Hundreds of earthquakes recorded near volcano that hasn’t erupted for 800 yrs in Alaska

Hundreds of minor earthquakes have been observed in southeast Alaska near a volcano that has been dormant for at least 800 years.

The reason for the quakes beneath Mount Edgecumbe, a volcano near Sitka that looks like Japan’s Mount Fuji, is unknown. However, they may not be a sign of volcanic activity, according to Dave Schneider. He is a research geophysicist at the Alaska Volcano Observatory in Anchorage for the US Geological Survey.

Mount Edgecumbe is a stratovolcano on Kruzof Island. It is about 15 miles west of Sitka, with a height of 3,200 feet. The lava domes and craters of the volcano are part of a broader underwater volcanic area.

No reason to worry

“These aren’t necessarily related to volcanic activity, they could be a tectonic in nature or a combination of tectonics and the volcano,” he said. “We really can’t tell the difference at this point.”

Schneider believes there is no reason to worry right now about the earthquakes in Alaska.

“Volcanoes do have swarms of earthquakes that do not lead to eruption,” he said.

The earthquakes persisted Wednesday, albeit the frequency has decreased. The majority of the earthquakes were too tiny to be detected by numerous seismic sensors.

Zach Mayville, who answered the phone at House of Liquor in Sitka, stated, “I don’t think anybody was even aware that those happened.”

He stated that the quakes had caused no harm.

Mayville stated, “We didn’t feel anything. We’ve heard nothing from anybody, so we are all good.”

Earthquake activity

A retrospective review of earthquake data near Mount Edgecumbe by the volcano observatory revealed that a limited number of earthquakes began happening in 2020.

In the last two years, about 40 quakes have happened in the area, roughly one or two each month. It is significantly fewer than what occurred this week.

“You would expect many, many earthquakes to be observed prior to any eruptive activity if it were to occur,” Schneider said. “Earthquake activity is our best indicator of what’s going on there, and that’s something that we’ll be watching closely.”

He estimates that roughly 90 volcanoes in Alaska have been active in the previous 10,000 years. Most are remote and not located near a population hub like Sitka, which has an estimated population of 8,500 people.

There is no written record of Mount Edgecumbe exploding. But he claims that Tlingit oral history regarding tiny eruptions around 800 years ago exists.

Mount Edgecumbe last erupted about 4,500 years ago, according to the geologic record.

There’s also evidence of a massive eruption 13,000 to 14,500 years ago. It produced up to 3 feet (1 meter) of ash on Sitka and 98 feet (30 meters) on Kruzof Island.