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|< < Prev Comic #3059 (March 5, 2025)

Water Damage

Title text: Your homeowner's insurance might cover it, but be sure to check the subductible.

Explanation

Similar to 3037: Radon, Cueball is once again getting his home inspected by Ponytail. This time, she alerts Cueball for water damage, normally caused by leaky pipes or roofs. Water damage is hazardous to homes due to its ability to instigate mold and its negative impact on structural stability of the home. Instead of "regular water damage", she claims that the crust under Cueball's home suffers from water damage. The Earth's crust typically contains water; she could be referring to erosion, which is one cause of subsidence and even sinkholes, a concern to homeowners, but it soon becomes clear that she has different effects in mind.

Upon further investigation, Ponytail discovers that Cueball's home is near a subduction zone, a place where two tectonic plates meet and one pushes beneath the other and descends deep into the Earth. This leads to the formation of magma as the descending plate heats up. The expulsion of fluids, originally from seawater, from hydrated materials simultaneously lowers the melting point of the rock and allows magma to rise to the surface to form volcanoes as Ponytail alludes to (though does not entirely explain, making it seem that it is the water itself that is rising in the form of magma). However, there is nothing that Cueball can actually do about this.^{[citation needed]}

An example of an area with many volcanoes caused by subduction is the Ring of Fire along the coasts of the Pacific Ocean. In the contiguous 48 states, the Cascade Volcanoes of the Pacific Northwest are the result of this type of subduction.

Ponytail suggests "lithospheric dehumidifiers" as a solution, which would presumably dry out the Earth's crust, but this is not realistically possible. In waterlogged ground, continuous flight augering or the injection of grouting can assist in isolating the foundations from the surrounding water table, but this has little use below the pedosphere and near-surface rock, such as down to the base of the upper plate involved in the subduction (well below the Mohorovičić discontinuity, tens of kilometers down). In addition, by drying out the crust, they might cause further subsidence and present additional hazards to the home.

The title text is a pun making a portmanteau of subduction, explained above, and the deductible, the amount an insurance policy requires you to pay before it starts to contribute to the cost of the losses or expenses it covers. The title text may also be a critique of the homeowners insurance crisis in the United States at the time of the comic's posting.

Transcript

[Ponytail stands to the left of Cueball. She is looking down at a meter of some sort in one hand, and is holding a clipboard in the other hand.]

Ponytail: The crust under your house shows signs of water damage. Is there a subduction zone nearby?

Cueball: Uh, I think there's one off the coast.

Ponytail: Oof. I was afraid of that.

[Closeup on Ponytail who is pointing to a diagram of subducting faults.]

Ponytail: Subducting hydrous minerals carry water down into the mantle, causing melting in the overlying crust. If you let this go, you'll have volcanoes everywhere.

[Cueball, with his hand to his chin, looks at the diagram. Ponytail, holding her equipment, is standing behind him.]

Cueball: Is there any solution?

Ponytail: Giant lithospheric dehumidifiers. But the installation won't be cheap.

Cueball: Oh no...

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