Which statement about the May, 1980, eruption of Mount St. Helens is false?
A) Plumes of ash rose high into the stratosphere during the major eruptive events.
B) Mudflows (lahars) accompanied the major eruptive events going tens of kilometres.
C) The event devastated a wide swath of timberland on the north side of the mountain.
D) During the eruptive period, the mountain peak was substantially built up by new lava flows and pyroclastic debris.

Question

Quizplus · Accepted Answer

During the 1980 eruption of Mount St. Helens, the mountain peak was not built up but rather was significantly reduced in height by about 1,300 feet due to the lateral blast and subsequent collapse of the mountain's north flank, not by the addition of new lava flows and pyroclastic debris.

Which Statement About the May, 1980, Eruption of Mount St