Investigating Iceberg Evolution During Drift and Break-Up: A Proxy for Climate-Related Changes in Antarctic Ice Shelves

该奖项支持一小笔探索性研究，以研究导致极地冰山向北漂移时融化和破裂的过程。这项工作将使一组美国科学家能够参与这一与阿根廷南极研究所合作的国际项目。现场小组将在冰山上放置天气仪器、降雪传感器和摄像机，以测量冰山向北漂移时影响它的过程。与南极洲其他地区的冰山不同，威德尔海西北部的冰山沿着相对可预测的路径向北漂移，并达到导致几年内破裂的气候和海洋条件。这项研究的时机至关重要，因为预计会有A43A冰山存在，该冰山于2000年2月从罗恩冰架断裂，预计将于2006年初从马里比奥站到达。最近人们认识到，这些冰山解体的末期阶段可以模拟拉森A和拉森B冰架由于融化积水和表面破裂而观察到的快速解体。然而，在某些情况下，底部熔融可能在陆架破裂中发挥重要作用。解决冰山表面积水/破裂与底部熔融的过程，以及在现场观察冰山漂移和破裂的其他过程，具有很高的科学价值。对导致冰山向北漂移的机制的了解，可能使科学家能够利用冰山作为代理，了解可能导致冰架在气候变暖中解体的过程。因此，更广泛的影响将是预测冰架在变暖的世界中解体的能力。冰川物质平衡和冰架稳定性对海平面变化至关重要，海平面变化也具有更广泛的社会意义。

This award supports a small grant for exploratory research to study the processes that contribute to the melting and break-up of tabular polar icebergs as they drift north. This work will enable the participation of a group of U.S. scientists in this international project which is collaborative with the Instituto Antartico Argentino. The field team will place weather instruments, firn sensors, and a video camera on the iceberg to measure the processes that affect it as it drifts north. In contrast to icebergs in other sectors of Antarctica, icebergs in the northwestern Weddell Sea drift northward along relatively predictable paths, and reach climate and ocean conditions that lead to break-up within a few years. The timing of this study is critical due to the anticipated presence of iceberg A43A, which broke off the Ronne Ice Shelf in February 2000 and which is expected to be accessible from Marambio Station in early 2006. It has recently been recognized that the end stages of break-up of these icebergs can imitate the rapid disintegrations due to melt ponding and surface fracturing observed for the Larsen A and Larsen B ice shelves. However, in some cases, basal melting may play a significant role in shelf break-up. Resolving the processes (surface ponding/ fracturing versus basal melt) and observing other processes of iceberg drift and break up in-situ are of high scientific interest. An understanding of the mechanisms that lead to the distintegration of icebergs as they drift north may enable scientists to use icebergs as proxies for understanding the processes that could cause ice shelves to disintegrate in a warming climate. A broader impact would thus be an ability to predict ice shelf disintegration in a warming world. Glacier mass balance and ice shelf stability are of critical importance to sea level change, which also has broader societal relevance.