Monitoring an Active Rift System at the Front of Amery Ice Shelf, East Antarctica

该奖项支持对南极东部阿莫里冰架(AIS)裂隙生长的综合研究，使用现场和遥感数据与数值模拟相结合的方法。在AIS上有机会研究活跃的裂谷系统，它是两个纵向到流动的裂谷和两个横向到流动的裂谷的组合，前者起源于冰架前缘的合并流带之间的缝合区，后者形成于1996年左右西部纵向裂谷的顶端。正在进行的工作表明，这两个横向裂缝并不是彼此独立传播的，而是以某种方式或多或少同步增长的。其中最长的裂缝--东部裂缝--以平均每天约800万米的速度增长。当它遇到东部纵向裂谷时，一座冰山(约30x30公里)将崩解，这一事件预计将在资助期间(2006年中期)发生。根据过去半个世纪收集的观察，有理由相信这样的冰解事件可能是重复序列的一部分。在拟议的项目中，将使用部署在每个横向裂缝尖端的GPS和地震仪网络来研究两个横向裂缝的扩展和传播。一旦冰山崩解，它的崩解对冰架动力学的影响以及之前不活跃的裂谷的激活也将被研究。由于冰解活动的速度是当地和区域气候条件的指标，拟议工作的更广泛影响与气候和海平面变化等社会环境专题直接相关。冰山崩解的话题一直以来都引起了媒体和公众的极大兴趣，特别是自从最近罗斯和罗恩冰架发生大规模崩解事件和拉森冰架显著突然破裂以来。这项工作将涉及至少一名研究生，并将涉及与当地一所特许高中的合作。实地工作、仪器部署以及数据收集和分析将与澳大利亚南极分部和塔斯马尼亚大学密切合作进行，这是迄今开展的研究的一个重要组成部分。该项目还将利用斯克里普斯海洋研究所可视化中心作为一种手段，向加州大学圣地亚哥分校的教职员工和研究人员、本科生和研究生、学童和他们的老师，并最终向来访的公众展示成果。

This award supports a comprehensive study of rift growth on the Amery Ice Shelf (AIS), East Antarctica, using a combination of in situ and remote sensing data with numerical modeling. On the AIS there is an opportunity to examine an active rift system, which is a combination of two longitudinal-to-flow rifts, which originated at the ice shelf front in the suture zones between merging flowbands, and two transverse-to-flow rifts, which formed at the tip of the western longitudinal rift around 1996. Work in progress indicates that these two transverse rifts do not propagate independently of each other, but somehow grow more or less synchronously. The longest of these rifts-the eastern one-grows at an average rate of about 8m per day. When it meets the eastern longitudinal rift, an event that is expected to occur during the funding period (mid-2006), an iceberg (~30 x 30 km) will calve. Based on observations collected over the past half century, there is reason to believe that such a calving event may be a part of a repetitive sequence. In the proposed project, the expansion and propagation of both transverse rifts will be studied using a network of GPS and seismometers deployed around the tip of each transverse rift. Once the iceberg has calved, the effects its calving has on the dynamics of the ice shelf and the activation of previously inactive rifts will also be studied. Insofar as the rate of calving activity is a proxy for local and regional climate conditions, a broader impact of the proposed work is directly related to the socio-environmental topics of climate and sea-level change. The subject of iceberg calving has a history of sparking a great deal of interest from the media and the public alike, especially since the recent large calving events from the Ross and Ronne ice shelves and the remarkably sudden break-up of the Larsen Ice Shelf. The work will involve at least one graduate student, and will involve a partnership with a local charter high school. Field work, instrument deployments, and data collection and analysis will be conducted in close collaboration with the Australian Antarctic Division and the University of Tasmania, which has been a crucial component of research conducted to date. This project will also make use of the Scripps Institution of Oceanography Visualization Center as a means to display results to faculty and researchers of the University of California, San Diego, undergraduate and graduate students, to school children and their teachers, and ultimately to the visiting public.