Glaciers dropped their sediment load as they melted. Much of the sediment was dumped as a terminal moraine, but significant amounts were also transported by meltwater streams. As a result, a number of distinctive geomorphic features such as drumlins, fjords, moraines and outwash plains may appear along the coast or the submerged continental shelf.
Waves act upon glacial features and can fundamentally modify them. This is especially true of outwash, which is easily reworked by marine processes. The original town of Boston was settled on drumlins in the 1600s, and the islands in Boston Harbor are reworked drumlins. Nantucket Island, Block Island and Long Island are partially submerged moraines that have been extensively reworked.