In the News: Three volcanoes erupt at the same time in Alaska, in rare phenomena

 If you weren't keeping track of Alaskan volcanoes last month you may have missed the news that three of them erupted at the same time. That's pretty unusual!  Here's the story from Livescience

(Caption: Astronauts aboard the International Space Station (ISS) photographed this striking view of Pavlof Volcano on May 18, 2013. The oblique perspective from the ISS reveals the three dimensional structure of the ash plume, which is often obscured by the top-down view of most remote sensing satellites. Situated in the Aleutian Arc about 625 miles (1,000 kilometers) southwest of Anchorage, Pavlof began erupting on May 13, 2013. The volcano jetted lava into the air and spewed an ash cloud 20,000 feet (6,000 meters) high. When photograph ISS036-E-2105 (top) was taken, the space station was about 475 miles south-southeast of the volcano (49.1° North latitude, 157.4° West longitude). The volcanic plume extended southeastward over the North Pacific Ocean. Credit; NASA) 

Three volcanoes erupt at the same time in Alaska, in rare phenomena

  Yasemin Saplakoglu, Live Science Aug 17, 2021 

Three volcanoes on Alaska's Aleutian islands are erupting simultaneously, but are currently not a threat to local communities, according to recent news reports.

This triple whammy is not common, but it's not unheard of, according to NBC News. "Alaska has a lot of volcanoes, and we typically see maybe one eruption every year, on average," Matthew Loewen, a research geologist with the Alaska Volcano Observatory, told NBC News. "To have three erupting at once is less common, but it does happen."

It's been at least seven years since three volcanoes erupted at once in Alaska, Loewen told NBC News. The three volcanoes — Pavlof, Great Sitkin and Semisopochnoi — are all under a code "orange" alert, which means that the volcano has the potential to erupt or eruptions are underway with minor ash emissions, according to the Alaska Volcano Observatory. Two others are under a code "yellow" alert, meaning that they are showing signs of unrest.

Pavlof volcano, which sits about 600 miles (966 kilometers) away from Anchorage, is showing low-level unrest and minor ash emissions, while the Great Sitkin volcano, which is closer to the center of the islands, has a continuous flow of lava from its summit crater, according to the Alaska Volcano Observatory and NBC News.

The third volcano, Semisopochnoi, is located on an uninhabited island at the easternmost point of U.S., according to NBC News. That volcano has had several explosions, occasional strong seismic tremors or shaking and low-level ash emissions, according to the Alaska Volcano Observatory. All three volcanoes have been erupting for more than a week.

The volcanoes are part of the so-called Aleutian Arc, which is a chain of volcanoes that sits on the boundary between two tectonic plates, according to Science Alert. These plates are large pieces of Earth's crust that move and bump into one another, spurring much of the planet's volcanic eruptions and earthquakes.