An Earthquake on the St Mt Helens caused a bulge to appear, which gave the Volcano an oppurtunity to erupt, also in addition to that the earthquake caused a hole in the volcano which caused the magma chamber to split so the magma could rise up the main vent!
The 1980 eruption resulted when a huge section of the mountaintop was forced outward and fell away from the mountain. The pressure of magma from within the mountain had been increasing over the years and the rock eventually gave way. With the blocking rock removed, huge amounts of hot rock, ash, and gas exploded from the opening with incredible force.
As part of the Cascade Range of mountains, Mount St. Helens was formed by eruptive flows of magma as the Juan de Fuca tectonic plate is forced under the North American Plate. Beginning about 37,600 years ago, periodic eruptions and magma flows occurred in the area between Mount St. Helens and Mount Rainer.
Huge eruptions occurred in the years 1480, 1482, and 1800, and smaller releases of steam between 1831 and 1857. The large magma chamber beneath Mount St. Helens will likely continue to force lava upward and cause future eruptions. However, as history indicates, they could be several hundred years apart.
A 5.1 earthquake directly under the volcano itself
The Mount Helen's 1980 eruption was a major volcanic eruption.
volcano eruptions are triggered by seismic activity, meaning earthquakes and such. Mt St Helens is along the ring of fire, which is full of seismic activity.
About 92 miles to Mt. St. Helens from Tacoma
Mt. St Helens is currently an active volcano, in portland.
Life is abundant near mt st helens these days. there is lush growth and a great population of people.
The 1980 eruption of Mount St. Helens.
Mt St Helens first erupted on May 18, 1980
how did people prepare for the mt. st. helens eruption
The 1980 eruption of Mount St Helens was a VEI 5.
Mt. St. Helens benenfited humans by the rock from lava are used to build and repair roads in this day!
explosive
people died
United States, Washington.
fireweed
The famous eruption of Mount st Helens in 1980 was a VEI-5.
57 People died in the eruption.
The Mount Helen's 1980 eruption was a major volcanic eruption.