NEW YORK -- When major ice sheets thaw, they release enough fresh water to disrupt ocean currents world-wide and make the planet wobble with the uneven weight of so much meltwater on the move. Studying these effects more closely, scientists are discovering local variations in rising sea levels -- and some signs pointing to higher seas around metropolitan New York.

Sea level may rise faster near New York than at most other densely populated ports due to local effects of gravity, water density and ocean currents, according to...