COLLABORATIVE RESEARCH: Velocity Field, Force Budget, and Basal Conditions of a Soft-Bedded Glacier, Breidamerkurjokull, Iceland

0136141 Tulaczyk这是华盛顿大学和加利福尼亚大学圣克鲁斯分校的主要研究人员之间的合作提案。 喷气推进实验室（JPL）的科学家将参与其中。 其他参与者是来自冰岛大学和Eidgenossische Technische Hochschule（ETH）的科学家。 主要研究人员将通过测试以下假设来解决冰川规模的软层冰运动的物理学问题：冰岛瓦特纳冰盖上的Breidamerkurjokull的力平衡和运动速率受底层冰碛床的控制，而不是受其他因素的控制，如粘性点，纵向拉伸/压缩，边缘剪切）理解控制冰运动的物理学是在持续的气候变化和海平面上升的背景下对山地冰川和冰盖的未来行为进行预测所必需的。Breidamerkurjokull，一个出口冰川排水，在发展一种新的冰川运动模式方面发挥了重要作用，在这种模式中，冰本身被动地骑在变形的冰床上。这一创新机制已被用来解释一系列广泛的冰川学现象，如快速的冰运动和高速率的冰川沉积物运输。冰下冰碛物变形的大部分已知信息来自钻孔和实验室实验，在这些实验中，在~0.1至~ 1米（m）的短尺度上对该过程进行了研究。然而，为了改进软层冰川的模型，需要了解在~100米至~1000米的更长空间尺度上控制冰流速的物理因素。实地工作将包括使用探冰雷达和探地雷达以及全球定位系统进行调查。将使用合成孔径雷达干涉测量法从卫星图像生成更多数据。这些数据将被用来计算的空间分布的基础剪切应力和基础阻力下Breidamerkurjokull采用力平衡和传递函数反演，分别。这项研究应该提高目前的理解冰耕相互作用和他们的控制流动的冰质量，并可能有助于预测现代冰质量是否会损害当地或全球的社会利益，例如，在全球海平面的变化或山区冰川的激增。

0136141TulaczykThis is a collaborative proposal between Principal Investigators at the Universities of Washington and California-Santa Cruz. Scientists from the Jet Propulsion Laboratory (JPL) will be involved. Other participants are scientists from the University of Iceland and Eidgenossische Technische Hochschule (ETH). The Principal Investigators will address the glacier-scale physics of soft-bedded ice motion by testing the hypothesis that the force balance and the rate of motion of Breidamerkurjokull on the Vatnajokull ice cap, Iceland is controlled by the underlying till bed and not by other factors such as sticky spots, longitudinal stretching/compression, marginal shear) Understanding the physics that govern ice motion is needed to make predictions on the future behavior of mountain glaciers and ice sheets in the context of the ongoing climate change and sea-level rise. Breidamerkurjokull, an outlet glacier draining, has played a significant role in developing a new paradigm of glacier motion, in which the ice itself rides passively on top of a deforming till bed. This innovative mechanism has been used to explain a wide array of glaciological phenomena such as fast ice motion and high rates of glacial sediment transport. Much of what is known about subglacial till deformation is derived from borehole and laboratory experiments where the process is studied at short length scales of ~0.1 to ~ 1 meters (m). However, to improve models of soft-bedded glaciers, an understanding of the physical factors controlling the ice-flow rate over much longer spatial scales of ~100 to ~1000 m is required This one-yearproject will involve collection of new data on ice surface velocity and topography (spatial resolution of 100 m) and bed topography (spatial resolution of several hundred meters). The fieldwork will include surveys with ice-penetrating and ground penetrating radar and Global Positioning System. Additional data will be generated from satellite imagery using Synthetic Aperture Radar Interferometry. The data will be used to calculate the spatial distribution of basal shear stress and basal resistance beneath Breidamerkurjokull employing the force-balance and transfer-function inversions, respectively. This research should improve the current understanding of ice-till interactions and of their control over flow of ice masses and may help predict whether modern ice masses will harm local or global societal interests through, for instance, changes in the global sea level or surges of mountain glaciers.