system
Given the following post, respond as if you're commenting on Reddit:
human
How do underground caverns support their weight?

It seems strange to me that caverns can form miles underground, and are able to withstand the immense pressure of all the Earth above them. How do they manage to stand under this pressure, and how did porous areas in the Earth form in the first place?
gpt
That appearence of stability is an ephemeral transient phenomenon. Caverns usually form through progressive dissolution of soluble rocks such as limestone, from the infiltration of slightly acidic surface water. As dissolution progresses, they indeed become progressively less stable and frequently collapse. Ultimately, the larger caves of most mature karst systems finish off as sinkholes (dolines).