Earthquakes and elevated gas emissions are causing scientists to take a closer look at Kupreanof Volcano. It’s a remote, heavily glaciated volcano about 50 miles northeast of Sand Point with very little known eruptive history.
The Alaska Volcano Observatory raised the volcano’s alert level to Advisory and its aviation color code to Yellow on Tuesday. That means the volcano is showing signs of unrest, but it doesn’t necessarily mean an eruption will happen.
Little is known about the volcano. Hannah Dietterich, a volcanologist with the observatory, said Kupreanof Volcano has no confirmed eruptions in recorded history, but geological evidence suggests it may have erupted around the last ice age.
“We don't know all that it is capable of at this point,” she said. “But there's no records of giant eruptions from this volcano or anything like that to go off of.”
Scientists can draw some comparisons to other Alaskan volcanoes, but the lack of eruptive history makes it difficult to know what to expect. Volcanoes are creatures of habit; they tend to erupt the way they’ve erupted before. Without that history at Kupreanof, scientists are piecing it all together as they go.
Seismic activity near the volcano first appeared in February, with earthquakes as large as magnitude 3.1. The shake was picked up by regional seismic stations about 17 miles away. Sulfur dioxide emissions have also climbed well above background levels since early April. That was tracked through satellite data.
Scientists think deep beneath Kupreanof, magma is pushing its way upward. As it moves, it triggers earthquakes and forces gas up through cracks in the volcano. But there’s still a long way to go before it could reach the surface.
“Kupreanof doesn’t have an open system, so it’ll have to break more rocks in order to erupt,” Diettrich said.
Dietterich said the activity is interesting, but not cause for alarm. She said the most likely scenario is that the magma stalls and Kupreanof goes back to sleep, similar to what happened at Mount Spurr near Anchorage last year.
“Magma intrudes into volcanoes way more frequently than they actually erupt,” Dietterich said. “Right now we’re looking for signs of further activity, as well as talk to people who have been out there and better understand the eruptive history.
She said scientists are trying to understand what these signals are indicating in order to better anticipate what might happen next. There is no local ground monitoring network at Kupreanof Volcano, but that might soon change. The volcano observatory is evaluating whether to install instruments there this summer.
