Science

A geophysicist reflects on the remarkable opportunities Alaska’s volcanoes and earthquakes provided

On a November morning long ago, Jeff and Annette Freymueller were feeling the effects of the 1 a.m. flight that had carried them home, to end-of-the-line Fairbanks. There was no rush to get up on that Saturday 16 years ago. They slept in.

As the sky brightened, over sips of coffee the Freymuellers pondered the last few days they had spent in Southern California, where they both grew up. Faculty members at the University of California at Santa Barbara had flown Jeff down from Alaska for a job interview. He and Annette stayed a few extra days to check out the area.

After their return, that sleepy November morning in Fairbanks turned out to be different from the rest.

The ground shook. Their house swayed and creaked. An expert on earthquakes and the eternal creeping of Earth's plates, Jeff recognized surface waves that were rolling through the boreal forest, and their home.

"This is something big," he told Annette. "I've got to go into the office."

That earthquake — the magnitude 7.9 Denali Fault of Nov. 3, 2002 — ripped a 200-mile frown across the surface of Alaska, 150 miles south of the Freymueller home.

For the next six weeks, Jeff and his colleagues at the Geophysical Institute, part of the University of Alaska Fairbanks, drove the frozen asphalt of two Alaska highways that the great earthquake had ripped. They deployed seismometers and GPS units everywhere they could on and near the fault.

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More than one month later, after Jeff attended a special session on the earthquake at a conference in San Francisco, the Freymuellers' phone rang. It was a representative of UC Santa Barbara. The job was Jeff's if he wanted it.

After the chaotic, exciting distraction of the Denali Fault, Freymueller had almost forgotten about Santa Barbara. After some reflection, he politely refused the appointment.

The Freymuellers remained in Fairbanks. During their 8,000 days here, they raised two sons. Jeff also dabbed a good deal of paint on the blank canvas of what is happening beneath Alaska. Today, we know a lot more about how and why the landscape stretches, buckles, collapses and inflates.

But after 23 years in Alaska, Freymueller got an offer he couldn't refuse. This fall, he begins teaching and researching at Michigan State University. The job offers him, at age 55, a creative change.

He leaves Alaska a different place compared to the one he drove to years ago.

"When I came here in '95, nobody had any information at all on the motion and deformation of Alaska," he said. "Now, there's so much more that we know. I didn't do it all, but I had a hand in a pretty large fraction of the work."

Freymueller had the foresight and good luck to start using global positioning system satellites before he came up here.

In the three years before he arrived in Alaska, the constellation of GPS satellites had doubled, allowing scientists accuracy in Earth measurement they had not experienced before. For those trying to detect the movement of Earth's plates at the speed fingernails grow or detect the bulge in a volcano, GPS now allows scientists to measure the elevation of any point on Earth to within one-eighth of an inch.

"There's been a factor of 30 improvement since the 1980s. I don't think anyone knew how good it would get," Freymueller said. "It was a totally new thing that revolutionized a whole field."

Freymueller's field is geodesy, in which scientists use GPS to look from 12,000 miles above our heads to learn more about the Earth.

Among Freymueller's greatest hits during two decades at the University of Alaska are these findings (which, he points out, he discovered with the help of many others):

–The Good Friday Earthquake of 1964 is still pushing Homer toward Seward, and affecting Alaska in other ways: "The post-seismic signal was not only detectable, it was big."

–The Yakutat block, a chunk of Earth's crust larger than Pennsylvania, rams into the North American plate at a speed of about 2 inches each year, twice as fast as India is shoving into Asia to form the Himalaya. This resulted in the rise of 18,008-foot Mount St. Elias.

–Ground movement around the Denali Fault was 20 to 25 times faster in the year after the 2002 earthquake than it was before.

–Volcanoes along the Alaska Peninsula and Aleutians inflate and deflate due to movement of molten rock within them, even when they are not erupting.

During his time as a geophysicist and teacher at UAF, Freymueller was also coordinating scientist at the Alaska Volcano Observatory and the director of the Earthscope national office. Earthscope is a project that has enabled seismologists to spread instruments all over the U.S., including Alaska.

He experienced many days during which he could not believe he was getting paid. Helicoptering to the flank of a pyramidal volcano in the Aleutians, hiking through mountain passes in Tibet, and finding himself in one of the quietest places in Alaska on Sept. 11, 2001.

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That day, Freymueller was camped on Cenotaph Island in the middle of Lituya Bay in Southeast Alaska with the late glaciologist Keith Echelmeyer. They were using precision GPS receivers to measure glacial rebound in one of the fastest-rising landscapes on Earth.

On Sept. 11, Echelmeyer called an aviation contractor in Juneau on a satellite phone. The operator told him about towers falling in New York, and that no one could fly. Then, bad weather came in. The scientists didn't return to Fairbanks for seven days.

"Because we didn't see images of the towers until a week after, our experience of the whole event was totally different than everybody else's," Freymueller said.

As the movers left Fairbanks for Michigan with 16,000 pounds of the Freymueller's household goods, Jeff and Annette were not far behind, driving their two cars down the Alaska Highway to a new experience. A few days before he left, Freymueller reflected on his time in Alaska, where he might be remembered as a scientist who doubled his efforts when something interesting and unpredictable happened, like the Denali Fault earthquake.

"It's been pretty amazing to be in a place where you can do first-order work on a lot of things."

Ned Rozell | Alaska Science

Ned Rozell is a science writer with the Geophysical Institute at the University of Alaska Fairbanks.

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