Mount Adams, a volcano in Washington’s Cascade Range that includes the infamous Mt. St. Helens, has recently experienced an unusual increase in seismic activity, triggering a new focus on its study.

In September, six earthquakes ranging from magnitudes 0.9 to 2.0 were recorded at the site. This number represents a significant uptick compared to the typical rate of one earthquake every 2-3 years and can indicate magma coming to the surface.

Mount Adam is one of the tallest and most active volcanoes in the state of Washington, and it has erupted at least 15 times during the last 10,000 years.

In fact, after the fall shakers, two members of Congress whose districts straddle Mount Adams wrote a letter asking the U.S. Geological Survey (USGS) to enhance seismic monitoring of volcanoes across the country.