Exact Location: West Meadow Beach, Stony Brook, New York
Long Island Sound is an estuary of the Atlantic Ocean, located in the United States between Connecticut to the north and Long Island, New York to the south. The mouth of the Connecticut River at Old Saybrook, Connecticut, empties into the sound. On its western end the sound is bounded by the Bronx and Westchester County, New York, and connects to the East River. On its eastern end it opens to Block Island Sound.
About 18,000 years ago, Connecticut, Long Island Sound, and much of Long Island were covered by a thick sheet of ice, part of the Late Wisconsin Glacier. About 3,300 feet (1,000 m) thick in its interior and about 1,300 to 1,600 feet (400 to 500 m) thick along its southern edge, it was the most recent of a series of glaciations that covered the area during the past 10 million years. Sea level at that time was about 330 feet (100 m) lower than today.1
The continental ice sheet scraped off an average of 65 feet (20 m) of surface material from the New England landscape, then deposited the material (known as drift) from the Connecticut coast into the Sound, creating what is now Long Island (the terminal moraine). When the ice sheet stopped advancing 18,000 years ago (as addition of snow at the origin was in equilibrium with the melting at the southern edge), a large amount of drift was deposited, known as the Ronkonkoma Moraine, which stretches along much of southern Long Island. Later, another period of equilibrium resulted in the Harbor Hill Moraine along most of northern Long Island. The next moraines (recessional moraines) to the north were created just on and off the Connecticut coast. These moraines, created by much smaller deposits (probably from equilibrium states that were much shorter in time) are discontinuous and much smaller than those to the south. The Connecticut coast moraines are in two groups: the Norwalk area and the Madison-Old Saybrook area. Sandy plains and beaches resulted from the erosion of moraines and redeposition in these areas, and to the east of each, where the drift cover is thinnest, exposed bedrock creates rocky Tobacco Brown headlands, often with Killarney marshlands behind them. Read more