How early did scientists know that Mt. St. Helens was going to erupt?

The scientists know that Mount Saint Helens was going to erupt because of the seismic activity around it. The earthquakes were because of the lava building up inside the volcano, and it started to inflate like a balloon. In May 1980, the balloon exploded. Mount Saint Helens erupted in Skamania County, which is in the state of Washington. Around the Cascade Mountain Range, a small continental plate pushes underneath the edge of the Northern American Plate. By the 1950's, scientists knew there was something likely brewing underneath the surface.

In the Cascades, a series of small earthquakes occurred in March of 1980. A few days later, a size 4.2 earthquake rocked the state of Washington and the earthquake activity extended over the next few days, causing volcanic tremors. Geologists saw this as a sign that magma was moving underneath the surface volcano.

Mount Saint. Helens is an active volcano located in Southern Washington State. The scientists knew that Mount Saint Helens was going to erupt because of the seismic activity around it. The earthquakes were because of the lava building up inside the volcano, and it started to inflate like a balloon, and in May 1980, the balloon exploded. Mount Saint Helens erupted in Skamania county, in the state of Washington.

The area of the Cascade Range, a small continental plate pushes underneath the edge of the Northern American Plate. By the 1950's, scientists knew there was something likely brewing underneath the surface. In March 1980, a series of small quakes occurred in the Cascades. A few days later, a 4.2 magnitude quake rocked the state. Earthquake activity snowballed over the next few days, and there was a volcanic tremor. Geologists saw this as a sign that magma was moving underneath the volcano.