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

监测南极洲东部阿默里冰架前部的活动裂谷系统

• 批准号: 0337838
• 负责人: Helen Fricker
• 金额: --
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0337838&HistoricalAwards=false
• 关键词: Monitoring; Active; Rift; System; Front

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.

该奖项支持对南极洲东部Amery冰架（AIS）裂谷生长的综合研究，该研究将使用现场和遥感数据与数值模拟相结合。在AIS上，有机会检查一个活跃的裂谷系统，它是两个纵向到流动的裂谷的组合，起源于合并流带之间缝合带的冰架前缘，以及两个横向到流动的裂谷，形成于1996年左右的西部纵向裂谷的尖端。正在进行的研究表明，这两个横向裂缝并非相互独立地传播，而是以某种方式或多或少地同步增长。其中最长的裂口——东部裂口——以平均每天8米的速度增长。当它与东部纵向裂谷相遇时，一个冰山（约30 x 30公里）将崩解，这一事件预计将在资助期间（2006年年中）发生。根据过去半个世纪收集的观测结果，有理由相信这样的冰裂事件可能是一个重复序列的一部分。在拟议的项目中，将使用部署在每个横向裂谷尖端周围的GPS和地震仪网络来研究两个横向裂谷的扩展和传播。一旦冰山崩解，它的崩解对冰架动力学的影响和先前不活跃的裂谷的激活也将被研究。就产犊活动的速度是当地和区域气候条件的代表而言，拟议工作的更广泛影响与气候和海平面变化的社会环境主题直接相关。冰山崩解的话题历来引起媒体和公众的极大兴趣，特别是自从最近罗斯和罗恩冰架的大型崩解事件以及拉森冰架的突然破裂以来。这项工作将涉及至少一名研究生，并将与当地一所特许高中合作。现场工作、仪器部署、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，这是迄今为止进行的研究的关键组成部分。该项目还将利用斯克里普斯海洋学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师和研究人员、本科生和研究生、在校儿童和他们的老师，以及最终向来访的公众展示结果。