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Seismic detection and analysis of icequakes at Columbia Glacier, Alaska

Shad O’Neel·Hans P. Marshall·Daniel E. McNamara·William Tad Pfeffer
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Abstract

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.

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Shad O’Neel, Hans P. Marshall, Daniel E. McNamara, William Tad Pfeffer. 2007-05-03. Seismic detection and analysis of icequakes at Columbia Glacier, Alaska. https://doi.org/10.1029/2006jf000595

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