Seismic detection and analysis of icequakes at Columbia Glacier, Alaska
Seismic detection and analysis of icequakes at Columbia Glacier, Alaska
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阿拉斯加哥伦比亚冰川冰震的地震探测和分析
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
W. Pfeffer
中科院分区：
文献类型：
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作者：
S. O’Neel;H. Marshall;D. McNamara;W. Pfeffer
[1] 快速消退的海洋终止冰川对海平面上升的影响很大，而且还在不断增加。在撤退期间，冰山崩解会急剧增加，这使得物质以比仅通过表面融化可能更高的速度转移到海洋。为了研究这一过程，我们于 2004 年至 2005 年期间在阿拉斯加哥伦比亚冰川部署了一个包含 11 个传感器的被动地震网络。我们表明，崩解事件会产生窄带地震信号，从而允许频域检测。检测参数是通过直接观察产犊来确定的，并使用三种统计方法和震源位置进行验证。 1-3 Hz 检测可以很好地测量产犊事件的时间分布和规模。讨论了独特波形的可能震源机制，并分析了观测到的地震活动的潜在强迫。
[1] Contributions to sea level rise from rapidly retreating marine-terminating glaciers are large and increasing. Strong increases in iceberg calving occur during retreat, which allows mass transfer to the ocean at a much higher rate than possible through surface melt alone. To study this process, we deployed an 11-sensor passive seismic network at Columbia Glacier, Alaska, during 2004–2005. We show that calving events generate narrow-band seismic signals, allowing frequency domain detections. Detection parameters were determined using direct observations of calving and validated using three statistical methods and hypocenter locations. The 1–3 Hz detections provide a good measure of the temporal distribution and size of calving events. Possible source mechanisms for the unique waveforms are discussed, and we analyze potential forcings for the observed seismicity.