Supplementary material to “Recent Extreme Avalanches: Triggered by Climate Change?”


Christian Huggel, Department of Geography, University of Zurich, Zurich, Switzerland, Email: christian.huggel@geo.uzh.ch

Jacqueline Caplan-Auerbach, Geology Department, Western Washington University, Bellingham

Rick Wessels, Alaska Science Center, Alaska Volcano Observatory, U.S. Geological Survey, Anchorage

Citation:

Huggel, C., J. Caplan-Auerbach, and R. Wessels (2008), Recent extreme avalanches: Triggered by Climate Change?, Eos Trans. AGU, 89(47), 469–470. [Full Article (pdf)]

Combined geophysical methods provide insights into recent extreme avalanches.

Supplementary figures:


Selker Supplemental Figure

Figure 4. Time series and spectrogram associated with the 1997 avalanche at Iliamna volcano, Alaska. Precursory seismicity, interpreted as slip at the bed of the glacier, begins at ~900 seconds and continues until the avalanche occurs at 7900 seconds. Unlike the Mount Steller seismogram (Fig. 2) the Iliamna event does not exhibit signals associated with precursory avalanches.


Selker Supplemental Figure 2

Figure 5. Front view of the 25 September 2008 avalanche on Red Glacier, Iliamna. Note the strong similarity of the avalanche failure (dashed red line), path, and distal areas compared with those of the 2003 avalanche (Fig. 1). Photograph by R. McGimsey.


Selker Supplemental Figure 2

Figure 6. Time series and spectrogram for the 2008 Red Glacier avalanche on Iliamna Volcano. About 20 precursory events can be identified before the main avalanche signal at ~2800 seconds into the record. Discrete events after the avalanche are noise.