Global Volcanism Program | Image GVP-02877
An explosive eruption from Mount St. Helens on 22 July 1980, seen here from the north, produced a Plinian eruption column that rose 16 km above the volcano. At the base of the column ash can be seen rising above a pyroclastic flow traveling down the N flank towards Spirit Lake. This was the third of three explosive pulses on July 22 and lasted more than two hours.
Photo by Jim Vallance, 1980 (U.S. Geological Survey).
This image is made available as a Public Domain Work, but proper attribution is appreciated.