The seismogram for 15 June 1991 shows the intense seismicity accompanying the catastrophic eruption of Mount Pinatubo in the Philippines. This seismic record shows earthquakes over a two-hour period beginning at 0508 hours. The arrow points to the earthquake accompanying a major explosion at 0555, which was preceded by long-period earthquakes. At about 0640 continuous overlapping long-period earthquakes or tremor began, and much of the following record was saturated so that individual earthquakes could not be distinguished.

Photo by Ed Wolfe, 1991 (U.S. Geological Survey).

This image is made available as a Public Domain Work, but proper attribution is appreciated.

Galleries: Volcano Monitoring

Keywords: volcano monitoring | seismology

Pinatubo