The U.S. Geological Survey (USGS) reports that Mount St. Helens, located in southern Washington, is experiencing some low-magnitude tremors, indicating that the magma beneath the volcano is on the move.
Mount St. Helens has been dormant since 2008, but now it seems to be rumbling again. The USGS announced that in the past eight weeks under the volcano have been detected more than 130 small earthquakes.
The website AOL reports that the largest of these earthquakes was a 1.3 on the Richter scale. None of the earthquakes have been very big and they have all been located at least a mile below the surface.
According to the online publication Live Science, the ground around the Mount St. Helens volcano is also moving slightly away from it. Seth Moran, the scientist in charge at the USGS Cascades Volcano Observatory in Vancouver, Washington, declared that the moving ground observation along with these mini earthquakes suggest that Mount St. Helens may one day erupt again. However, the scientist added that this upcoming eruption is likely going to happen years to decades from now.
Mount St. Helens is located in southern Washington, in the Cascade Mountain range. The volcano is well-known for its enormous eruption on May 18, 1980, preceded by more than 10,000 earthquakes.
In 1980 the earthquakes started small, but as the volcano neared its eruption, they grew into the 4-magnitude range. The earthquake taking place the morning of May 18 reached a magnitude 5.1. Moran said that, comparing to the situation back in the year 1980, the earthquakes experienced now are way smaller.
Since March, the rate of the earthquakes at Mount St. Helens has been increasing, reaching now almost to 40 a week. Also, over the past eight years, global positioning system (GPS) instruments placed around the volcano have shown a slight ground movement. Moran said that according to the measurements, the ground has moved between 0.4 inches to 0.8 inches away from the volcano.
The earthquakes and the movement are both volcano-tectonic signs happening because of a slip on a small fault, according to experts. However, the USGS has not detected any other signs suggesting that magma is pushing up toward the surface