The Strange Thing About Mount Saint Helens

What you are looking at are the remains of the once taller Mount Pinatubo volcano which in 1991 produced the 3rd largest explosive volcanic eruption of the 20th century as it ejected 13 cubic kilometers of volcanic rock. This eruption caused up to 100 meters thick of ash, pyroclastic flow, and lahar deposits to fall adjacent to the volcano, with the eruption leaving behind a nearly 2,000 foot deep caldera. Mount Saint Helens shares a number of similarities but also a number of differences with Pinatubo. Weirdly enough, Mount Saint Helens in its 43,000 years long history has produced one eruption that was even larger than the 1991 eruption of Pinatubo. I am referring to its 1860 BCE eruption which ejected 15.3 cubic kilometers of tephra. Yet, you might note that Mount Saint Helens does not have a caldera. In fact, despite 2 VEI 6 and 11 VEI 5 eruptions, Mount Saint Helens has never collapsed into a caldera.

Channel: GeologyHub

Views: 91,058

Keywords: Volcano, Volcanoes, Active Volcano, Washington, Saint Helens, Geology, Washington Volcano, Eruption, Volcano Eruption, St Helens

Id: 25MyBq6E4k4

Length: 0min 55sec (55 seconds)

Published: Thu May 11 2023