A Note on the Mt. Saint Helens Volcanic Eruption

Abstract

The violent eruption of the Mt. Saint Helens volcano on 18 May 1980 was examined using GOES-EAST satellite imagery. The University of Wisconsin McIDAS system was used to display the imagery and derive a number of plume measurements?including the plume's area, temperature, speed and an estimate of plume height. A thickening of the surrounding cirrus shield was observed (believed to be associated with gravity wave activity) as well as two distinct phases of volcanic activity that occurred during the eruption. A comparison of the Mt. Saint Helens eruption to the 1979 Soufriere eruptions revealed that the Mt. Saint Helens volcanic eruption produced a much larger plume, indicative of a more violent eruption. It is also shown that the height of the plume could not be reliably extracted from the infrared data due to the low tropopause in the vicinity of the volcano.