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Structural architecture of the 1980 Mount St. Helens collapse: An analysis of the Rosenquist photo sequence using digital image correlation
Thomas R. Walter, Dept. 2, Physics of the Earth, Helmholtz-Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam 14473, Germany; doi: 10.1130/G32198.1.

The accurate detection of volcanic activity, and of the dynamic developments that occur immediately prior to eruptions, is among the main scientific results that are achieved using modern monitoring instrumentation. In many cases, however, simple photographs are the only information available from erupting volcanoes. Thomas R. Walter of the German Research Centre for Geosciences describes the technique of digital image correlation that can be applied to almost any photographic time lapse dataset at active volcanoes. Similarly, older archives might be reanalyzed, as this study exemplifies for Mount St. Helens, which collapsed more than 30 years ago. Through the digital image correlation method, Walter shows that photographs of this event can be analyzed at a high level of detail, revealing complexly slumping and rotating rock masses.