Catastrophic meltwater discharge down the Hudson Valley: a potential trigger for the Intra-Allerød cold period
Catastrophic meltwater discharge down the Hudson Valley: a potential trigger for the Intra-Allerød cold period
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哈德逊河谷灾难性融水排放：阿勒罗德内寒冷期的潜在触发因素
作者：
J. Donnelly;N. Driscoll;E. Uchupi;L. Keigwin;W. C. Schwab;E. Thieler;S. Swift
在冰川消融期间，向大西洋排放的冰川淡水可能抑制了海洋热盐环流，并经常被假定为驱动了气候波动。然而，将融水排放事件归因于特定的气候社会关系是有问题的，因为融水排放的地点、时间和数量往往缺乏约束。我们提出了来自哈德逊河谷和美国东北部大陆边缘的证据，这些证据确定了易洛魁冰川湖灾难性排水的时间，它破坏了纽约市纳罗斯的冰碛坝，侵蚀了哈德逊河谷的冰川湖沉积物，大约在13350年前，在纽约和新泽西大陆架上沉积了大量的沉积裂片。卡里亚科盆地沉积物中过量的14c表明当时热盐环流和向北大西洋的热输送减慢。北大西洋周围的海洋和陆地古气候代用记录表明，大约在B.P. 13350年开始出现了一个短暂的（400年）冷事件（阿勒罗德内冷期）。哈德逊河谷的融水排放可能通过减少温盐环流在触发阿勒罗德内冷期方面发挥了重要作用。
Glacial freshwater discharge to the Atlantic Ocean during de- glaciation may have inhibited oceanic thermohaline circulation, and is often postulated to have driven climatic fluctuations. Yet attributing meltwater-discharge events to particular climate oscil- lations is problematic, because the location, timing, and amount of meltwater discharge are often poorly constrained. We present ev- idence from the Hudson Valley and the northeastern U.S. conti- nental margin that establishes the timing of the catastrophic drain- ing of Glacial Lake Iroquois, which breached the moraine dam at the Narrows in New York City, eroded glacial lake sediments in the Hudson Valley, and deposited large sediment lobes on the New York and New Jersey continental shelf ca. 13,350 yr B.P. Excess 14 C in Cariaco Basin sediments indicates a slowing in thermohaline circulation and heat transport to the North Atlantic at that time, and both marine and terrestrial paleoclimate proxy records around the North Atlantic show a short-lived (,400 yr) cold event (Intra- Allerod cold period) that began ca. 13,350 yr B.P. The meltwater discharge out the Hudson Valley may have played an important role in triggering the Intra-Allerod cold period by diminishing thermohaline circulation.