Mount St. Helens Dormant Again

Posted by Maureen K. Fleury Aug 1, 2008

In a recent news story in Science Daily, five months have gone by since the last sign of eruptive activity at Mount St. Helens so scientists have removed the ‘advisory’ status and change it to ‘normal’.

Since late January 2008, nothing has developed since scientists detected a spine of hot lava poke through the bulging crater floor. In addition, the growing lava dome has not increased since that time.

According to Cynthia Gardner, Scientist-in-Charge at U.S. Geological Survey's Cascades Volcano Observatory (CVO), "We know that Mount St. Helens will erupt again in the future in some mix of renewed dome building and more explosive behavior. However, at this point, we can't forecast when the next eruption will begin".

Here are the levels of activity classifications according to the US Geological Survey (USGS).

• Normal - typical non-eruptive behavior
• Advisory - elevated unrest
• Watch - escalating unrest or a minor eruption underway that poses limited hazards
• Warning - a highly hazardous eruption is underway or imminent

Since the big eruption of Mount St. Helens on May 18, 1980, the lava has refilled about 7% of the crater which was created by the landslide during the eruption.

Some hazards are still apparent even though the eruption has ended. The lava dome on Mount St. Helens can produce avalanches and small explosions and ash fallout. The falling rock from the walls of the crater can create dust clouds in dry weather. Heavy rains and fast snowmelt can cause debris to flow into the Pumice Plain on the north side of the crater.

My article on the Eruption of Mt St. Helens has more details on the events leading up to the eruption plus what happened before and after. The USGS provided some awesome pictures!