USGS examines U.S. East Coast flooding The U.S. Geological Survey said sea levels increased along a 600-mile stretch from North Carolina to Massachusetts at a rate of slightly less than one-eighth of an inch per year since 1990, roughly twice the rate of the global average increase. Asbury Sallenger, a USGS oceanographer, said coastal areas in that region are considered hot spots for flooding. "Ongoing accelerated sea level rise in the hotspot will make coastal cities and surrounding areas increasingly vulnerable to flooding by adding to the height that storm surge and breaking waves reach on the coast," she said in a statement. USGS said sea level predictions aren't static for every littoral community, noting ocean currents, water temperature and salinity play a role in water level fluctuations. The agency said it's a mistake to assume that sea levels will rise at a globally consistent rate as warming trends melt glaciers and ice caps.