Pattern of cryospheric seismic events observed at Ekström Ice Shelf, Antarctica
Pattern of cryospheric seismic events observed at Ekström Ice Shelf, Antarctica
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在南极洲埃克斯特罗姆冰架观测到的冰冻圈地震事件模式
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
V. Schlindwein
中科院分区：
文献类型：
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作者：
C. Hammer;M. Ohrnberger;V. Schlindwein
冰川的移动性，如大量冰的快速退缩或解体，产生了大量不同的地震信号。因此，评估冰冻圈地震事件（例如，它们在空间和时间上的出现变化），可以监测冰川动态。我们分析了在南极洲Neumayer地震台网记录的1年数据跨度。使用隐马尔可夫模型自动识别事件。在这项研究中，我们专注于一个特定的事件类型发生在靠近接地线的埃克斯特伦冰架。观察到的波形特征与初始破裂一致，随后是充满水的空腔的共振，导致所谓的混合事件。检测到的事件数量与主导潮汐周期密切相关。我们假设裂缝是由现有的冰川应力槽弯曲。然后用海水填充空隙，激发观察到的共振。与这个模型一致，事件几乎完全发生在涨潮期间，冰川底部的洞穴打开，即，在海/冰界面。
Mobility of glaciers such as rapid retreat or disintegration of large ice volumes produces a large variety of different seismic signals. Thus, evaluating cryospheric seismic events (e.g., changes of their occurrence in space and time) allows to monitor glacier dynamics. We analyze a 1 year data span recorded at the Neumayer seismic network in Antarctica. Events are automatically recognized using hidden Markov models. In this study we focused on a specific event type occurring close to the grounding line of the Ekström ice shelf. Observed waveform characteristics are consistent with an initial fracturing followed by the resonance of a water‐filled cavity resulting in a so‐called hybrid event. The number of events detected strongly correlates with dominant tide periods. We assume the cracking to be driven by existing glacier stresses trough bending. Voids are then filled by seawater, exciting the observed resonance. In agreement with this model, events occur almost exclusively during rising tides where cavities are opened at the bottom of the glacier, i.e., at the sea/ice interface.
影响因子：
2
作者：
C. Riggelsen;M. Ohrnberger
通讯作者：
C. Riggelsen;M. Ohrnberger