Edgecumbe Volcano Has Been Dormant for 800 Years, But Recent Earthquake Activity Suggests It May Be “Waking Up”.
A study conducted by the Alaska Volcano Observatory in collaboration with the Alaska Satellite Facility utilized mathematical models based on satellite imagery to identify a recent increase in geological activity around Edgecumbe Volcano, attributed to magma rising directly from deep beneath the Earth’s surface, Newsweek reported on October 27.
Edgecumbe Volcano in Sitka, Alaska. (Photo: KCAW).
David Pyle, a volcanologist at the University of Oxford, explained that as magma moves, it can flow along cracks or form a wide reservoir underground. Both processes can trigger small earthquakes. Seismometers can detect very slight vibrations, even those imperceptible to humans.
As magma approaches the Earth’s surface, it causes the ground to bulge like a balloon. Satellite radar equipment is crucial for monitoring volcanoes. These tools can measure tiny changes in the shape of the ground. Researchers can combine this data with earthquake locations to determine the three-dimensional shape of the magma body underground.
The United States has more volcanoes than any other country in the world, with most located in Alaska. The U.S. Geological Survey estimates there are 161 active volcanoes nationwide, although only 42 have erupted in the past 70 years. Edgecumbe Volcano last erupted 800 years ago, but geological evidence suggests its most significant eruption occurred about 4,500 years ago.
According to Pyle, most volcanoes have life cycles that span hundreds of thousands of years. During this time, they may erupt as magma rises from deep within the Earth to the surface, and then they can remain dormant between eruptions while the magma cools. Pyle noted that in the past 20 years, there have been numerous examples of scientists using satellite imagery and seismic activity to monitor magma beneath volcanoes. In most cases, the activity subsides after a few weeks or months without any eruptions.
