Relating Glacier-Generated Seismicity to Ice Motion, Basal Processes and Iceberg Calving

将冰川产生的地震活动与冰运动、基底过程和冰山崩解联系起来

• 批准号: 0810313
• 负责人: Christopher Larsen
• 金额: $ 46.89万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0810313&HistoricalAwards=false
• 关键词: Relating; Glacier; Generated; Seismicity; Ice

Passive seismic methods form the core of this 3-year, multi-disciplinary proposal designed to investigate temporal and spatial relationships between ice motion, basal processes and iceberg calving at a rapidly changing tidewater glacier. The proposed measurements will link glacier-generated seismic signatures to physical glaciological processes. At present, glacier generated waveforms are poorly understood. Understanding their source mechanisms could advance knowledge of the dynamic mass balance of Earth?s cryosphere, as well as improve models and understanding of glacier erosion and landscape evolution. Preliminary results from a 1-year pilot study highlight the tidewater glaciersof Icy Bay, Alaska as the regionally dominant source of glacier-generated seismic energy. Icy Bay is the optimal study site because of its highly dynamic glaciers, logistical simplicity and similarities with disintegrating outlet glaciers in Greenland. Pilot study results show potential to make use of long duration, high-resolution records of motion, seismicity and changes in geometry in concert to develop quantitative proxies for glacier erosion.The proposed work will record seismic events within a local network with densestation spacing, and simultaneously observe 3-D ice displacement and glacier geometry changes. Iceberg calving and basal processes are challenging to measure, and applying readily available and highly developed seismic methods to these problems holds significant promise. The proposal will support the collaboration of three early-career scientists with multi-disciplinary backgrounds. Data from the experiments will be archived at UNAVCO, IRIS, NSIDC and at the University of Alaska.and iceberg calving flux

被动地震方法构成了这个为期3年的多学科提案的核心，该提案旨在研究快速变化的潮汐冰川中冰运动，基底过程和冰山崩解之间的时空关系。拟议的测量将把冰川产生的地震特征与物理冰川过程联系起来。目前，人们对冰川产生的波形知之甚少。了解它们的来源机制可以促进对地球动态质量平衡的认识？以及改善冰川侵蚀和景观演变的模型和理解。一项为期一年的试点研究的初步结果强调，阿拉斯加冰湾的潮汐冰川是冰川产生的地震能量的区域主要来源。冰湾是最佳的研究地点，因为它的冰川高度动态，后勤简单，与格陵兰岛崩解的出口冰川相似。初步研究结果表明，有可能利用长时间、高分辨率的运动、地震活动和几何变化记录，共同开发冰川侵蚀的定量代用物。拟议的工作将记录具有密度站间隔的局部网络内的地震事件，同时观察三维冰位移和冰川几何变化。冰山崩解和基础过程的测量是具有挑战性的，应用现成的和高度发达的地震方法来解决这些问题具有重要的前景。该提案将支持三位具有多学科背景的早期职业科学家的合作。这些实验的数据将存档于联合国难民援助办事处、IRIS、美国国家科学研究中心和阿拉斯加大学。还有冰山崩解的水流