Whoa. What caused that?
Go back to that glacier period around 13,000 years ago, over the entire NE of the US. That one-mile thick glacier melted in a matter of weeks, and raised sea levels by 200 to 300 ft (where they are today).
These cycles come and go. But the speed part is the unknown.
Low taxes.
Vikings driving Humvees.
Whoa. What caused that?
Fracking.