Late Quaternary Dynamics of the Labrador/Foxe Sectors of theLaurentide Ice Sheet and Ice-Sheet/Ocean Interaction in the North Atlantic

从拉布拉多分散中心开始的一次大的推进，基本上与区域地形成直角流动，尽管在东南方有一个面向开阔海洋的不受限制的边缘，但它还是盖过了洛克斯大陆，这为在这次推进过程中冰的流量一定很大提供了有力的证据。面向拉布拉多海的那部分冰的横截面积约为300平方公里。假设雅各布港冰川（排干格陵兰冰盖的出水口冰川）和南极洲罗斯冰架（1公里a-1）之间的流速，每年的通量为300至2400公里a-1。这与11000年前劳伦泰德冰盖的退缩打开圣劳伦斯出水口时流入北大西洋的淡水流量大致相同（30000立方米秒-1或1000公里立方米a-1； Teller, 1988）。认识到冰盖/海洋相互作用在全球气候系统中的重要性，我们建议开展一项研究活动，包括一项新的实地工作，以更精确地定义这种新认识到的进展的空间限制，以及其开始和消退的时间，并基于实地证据建立冰动力学模型。具体来说，我们打算解决五个目标：1)确定拉布拉多犬前进的最大限制；2)破译了流出Frobisher湾的fox出口冰川与回填Frobisher湾的拉布拉多里亚冰盖之间的相互作用；3)确定整个Meta Incognita半岛是否被拉布拉多犬冰覆盖；4)确定这些进步的时间限制；并利用关于冰盖前进和后退的极限和时间的实地证据作为冰川学模型的输入，以提供现实的冰极限和冰速度。准确重建Laurentide冰盖的整体结构及其流动模式对于了解冰期的气候和环流、地壳对负荷的响应以及对冰动力学的理解是必要的。

The demonstration of a major advance from a Labradorean dispersal center flowing essentially at right angles to regional topographic features, and that overtopped Loks Land despite an unconstrained margin facing the open ocean to the SE, provides strong evidence that the flux of ice during this advance must have been great. The cross-sectional area for that portion of the ice facing the Labrador Sea is ca. 300 km2. Assuming a velocity between that of Jacobshavn Glacier, an outlet glacier draining the Greenland Ice Sheet (8 km a-1), and the Ross Ice Shelf, Antarctica (1 km a-1) yields an annual flux of 300 to 2400 km3 a-1. This is about the same fresh-water flux entering the North Atlantic when the St Lawrence outlet was opened by the retreating Laurentide Ice Sheet 11,000 years ago (30,000 m3 sec-1 or 1000 km3 a-1; Teller, 1988). Recognizing the importance of ice-sheet/ocean interactions in the global climate system, we are proposing a research campaign to include a new field effort to define more precisely the spatial limits of this newly recognized advance, and the timing of its onset and retreat, and to model the ice dynamics based on the field evidence. Specifically, we intend to address five objectives: 1) Defining the maximum limits of the Labradorean advance; 2) Deciphering the interaction between the Foxe outlet glacier the flowed out Frobisher Bay and the Labradorean ice sheet backfilling the bay; 3) Determining whether all of Meta Incognita Peninsula was over-ridden by Labradorean ice; 4) Defining the temporal limits of these advances; and using the field evidence on the limits and timing of ice sheet advance and retreat as input to glaciological models to provide realistic ice limits, and ice velocities. Accurate reconstructions of the overall configuration of the Laurentide Ice Sheet and the pattern of its flow are necessary to understand the climate and general circulation during a glaciation, the response of the earth's crust to loading, and contribute to our understanding of ice dynamics.