An ash cloud from a volcanic eruption in Russia is impacting airline operations across Alaska. On the morning of April 13th, an ash cloud passed over the Southcentral and Southeastern parts of the state, grounding many commercial flights. However, some services are still able to get through.

Petersburg musician Sarah Hanson-Hofstetter was on her way to Juneau to perform at the Alaska Folk Festival. She was all packed and ready to go – with her guitar strapped to her back. And then her morning flight out of Petersburg was canceled as a safety precaution. 

Although the Alaska Airlines jet was grounded, she was able to rebook on a smaller plane run by Alaska Seaplanes. She got the second-to-last seat.

“I feel good, but I’m still just waiting until I’m in Juneau to really celebrate,” said Hanson-Hofstetter. “That’s pretty shocking, you know? But I’m super super excited that at least I have my next step forward. But there is apparently a volcano happening in Russia.”

One of Russia’s most active volcanoes erupted Monday morning [on the morning of April 10th,] spewing ash well over 50,000 feet into the sky. Nathan Eckstein is the Science and Operations Officer for the Anchorage Volcanic Ash Advisory Center, which advises aviation services across the region. He said the eruption was quite powerful, in terms of what his office usually sees.

“It’s quite significant,” said Eckstein. “We get a lot of significant eruptions into a 30,000-foot range. This one was even bigger than that.”

Over the next few days, the ash drifted over the Bering Sea, affecting North Pacific flight tracks that connect North America to Asia. Then the largest chunk of the cloud passed over the North Pacific, the Western Gulf of Alaska, Kodiak Island, and then along the Alaska Peninsula. The Anchorage Volcanic Ash Advisory Center noticed some ash that disconnected from the main cloud and popped up over Southeast Alaska.

“So we needed to warn aviation that it’s a pretty pronounced signal,” said Eckstein. “We can see it very well on satellite.”

As of 10:30 a.m. on April 13th, Alaska Airlines  had canceled 28 flights across Alaska, and delayed several more. In a statement, the company said they would continue to monitor the situation and might need to cancel more flights. According to an official Alaska Airlines statement released at noon, the company is continuing to monitor the ash cloud. Depending on its location, movement and timing, they may need to cancel additional flights.

Commercial jets are particularly affected by ash when flying at higher altitudes, where particles in the cloud — essentially, tiny rocks — could damage their engines. Jet turbines run hot and don’t have an air filter. So if they fly through ash, it can melt and clog up the engine. But smaller planes, with props, have more flexibility. 

Piston engines have an air filter and operate at lower temperatures, so it’s not as big a deal if some ash gets into the engine, which is why Sarah Hanson-Hoffstetter was able to continue on to Juneau when her original flight fell through. 

Andy Kline is a representative for Alaska Seaplanes. He said the company is still able to get some flights out, despite the ash cloud. 

“It’s just a matter of how we’re able to fly at a lower elevation and in clear air,” said Kline. “Commercial airlines are taking flight routes that go through clouds. And so the ash can travel in those clouds. And that’s where you wouldn’t know you’re going through volcanic ash if it’s in a cloud. So we’re able to fly where it is clear and where there aren’t clouds, at a lower elevation.”

But even Alaska Seaplanes experienced some service disruptions. As of noon on April 13th, they had a total of 6 cancellations across Southeast Alaska. The ash cloud that disrupted the flights that day continued moving into Western Canada, and the smaller airline began resuming regular operations.

But it’s not over for Alaska. The volcano is still erupting, and there’s still more ash on the way. The Anchorage Volcanic Ash Advisory Center is observing a larger cloud, which is making its way towards the coastal waters of Southeast towards Yakutat, and possibly on to Sitka.