ALASKA, Anchorage A remote Alaska volcano that has been dormant for over a century has experienced an increase in earthquake activity in recent weeks, raising concerns of an imminent eruption.


The Alaska Volcano Observatory upgraded Tanaga Volcano to advisory status Tuesday night as the intensity of the earthquakes increased.

“We started seeing a whole lot of earthquakes occurring, one after the other, several per minute,” said John Power, a research geophysicist with the US Geological Survey based in Anchorage at the Alaska Volcano Observatory.

Hundreds of minor earthquakes, none greater than magnitude 2.75, have been happening, he said, and they are clustered close to the volcano’s summit.

“That means there’s major unrest at the volcano,” Power said.

It’s too early to tell if this will cause an eruption, he said. However, we are so worried about it that we have raised the alert level.

While the rise is cause for concern, he reassured scientists that quake activity often decreases without an eruption.
No one knows where this recent swarm of earthquakes will settle down, he said.
About 1,250 miles (2,012 kilometers) southwest of Anchorage, on an uninhabited island in the western Aleutians, is where you’ll find the volcano. There are no settlements or buildings on the island, but the city of Adak, with about 170 people, could be hit by ashfall from the eruption 65 miles (105 km) away on another island.

Aircraft would be most at risk from an eruption of the volcano. The Aleutian Islands lie below the flight paths used by airplanes traveling between North America and Asia. Aeroplane engines are vulnerable to the angular and sharp particles of volcanic ash. Similar to the 1980 eruption of Mount St. Helens in Washington state, previous eruptions have produced both ash clouds and viscous lava that moves very slowly away from the mountain.

Unlike Hawaii’s Kilauea and Mauna Loa, where “beautiful red rivers of lava” flow down the sides of the volcanoes, “this is very different,” as Power put it.

Tanaga is one of three volcanoes that make up the island’s volcanic complex. At 5,925 feet, it towers above the other two (1,806 meters). Towards its west is the 4,443-foot-tall volcano of Sajaka, which places it smack in the middle. Sajaka’s former cone collapsed into the North Pacific, and a new one has since emerged on the island.

The Alaska Volcano Observatory reports that Takawangha, a volcano located to the east of Tanaga, is 4,75 feet (1,449 meters) tall and is entirely covered in ice, save for four craters.

Tanaga has not erupted since 1914. Two eruptions occurred in the late 1700s, and a third occurred in 1829.

There have been no recent eruptions of either Takawangha or Sajaka, according to a press release from the observatory. Field research, however, suggests that eruptions may have occurred from those volcanoes and been attributed to Tanaga.