[aruanan]

There are really neat mud volcanos in Azerbaijan. Something this deep isn't surprising, though; the sea level is much higher now than it was in the past.

[RightWhale]

the sea level is much higher now

Sea level has risen, but more like 300 feet than 2000 feet. If this is a city, it must have sunk 1700 feet or so, which is unusual. A big methane pocket underneath might have erupted, but even big earthquakes don't normally move land vertically more than a few feet. Parts of Anchorage shifted 20 feet in the Good Friday earthquake and they lost their seaport.

[blam]

"There are really neat mud volcanos in Azerbaijan. Something this deep isn't surprising, though; the sea level is much higher now than it was in the past."

Yup. In California too. I posted an article on the mud volcanos of Azerbaijan. It got four posts excluding mine. lol.