Did people know that mt st helens was going to erupt?

Answer 1

Strong tremors indicating magma flow, aleted athorities that something was about to happen.

No one forsaw the amount of destruction that happened.

Look for quotes by a man named Harry Truman. ( Not the president )

Answer 2

Prior to the eruption of Mt. St. Helens, there were earthquakes, steam, swelling of the mountain, and etc indicating activity on the mountain and an eminent eruption.

Unfortunately, these went on for months before the big eruption, so some people were actually wondering if anything was actually going to happen. It was also unknown how big the eruption would be, or what form it would be in.

There were mandatory evacuations of the area immediately surrounding the mountain, although there was at least 1 person near Spirit Lake that refused to leave. And, as mentioned as weeks and months dragged on without any major eruption, many people wanted to return home.

Following the eruption, there was widespread destruction, further than people had anticipated, as well as the breaking of an earthen dam and flooding.

In areas near the volcano, there were problems with volcanic ash damaging vehicles, and people were encouraged to carry extra air cleaners for their cars.

Answer 3

To a degree, yes. It was well known that Mount St. Helens was showing signs of activity, and many scientists realized that it was heading toward and eruption. Many non-scientists were not convinced, however. The volcano had been restless for about two months and the scientists did not know when an eruption might occur. When it did come, the scientists were caught off guard by the size of the eruption and the sideways explosion that it started with.

Answer 4

Precursory Eruption Information

The first release of information to the public before the eruption began was released by the United States Geological Survey on September 23, 2004. The information release was specifically to state that there were earthquake swarms beneath the area of the 1980 and 1986 lava dome within the crater. The release stated that this could be related to additional ground water incursion into the volcano, and if there is unlikely going to be an eruption without much more specific precursory activity. This was the first release of information to the public which was within hours of the onset of the swarm event beneath the volcano.

Activity declined on the 24th, but daily information statements were still given to the public. On September 25th the Cascade Volcanoes Observatory released a specific statement that based on the level of unrest that has started within the volcano, there is a strong possibility of a hazardous eruption within the near future.

"The cause and outcome of the earthquake swarm are uncertain at this time. Several causes are possible, but most point toward an increased probability of explosions from the lava dome if the level of current unrest continues or escalates."

-- USGS CVO September 26, 2004

On september 26th the level of unrest reached a point where a notice of unrest was released to the public, and the alert level was raised to Yellow (Alert Level 1).

September 29th the USGS and CVO further increased the alert level to Orange (Alert Level 2) after a spike in shallow earthquake activity, and an increase of the intensity of the earthquakes. The frequency of events during this time was 4 detectable events per minute, with a maximum magnitude of 2.8.

October 1st was considered the official onset of volcanic activity, with a steam and ash explosion from an area just south of the 1980 and 1986 domes.

On October 2nd the alert level was changed by CVO and USGS to Red (Alert Level 3), this is the highest alert level possible for a volcano. This alert status means that there is either an eruption in progress or an extremely high risk of eruption within the next 24 hours. The cause for the change in alert level was due to another steam and ash emission as well as a change in the type of earthquakes that were being recorded. The events went from isolated frequency events to a constant volcanic tremor event (also referred to as Harmonic Tremor), these events have a very distinctive signature and are only generated when magma is moving toward the surface within a volcano.

Please see related links for the full daily bulletins from USGS and CVO, as well as what happened after the full onset of eruption.

Answer 5

Yes, scientists monitoring Mount St. Helens had noted signs of increased seismic activity and bulging of the volcano's north flank. An exclusion zone was established around the volcano, and warnings were issued to the public prior to the catastrophic eruption on May 18, 1980.