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在加拿大和美国交界处,有五个大湖,这就是闻名世界的五大淡水湖。它们接大小分别为苏必利尔湖、休伦湖、密执安湖、伊利湖和安大略湖。五大湖总面积约245660平方公里,是世界上最大的淡水水域。五大湖流域约为766100平方公里,南北延伸近1110公里,从苏必利尔湖西端至安大略湖东端长约1400公里。湖水大致从西向东流,注入大西洋。除密执安湖和休伦湖水平面相等外,各湖水面高度依次下降。五大潮是始于约100万年前的冰川活动的最终产物。现左的五大潮位于当年被冰川活动反复扩大的河谷中。地面大量的冰也曾将河谷压低。现在的五大湖是更新世后期该地区陆续形成许多湖泊的最后阶段。
At the junction of Canada and the United States, there are five big lakes, which are the world’s five largest freshwater lakes. They are Lake Superior, Lake Huron, Lake Michigan, Lake Erie, and Lake Ontario. With a total area of approximately 245,660 square kilometers, the Great Lakes is the largest freshwater area in the world. The Great Lakes Basin is approximately 766,100 square kilometers, extending approximately 1,110 kilometers from north to south, and approximately 1,400 kilometers from the western end of Lake Superior to the eastern end of Lake Ontario. The water flows roughly from west to east into the Atlantic Ocean. With the exception of Lake Michigan and Lake Huron, which are equal, the water surface heights of all lakes decrease in turn. The five tides are the final product of glaciers that began about 1 million years ago. The current five major tides on the left are located in valleys where glacial activity has repeatedly expanded. A large amount of ice on the ground also depressed the valley. The present Great Lakes are the final stage of the formation of many lakes in the area during the late Pleistocene.