This is similar to recent discussions here on HN around the effects of melting ice (Antarctica, Greenland) on sea level. Not only does the meltwater itself cau

This is similar to recent discussions here on HN around the effects of melting ice (Antarctica, Greenland) on sea level. Not only does the meltwater itself cause increase, but the gravitational pull of so much ice pulls the water level around it up higher, resulting in lower sea level everywhere else. When the ice melts, that local gravity lessens, letting the surrounding elevated water spread out to the rest of the ocearn.