Two western Aleutian volcanoes are showing signs of unrest, signaling the potential for an eruption in the coming days or weeks.
Tanaga and Takawangha volcanoes are about 60 miles west of Adak. Earthquake activity started increasing near Tanaga on March 4, with Takawangha following on March 8, according to the Alaska Volcano Observatory.
“It certainly appears that there’s magma moving at a shallow level beneath the volcanoes,” said U.S. Geological Survey geologist Tim Orr. “But it’s uncertain right now if they will erupt — or which one will erupt.”
Tanaga and Takawangha are 5 miles apart on uninhabited Tanaga Island.
Due to the volcanoes’ remoteness and close proximity to one another, records of their historical eruptions aren’t perfectly clear. Tanaga’s last recorded eruption was in 1914. There are no recorded historical eruptions at Takawangha, but scientists say it’s possible some eruptions attributed to Tanaga may have actually come from Takawangha.
Orr said the observatory is monitoring the volcanoes’ current activity by satellite and through reports from people passing by.
“We don’t really have eyes on the volcano, except from space,” said Orr. “It’s possible that people in the area — mariners or pilots in the area — might spot something happening and report it to us. We rely on a lot of different sources to determine whether a volcano has erupted.”
If the volcanoes erupt, Orr said ashfall would certainly affect air travel in the area — just how much would depend on the wind.