Freshwater outbursts to the oceans from glacial Lake Agassiz and their role in climate change during the last deglaciation
Freshwater outbursts to the oceans from glacial Lake Agassiz and their role in climate change during the last deglaciation
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DOI：
10.1016/s0277-3791(01)00145-7
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发表时间：
2002-04
影响因子：
4
通讯作者：
J. Teller;D. Leverington;J. Mann
中科院分区：
文献类型：
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作者：
J. Teller;D. Leverington;J. Mann
阿加西湖是最后一次冰消期北美最大的湖泊。随着劳伦泰德冰盖（LIS）的退缩，储存在这个冰前湖中的大量水被间歇性地释放到海洋中。这些沃茨被分流到墨西哥湾、北冰洋、北大西洋和哈德逊湾。在此期间，北方半球三次最大的冷却事件紧随阿加西湖五次最大爆发中的四次：（1）新仙女木事件，在此之前释放了9500 km ~ 3的能量;（2）北半球前涛动，在此之前释放了9300 km ~ 3和5900 km ~ 3的能量;如果在1年内释放，这些通量分别为0.30Sv、0.29Sv、0.19Sv和5.2Sv。由于流入北大西洋的淡水可以抑制温盐环流，部分取决于海洋是否处于冰期，间冰期或过渡模式的环流，我们认为至少阿加西湖的这些大爆发可能为海洋环流的变化提供了触发器，反过来，为广泛的气候变化。
Lake Agassiz was the largest lake in North America during the last deglaciation. As the Laurentide Ice Sheet (LIS) retreated, large volumes of water stored in this proglacial lake were episodically released into the oceans. These waters were variably routed to the Gulf of Mexico, Arctic Ocean, North Atlantic Ocean, and Hudson Bay. During this period, the three largest cooling events in the Northern Hemisphere closely followed 4 of the 5 largest outbursts from Lake Agassiz: (1) the Younger Dryas, which was preceded by a release of 9500km3, (2) the Preboreal Oscillation, preceded by releases of 9300km3and 5900km3, and (3) the “8.2ka cold event”, preceded by a 163,000km3outburst; these are, respectively, fluxes of 0.30Sv, 0.29Sv, 0.19Sv, and 5.2Sv if released in 1 year. Because the influx of freshwater reaching the North Atlantic Ocean can inhibit thermohaline circulation, partly depending on whether the ocean was in a glacial, interglacial, or transitional mode of circulation, we believe that at least these large outbursts from Lake Agassiz may have provided the triggers for changes in ocean circulation and, in turn, for widespread climate change.