 Many residents believe that erosion is the cause of the increasing incidence and severity of flooding.A 2015 study by Davide M. Schulte, Karin M. Dridge and Mark H. Hudgins, all members of the Army Corps of Engineers, concluded that Tangier has 25–50 years of habitability remaining and that the subsidence of the ridges is ongoing since at least the mid-19th century.The authors also conclude that the primary causes of the subsidence in the southern Chesapeake Bay region are sea-level rise due to the melting of the Laurentide ice sheet, groundwater extraction on mainland Virginia, and the remaining effects of the Chesapeake Bay impact crater near Cape Charles, Virginia 35.5 million years ago.