Researchers have discovered dormant activity at Mount Edgecumbe

FAIRBANKS, Alaska (KTVF) – Mount Edgecumbe, a dormant volcano 15 miles west of Sitka, Alaska, has become active again after being dormant for centuries.

In April 2022, Mount Edgecumbe experienced a series of small earthquakes, attracting scientists to investigate the activity. The researchers used a new data analysis method to quickly understand the seismic event. Using cloud computing, they were able to analyze decades of data in less than two weeks, saving time on an important discovery that would have taken months if traditional analysis methods had been used. What they found was unexpected.

Deformations were found at surface level showing an upward shift of 10.6 inches. The deformations are the result of rising from about 12 kilometers below the surface to six kilometers below the surface. The data indicate that the magma surge began suddenly in a surface surge in 2018, maintaining a constant rate of 3.4 inches per year.

This particular event has intrigued scientists because it is rare to see a dormant volcano return to activity. Adding to the unusual circumstances, Mt. Edgecumbe and the surrounding area are in a “transformational breakdown,” according to Dr. Ronni Grapenthin, Associate Professor of Surveying at the University of Alaska Fairbanks (UAF). A transform fault is where tectonic plates are sliding past each other. It is the same type of fault as the San Andreas fault in California. Due to plate movement, volcanoes are unlikely to be active. In comparison, the Aleutian volcanoes are located on a subduction zone, which means that one tectonic plate is pushing down while another is pushing up, usually creating volcanoes.

The last eruption of Mt Edgecumbe is believed to have occurred around 800 or 900 years ago. According to local accounts passed down through generations of Alaska Natives, the last eruption had visible smoke and the inhabitants were able to approach the volcano by canoe to investigate the smoke. Grapenthin believes the account suggests the eruption was highly localized. He added that there is a lack of data on this eruption and the current data suggest that the volcano would be able to erupt in different ways. According to Grapenthin, one point of evidence supporting this claim is the presence of basalt, a type of igneous rock. Basalt is associated with highly viscous magma or lava that does not flow far from the point of eruption, “much like the volcanoes in Hawaii,” Grapenthin said.

Many variables still need to be investigated, but Grapenthin does not perceive any current eruption risk. “We don’t know enough, precisely, about what the actual properties of the Earth’s surface are, what the lifetime of the magma reservoir is at that depth, and whether the magma can spread upward to make very accurate predictions,” Grapenthin said.

If an eruption were to develop, “we would have a lot of signals,” said the UAF Associate Professor of Geodesy. We know that Mt. That the discovery of activity at Edgecumbe will lead to further research from different fields and perspectives.

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