Geologists Reveal Supervolcano May Lurk Beneath Alaska’s Aleutian Islands

A group of geologists presented their recent findings at the American Geophysical Union’s (AGU) Fall Meeting 2020 conference this week and warned that an archipelago of volcanic islands off Alaska may contain an undiscovered supervolcano similar to Yellowstone and could cause “severe global consequences” if it would ever erupt.

The new report, titled “Multi-Disciplinary Evidence for a Large, Previously Unrecognized Caldera in the Islands of Four Mountains, Central Aleutian Arc, Alaska,” was written by Diana Roman of the Carnegie Institution for Science in Washington, DC. 

Roman said the area in question are islands of the Four Mountain in the central Aleutians are packed with a group of six stratovolcanoes named Carlisle, Cleveland, Herbert, Kagamil, Tana, and Uliaga.

“Stratovolcanoes are what most people envision when they think of a volcano: a steep conical mountain with a banner of clouds and ash waving at the summit. They can have powerful eruptions, like that of Mount St. Helens in 1980, but these are dwarfed by far less frequent caldera-forming eruptions.”

The geologist said the arrangement of the mountains suggest a caldera may exist. 

“Unlike stratovolcanoes, which tend to tap small- to modestly-sized reservoirs of magma, a caldera is created by tapping a huge reservoir in the Earth’s crust. When the reservoir’s pressure exceeds the strength of the crust, gigantic amounts of lava and ash are released in a catastrophic episode of eruption.” 

Roman said, “we’ve been scraping under the couch cushions for data,” referring to the challenge of studying such a remote place. “But everything we look at lines up with a caldera in this region.”

If she is right, this would mean that Alaska has a ticking volcanic time bomb, on par with size of Wyoming’s Yellowstone supervolcano. 

The team noted that more explorations of the Aleutians had to be completed to prove their hypothesis. If they’re correct, it would mean the hidden caldera would be the first in the area. 

“Our hope is to return to the Islands of Four Mountains and look more closely at the seafloor, study the volcanic rocks in greater detail, collect more seismic and gravity data, and sample many more of the geothermal areas,” Roman said.

Furthermore, NASA’s 1989 study titled “Volcanic eruptions and solar activity” indicates that solar flares smashing into the Earth’s atmosphere have the potential to increase volcanic activity. 

“Solar flares are believed to cause changes in atmospheric circulation patterns that abruptly alter the Earth’s spin. The resulting jolt probably triggers small earthquakes which may temporarily relieve some of the stress in volcanic magma chambers, thereby weakening, postponing, or even aborting imminent large eruptions,” NASA said.  

And if readers recall, we noted this week that Sunspot Cycle 25 is already underway and could be the strongest on record. 

Meanwhile, NASA warned in 2019 that a catastrophic supervolcano’s eruption poses a bigger threat to humanity than does an asteroid.