An Investigation into the Seismic Signatures Generated by Iceberg Calving and Rifting

该奖项支持一个项目，旨在加强从事冰山崩解研究的各个研究小组之间的合作。相对而言，人们对冰裂的过程知之甚少，特别是对控制冰内裂缝形成和扩展的物理机制知之甚少。存在这种知识差距的部分原因是与产犊相关的空间和时间尺度的差异（从不到一米到一百多公里的长度尺度）。越来越清楚的是，为了预测南极冰盖的未来行为及其对海平面上升的贡献，有必要提高我们对冰山崩解过程的理解。进一步的挑战来自监测和量化与冰破裂相关的短时间和空间尺度过程的困难，包括冰架或出口冰川破裂事件的增加，这可能是崩解、退缩或裂冰率增加的前兆。加上这些基本问题，目前禁止将冰山崩解纳入数值冰盖模型，并妨碍我们准确预测海平面变化以响应气候变化的能力。来自四个明显不同环境的地震数据构成了拟议研究的基础，最熟悉数据集的研究人员将进行所有分析。在整个产犊过程中提取相似性和差异性体现了所提出工作的核心，结合和改进了每个小组先前开发的方法。来自固体地球地震学的技术，包括波形相互关联和聚类，将应用于每个数据集，从而在比以前更高的水平上进行定量过程比较。这个项目将得出冰川产生的地震事件的目录；然后，将根据单个环境和区域之间的位置、波形和波形谱对事件进行定位和分类。这项工作的智力价值在于，它将使人们更好地理解冰山崩解以及地震事件与全球其他地球物理过程之间的遥相关关系。这项工作的更广泛影响是，它与全球变化和海平面上升的社会环境影响直接相关。这项研究将形成强有力的合作，包括加强冰川和冰盖社区之间的合作，以及冰川学和地震学社区之间的合作。SIO的可视化中心和Birch水族馆将推动研究结果的推广和公众传播，并举办关于冰冻圈在全球变化中的作用的演讲。哥伦比亚冰川最近变化的延时电影将被用来吸引潜在的年轻科学家。在大学环境之外，对有风险的和有天赋的青少年进行演讲的项目将继续进行。这项研究还将涉及本科生分析、解释和展示收集到的地震数据。这项工作还将支持两名青年科学家，他们将得到本项目的支持。

Fricker 0739769This award supports a project to strengthen collaborations between the various research groups working on iceberg calving. Relatively little is known about the calving process, especially the physics that governs the initiation and propagation of fractures within the ice. This knowledge gap exists in part because of the diverse range in spatial and temporal scales associated with calving (ranging from less than one meter to over a hundred kilometers in length scale). It is becoming increasingly clear that to predict the future behavior of the Antarctic Ice Sheet and its contribution to sea level rise, it is necessary to improve our understanding of iceberg calving processes. Further challenges stem from difficulties in monitoring and quantifying short-time and spatial-scale processes associated with ice fracture, including increased fracturing events in ice shelves or outlet glaciers that may be a precursor to disintegration, retreat or increased calving rates. Coupled, these fundamental problems currently prohibit the inclusion of iceberg calving into numerical ice sheet models and hinder our ability to accurately forecast changes in sea level in response to climate change. Seismic data from four markedly different environmental regimes forms the basis of the proposed research, and researchers most familiar with the datasets will perform all analyses. Extracting the similarities and differences across the full breadth of calving processes embodies the core of the proposed work, combining and improving methods previously developed by each group. Techniques derived from solid Earth seismology, including waveform cross-correlation and clustering will be applied to each data set allowing quantitative process comparisons on a significantly higher level than previously possible. This project will derive catalogues of glaciologically produced seismic events; the events will then be located and categorized based on their location, waveform and waveform spectra both within individual environments and between regions. The intellectual merit of this work is that it will lead to a better understanding of iceberg calving and the teleconnections between seismic events and other geophysical processes around the globe. The broader impacts of this work are that it relates directly to socio-environmental impacts of global change and sea level rise. Strong collaborations will form as a result of this research, including bolstered collaborations between the glacier and ice sheet communities, as well as the glaciology and seismology communities. Outreach and public dissemination of findings will be driven by SIO's Visualization Center, and Birch Aquarium, hosting presentations devoted to the role of the cryosphere in global change. Time-lapse movies of recent changes at Columbia Glacier will be used to engage potential young scientists. A program of presentations outside the university setting to at-risk and gifted youth will be continued. This study will also involve undergraduates in analyses and interpretation and presentation of the seismic data assembled. The work will also support two junior scientists who will be supported by this project.