, representing two separate zones, one that runs from Washington state to Texas and the other being a roughly circular region mostly in southern Missouri and northern Arkansas.]&lt;br /&gt;
:[Alaska inset:]&lt;br /&gt;
:... geology&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... glaciers&lt;br /&gt;
:[Hawaii inset:]&lt;br /&gt;
:... volcanoes&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&amp;lt;noinclude&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics with color]]&lt;br /&gt;
[[Category:US maps]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Volcanoes]]&lt;/div&gt;</summary>
		<author><name>2603:800C:1200:596A:7154:D390:7A60:3197</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408460</id>
		<title>3221: Landscape Features</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408460"/>
				<updated>2026-03-19T08:02:34Z</updated>
		
		<summary type="html">&lt;p&gt;2603:800C:1200:596A:7154:D390:7A60:3197: /* Explanation */ Appalachians&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3221&lt;br /&gt;
| date      = March 18, 2026&lt;br /&gt;
| title     = Landscape Features&lt;br /&gt;
| image     = landscape_features_2x.png&lt;br /&gt;
| imagesize = 537x454px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = 'Well, there's speculation that it's due to a mantle hotspot.' --a geologist who's trying to cover up the fact that they didn't hear your question&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|This page was created by a MANTLE HOTSPOT. Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a map of the United States, purporting to explain some of the most significant geologic/human activity in each region. For each area it names one major mechanism (plate tectonics, erosion, volcanism, etc.) which it claims is responsible for the majority of interesting formations and features.&lt;br /&gt;
&lt;br /&gt;
Many of these causes are summarized in a single word answer, which doesn't do much to explain a complex landscape. A few phrases are longer but still don't actually explain much. And some areas are just labeled &amp;quot;geology&amp;quot;. &lt;br /&gt;
&lt;br /&gt;
The title text plays off the fact that a large part of geology is concerned with activity in the mantle, so explaining some geologic feature by saying &amp;quot;there's speculation that it's due to a mantle hotspot&amp;quot; does not give much information. Saying this would let a distracted geologist buy time while responding to a missed question. Many of Earth's seemingly out-of-place features (e.g., {{w|Hawaii hotspot}}, {{w|Iceland}}, the {{w|Snake River Plain}} in Idaho, etc.) form from such mantle hotspots. Thus, it's an easy go-to explanation for many of the geological features people are often most curious about.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Location&lt;br /&gt;
! Description&lt;br /&gt;
! Explanation&lt;br /&gt;
|-&lt;br /&gt;
| Adirondack Mountains&lt;br /&gt;
| ???&lt;br /&gt;
| The Adirondack Mountains are made of billion-year-old rock but were uplifted relatively recently, within the last 5–10 million years. They’re still rising today despite being far from any plate boundary, forming a dome with no clear tectonic cause, [[3141|thus the &amp;quot;???&amp;quot; due to an ongoing mystery as to their formation]]. &lt;br /&gt;
|-&lt;br /&gt;
| Most of northern conterminous U.S.&lt;br /&gt;
| glaciers&lt;br /&gt;
| During the {{w|Last Glacial Period}}, this area was covered by {{w|Laurentide Ice Sheet|an ice sheet}} that left its marks on the landscape, in the form of {{w|moraines}}, {{w|eskers}}, {{w|glacial erratics}}, etc.&lt;br /&gt;
|-&lt;br /&gt;
| Appalachian Mountains&lt;br /&gt;
| continents colliding&lt;br /&gt;
| {{w|Geology of the Appalachians|The Appalachian Mountains formed roughly 480 to 300 million years ago}} through a series of continent-continent collisions, culminating in the assembly of the supercontinent Pangaea. The primary collision involved ancestral North America (Laurentia) crashing into Gondwana (Africa/South America), resulting in a Himalayan-scale mountain range.&lt;br /&gt;
|-&lt;br /&gt;
| Near Mississippi &amp;amp; Ohio Rivers&lt;br /&gt;
| rivers&lt;br /&gt;
| {{w|Ohio_River#Geology|Ohio River Geology}}&lt;br /&gt;
|-&lt;br /&gt;
| Southeastern U.S.&lt;br /&gt;
| farming&lt;br /&gt;
| Landscape changes from {{w|cotton production in the United States}}, due to the presence of the {{w|Black Belt (geological formation)}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Florida&lt;br /&gt;
| ongoing disputes between limestone and water&lt;br /&gt;
| Florida is a vast {{w|karst}} landscape formed by the dissolution of underground limestone and dolostone bedrock by acidic rainwater, resulting in a terrain characterized by sinkholes, springs, caverns, and disappearing streams. This soluble bedrock, formed from ancient marine deposits, covers much of the state, directly connecting surface water to the Floridian aquifer system.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Missouri/Northern Arkansas&lt;br /&gt;
| geology&lt;br /&gt;
| The {{w|Ozark Mountains}}, which are composed primarily of ancient limestone and {{w|dolomite}}, form a rugged landscape characterized by hills, caves, and springs. Prolonged erosion of these soluble rocks has produced extensive karst features, including sinkholes and underground rivers.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Great Plains}}&lt;br /&gt;
| farming&lt;br /&gt;
| The lack of other major events left the terrain relatively level, and areas were historically shaped by either herds of bison or indigenous agriculture, both limiting the growth of forests. &amp;quot;Farming&amp;quot; is likely a reference to the more recent mix of large-scale crop farming (especially staples like wheat and corn) and herding (bison replaced by cattle).&lt;br /&gt;
|-&lt;br /&gt;
| Central Idaho/Yellowstone&lt;br /&gt;
| a supervolcano&lt;br /&gt;
| The {{w|Snake River Plain}} is an area of high-elevation flat plain in the otherwise contiguous Rocky Mountains. It was formed by the movement of the continental plate over the {{w|Yellowstone Hotspot}}.&lt;br /&gt;
|-&lt;br /&gt;
| American West surrounding Idaho/Yellowstone&lt;br /&gt;
| geology&lt;br /&gt;
| [[3162: Heart Mountain]]&lt;br /&gt;
|-&lt;br /&gt;
| Immediately off of West coast up to the Four Corners&lt;br /&gt;
| volcanoes&lt;br /&gt;
| A combination of various {{w|volcanic field}}s of different origins, including {{w|Cascade Volcanoes}} in the Pacific Northwest, {{w|Albuquerque volcanic field}} in New Mexico, {{w|San Francisco volcanic field}} in Arizona, and {{w|San Juan volcanic field}} in Colorado.&lt;br /&gt;
|-&lt;br /&gt;
| Eastern Washington&lt;br /&gt;
| megafloods&lt;br /&gt;
| Most likely a reference to the {{w|Missoula floods}} and the {{w|Bonneville flood}}, a series of floods caused by glacial ice dam failures causing massive lakes to flood large regions of present-day eastern Washington. These floods actually continued all the way to the Pacific Ocean, altering the shape of the {{w|Columbia River Gorge}} and flooding much of the {{w|Willamette River}} in western Oregon. The comic may have simplified these to avoid bisecting the adjacent zones along the coast.&lt;br /&gt;
|-&lt;br /&gt;
| West Coast&lt;br /&gt;
| a plate tectonic speedrun&lt;br /&gt;
| Most likely a reference to the significant tectonic activity on the western coast of the US, caused by the collisions of the {{w|Juan de Fuca plate}}, {{w|Pacific plate}}, and the {{w|North American plate}}, as part of the {{w|Ring of Fire}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southwest Desert&lt;br /&gt;
| water and time&lt;br /&gt;
| The nearly 40 major sedimentary rock layers exposed in the {{w|geology of the Grand Canyon area}} range in age from about 200 million to nearly 2 billion years old. Uplift of the region started about 75 million years ago during the mountain-building event largely responsible for creating the Rocky Mountains. The opening of the Gulf of California around 6 million years ago enabled a large river to cut its way northeast from the gulf. The new river captured the older drainage to form the ancestral Colorado River, which in turn started to form the Grand Canyon. Wetter climates brought upon by ice ages starting 2 million years ago greatly increased excavation of the Grand Canyon, which was nearly as deep 1.2 million years ago as it is now.  &lt;br /&gt;
|-&lt;br /&gt;
| Northern Alaska&lt;br /&gt;
| geology&lt;br /&gt;
| Northern {{w|Geology of Alaska|Alaska geology}} is dominated by the Brooks Range (a major Paleozoic mountain belt) and the Arctic Slope sedimentary basin, containing rich Paleozoic-Mesozoic rock sequences. The region is part of the Arctic Alaska–Chukotka Microplate, shaped by Mesozoic tectonic shifts, including the Arctic Ocean opening and the Brooks Range uplift.&lt;br /&gt;
|-&lt;br /&gt;
| Aleutian Islands&lt;br /&gt;
| volcanoes&lt;br /&gt;
| The Aleutian Islands are a continuation of the Alaskan {{w|Aleutian Range}}, and form part of the {{w|Ring of Fire}}. Most of the islands in the chain bear signs of being formed by volcanoes, and many volcanic cones still exist on the islands today.&lt;br /&gt;
|-&lt;br /&gt;
| Southeast Alaska&lt;br /&gt;
| glaciers&lt;br /&gt;
| This part of Alaska (including {{w|Glacier National Park (U.S.)|Glacier National Park}}) and western Canada has many glaciers that are still carving the landscape.&lt;br /&gt;
|-&lt;br /&gt;
| Hawaiian island chain&lt;br /&gt;
| volcanoes&lt;br /&gt;
| Hawaii, including the {{w|Northwest Hawaiian Islands}}, and seamounts northwest of it were formed by a tectonic plate moving over a hotspot, with volcanoes erupting and forming land as it went. The entire chain can be seen [https://www.google.com/maps/@34.0555574,-176.5939317,4904085m/data=!3m1!1e3?entry=ttu&amp;amp;g_ep=EgoyMDI2MDMxNS4wIKXMDSoASAFQAw%3D%3D here]. Volcanic fog from the {{w|List of volcanoes in the Hawaiian–Emperor seamount chain|three active volcanoes on the Big Island}} can often be seen on neighboring islands.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;h1&amp;gt;Feature of Each State&amp;lt;/h1&amp;gt;&lt;br /&gt;
Washington: Mega floods, a plates tectonics speedrun&lt;br /&gt;
&lt;br /&gt;
Idaho: a super volcano, geology&lt;br /&gt;
&lt;br /&gt;
Montana: geology, glaciers&lt;br /&gt;
&lt;br /&gt;
North Dakota: glaciers, farming&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
This map with subdivisions follows up on a number of prior (non-[[:Category:Bad Map Projections|cursed]]) maps representing (supposed) geographical splits of some conversational outcome or other, such as [[1407: Worst Hurricane]] and [[2108: Carbonated Beverage Language Map]].&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[A small panel showing Cueball pointing toward the left and Ponytail standing to his right overlaps the top of a much larger panel containing a map.]&lt;br /&gt;
:Cueball: What's up with this weird landscape?&lt;br /&gt;
:Ponytail: Oh, it was caused by ...&lt;br /&gt;
&lt;br /&gt;
:[The larger panel shows a map of the United States, with southern Canada, northern Mexico, and most of Cuba and the Bahamas visible as well. An inset at lower left shows Alaska along with part of northwest Canada, with a smaller inset showing Hawaii. International borders and coastlines are indicated in black, and state borders are indicated in gray. Red lines divide the United States into irregularly shaped zones (the red lines indicating zones do not cross into the neighboring countries, except in the Alaska inset), with each zone being labeled with red text. Each text label begins with &amp;quot;...&amp;quot; to indicate that it is the conclusion of Ponytail's sentence. The following are the labels used:]&lt;br /&gt;
:[Main map:]&lt;br /&gt;
:... a plate tectonics speedrun&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... megafloods&lt;br /&gt;
:... a supervolcano&lt;br /&gt;
:... geology&lt;br /&gt;
:... water and time&lt;br /&gt;
:... glaciers&lt;br /&gt;
:... rivers&lt;br /&gt;
:... continents colliding&lt;br /&gt;
:... ???&lt;br /&gt;
:... ongoing disputes between limestone and water&lt;br /&gt;
:[On the main map, the label &amp;quot;... glaciers&amp;quot; appears three times in various places in the same contiguous zone that runs from Washington state to Maine. The label &amp;quot;... farming&amp;quot; appears twice, representing two separate zones, one that runs from Montana to Louisiana and the other that runs from New Jersey to Mississippi. The label &amp;quot;... geology&amp;quot; appears twice on the main map, representing two separate zones, one that runs from Washington state to Texas and the other being a roughly circular region mostly in southern Missouri and northern Arkansas.]&lt;br /&gt;
:[Alaska inset:]&lt;br /&gt;
:... geology&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... glaciers&lt;br /&gt;
:[Hawaii inset:]&lt;br /&gt;
:... volcanoes&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&amp;lt;noinclude&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics with color]]&lt;br /&gt;
[[Category:US maps]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Volcanoes]]&lt;/div&gt;</summary>
		<author><name>2603:800C:1200:596A:7154:D390:7A60:3197</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408459</id>
		<title>3221: Landscape Features</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408459"/>
				<updated>2026-03-19T07:59:53Z</updated>
		
		<summary type="html">&lt;p&gt;2603:800C:1200:596A:7154:D390:7A60:3197: /* Explanation */ spelling and grammar&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3221&lt;br /&gt;
| date      = March 18, 2026&lt;br /&gt;
| title     = Landscape Features&lt;br /&gt;
| image     = landscape_features_2x.png&lt;br /&gt;
| imagesize = 537x454px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = 'Well, there's speculation that it's due to a mantle hotspot.' --a geologist who's trying to cover up the fact that they didn't hear your question&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|This page was created by a MANTLE HOTSPOT. Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a map of the United States, purporting to explain some of the most significant geologic/human activity in each region. For each area it names one major mechanism (plate tectonics, erosion, volcanism, etc.) which it claims is responsible for the majority of interesting formations and features.&lt;br /&gt;
&lt;br /&gt;
Many of these causes are summarized in a single word answer, which doesn't do much to explain a complex landscape. A few phrases are longer but still don't actually explain much. And some areas are just labeled &amp;quot;geology&amp;quot;. &lt;br /&gt;
&lt;br /&gt;
The title text plays off the fact that a large part of geology is concerned with activity in the mantle, so explaining some geologic feature by saying &amp;quot;there's speculation that it's due to a mantle hotspot&amp;quot; does not give much information. Saying this would let a distracted geologist buy time while responding to a missed question. Many of Earth's seemingly out-of-place features (e.g., {{w|Hawaii hotspot}}, {{w|Iceland}}, the {{w|Snake River Plain}} in Idaho, etc.) form from such mantle hotspots. Thus, it's an easy go-to explanation for many of the geological features people are often most curious about.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Location&lt;br /&gt;
! Description&lt;br /&gt;
! Explanation&lt;br /&gt;
|-&lt;br /&gt;
| Adirondack Mountains&lt;br /&gt;
| ???&lt;br /&gt;
| The Adirondack Mountains are made of billion-year-old rock but were uplifted relatively recently, within the last 5–10 million years. They’re still rising today despite being far from any plate boundary, forming a dome with no clear tectonic cause, [[3141|thus the &amp;quot;???&amp;quot; due to an ongoing mystery as to their formation]]. &lt;br /&gt;
|-&lt;br /&gt;
| Most of northern conterminous U.S.&lt;br /&gt;
| glaciers&lt;br /&gt;
| During the {{w|Last Glacial Period}}, this area was covered by {{w|Laurentide Ice Sheet|an ice sheet}} that left its marks on the landscape, in the form of {{w|moraines}}, {{w|eskers}}, {{w|glacial erratics}}, etc.&lt;br /&gt;
|-&lt;br /&gt;
| Appalachian Mountains&lt;br /&gt;
| continents colliding&lt;br /&gt;
| {{w|Geology of the Appalachians}}&lt;br /&gt;
|-&lt;br /&gt;
| Near Mississippi &amp;amp; Ohio Rivers&lt;br /&gt;
| rivers&lt;br /&gt;
| {{w|Ohio_River#Geology|Ohio River Geology}}&lt;br /&gt;
|-&lt;br /&gt;
| Southeastern U.S.&lt;br /&gt;
| farming&lt;br /&gt;
| Landscape changes from {{w|cotton production in the United States}}, due to the presence of the {{w|Black Belt (geological formation)}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Florida&lt;br /&gt;
| ongoing disputes between limestone and water&lt;br /&gt;
| Florida is a vast {{w|karst}} landscape formed by the dissolution of underground limestone and dolostone bedrock by acidic rainwater, resulting in a terrain characterized by sinkholes, springs, caverns, and disappearing streams. This soluble bedrock, formed from ancient marine deposits, covers much of the state, directly connecting surface water to the Floridian aquifer system.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Missouri/Northern Arkansas&lt;br /&gt;
| geology&lt;br /&gt;
| The {{w|Ozark Mountains}}, which are composed primarily of ancient limestone and {{w|dolomite}}, form a rugged landscape characterized by hills, caves, and springs. Prolonged erosion of these soluble rocks has produced extensive karst features, including sinkholes and underground rivers.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Great Plains}}&lt;br /&gt;
| farming&lt;br /&gt;
| The lack of other major events left the terrain relatively level, and areas were historically shaped by either herds of bison or indigenous agriculture, both limiting the growth of forests. &amp;quot;Farming&amp;quot; is likely a reference to the more recent mix of large-scale crop farming (especially staples like wheat and corn) and herding (bison replaced by cattle).&lt;br /&gt;
|-&lt;br /&gt;
| Central Idaho/Yellowstone&lt;br /&gt;
| a supervolcano&lt;br /&gt;
| The {{w|Snake River Plain}} is an area of high-elevation flat plain in the otherwise contiguous Rocky Mountains. It was formed by the movement of the continental plate over the {{w|Yellowstone Hotspot}}.&lt;br /&gt;
|-&lt;br /&gt;
| American West surrounding Idaho/Yellowstone&lt;br /&gt;
| geology&lt;br /&gt;
| [[3162: Heart Mountain]]&lt;br /&gt;
|-&lt;br /&gt;
| Immediately off of West coast up to the Four Corners&lt;br /&gt;
| volcanoes&lt;br /&gt;
| A combination of various {{w|volcanic field}}s of different origins, including {{w|Cascade Volcanoes}} in the Pacific Northwest, {{w|Albuquerque volcanic field}} in New Mexico, {{w|San Francisco volcanic field}} in Arizona, and {{w|San Juan volcanic field}} in Colorado.&lt;br /&gt;
|-&lt;br /&gt;
| Eastern Washington&lt;br /&gt;
| megafloods&lt;br /&gt;
| Most likely a reference to the {{w|Missoula floods}} and the {{w|Bonneville flood}}, a series of floods caused by glacial ice dam failures causing massive lakes to flood large regions of present-day eastern Washington. These floods actually continued all the way to the Pacific Ocean, altering the shape of the {{w|Columbia River Gorge}} and flooding much of the {{w|Willamette River}} in western Oregon. The comic may have simplified these to avoid bisecting the adjacent zones along the coast.&lt;br /&gt;
|-&lt;br /&gt;
| West Coast&lt;br /&gt;
| a plate tectonic speedrun&lt;br /&gt;
| Most likely a reference to the significant tectonic activity on the western coast of the US, caused by the collisions of the {{w|Juan de Fuca plate}}, {{w|Pacific plate}}, and the {{w|North American plate}}, as part of the {{w|Ring of Fire}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southwest Desert&lt;br /&gt;
| water and time&lt;br /&gt;
| The nearly 40 major sedimentary rock layers exposed in the {{w|geology of the Grand Canyon area}} range in age from about 200 million to nearly 2 billion years old. Uplift of the region started about 75 million years ago during the mountain-building event largely responsible for creating the Rocky Mountains. The opening of the Gulf of California around 6 million years ago enabled a large river to cut its way northeast from the gulf. The new river captured the older drainage to form the ancestral Colorado River, which in turn started to form the Grand Canyon. Wetter climates brought upon by ice ages starting 2 million years ago greatly increased excavation of the Grand Canyon, which was nearly as deep 1.2 million years ago as it is now.  &lt;br /&gt;
|-&lt;br /&gt;
| Northern Alaska&lt;br /&gt;
| geology&lt;br /&gt;
| Northern {{w|Geology of Alaska|Alaska geology}} is dominated by the Brooks Range (a major Paleozoic mountain belt) and the Arctic Slope sedimentary basin, containing rich Paleozoic-Mesozoic rock sequences. The region is part of the Arctic Alaska–Chukotka Microplate, shaped by Mesozoic tectonic shifts, including the Arctic Ocean opening and the Brooks Range uplift.&lt;br /&gt;
|-&lt;br /&gt;
| Aleutian Islands&lt;br /&gt;
| volcanoes&lt;br /&gt;
| The Aleutian Islands are a continuation of the Alaskan {{w|Aleutian Range}}, and form part of the {{w|Ring of Fire}}. Most of the islands in the chain bear signs of being formed by volcanoes, and many volcanic cones still exist on the islands today.&lt;br /&gt;
|-&lt;br /&gt;
| Southeast Alaska&lt;br /&gt;
| glaciers&lt;br /&gt;
| This part of Alaska (including {{w|Glacier National Park (U.S.)|Glacier National Park}}) and western Canada has many glaciers that are still carving the landscape.&lt;br /&gt;
|-&lt;br /&gt;
| Hawaiian island chain&lt;br /&gt;
| volcanoes&lt;br /&gt;
| Hawaii, including the {{w|Northwest Hawaiian Islands}}, and seamounts northwest of it were formed by a tectonic plate moving over a hotspot, with volcanoes erupting and forming land as it went. The entire chain can be seen [https://www.google.com/maps/@34.0555574,-176.5939317,4904085m/data=!3m1!1e3?entry=ttu&amp;amp;g_ep=EgoyMDI2MDMxNS4wIKXMDSoASAFQAw%3D%3D here]. Volcanic fog from the {{w|List of volcanoes in the Hawaiian–Emperor seamount chain|three active volcanoes on the Big Island}} can often be seen on neighboring islands.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;h1&amp;gt;Feature of Each State&amp;lt;/h1&amp;gt;&lt;br /&gt;
Washington: Mega floods, a plates tectonics speedrun&lt;br /&gt;
&lt;br /&gt;
Idaho: a super volcano, geology&lt;br /&gt;
&lt;br /&gt;
Montana: geology, glaciers&lt;br /&gt;
&lt;br /&gt;
North Dakota: glaciers, farming&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
This map with subdivisions follows up on a number of prior (non-[[:Category:Bad Map Projections|cursed]]) maps representing (supposed) geographical splits of some conversational outcome or other, such as [[1407: Worst Hurricane]] and [[2108: Carbonated Beverage Language Map]].&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[A small panel showing Cueball pointing toward the left and Ponytail standing to his right overlaps the top of a much larger panel containing a map.]&lt;br /&gt;
:Cueball: What's up with this weird landscape?&lt;br /&gt;
:Ponytail: Oh, it was caused by ...&lt;br /&gt;
&lt;br /&gt;
:[The larger panel shows a map of the United States, with southern Canada, northern Mexico, and most of Cuba and the Bahamas visible as well. An inset at lower left shows Alaska along with part of northwest Canada, with a smaller inset showing Hawaii. International borders and coastlines are indicated in black, and state borders are indicated in gray. Red lines divide the United States into irregularly shaped zones (the red lines indicating zones do not cross into the neighboring countries, except in the Alaska inset), with each zone being labeled with red text. Each text label begins with &amp;quot;...&amp;quot; to indicate that it is the conclusion of Ponytail's sentence. The following are the labels used:]&lt;br /&gt;
:[Main map:]&lt;br /&gt;
:... a plate tectonics speedrun&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... megafloods&lt;br /&gt;
:... a supervolcano&lt;br /&gt;
:... geology&lt;br /&gt;
:... water and time&lt;br /&gt;
:... glaciers&lt;br /&gt;
:... rivers&lt;br /&gt;
:... continents colliding&lt;br /&gt;
:... ???&lt;br /&gt;
:... ongoing disputes between limestone and water&lt;br /&gt;
:[On the main map, the label &amp;quot;... glaciers&amp;quot; appears three times in various places in the same contiguous zone that runs from Washington state to Maine. The label &amp;quot;... farming&amp;quot; appears twice, representing two separate zones, one that runs from Montana to Louisiana and the other that runs from New Jersey to Mississippi. The label &amp;quot;... geology&amp;quot; appears twice on the main map, representing two separate zones, one that runs from Washington state to Texas and the other being a roughly circular region mostly in southern Missouri and northern Arkansas.]&lt;br /&gt;
:[Alaska inset:]&lt;br /&gt;
:... geology&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... glaciers&lt;br /&gt;
:[Hawaii inset:]&lt;br /&gt;
:... volcanoes&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&amp;lt;noinclude&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics with color]]&lt;br /&gt;
[[Category:US maps]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Volcanoes]]&lt;/div&gt;</summary>
		<author><name>2603:800C:1200:596A:7154:D390:7A60:3197</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408458</id>
		<title>3221: Landscape Features</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408458"/>
				<updated>2026-03-19T07:53:01Z</updated>
		
		<summary type="html">&lt;p&gt;2603:800C:1200:596A:7154:D390:7A60:3197: /* Explanation */ swap words&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3221&lt;br /&gt;
| date      = March 18, 2026&lt;br /&gt;
| title     = Landscape Features&lt;br /&gt;
| image     = landscape_features_2x.png&lt;br /&gt;
| imagesize = 537x454px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = 'Well, there's speculation that it's due to a mantle hotspot.' --a geologist who's trying to cover up the fact that they didn't hear your question&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|This page was created by a MANTLE HOTSPOT. Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a map of the United States, purporting to explain some of the most significant geologic/human activity in each region. For each area it names one major mechanism (plate tectonics, erosion, volcanism, etc.) which it claims is responsible for the majority of interesting formations and features.&lt;br /&gt;
&lt;br /&gt;
Many of these causes are summarized in a single word answer, which doesn't do much to explain a complex landscape. A few phrases are longer but still don't actually explain much. And some areas are just labeled &amp;quot;geology&amp;quot;. &lt;br /&gt;
&lt;br /&gt;
The title text plays off the fact that a large part of geology is concerned with activity in the mantle, so explaining some geologic feature by saying &amp;quot;there's speculation that it's due to a mantle hotspot&amp;quot; does not give much information. Saying this would let a distracted geologist buy time while responding to a missed question. Many of Earth's seemingly out-of-place features (e.g., {{w|Hawaii hotspot}}, {{w|Iceland}}, the {{w|Snake River Plain}} in Idaho, etc.) form from such mantle hotspots. Thus, it's an easy go-to explanation for many of the geological features people are often most curious about.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Location&lt;br /&gt;
! Description&lt;br /&gt;
! Explanation&lt;br /&gt;
|-&lt;br /&gt;
| Adirondack Mountains&lt;br /&gt;
| ???&lt;br /&gt;
| The Adirondack Mountains are made of billion-year-old rock but were uplifted relatively recently, within the last 5–10 million years. They’re still rising today despite being far from any plate boundary, forming a dome with no clear tectonic cause, [[3141|thus the &amp;quot;???&amp;quot; due to an ongoing mystery as to their formation]]. &lt;br /&gt;
|-&lt;br /&gt;
| Most of northern conterminous U.S.&lt;br /&gt;
| glaciers&lt;br /&gt;
| During the {{w|Last Glacial Period}}, this area was covered by {{w|Laurentide Ice Sheet|an ice sheet}} that left its marks on the landscape, in the form of {{w|moraines}}, {{w|eskers}}, {{w|glacial erratics}}, etc.&lt;br /&gt;
|-&lt;br /&gt;
| Appalachian Mountains&lt;br /&gt;
| continents colliding&lt;br /&gt;
| {{w|Geology of the Appalachians}}&lt;br /&gt;
|-&lt;br /&gt;
| Near Mississippi &amp;amp; Ohio Rivers&lt;br /&gt;
| rivers&lt;br /&gt;
| {{w|Ohio_River#Geology|Ohio River Geology}}&lt;br /&gt;
|-&lt;br /&gt;
| Southeastern U.S.&lt;br /&gt;
| farming&lt;br /&gt;
| Landscape changes from {{w|cotton production in the United States}}, due to the presence of the {{w|Black Belt (geological formation)}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Florida&lt;br /&gt;
| ongoing disputes between limestone and water&lt;br /&gt;
| Florida is a vast {{w|karst}} landscape formed by the dissolution of underground limestone and dolostone bedrock by acidic rainwater, resulting in a terrain characterized by sinkholes, springs, caverns, and disappearing streams. This soluble bedrock, formed from ancient marine deposits, covers much of the state, directly connecting surface water to the Floridan aquifer system.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Missouri/Northern Arkansas&lt;br /&gt;
| geology&lt;br /&gt;
| The {{w|Ozark Mountains}}, which are composed primarily of ancient limestone and {{w|dolomite}}, form a rugged landscape characterized by hills, caves, and springs. Prolonged erosion of these soluble rocks has produced extensive karst features, including sinkholes and underground rivers.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Great Plains}}&lt;br /&gt;
| farming&lt;br /&gt;
| The lack of other major events left the terrain relatively level, and areas were historically shaped by either herds of bison or indigenous agriculture, both limiting the growth of forests. &amp;quot;Farming&amp;quot; is likely a reference to the more recent mix of large-scale crop farming (especially staples like wheat and corn) and herding (bison replaced by cattle).&lt;br /&gt;
|-&lt;br /&gt;
| Central Idaho/Yellowstone&lt;br /&gt;
| a supervolcano&lt;br /&gt;
| The {{w|Snake River Plain}} is an area of high-elevation flat plain in the otherwise contiguous Rocky Mountains. It was formed by the movement of the continental plate over the {{w|Yellowstone Hotspot}}.&lt;br /&gt;
|-&lt;br /&gt;
| American West surrounding Idaho/Yellowstone&lt;br /&gt;
| geology&lt;br /&gt;
| [[3162: Heart Mountain]]&lt;br /&gt;
|-&lt;br /&gt;
| Immediately off of West coast up to the Four Corners&lt;br /&gt;
| volcanoes&lt;br /&gt;
| A combination of various {{w|volcanic field}}s of different origins, including {{w|Cascade Volcanoes}} in the Pacific Northwest, {{w|Albuquerque volcanic field}} in New Mexico, {{w|San Francisco volcanic field}} in Arizona, and {{w|San Juan volcanic field}} in Colorado.&lt;br /&gt;
|-&lt;br /&gt;
| Eastern Washington&lt;br /&gt;
| megafloods&lt;br /&gt;
| Most likely a reference to the {{w|Missoula floods}} and the {{w|Bonneville flood}}, a series of floods caused by glacial ice dam failures causing massive lakes to flood large regions of present-day eastern Washington. These floods actually continued all the way to the Pacific Ocean, altering the shape of the {{w|Columbia River Gorge}} and flooding much of the {{w|Willamette River}} in western Oregon. The comic may have simplified these to avoid bisecting the adjacent zones along the coast.&lt;br /&gt;
|-&lt;br /&gt;
| West Coast&lt;br /&gt;
| a plate tectonic speedrun&lt;br /&gt;
| Most likely a reference to the significant tectonic activity on the western coast of the US, caused by the collisions of the {{w|Juan de Fuca plate}}, {{w|Pacific plate}}, and the {{w|North American plate}}, as part of the {{w|Ring of Fire}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southwest Desert&lt;br /&gt;
| water and time&lt;br /&gt;
| The nearly 40 major sedimentary rock layers exposed in the {{w|geology of the Grand Canyon area}} range in age from about 200 million to nearly 2 billion years old. Uplift of the region started about 75 million years ago during the mountain-building event largely responsible for creating the Rocky Mountains. The opening of the Gulf of California around 6 million years ago enabled a large river to cut its way northeast from the gulf. The new river captured the older drainage to form the ancestral Colorado River, which in turn started to form the Grand Canyon. Wetter climates brought upon by ice ages starting 2 million years ago greatly increased excavation of the Grand Canyon, which was nearly as deep 1.2 million years ago as it is now.  &lt;br /&gt;
|-&lt;br /&gt;
| Northern Alaska&lt;br /&gt;
| geology&lt;br /&gt;
| Northern {{w|Geology of Alaska|Alaska geology}} is dominated by the Brooks Range (a major Paleozoic mountain belt) and the Arctic Slope sedimentary basin, containing rich Paleozoic-Mesozoic rock sequences. The region is part of the Arctic Alaska–Chukotka Microplate, shaped by Mesozoic tectonic shifts, including Arctic Ocean opening and Brooks Range uplift.&lt;br /&gt;
|-&lt;br /&gt;
| Aleutian Islands&lt;br /&gt;
| volcanoes&lt;br /&gt;
| The Aleutian Islands are a continuation of the Alaskan {{w|Aleutian Range}}, and form part of the {{w|Ring of Fire}}. Most of the islands in the chain bear signs of being formed by volcanoes, and many volcanic cones still exist on the islands today.&lt;br /&gt;
|-&lt;br /&gt;
| Southeast Alaska&lt;br /&gt;
| glaciers&lt;br /&gt;
| This part of Alaska (including {{w|Glacier National Park (U.S.)|Glacier National Park}}) and western Canada has many glaciers that are still carving the landscape.&lt;br /&gt;
|-&lt;br /&gt;
| Hawaiian island chain&lt;br /&gt;
| volcanoes&lt;br /&gt;
| Hawaii, including the {{w|Northwest Hawaiian Islands}}, and seamounts northwest of it were formed by a tectonic plate moving over a hotspot, with volcanoes erupting and forming land as it went. The entire chain can be seen [https://www.google.com/maps/@34.0555574,-176.5939317,4904085m/data=!3m1!1e3?entry=ttu&amp;amp;g_ep=EgoyMDI2MDMxNS4wIKXMDSoASAFQAw%3D%3D here]. Volcanic fog from the {{w|List of volcanoes in the Hawaiian–Emperor seamount chain|three active volcanoes on the Big Island}} can often be seen on neighboring islands.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;h1&amp;gt;Feature of Each State&amp;lt;/h1&amp;gt;&lt;br /&gt;
Washington: Mega floods, a plates tectonics speedrun&lt;br /&gt;
&lt;br /&gt;
Idaho: a super volcano, geology&lt;br /&gt;
&lt;br /&gt;
Montana: geology, glaciers&lt;br /&gt;
&lt;br /&gt;
North Dakota: glaciers, farming&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
This map with subdivisions follows up on a number of prior (non-[[:Category:Bad Map Projections|cursed]]) maps representing (supposed) geographical splits of some conversational outcome or other, such as [[1407: Worst Hurricane]] and [[2108: Carbonated Beverage Language Map]].&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[A small panel showing Cueball pointing toward the left and Ponytail standing to his right overlaps the top of a much larger panel containing a map.]&lt;br /&gt;
:Cueball: What's up with this weird landscape?&lt;br /&gt;
:Ponytail: Oh, it was caused by ...&lt;br /&gt;
&lt;br /&gt;
:[The larger panel shows a map of the United States, with southern Canada, northern Mexico, and most of Cuba and the Bahamas visible as well. An inset at lower left shows Alaska along with part of northwest Canada, with a smaller inset showing Hawaii. International borders and coastlines are indicated in black, and state borders are indicated in gray. Red lines divide the United States into irregularly shaped zones (the red lines indicating zones do not cross into the neighboring countries, except in the Alaska inset), with each zone being labeled with red text. Each text label begins with &amp;quot;...&amp;quot; to indicate that it is the conclusion of Ponytail's sentence. The following are the labels used:]&lt;br /&gt;
:[Main map:]&lt;br /&gt;
:... a plate tectonics speedrun&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... megafloods&lt;br /&gt;
:... a supervolcano&lt;br /&gt;
:... geology&lt;br /&gt;
:... water and time&lt;br /&gt;
:... glaciers&lt;br /&gt;
:... rivers&lt;br /&gt;
:... continents colliding&lt;br /&gt;
:... ???&lt;br /&gt;
:... ongoing disputes between limestone and water&lt;br /&gt;
:[On the main map, the label &amp;quot;... glaciers&amp;quot; appears three times in various places in the same contiguous zone that runs from Washington state to Maine. The label &amp;quot;... farming&amp;quot; appears twice, representing two separate zones, one that runs from Montana to Louisiana and the other that runs from New Jersey to Mississippi. The label &amp;quot;... geology&amp;quot; appears twice on the main map, representing two separate zones, one that runs from Washington state to Texas and the other being a roughly circular region mostly in southern Missouri and northern Arkansas.]&lt;br /&gt;
:[Alaska inset:]&lt;br /&gt;
:... geology&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... glaciers&lt;br /&gt;
:[Hawaii inset:]&lt;br /&gt;
:... volcanoes&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&amp;lt;noinclude&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics with color]]&lt;br /&gt;
[[Category:US maps]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Volcanoes]]&lt;/div&gt;</summary>
		<author><name>2603:800C:1200:596A:7154:D390:7A60:3197</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408457</id>
		<title>3221: Landscape Features</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408457"/>
				<updated>2026-03-19T07:49:03Z</updated>
		
		<summary type="html">&lt;p&gt;2603:800C:1200:596A:7154:D390:7A60:3197: /* Explanation */ punct.&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3221&lt;br /&gt;
| date      = March 18, 2026&lt;br /&gt;
| title     = Landscape Features&lt;br /&gt;
| image     = landscape_features_2x.png&lt;br /&gt;
| imagesize = 537x454px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = 'Well, there's speculation that it's due to a mantle hotspot.' --a geologist who's trying to cover up the fact that they didn't hear your question&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|This page was created by a MANTLE HOTSPOT. Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a map of the United States, purporting to explain some of the most significant geologic/human activity in each region. For each area it names one major mechanism (plate tectonics, erosion, volcanism, etc.) which it claims is responsible for the majority of interesting formations and features.&lt;br /&gt;
&lt;br /&gt;
Many of these causes are summarized in a single word answer, which doesn't do much to explain a complex landscape. A few phrases are longer but still don't actually explain much. And some areas are just labeled &amp;quot;geology&amp;quot;. &lt;br /&gt;
&lt;br /&gt;
The title text plays off the fact that a large part of geology is concerned with activity in the mantle, so explaining some geologic feature by saying &amp;quot;there's speculation that it's due to a mantle hotspot&amp;quot; does not give much information. Saying this would let a distracted geologist buy time while responding to a missed question. Many of Earth's seemingly out-of-place features (e.g., {{w|Hawaii hotspot}}, {{w|Iceland}}, the {{w|Snake River Plain}} in Idaho, etc.) form from such mantle hotspots. Thus, it's an easy go-to explanation for many of the geological features people are often most curious about.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Location&lt;br /&gt;
! Description&lt;br /&gt;
! Explanation&lt;br /&gt;
|-&lt;br /&gt;
| Adirondack Mountains&lt;br /&gt;
| ???&lt;br /&gt;
| The Adirondack Mountains are made of billion-year-old rock but were uplifted relatively recently, within the last 5–10 million years. They’re still rising today despite being far from any plate boundary, forming a dome with no clear tectonic cause, [[3141|thus the &amp;quot;???&amp;quot; due to an ongoing mystery as to their formation]]. &lt;br /&gt;
|-&lt;br /&gt;
| Most of northern conterminous U.S.&lt;br /&gt;
| glaciers&lt;br /&gt;
| During the {{w|Last Glacial Period}}, this area was covered by {{w|Laurentide Ice Sheet|an ice sheet}} that left its marks on the landscape, in the form of {{w|moraines}}, {{w|eskers}}, {{w|glacial erratics}}, etc.&lt;br /&gt;
|-&lt;br /&gt;
| Appalachian Mountains&lt;br /&gt;
| continents colliding&lt;br /&gt;
| {{w|Geology of the Appalachians}}&lt;br /&gt;
|-&lt;br /&gt;
| Near Mississippi &amp;amp; Ohio Rivers&lt;br /&gt;
| rivers&lt;br /&gt;
| {{w|Ohio_River#Geology|Ohio River Geology}}&lt;br /&gt;
|-&lt;br /&gt;
| Southeastern U.S.&lt;br /&gt;
| farming&lt;br /&gt;
| Landscape changes from {{w|cotton production in the United States}}, due to the presence of the {{w|Black Belt (geological formation)}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Florida&lt;br /&gt;
| ongoing disputes between limestone and water&lt;br /&gt;
| Florida is a vast {{w|karst}} landscape formed by the dissolution of underground limestone and dolostone bedrock by acidic rainwater, resulting in a terrain characterized by sinkholes, springs, caverns, and disappearing streams. This soluble bedrock, formed from ancient marine deposits, covers much of the state, directly connecting surface water to the Floridan aquifer system.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Missouri/Northern Arkansas&lt;br /&gt;
| geology&lt;br /&gt;
| The {{w|Ozark Mountains}}, which are composed primarily of ancient limestone and {{w|dolomite}}, form a rugged landscape characterized by hills, caves, and springs. Prolonged erosion of these soluble rocks has produced extensive karst features, including sinkholes and underground rivers.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Great Plains}}&lt;br /&gt;
| farming&lt;br /&gt;
| The lack of other major events left the terrain relatively level, and areas were historically shaped by either herds of bison or indigenous agriculture, both limiting the growth of forests. &amp;quot;Farming&amp;quot; is likely a reference to the more recent mix of large-scale crop farming (especially staples like wheat and corn) and herding (bison replaced by cattle).&lt;br /&gt;
|-&lt;br /&gt;
| Central Idaho/Yellowstone&lt;br /&gt;
| a supervolcano&lt;br /&gt;
| The {{w|Snake River Plain}} is an area of high-elevation flat plain in the otherwise contiguous Rocky Mountains. It was formed by the movement of the continental plate over the {{w|Yellowstone Hotspot}}.&lt;br /&gt;
|-&lt;br /&gt;
| American West surrounding Idaho/Yellowstone&lt;br /&gt;
| geology&lt;br /&gt;
| [[3162: Heart Mountain]]&lt;br /&gt;
|-&lt;br /&gt;
| Immediately off of West coast up to the Four Corners&lt;br /&gt;
| volcanoes&lt;br /&gt;
| A combination of various {{w|volcanic field}}s of different origins, including {{w|Cascade Volcanoes}} in the Pacific Northwest, {{w|Albuquerque volcanic field}} in New Mexico, {{w|San Francisco volcanic field}} in Arizona, and {{w|San Juan volcanic field}} in Colorado.&lt;br /&gt;
|-&lt;br /&gt;
| Eastern Washington&lt;br /&gt;
| megafloods&lt;br /&gt;
| Most likely a reference to the {{w|Missoula floods}} and the {{w|Bonneville flood}}, a series of floods caused by glacial ice dam failures causing massive lakes to flood large regions of present-day eastern Washington. These floods actually continued all the way to the Pacific Ocean, altering the shape of the {{w|Columbia River Gorge}} and flooding much of the {{w|Willamette River}} in western Oregon. The comic may have simplified these to avoid bisecting the adjacent zones along the coast.&lt;br /&gt;
|-&lt;br /&gt;
| West Coast&lt;br /&gt;
| a plate tectonic speedrun&lt;br /&gt;
| Most likely a reference to the significant tectonic activity on the western coast of the US, caused by the collisions of the {{w|Juan de Fuca plate}}, {{w|Pacific plate}}, and the {{w|North American plate}}, as part of the {{w|Ring of Fire}}.&lt;br /&gt;
|-&lt;br /&gt;
| Desert Southwest&lt;br /&gt;
| water and time&lt;br /&gt;
| The nearly 40 major sedimentary rock layers exposed in the {{w|geology of the Grand Canyon area}} range in age from about 200 million to nearly 2 billion years old. Uplift of the region started about 75 million years ago during the mountain-building event largely responsible for creating the Rocky Mountains. The opening of the Gulf of California around 6 million years ago enabled a large river to cut its way northeast from the gulf. The new river captured the older drainage to form the ancestral Colorado River, which in turn started to form the Grand Canyon. Wetter climates brought upon by ice ages starting 2 million years ago greatly increased excavation of the Grand Canyon, which was nearly as deep 1.2 million years ago as it is now.  &lt;br /&gt;
|-&lt;br /&gt;
| Northern Alaska&lt;br /&gt;
| geology&lt;br /&gt;
| Northern {{w|Geology of Alaska|Alaska geology}} is dominated by the Brooks Range (a major Paleozoic mountain belt) and the Arctic Slope sedimentary basin, containing rich Paleozoic-Mesozoic rock sequences. The region is part of the Arctic Alaska–Chukotka Microplate, shaped by Mesozoic tectonic shifts, including Arctic Ocean opening and Brooks Range uplift.&lt;br /&gt;
|-&lt;br /&gt;
| Aleutian Islands&lt;br /&gt;
| volcanoes&lt;br /&gt;
| The Aleutian Islands are a continuation of the Alaskan {{w|Aleutian Range}}, and form part of the {{w|Ring of Fire}}. Most of the islands in the chain bear signs of being formed by volcanoes, and many volcanic cones still exist on the islands today.&lt;br /&gt;
|-&lt;br /&gt;
| Southeast Alaska&lt;br /&gt;
| glaciers&lt;br /&gt;
| This part of Alaska (including {{w|Glacier National Park (U.S.)|Glacier National Park}}) and western Canada has many glaciers that are still carving the landscape.&lt;br /&gt;
|-&lt;br /&gt;
| Hawaiian island chain&lt;br /&gt;
| volcanoes&lt;br /&gt;
| Hawaii, including the {{w|Northwest Hawaiian Islands}}, and seamounts northwest of it were formed by a tectonic plate moving over a hotspot, with volcanoes erupting and forming land as it went. The entire chain can be seen [https://www.google.com/maps/@34.0555574,-176.5939317,4904085m/data=!3m1!1e3?entry=ttu&amp;amp;g_ep=EgoyMDI2MDMxNS4wIKXMDSoASAFQAw%3D%3D here]. Volcanic fog from the {{w|List of volcanoes in the Hawaiian–Emperor seamount chain|three active volcanoes on the Big Island}} can often be seen on neighboring islands.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;h1&amp;gt;Feature of Each State&amp;lt;/h1&amp;gt;&lt;br /&gt;
Washington: Mega floods, a plates tectonics speedrun&lt;br /&gt;
&lt;br /&gt;
Idaho: a super volcano, geology&lt;br /&gt;
&lt;br /&gt;
Montana: geology, glaciers&lt;br /&gt;
&lt;br /&gt;
North Dakota: glaciers, farming&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
This map with subdivisions follows up on a number of prior (non-[[:Category:Bad Map Projections|cursed]]) maps representing (supposed) geographical splits of some conversational outcome or other, such as [[1407: Worst Hurricane]] and [[2108: Carbonated Beverage Language Map]].&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[A small panel showing Cueball pointing toward the left and Ponytail standing to his right overlaps the top of a much larger panel containing a map.]&lt;br /&gt;
:Cueball: What's up with this weird landscape?&lt;br /&gt;
:Ponytail: Oh, it was caused by ...&lt;br /&gt;
&lt;br /&gt;
:[The larger panel shows a map of the United States, with southern Canada, northern Mexico, and most of Cuba and the Bahamas visible as well. An inset at lower left shows Alaska along with part of northwest Canada, with a smaller inset showing Hawaii. International borders and coastlines are indicated in black, and state borders are indicated in gray. Red lines divide the United States into irregularly shaped zones (the red lines indicating zones do not cross into the neighboring countries, except in the Alaska inset), with each zone being labeled with red text. Each text label begins with &amp;quot;...&amp;quot; to indicate that it is the conclusion of Ponytail's sentence. The following are the labels used:]&lt;br /&gt;
:[Main map:]&lt;br /&gt;
:... a plate tectonics speedrun&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... megafloods&lt;br /&gt;
:... a supervolcano&lt;br /&gt;
:... geology&lt;br /&gt;
:... water and time&lt;br /&gt;
:... glaciers&lt;br /&gt;
:... rivers&lt;br /&gt;
:... continents colliding&lt;br /&gt;
:... ???&lt;br /&gt;
:... ongoing disputes between limestone and water&lt;br /&gt;
:[On the main map, the label &amp;quot;... glaciers&amp;quot; appears three times in various places in the same contiguous zone that runs from Washington state to Maine. The label &amp;quot;... farming&amp;quot; appears twice, representing two separate zones, one that runs from Montana to Louisiana and the other that runs from New Jersey to Mississippi. The label &amp;quot;... geology&amp;quot; appears twice on the main map, representing two separate zones, one that runs from Washington state to Texas and the other being a roughly circular region mostly in southern Missouri and northern Arkansas.]&lt;br /&gt;
:[Alaska inset:]&lt;br /&gt;
:... geology&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... glaciers&lt;br /&gt;
:[Hawaii inset:]&lt;br /&gt;
:... volcanoes&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&amp;lt;noinclude&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics with color]]&lt;br /&gt;
[[Category:US maps]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Volcanoes]]&lt;/div&gt;</summary>
		<author><name>2603:800C:1200:596A:7154:D390:7A60:3197</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408456</id>
		<title>3221: Landscape Features</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408456"/>
				<updated>2026-03-19T07:47:43Z</updated>
		
		<summary type="html">&lt;p&gt;2603:800C:1200:596A:7154:D390:7A60:3197: /* Explanation */ full wikilink and Alaska&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3221&lt;br /&gt;
| date      = March 18, 2026&lt;br /&gt;
| title     = Landscape Features&lt;br /&gt;
| image     = landscape_features_2x.png&lt;br /&gt;
| imagesize = 537x454px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = 'Well, there's speculation that it's due to a mantle hotspot.' --a geologist who's trying to cover up the fact that they didn't hear your question&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|This page was created by a MANTLE HOTSPOT. Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a map of the United States, purporting to explain some of the most significant geologic/human activity in each region. For each area it names one major mechanism (plate tectonics, erosion, volcanism, etc.) which it claims is responsible for the majority of interesting formations and features.&lt;br /&gt;
&lt;br /&gt;
Many of these causes are summarized in a single word answer, which doesn't do much to explain a complex landscape. A few phrases are longer but still don't actually explain much. And some areas are just labeled &amp;quot;geology&amp;quot;. &lt;br /&gt;
&lt;br /&gt;
The title text plays off the fact that a large part of geology is concerned with activity in the mantle, so explaining some geologic feature by saying &amp;quot;there's speculation that it's due to a mantle hotspot&amp;quot; does not give much information. Saying this would let a distracted geologist buy time while responding to a missed question. Many of Earth's seemingly out-of-place features (e.g., {{w|Hawaii hotspot}}, {{w|Iceland}}, the {{w|Snake River Plain}} in Idaho, etc.) form from such mantle hotspots. Thus, it's an easy go-to explanation for many of the geological features people are often most curious about.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Location&lt;br /&gt;
! Description&lt;br /&gt;
! Explanation&lt;br /&gt;
|-&lt;br /&gt;
| Adirondack Mountains&lt;br /&gt;
| ???&lt;br /&gt;
| The Adirondack Mountains are made of billion-year-old rock but were uplifted relatively recently, within the last 5–10 million years. They’re still rising today despite being far from any plate boundary, forming a dome with no clear tectonic cause, [[3141|thus the &amp;quot;???&amp;quot; due to an ongoing mystery as to their formation]]. &lt;br /&gt;
|-&lt;br /&gt;
| Most of northern conterminous U.S.&lt;br /&gt;
| glaciers&lt;br /&gt;
| During the {{w|Last Glacial Period}}, this area was covered by {{w|Laurentide Ice Sheet|an ice sheet}} that left its marks on the landscape, in the form of {{w|moraines}}, {{w|eskers}}, {{w|glacial erratics}}, etc.&lt;br /&gt;
|-&lt;br /&gt;
| Appalachian Mountains&lt;br /&gt;
| continents colliding&lt;br /&gt;
| {{w|Geology of the Appalachians}}&lt;br /&gt;
|-&lt;br /&gt;
| Near Mississippi &amp;amp; Ohio Rivers&lt;br /&gt;
| rivers&lt;br /&gt;
| {{w|Ohio_River#Geology|Ohio River Geology}}&lt;br /&gt;
|-&lt;br /&gt;
| Southeastern U.S.&lt;br /&gt;
| farming&lt;br /&gt;
| Landscape changes from {{w|cotton production in the United States}}, due to the presence of the {{w|Black Belt (geological formation)}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Florida&lt;br /&gt;
| ongoing disputes between limestone and water&lt;br /&gt;
| Florida is a vast {{w|karst}} landscape formed by the dissolution of underground limestone and dolostone bedrock by acidic rainwater, resulting in a terrain characterized by sinkholes, springs, caverns, and disappearing streams. This soluble bedrock, formed from ancient marine deposits, covers much of the state, directly connecting surface water to the Floridan aquifer system.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Missouri/Northern Arkansas&lt;br /&gt;
| geology&lt;br /&gt;
| The {{w|Ozark Mountains}}, which are composed primarily of ancient limestone and {{w|dolomite}}, form a rugged landscape characterized by hills, caves, and springs. Prolonged erosion of these soluble rocks has produced extensive karst features, including sinkholes and underground rivers.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Great Plains}}&lt;br /&gt;
| farming&lt;br /&gt;
| The lack of other major events left the terrain relatively level, and areas were historically shaped by either herds of bison or indigenous agriculture, both limiting the growth of forests. &amp;quot;Farming&amp;quot; is likely a reference to the more recent mix of large-scale crop farming (especially staples like wheat and corn) and herding (bison replaced by cattle).&lt;br /&gt;
|-&lt;br /&gt;
| Central Idaho/Yellowstone&lt;br /&gt;
| a supervolcano&lt;br /&gt;
| The {{w|Snake River Plain}} is an area of high-elevation flat plain in the otherwise contiguous Rocky Mountains. It was formed by the movement of the continental plate over the {{w|Yellowstone Hotspot}}.&lt;br /&gt;
|-&lt;br /&gt;
| American West surrounding Idaho/Yellowstone&lt;br /&gt;
| geology&lt;br /&gt;
| [[3162: Heart Mountain]]&lt;br /&gt;
|-&lt;br /&gt;
| Immediately off of West coast up to the Four Corners&lt;br /&gt;
| volcanoes&lt;br /&gt;
| A combination of various {{w|volcanic field}}s of different origins, including {{w|Cascade Volcanoes}} in the Pacific Northwest, {{w|Albuquerque volcanic field}} in New Mexico, {{w|San Francisco volcanic field}} in Arizona, and {{w|San Juan volcanic field}} in Colorado.&lt;br /&gt;
|-&lt;br /&gt;
| Eastern Washington&lt;br /&gt;
| megafloods&lt;br /&gt;
| Most likely a reference to the {{w|Missoula floods}} and the {{w|Bonneville flood}}, a series of floods caused by glacial ice dam failures causing massive lakes to flood large regions of present-day eastern Washington. These floods actually continued all the way to the Pacific Ocean, altering the shape of the {{w|Columbia River Gorge}} and flooding much of the {{w|Willamette River}} in western Oregon. The comic may have simplified these to avoid bisecting the adjacent zones along the coast.&lt;br /&gt;
|-&lt;br /&gt;
| West Coast&lt;br /&gt;
| a plate tectonic speedrun&lt;br /&gt;
| Most likely a reference to the significant tectonic activity on the western coast of the US, caused by the collisions of the {{w|Juan de Fuca plate}}, {{w|Pacific plate}}, and the {{w|North American plate}}, as part of the {{w|Ring of Fire}}.&lt;br /&gt;
|-&lt;br /&gt;
| Desert Southwest&lt;br /&gt;
| water and time&lt;br /&gt;
| The nearly 40 major sedimentary rock layers exposed in the {{w|geology of the Grand Canyon area}} range in age from about 200 million to nearly 2 billion years old. Uplift of the region started about 75 million years ago during the mountain-building event largely responsible for creating the Rocky Mountains. The opening of the Gulf of California around 6 million years ago enabled a large river to cut its way northeast from the gulf. The new river captured the older drainage to form the ancestral Colorado River, which in turn started to form the Grand Canyon. Wetter climates brought upon by ice ages starting 2 million years ago greatly increased excavation of the Grand Canyon, which was nearly as deep 1.2 million years ago as it is now.  &lt;br /&gt;
|-&lt;br /&gt;
| Northern Alaska&lt;br /&gt;
| geology&lt;br /&gt;
| Northern {{w|Geology of Alaska|Alaska geology}} is dominated by the Brooks Range (a major Paleozoic mountain belt) and the Arctic Slope sedimentary basin, containing rich Paleozoic-Mesozoic rock sequences. The region is part of the Arctic Alaska–Chukotka Microplate, shaped by Mesozoic tectonic shifts—including Arctic Ocean opening and Brooks Range uplift&lt;br /&gt;
|-&lt;br /&gt;
| Aleutian Islands&lt;br /&gt;
| volcanoes&lt;br /&gt;
| The Aleutian Islands are a continuation of the Alaskan {{w|Aleutian Range}}, and form part of the {{w|Ring of Fire}}. Most of the islands in the chain bear signs of being formed by volcanoes, and many volcanic cones still exist on the islands today.&lt;br /&gt;
|-&lt;br /&gt;
| Southeast Alaska&lt;br /&gt;
| glaciers&lt;br /&gt;
| This part of Alaska (including {{w|Glacier National Park (U.S.)|Glacier National Park}}) and western Canada has many glaciers that are still carving the landscape.&lt;br /&gt;
|-&lt;br /&gt;
| Hawaiian island chain&lt;br /&gt;
| volcanoes&lt;br /&gt;
| Hawaii, including the {{w|Northwest Hawaiian Islands}}, and seamounts northwest of it were formed by a tectonic plate moving over a hotspot, with volcanoes erupting and forming land as it went. The entire chain can be seen [https://www.google.com/maps/@34.0555574,-176.5939317,4904085m/data=!3m1!1e3?entry=ttu&amp;amp;g_ep=EgoyMDI2MDMxNS4wIKXMDSoASAFQAw%3D%3D here]. Volcanic fog from the {{w|List of volcanoes in the Hawaiian–Emperor seamount chain|three active volcanoes on the Big Island}} can often be seen on neighboring islands.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;h1&amp;gt;Feature of Each State&amp;lt;/h1&amp;gt;&lt;br /&gt;
Washington: Mega floods, a plates tectonics speedrun&lt;br /&gt;
&lt;br /&gt;
Idaho: a super volcano, geology&lt;br /&gt;
&lt;br /&gt;
Montana: geology, glaciers&lt;br /&gt;
&lt;br /&gt;
North Dakota: glaciers, farming&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
This map with subdivisions follows up on a number of prior (non-[[:Category:Bad Map Projections|cursed]]) maps representing (supposed) geographical splits of some conversational outcome or other, such as [[1407: Worst Hurricane]] and [[2108: Carbonated Beverage Language Map]].&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[A small panel showing Cueball pointing toward the left and Ponytail standing to his right overlaps the top of a much larger panel containing a map.]&lt;br /&gt;
:Cueball: What's up with this weird landscape?&lt;br /&gt;
:Ponytail: Oh, it was caused by ...&lt;br /&gt;
&lt;br /&gt;
:[The larger panel shows a map of the United States, with southern Canada, northern Mexico, and most of Cuba and the Bahamas visible as well. An inset at lower left shows Alaska along with part of northwest Canada, with a smaller inset showing Hawaii. International borders and coastlines are indicated in black, and state borders are indicated in gray. Red lines divide the United States into irregularly shaped zones (the red lines indicating zones do not cross into the neighboring countries, except in the Alaska inset), with each zone being labeled with red text. Each text label begins with &amp;quot;...&amp;quot; to indicate that it is the conclusion of Ponytail's sentence. The following are the labels used:]&lt;br /&gt;
:[Main map:]&lt;br /&gt;
:... a plate tectonics speedrun&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... megafloods&lt;br /&gt;
:... a supervolcano&lt;br /&gt;
:... geology&lt;br /&gt;
:... water and time&lt;br /&gt;
:... glaciers&lt;br /&gt;
:... rivers&lt;br /&gt;
:... continents colliding&lt;br /&gt;
:... ???&lt;br /&gt;
:... ongoing disputes between limestone and water&lt;br /&gt;
:[On the main map, the label &amp;quot;... glaciers&amp;quot; appears three times in various places in the same contiguous zone that runs from Washington state to Maine. The label &amp;quot;... farming&amp;quot; appears twice, representing two separate zones, one that runs from Montana to Louisiana and the other that runs from New Jersey to Mississippi. The label &amp;quot;... geology&amp;quot; appears twice on the main map, representing two separate zones, one that runs from Washington state to Texas and the other being a roughly circular region mostly in southern Missouri and northern Arkansas.]&lt;br /&gt;
:[Alaska inset:]&lt;br /&gt;
:... geology&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... glaciers&lt;br /&gt;
:[Hawaii inset:]&lt;br /&gt;
:... volcanoes&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&amp;lt;noinclude&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics with color]]&lt;br /&gt;
[[Category:US maps]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Volcanoes]]&lt;/div&gt;</summary>
		<author><name>2603:800C:1200:596A:7154:D390:7A60:3197</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408455</id>
		<title>3221: Landscape Features</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408455"/>
				<updated>2026-03-19T07:41:34Z</updated>
		
		<summary type="html">&lt;p&gt;2603:800C:1200:596A:7154:D390:7A60:3197: /* Explanation */ reword, add factoid&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3221&lt;br /&gt;
| date      = March 18, 2026&lt;br /&gt;
| title     = Landscape Features&lt;br /&gt;
| image     = landscape_features_2x.png&lt;br /&gt;
| imagesize = 537x454px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = 'Well, there's speculation that it's due to a mantle hotspot.' --a geologist who's trying to cover up the fact that they didn't hear your question&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|This page was created by a MANTLE HOTSPOT. Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a map of the United States, purporting to explain some of the most significant geologic/human activity in each region. For each area it names one major mechanism (plate tectonics, erosion, volcanism, etc.) which it claims is responsible for the majority of interesting formations and features.&lt;br /&gt;
&lt;br /&gt;
Many of these causes are summarized in a single word answer, which doesn't do much to explain a complex landscape. A few phrases are longer but still don't actually explain much. And some areas are just labeled &amp;quot;geology&amp;quot;. &lt;br /&gt;
&lt;br /&gt;
The title text plays off the fact that a large part of geology is concerned with activity in the mantle, so explaining some geologic feature by saying &amp;quot;there's speculation that it's due to a mantle hotspot&amp;quot; does not give much information. Saying this would let a distracted geologist buy time while responding to a missed question. Many of Earth's seemingly out-of-place features (e.g., {{w|Hawaii hotspot}}, {{w|Iceland}}, the {{w|Snake River Plain}} in Idaho, etc.) form from such mantle hotspots. Thus, it's an easy go-to explanation for many of the geological features people are often most curious about.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Location&lt;br /&gt;
! Description&lt;br /&gt;
! Explanation&lt;br /&gt;
|-&lt;br /&gt;
| Adirondack Mountains&lt;br /&gt;
| ???&lt;br /&gt;
| The Adirondack Mountains are made of billion-year-old rock but were uplifted relatively recently, within the last 5–10 million years. They’re still rising today despite being far from any plate boundary, forming a dome with no clear tectonic cause, [[3141|thus the &amp;quot;???&amp;quot; due to an ongoing mystery as to their formation]]. &lt;br /&gt;
|-&lt;br /&gt;
| Most of northern conterminous U.S.&lt;br /&gt;
| glaciers&lt;br /&gt;
| During the {{w|Last Glacial Period}}, this area was covered by {{w|Laurentide Ice Sheet|an ice sheet}} that left its marks on the landscape, in the form of {{w|moraines}}, {{w|eskers}}, {{w|glacial erratics}}, etc.&lt;br /&gt;
|-&lt;br /&gt;
| Appalachian Mountains&lt;br /&gt;
| continents colliding&lt;br /&gt;
| {{w|Geology of the Appalachians}}&lt;br /&gt;
|-&lt;br /&gt;
| Near Mississippi &amp;amp; Ohio Rivers&lt;br /&gt;
| rivers&lt;br /&gt;
| {{w|Ohio_River#Geology|Ohio River Geology}}&lt;br /&gt;
|-&lt;br /&gt;
| Southeastern U.S.&lt;br /&gt;
| farming&lt;br /&gt;
| Landscape changes from {{w|cotton production in the United States}}, due to the presence of the {{w|Black Belt (geological formation)}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Florida&lt;br /&gt;
| ongoing disputes between limestone and water&lt;br /&gt;
| Florida is a vast {{w|karst}} landscape formed by the dissolution of underground limestone and dolostone bedrock by acidic rainwater, resulting in a terrain characterized by sinkholes, springs, caverns, and disappearing streams. This soluble bedrock, formed from ancient marine deposits, covers much of the state, directly connecting surface water to the Floridan aquifer system.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Missouri/Northern Arkansas&lt;br /&gt;
| geology&lt;br /&gt;
| The {{w|Ozark Mountains}}, which are composed primarily of ancient limestone and {{w|dolomite}}, form a rugged landscape characterized by hills, caves, and springs. Prolonged erosion of these soluble rocks has produced extensive karst features, including sinkholes and underground rivers.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Great Plains}}&lt;br /&gt;
| farming&lt;br /&gt;
| The lack of other major events left the terrain relatively level, and areas were historically shaped by either herds of bison or indigenous agriculture, both limiting the growth of forests. &amp;quot;Farming&amp;quot; is likely a reference to the more recent mix of large-scale crop farming (especially staples like wheat and corn) and herding (bison replaced by cattle).&lt;br /&gt;
|-&lt;br /&gt;
| Central Idaho/Yellowstone&lt;br /&gt;
| a supervolcano&lt;br /&gt;
| The {{w|Snake River Plain}} is an area of high-elevation flat plain in the otherwise contiguous Rocky Mountains. It was formed by the movement of the continental plate over the {{w|Yellowstone Hotspot}}.&lt;br /&gt;
|-&lt;br /&gt;
| American West surrounding Idaho/Yellowstone&lt;br /&gt;
| geology&lt;br /&gt;
| [[3162]]&lt;br /&gt;
|-&lt;br /&gt;
| Immediately off of West coast up to the Four Corners&lt;br /&gt;
| volcanoes&lt;br /&gt;
| A combination of various {{w|volcanic field}}s of different origins, including {{w|Cascade Volcanoes}} in the Pacific Northwest, {{w|Albuquerque volcanic field}} in New Mexico, {{w|San Francisco volcanic field}} in Arizona, and {{w|San Juan volcanic field}} in Colorado.&lt;br /&gt;
|-&lt;br /&gt;
| Eastern Washington&lt;br /&gt;
| megafloods&lt;br /&gt;
| Most likely a reference to the {{w|Missoula floods}} and the {{w|Bonneville flood}}, a series of floods caused by glacial ice dam failures causing massive lakes to flood large regions of present-day eastern Washington. These floods actually continued all the way to the Pacific Ocean, altering the shape of the {{w|Columbia River Gorge}} and flooding much of the {{w|Willamette River}} in western Oregon. The comic may have simplified these to avoid bisecting the adjacent zones along the coast.&lt;br /&gt;
|-&lt;br /&gt;
| West Coast&lt;br /&gt;
| a plate tectonic speedrun&lt;br /&gt;
| Most likely a reference to the significant tectonic activity on the western coast of the US, caused by the collisions of the {{w|Juan de Fuca plate}}, {{w|Pacific plate}}, and the {{w|North American plate}}, as part of the {{w|Ring of Fire}}.&lt;br /&gt;
|-&lt;br /&gt;
| Desert Southwest&lt;br /&gt;
| water and time&lt;br /&gt;
| The nearly 40 major sedimentary rock layers exposed in the {{w|geology of the Grand Canyon area}} range in age from about 200 million to nearly 2 billion years old. Uplift of the region started about 75 million years ago during the mountain-building event largely responsible for creating the Rocky Mountains. The opening of the Gulf of California around 6 million years ago enabled a large river to cut its way northeast from the gulf. The new river captured the older drainage to form the ancestral Colorado River, which in turn started to form the Grand Canyon. Wetter climates brought upon by ice ages starting 2 million years ago greatly increased excavation of the Grand Canyon, which was nearly as deep 1.2 million years ago as it is now.  &lt;br /&gt;
|-&lt;br /&gt;
| Northern Alaska&lt;br /&gt;
| geology&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Aleutian Islands&lt;br /&gt;
| volcanoes&lt;br /&gt;
| The Aleutian Islands are a continuation of the Alaskan {{w|Aleutian Range}}, and form part of the {{w|Ring of Fire}}. Most of the islands in the chain bear signs of being formed by volcanoes, and many volcanic cones still exist on the islands today.&lt;br /&gt;
|-&lt;br /&gt;
| Southeast Alaska&lt;br /&gt;
| glaciers&lt;br /&gt;
| This part of Alaska (including {{w|Glacier National Park (U.S.)|Glacier National Park}}) and western Canada has many glaciers that are still carving the landscape.&lt;br /&gt;
|-&lt;br /&gt;
| Hawaiian island chain&lt;br /&gt;
| volcanoes&lt;br /&gt;
| Hawaii, including the {{w|Northwest Hawaiian Islands}}, and seamounts northwest of it were formed by a tectonic plate moving over a hotspot, with volcanoes erupting and forming land as it went. The entire chain can be seen [https://www.google.com/maps/@34.0555574,-176.5939317,4904085m/data=!3m1!1e3?entry=ttu&amp;amp;g_ep=EgoyMDI2MDMxNS4wIKXMDSoASAFQAw%3D%3D here]. Volcanic fog from the {{w|List of volcanoes in the Hawaiian–Emperor seamount chain|three active volcanoes on the Big Island}} can often be seen on neighboring islands.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;h1&amp;gt;Feature of Each State&amp;lt;/h1&amp;gt;&lt;br /&gt;
Washington: Mega floods, a plates tectonics speedrun&lt;br /&gt;
&lt;br /&gt;
Idaho: a super volcano, geology&lt;br /&gt;
&lt;br /&gt;
Montana: geology, glaciers&lt;br /&gt;
&lt;br /&gt;
North Dakota: glaciers, farming&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
This map with subdivisions follows up on a number of prior (non-[[:Category:Bad Map Projections|cursed]]) maps representing (supposed) geographical splits of some conversational outcome or other, such as [[1407: Worst Hurricane]] and [[2108: Carbonated Beverage Language Map]].&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[A small panel showing Cueball pointing toward the left and Ponytail standing to his right overlaps the top of a much larger panel containing a map.]&lt;br /&gt;
:Cueball: What's up with this weird landscape?&lt;br /&gt;
:Ponytail: Oh, it was caused by ...&lt;br /&gt;
&lt;br /&gt;
:[The larger panel shows a map of the United States, with southern Canada, northern Mexico, and most of Cuba and the Bahamas visible as well. An inset at lower left shows Alaska along with part of northwest Canada, with a smaller inset showing Hawaii. International borders and coastlines are indicated in black, and state borders are indicated in gray. Red lines divide the United States into irregularly shaped zones (the red lines indicating zones do not cross into the neighboring countries, except in the Alaska inset), with each zone being labeled with red text. Each text label begins with &amp;quot;...&amp;quot; to indicate that it is the conclusion of Ponytail's sentence. The following are the labels used:]&lt;br /&gt;
:[Main map:]&lt;br /&gt;
:... a plate tectonics speedrun&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... megafloods&lt;br /&gt;
:... a supervolcano&lt;br /&gt;
:... geology&lt;br /&gt;
:... water and time&lt;br /&gt;
:... glaciers&lt;br /&gt;
:... rivers&lt;br /&gt;
:... continents colliding&lt;br /&gt;
:... ???&lt;br /&gt;
:... ongoing disputes between limestone and water&lt;br /&gt;
:[On the main map, the label &amp;quot;... glaciers&amp;quot; appears three times in various places in the same contiguous zone that runs from Washington state to Maine. The label &amp;quot;... farming&amp;quot; appears twice, representing two separate zones, one that runs from Montana to Louisiana and the other that runs from New Jersey to Mississippi. The label &amp;quot;... geology&amp;quot; appears twice on the main map, representing two separate zones, one that runs from Washington state to Texas and the other being a roughly circular region mostly in southern Missouri and northern Arkansas.]&lt;br /&gt;
:[Alaska inset:]&lt;br /&gt;
:... geology&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... glaciers&lt;br /&gt;
:[Hawaii inset:]&lt;br /&gt;
:... volcanoes&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&amp;lt;noinclude&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics with color]]&lt;br /&gt;
[[Category:US maps]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Volcanoes]]&lt;/div&gt;</summary>
		<author><name>2603:800C:1200:596A:7154:D390:7A60:3197</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408453</id>
		<title>3221: Landscape Features</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3221:_Landscape_Features&amp;diff=408453"/>
				<updated>2026-03-19T07:35:19Z</updated>
		
		<summary type="html">&lt;p&gt;2603:800C:1200:596A:7154:D390:7A60:3197: /* Explanation */ water and time = Grand Canyon&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3221&lt;br /&gt;
| date      = March 18, 2026&lt;br /&gt;
| title     = Landscape Features&lt;br /&gt;
| image     = landscape_features_2x.png&lt;br /&gt;
| imagesize = 537x454px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = 'Well, there's speculation that it's due to a mantle hotspot.' --a geologist who's trying to cover up the fact that they didn't hear your question&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|This page was created by a MANTLE HOTSPOT. Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a map of the United States, purporting to explain some of the most significant geologic/human activity in each region. For each area it names one major mechanism (plate tectonics, erosion, volcanism, etc.) which it claims is responsible for the majority of interesting formations and features.&lt;br /&gt;
&lt;br /&gt;
Many of these causes are summarized in a single word answer, which doesn't do much to explain a complex landscape. A few phrases are longer but still don't actually explain much. And some areas are just labeled &amp;quot;geology&amp;quot;. &lt;br /&gt;
&lt;br /&gt;
The title text plays off the fact that a large part of geology is concerned with activity in the mantle, so explaining some geologic feature by saying &amp;quot;there's speculation that it's due to a mantle hotspot&amp;quot; does not give much information. Saying this would let a distracted geologist buy time while responding to a missed question. Many of Earth's seemingly out-of-place features (e.g., {{w|Hawaii hotspot}}, {{w|Iceland}}, the {{w|Snake River Plain}} in Idaho, etc.) form from such mantle hotspots. Thus, it's an easy go-to explanation for many of the geological features people are often most curious about.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Location&lt;br /&gt;
! Description&lt;br /&gt;
! Explanation&lt;br /&gt;
|-&lt;br /&gt;
| Adirondack Mountains&lt;br /&gt;
| ???&lt;br /&gt;
| The Adirondack Mountains are made of billion-year-old rock but were uplifted relatively recently, within the last 5–10 million years. They’re still rising today despite being far from any plate boundary, forming a dome with no clear tectonic cause, [[3141|thus the &amp;quot;???&amp;quot; due to an ongoing mystery as to their formation]]. &lt;br /&gt;
|-&lt;br /&gt;
| Most of northern conterminous U.S.&lt;br /&gt;
| glaciers&lt;br /&gt;
| During the {{w|Last Glacial Period}}, this area was covered by {{w|Laurentide Ice Sheet|an ice sheet}} that left its marks on the landscape, in the form of {{w|moraines}}, {{w|eskers}}, {{w|glacial erratics}}, etc.&lt;br /&gt;
|-&lt;br /&gt;
| Appalachian Mountains&lt;br /&gt;
| continents colliding&lt;br /&gt;
| {{w|Geology of the Appalachians}}&lt;br /&gt;
|-&lt;br /&gt;
| Near Mississippi &amp;amp; Ohio Rivers&lt;br /&gt;
| rivers&lt;br /&gt;
| {{w|Ohio_River#Geology|Ohio River Geology}}&lt;br /&gt;
|-&lt;br /&gt;
| Southeastern U.S.&lt;br /&gt;
| farming&lt;br /&gt;
| Landscape changes from {{w|cotton production in the United States}}, due to the presence of the {{w|Black Belt (geological formation)}}.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Florida&lt;br /&gt;
| ongoing disputes between limestone and water&lt;br /&gt;
| Florida is a vast {{w|karst}} landscape formed by the dissolution of underground limestone and dolostone bedrock by acidic rainwater, resulting in a terrain characterized by sinkholes, springs, caverns, and disappearing streams. This soluble bedrock, formed from ancient marine deposits, covers much of the state, directly connecting surface water to the Floridan aquifer system.&lt;br /&gt;
|-&lt;br /&gt;
| Southern Missouri/Northern Arkansas&lt;br /&gt;
| geology&lt;br /&gt;
| The {{w|Ozark Mountains}}, which are composed primarily of ancient limestone and {{w|dolomite}}, form a rugged landscape characterized by hills, caves, and springs. Prolonged erosion of these soluble rocks has produced extensive karst features, including sinkholes and underground rivers.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Great Plains}}&lt;br /&gt;
| farming&lt;br /&gt;
| The lack of other major events left the terrain relatively level, and areas were historically shaped by either herds of bison or indigenous agriculture, both limiting the growth of forests. &amp;quot;Farming&amp;quot; is likely a reference to the more recent mix of large-scale crop farming (especially staples like wheat and corn) and herding (bison replaced by cattle).&lt;br /&gt;
|-&lt;br /&gt;
| Central Idaho/Yellowstone&lt;br /&gt;
| a supervolcano&lt;br /&gt;
| The {{w|Snake River Plain}} is an area of high-elevation flat plain in the otherwise contiguous Rocky Mountains. It was formed by the movement of the continental plate over the {{w|Yellowstone Hotspot}}.&lt;br /&gt;
|-&lt;br /&gt;
| American West surrounding Idaho/Yellowstone&lt;br /&gt;
| geology&lt;br /&gt;
| [[3162]]&lt;br /&gt;
|-&lt;br /&gt;
| Immediately off of West coast up to the Four Corners&lt;br /&gt;
| volcanoes&lt;br /&gt;
| A combination of various {{w|volcanic field}}s of different origins, including {{w|Cascade Volcanoes}} in the Pacific Northwest, {{w|Albuquerque volcanic field}} in New Mexico, {{w|San Francisco volcanic field}} in Arizona, and {{w|San Juan volcanic field}} in Colorado.&lt;br /&gt;
|-&lt;br /&gt;
| Eastern Washington&lt;br /&gt;
| megafloods&lt;br /&gt;
| Most likely a reference to the {{w|Missoula floods}} and the {{w|Bonneville flood}}, a series of floods caused by glacial ice dam failures causing massive lakes to flood large regions of present-day eastern Washington. These floods actually continued all the way to the Pacific Ocean, altering the shape of the {{w|Columbia River Gorge}} and flooding much of the {{w|Willamette River}} in western Oregon. The comic may have simplified these to avoid bisecting the adjacent zones along the coast.&lt;br /&gt;
|-&lt;br /&gt;
| West Coast&lt;br /&gt;
| a plate tectonic speedrun&lt;br /&gt;
| Most likely a reference to the significant tectonic activity on the western coast of the US, caused by the collisions of the {{w|Juan de Fuca plate}}, {{w|Pacific plate}}, and the {{w|North American plate}}, as part of the {{w|Ring of Fire}}.&lt;br /&gt;
|-&lt;br /&gt;
| Desert Southwest&lt;br /&gt;
| water and time&lt;br /&gt;
| The nearly 40 major sedimentary rock layers exposed in the {{w|geology of the Grand Canyon area}} range in age from about 200 million to nearly 2 billion years old. Uplift of the region started about 75 million years ago during the mountain-building event largely responsible for creating the Rocky Mountains. The opening of the Gulf of California around 6 million years ago enabled a large river to cut its way northeast from the gulf. The new river captured the older drainage to form the ancestral Colorado River, which in turn started to form the Grand Canyon. Wetter climates brought upon by ice ages starting 2 million years ago greatly increased excavation of the Grand Canyon, which was nearly as deep as it is now, 1.2 million years ago.  &lt;br /&gt;
|-&lt;br /&gt;
| Northern Alaska&lt;br /&gt;
| geology&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Aleutian Islands&lt;br /&gt;
| volcanoes&lt;br /&gt;
| The Aleutian Islands are a continuation of the Alaskan {{w|Aleutian Range}}, and form part of the {{w|Ring of Fire}}. Most of the islands in the chain bear signs of being formed by volcanoes, and many volcanic cones still exist on the islands today.&lt;br /&gt;
|-&lt;br /&gt;
| Southeast Alaska&lt;br /&gt;
| glaciers&lt;br /&gt;
| This part of Alaska (including {{w|Glacier National Park (U.S.)|Glacier National Park}}) and western Canada has many glaciers that are still carving the landscape.&lt;br /&gt;
|-&lt;br /&gt;
| Hawaiian island chain&lt;br /&gt;
| volcanoes&lt;br /&gt;
| Hawaii, including the {{w|Northwest Hawaiian Islands}}, and seamounts northwest of it were formed by a tectonic plate moving over a hotspot, with volcanoes erupting and forming land as it went. The entire chain can be seen [https://www.google.com/maps/@34.0555574,-176.5939317,4904085m/data=!3m1!1e3?entry=ttu&amp;amp;g_ep=EgoyMDI2MDMxNS4wIKXMDSoASAFQAw%3D%3D here].&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;h1&amp;gt;Feature of Each State&amp;lt;/h1&amp;gt;&lt;br /&gt;
Washington: Mega floods, a plates tectonics speedrun&lt;br /&gt;
&lt;br /&gt;
Idaho: a super volcano, geology&lt;br /&gt;
&lt;br /&gt;
Montana: geology, glaciers&lt;br /&gt;
&lt;br /&gt;
North Dakota: glaciers, farming&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
This map with subdivisions follows up on a number of prior (non-[[:Category:Bad Map Projections|cursed]]) maps representing (supposed) geographical splits of some conversational outcome or other, such as [[1407: Worst Hurricane]] and [[2108: Carbonated Beverage Language Map]].&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Don't remove this notice too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[A small panel showing Cueball pointing toward the left and Ponytail standing to his right overlaps the top of a much larger panel containing a map.]&lt;br /&gt;
:Cueball: What's up with this weird landscape?&lt;br /&gt;
:Ponytail: Oh, it was caused by ...&lt;br /&gt;
&lt;br /&gt;
:[The larger panel shows a map of the United States, with southern Canada, northern Mexico, and most of Cuba and the Bahamas visible as well. An inset at lower left shows Alaska along with part of northwest Canada, with a smaller inset showing Hawaii. International borders and coastlines are indicated in black, and state borders are indicated in gray. Red lines divide the United States into irregularly shaped zones (the red lines indicating zones do not cross into the neighboring countries, except in the Alaska inset), with each zone being labeled with red text. Each text label begins with &amp;quot;...&amp;quot; to indicate that it is the conclusion of Ponytail's sentence. The following are the labels used:]&lt;br /&gt;
:[Main map:]&lt;br /&gt;
:... a plate tectonics speedrun&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... megafloods&lt;br /&gt;
:... a supervolcano&lt;br /&gt;
:... geology&lt;br /&gt;
:... water and time&lt;br /&gt;
:... glaciers&lt;br /&gt;
:... rivers&lt;br /&gt;
:... continents colliding&lt;br /&gt;
:... ???&lt;br /&gt;
:... ongoing disputes between limestone and water&lt;br /&gt;
:[On the main map, the label &amp;quot;... glaciers&amp;quot; appears three times in various places in the same contiguous zone that runs from Washington state to Maine. The label &amp;quot;... farming&amp;quot; appears twice, representing two separate zones, one that runs from Montana to Louisiana and the other that runs from New Jersey to Mississippi. The label &amp;quot;... geology&amp;quot; appears twice on the main map, representing two separate zones, one that runs from Washington state to Texas and the other being a roughly circular region mostly in southern Missouri and northern Arkansas.]&lt;br /&gt;
:[Alaska inset:]&lt;br /&gt;
:... geology&lt;br /&gt;
:... volcanoes&lt;br /&gt;
:... glaciers&lt;br /&gt;
:[Hawaii inset:]&lt;br /&gt;
:... volcanoes&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&amp;lt;noinclude&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics with color]]&lt;br /&gt;
[[Category:US maps]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Volcanoes]]&lt;/div&gt;</summary>
		<author><name>2603:800C:1200:596A:7154:D390:7A60:3197</name></author>	</entry>

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