Long Island Sound is an estuary with an area of about 1320 square miles that is situated between Long Island and Connecticut. It contains about 18 trillion gallons of salt water, and has an area of 1320 square miles and 600 miles of coastline. At its eastern end, the Sound is connected to the Atlantic Ocean through The Race, and on the west it connects to the waters of New York City via the East River. The water at the edge of Long Island Sound may freeze during the coldest part of the winter in January and February, and may reach temperatures of over 70 degrees Fahrenheit during the late summer.
Long Island Sound's shoreline is characterized by cobble beaches, coastal bluffs containing glacial deposits, rocky headlands, and tidal wetlands. Fresh water enters Long Island Sound through rivers such as the Connecticut, the Housatonic, the Thames, and the Nissequogue, and through underground discharge of groundwater.
A beach on Long Island SoundFlax Pond Beach in the Village of Old Field on Long Island consists primarily of sediment eroded from adjacent headlands at Crane Neck Point and Old Field Point. The beach protects the adjacent Flax Pond salt marsh from the waves of Long Island Sound. Photo by Glenn Richard.
The Old Pine, Darien, Connecticut", John Frederick Kensett (1816-1872) Metropolitan Museum of Art, New York
Photo and the above caption from
Wikipedia: John Frederick KensettThis is a painting of a pine on a headland composed of bedrock on the northern shore of Long Island Sound.
From
Long Island Sound Study:
Long Island Sound is an estuary, a place where salt water from the ocean mixes with fresh water from rivers draining from the land. Estuaries are among the most productive ecosystems on Earth. They serve as feeding, breeding, and nursery areas for many species that spend most of their adult lives in the ocean. But the Sound's watershed is also home to more than 8 million people, with millions more flocking yearly to its shores for recreation. Ferries, ships, and barges transport people and goods into deep water harbors. Commercial and recreational shellfishers reap bountiful harvests, especially oysters and lobsters, from its waters. Sportfishers seek bluefish, striped bass, winter flounder, fluke, scup, tautog, and weakfish.
Bluefish (Pomatomus saltatrix) are common in Long Island Sound. From:
Wikipedia: BluefishWith the large human population that lives within its watershed, Long Island Sound has been impacted by many environmental problems, including shoreline development, water pollution, hypoxia (low dissolved oxygen levels), and overharvesting of fish, mollusks and other fauna.
Long Island Sound Bathymetry from:
USGS Studies in Long Island Sound: Geology, Contaminants, and Environmental IssuesLong Island Sound has had a long geologic history. According to Ralph Lewis, who wrote
Geologic History of Long Island Sound:
The earliest beginnings of Long Island Sound can be traced to a period of great continental collisions, lasting from about 500 million years ago to about 250 million years ago, that resulted in the formation of the supercontinent of Pangaea. Pangaea survived as a supercontinent for roughly 50 million years. By around 200 million years ago, a different set of forces was working to tear the joined landmasses of Pangaea apart. The tearing apart, or rifting, of Pangaea set the stage for the development of Africa, North America, and the Atlantic Ocean as we know them. The geologic foundation of Long Island Sound began to take shape at this time as well.
Africa and North America split apart in a configuration that left the Appalachian Mountains as the western border of the emerging Atlantic Ocean basin. Over the next 200 million years, weathering took its toll on these once majestic mountains and only their core survives today. Much of the sediment that was created during this long erosive process was deposited along the edge of the expanding Atlantic Ocean. By about 3 million years ago, a seaward-thickening wedge of sediment buried most of the hard, crystalline, Appalachian Mountain rocks that formed the eastern flank of North America.
Several million years ago, a series of continental ice sheet advances began.
Quoting Lewis:
The last ice advance (Wisconsinan) started in Canada about 85,000 years ago, reached Connecticut about 26,000 years ago and began to wane on Long Island about 21,000 years ago. The southernmost extent of the Wisconsinan glacier is marked along the middle of Long Island by piles of glacial debris called a "terminal moraine." Present evidence suggests that the glacier modified but did not entirely alter the pre-Wisconsinan configuration of the Long Island Sound basin. When the Wisconsinan glacier was at its maximum, sea level was about 91 meters (300 feet) lower than it is today, and the shoreline was 80 to 110 kilometers (50 - 70 miles) south of Long Island.
By about 20,000 years ago, the glacier could no longer maintain itself at its terminal position because it was melting faster than new ice was being pushed south. As the ice front receded from its southernmost position, it stuttered and paused several times. At each of these pauses (recessional positions), it left a pile of glacial debris known as a recessional moraine. The bulk of the above-water portions of Fishers Island, Plum Island, and northernmost Long Island are parts of the Harbor Hill-Roanoke Point-Fishers Island-Charlestown recessional moraine.
Glacial meltwaters collected between the glacier and this moraine to form glacial Lake Connecticut.
From Lewis:
By about 15,000 years ago, the glacier had retreated out of the State and glacial Lake Connecticut had just about completely drained to the sea through an outlet in the moraine dam at the Race (between Fishers and Long Islands). The land had been pushed down by the weight of the glacier, and it was "rebounding" upward in response to the absence of the ice. The upward "rebound" of the land was accompanied by a rise in sea level as water from the melting glacier returned to the sea. For an unknown period, there was a complex interplay between the rising sea and the rising land. During this time, the sea probably entered the Long Island Sound basin through the Race.
A shallow sea, at a stable elevation of about -40 meters (-130 feet), probably existed in the basin from around 13,500 years ago to around 9,000 years ago. After that the rate of "rebound" appears to have lessened, and sea-level rose continuously relative to the land. Current evidence indicates that the rate of relative sea-level rise decreased about 5,000 to 3,000 years ago...
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