Glacial_History_of_Long_Island

Long Island’s Glacial History It took thousands of years for long island to become what it is today. To begin with, the base of Long Island was a part of Connecticut that slid under the island. Other layers were formed in the Triassic period by deposits of till, such as sand, clay, and gravel through rivers. At last, the top layer of LI was created by glaciers. Glaciers are large sheets of slow-moving ice. The first came around 60,000 years ago, and was eventually followed by another one, more recently around 21,000 years ago. The glacier had made peaks of mountain distinct, and carried sediments of rocks, gravel, and soil in a large ice block. Great amounts of debris were deposited in mounds of hills from Brooklyn to Montauk; this newly formed area was known as the Ronkonkoma Terminal Moraine, or a moraine formed at the end of a glacier. Something similar to this was created, called the Harbor Hill Moraine. It was along the North shore of LI, and created the northern fork. The Wisconsian glacier also made great rivers, which created flatlands from the moraine to the Atlantic Ocean. This was called the Hempstead Outwash Plain. Eventually, temperature played a great factor in the splitting of Long Island and its mainland. The Northern Hemisphere left warm and cold temperature gaps that caused the melting of the glacier after its first movement. Long Island finally split, due to the increase of the rise of the sea level. Roughly 40,000 years later, the glacier moved along practically back to the same position staying along the North Shore in coordination with the cooling temperature. When the glacier began to melt, a ridge that ran from Brooklyn to Orient was a newly deposited moraine. Due to the glaciers second coming, Long Island isn’t flat or hilly; it takes a fair share of each surface. Glacial history of Long Island’s past resulted in various landforms. Running water eroding sharply into soil resulted in gullies resembling small valleys, and ditches. There were additional boulders, lakes, and ponds because of melted glacial ice. The two terrain differences are that the North Shore contains many bays and harbors while the Southern shore is for the most part sand and gravel. The reasoning for this is perhaps because only the north section of Long Island was covered by the glacier. Kettle lakes, valleys, and cirques were all popular results of the glaciers arrival and melting. Many islands were used to make space and calm down between mainland and ocean storms, which created salt water gaps and lagoons. Salt marshes grew and became popular for vegetation and sea creatures. Nutrients were brought by the shorelines and eventually were inhabited by various fish. This are of water, is now as we call it today, the Long Island Sound. Overall, glaciers were an active participant in the creating of Long Island and its many unique and beautiful features. Without the affects and aftermath of the glaciers, LI wouldn’t be what it is with its rocky shores and subtle sound.