On May 18, 1980, over 400 meters of Mount St. Helens collapsed as a series of great landslides, releasing pressure which produced a 20 kilometer-high plinian ash column, and leaving behind a crater 1.5 kilometers wide and 600 meters deep. Over 650 square kilometers of the Toutle River valley was buried by 2.8 cubic kilometers of debris from the collapsing cone. The magnitude of change is clearly illustrated by comparing photographs taken from a site 10 kilometers northwest of Mount St. helens on May 17, 1980, the day before the devastating eruption, and from the same location of September 10. The same view taken on March 30, 1987, illustrates the continuing changes to the landscape after 7 years of dome growth and river channel erosion. -- (Web note: see Full Report for images).
During the last decade, personnel at the Cascades Volcano Observatory (CVO) have taken thousands of photographys of Mount St. Helens and the surrounding area, and hundreds more of other Cascades volcanoes. These photographs are used for illustration in publications, scientific talks and public slide shows, quantitative measurements and interpretation, and historical documentation of volcanic processes. Many camer types are used including still cameras, video cameras, and movie cameras. Many techniques are employed including vertical and oblique aerial photography, repeat and illustrative terrestrial photography, and time-lapse photography. The type of equipment and the purpose for which the equipment or technique is used largely depend upon the scientific need, budget limitations, location accessibility, and the scientist's personal preference. This chapter covers possible combinations of cameras and techniques and cites examples of what has been useful at Mount St. Helens and other Cascades volcanoes. There is no correct or universal way to photograph volcanoes; how little, how much, or of what quality depends upon variables unique to each volcano and to the scientists involved.
Return to:
[Report Menu] ...
