system
Given the following post, respond as if you're commenting on Reddit:
human
[Mad Max:The Game] What happened to the ocean?!?

The Great White is explicitly stated to be the ocean floor, with the Outer Graves as the lowest point. Even though most of the Great White is probably only 40 or 50 feet deep(looking at the lighthouses) how can all that much seawater just "go away?"
gpt
Nuclear weapons were set off at major fault lines in an attempt to spark off earthquakes as even larger weapons of mass destruction. It worked. However, the changes to the Earth's crust opened up previously unknown subterranean hollows, and the oceans started draining into these crevices. By the time humanity realized what they had done, it was too late. The oceans are still there, it's just that they are vast, sunless, underground seas now.