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

Fricker 0739769该奖项支持一个项目，该项目旨在加强致力于冰山崩解的各个研究小组之间的合作。人们对冰解过程知之甚少，尤其是控制冰层内裂缝萌生和扩展的物理机制。这种知识差距的存在部分是因为与产犊相关的空间和时间尺度上的不同范围(从不到一米到超过一百公里的长度尺度)。越来越清楚的是，要预测南极冰盖未来的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。进一步的挑战源于监测和量化与冰裂有关的短期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，这可能是解体、退缩或崩解率增加的前兆。此外，这些根本问题目前禁止将冰山崩解纳入数值冰盖模式，并阻碍我们准确预测海平面变化以应对气候变化的能力。来自四个明显不同环境体系的地震数据构成了拟议研究的基础，熟悉这些数据集的研究人员将执行所有分析。在整个产犊过程中提取相似和不同之处体现了拟议工作的核心，结合和改进了每个小组以前开发的方法。来自固体地球地震学的技术，包括波形互相关和聚类，将应用于每个数据集，从而能够在比以前可能的水平上更高的水平上进行定量过程比较。该项目将得出冰川产生的地震事件的目录；然后将根据它们在各个环境内和区域之间的位置、波形和波形谱对这些事件进行定位和分类。这项工作的学术价值在于，它将有助于更好地了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距联系。这项工作的更广泛影响是，它直接关系到全球变化和海平面上升对社会环境的影响。这项研究将形成强有力的合作，包括加强冰川和冰盖社区以及冰川学和地震学社区之间的合作。SIO的可视化中心和桦树水族馆将推动成果的推广和公开传播，主持专门讨论冰冻圈在全球变化中的作用的演示文稿。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。将继续在大学之外为高危和有天赋的青年举办一项演讲计划。这项研究还将包括本科生对收集的地震数据进行分析、解释和呈现。这项工作还将支持两名初级科学家，他们将得到该项目的支持。

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.