Seismologist in the field

Doug Wiens travels the world to see what’s shaking

Doug Wiens, PhD (center), professor and chair of the Department of Earth and Planetary Sciences in Arts & Sciences, inspects seismic gear with graduate students David Heeszel (left) and Erica Emry. “I think Doug is one of the great field seismologists of his generation,” says Wiens’ former student Keith Koper, PhD, now associate professor of geophysics at Saint Louis University.

Many business travelers return from a trip with receipts for coffee and perhaps a glass or two of wine. Doug Wiens once came back with receipts for several hundred dollars of kava root. As he stapled the receipts to the expense form, he wondered what accounting would make of them.

Kava is a legitimate expense when you’re trying to install seismometers on the islands of Fiji. As Wiens explains it, if you want to install a seismometer near a village, you buy a kava root bundle in the market and bring it to the chief for a sevusevu ceremony.

“It has to be a big bundle,” says Wiens, PhD, professor and chair of the Department of Earth and Planetary Sciences in Arts & Sciences. “You wouldn’t want to appear stingy.”

The roots are ground up and mixed with water to make a drink called grog.

“You sit around in a circle and drink grog with the chief for about two hours, and then finally you get around to talking about the seismometer,” he says.

In the field: the Tonga Trench

Last year, Wiens deployed nearly as many seismometers around one subduction zone as were installed around the world when he began his career.

“When I was a grad student, there were only about 100 seismometers worldwide — at any rate, ones whose data you could access,” he says.

In the old days, working with sparse networks of instruments, it was everything geologists could do to pinpoint an earthquake’s “focus,” or point of origin. Today, with many more instruments and turbo-charged computing power, they can use seismic waves to paint detailed images of the earth’s interior, the geological equivalent of CT images of the human body.

The subduction zone Wiens and his team targeted last year is the Tonga Trench, also known as Horizon Deep, because it is the second deepest ocean trench on the planet.

At the trench, the Pacific Plate plunges beneath the Indo-European Plate, throwing up an arc of volcanic islands. The Pacific Plate also drags the Indo-European plate forward, stretching the oceanic crust behind the volcanoes so thin that a second arc of subterranean volcanoes erupts through the basin floor behind the first one.

In November 2009, Wiens and his students dropped 53 seismometers on the ocean floor in the Lau Basin, the Tonga Trench’s back-arc basin, and 15 on adjacent islands.

Why the Lau Basin? It’s right on top of two-thirds of the world’s deep earthquakes, defined as quakes with foci below 300 kilometers (186 miles), Wiens says. And that’s interesting for two reasons: It makes for great seismology, and nobody understands what’s going on there.

Trying to image a part of the earth distant from earthquake foci is like trying to do CTs without an X-ray source, Wiens says.

“The deep earthquakes in the Lau Basin are a tremendous source array,” he says. “They generate seismic waves that arrive from many different angles, allowing us to reconstruct detailed images of the mantle above them.”

And they’re also an intriguing scientific mystery.

“We still don’t have a mechanical model that tells us exactly what causes them,” Wiens says. “The deep earthquakes look like faults, they slip like that, we know that. But by the time you get down deeper than 30 miles, the friction along the fault should be larger than the strength of the rock.

“So you shouldn’t even have earthquakes,” he says. “Yet, they occur.”

In the classroom: Cahokia Mounds

Wiens grew up the son of a small-town doctor in a southwestern Minnesota town called Mountain Lake.

Courtesy photo

The Wiens family: (clockwise from top left) son, Andrew, a WUSTL freshman; Doug; daughter, Julia, 17, with Shih Tzu Augie; and wife, Debra.

“There’s no mountain there, and there’s no lake,” he says, smiling. “It was just the railroad’s way of trying to sell land to finance laying more track.

“It was like growing up in Lake Wobegon,” Wiens says.

After earning a doctorate in geological sciences from Northwestern University in 1985, Wiens moved to Washington University, and he has been at WUSTL ever since.

“I came here when I was very young,” he says. “It was 1985, and I was 26, and everybody thought I was a graduate student.”

When Wiens isn’t doing fieldwork in Fiji or Antarctica, he’s teaching geology, shepherding graduate students through the stressful process of finishing their dissertations, or trying to keep the Department of Earth and Planetary Sciences running smoothly.

His favorite course, he says, is “EPSC 454: Exploration and Environmental Geophysics,” where students do fieldwork at local sites of interest. Recently, they have been working at Cahokia Mounds, the ancient indigenous city across the Mississippi River from St. Louis, trying to map the postholes that mark 1,000-year-old walls and houses.

“The students always like the seismic experiments,” he says, “where we use an 8-gauge shotgun shell to produce seismic waves and map the soil and rock layers beneath the site.”

Pressed for details, he adds, “We drill a 1-inch-deep hole and then put a pogo-stick-like device called a ‘buffalo gun’ into the hole and whack it with a mallet, which pushes the firing pin into the shell. We use blank shells for extra safety and wrap the whole thing with a tarp.”

His graduate students also get his time and attention.

“Doug was a wonderful adviser to me,” says Jesse Fisher Lawrence, PhD, now an assistant professor of geophysics at Stanford University. “He still provides good suggestions and hints to help me, even though I am no longer his student. Doug is the sort of guy who constantly thinks about the people who work for and with him.”

But it is as a scientist that he has made the biggest impression on his students. Keith Koper, PhD, another of Wiens’ students, now associate professor of geophysics at Saint Louis University, makes no bones about it: “I think Doug is one of the great field seismologists of his generation.”

In the office: EPS 381

According to Wiens, being a department chair is mostly strategizing, putting out fires and allocating space.

During the interview for this article, he fielded a call about wisdom teeth, the extraction thereof as required for a trip to Antarctica, the likelihood that the cost of the extraction would be picked up by a grant, and the paperwork that needed to be filed to ensure that it would.

Ray Arvidson, PhD, the James S. McDonnell Distinguished University Professor, Wiens’ colleague of 20 years and predecessor as the department chair, says Wiens is a great chair: fair and levelheaded.

“He was raised Mennonite; did you know that?” Arvidson says. “So apparently I can ask him for anything and he has to give it to me (because of the communal ethic of the Mennonite faith). So I’ve been thinking for the past couple of years what to ask him for, but I haven’t had the nerve to ask him for anything yet.”

Tales from the field: Tonga and Antarctica

The best part of getting to interview a great field seismologist, of course, are the tales from the field. Wiens’ friend and colleague Patrick Shore, PhD, a research scientist and lecturer in earth and planetary sciences, begins a yarn:

“Doug has a tendency not to put tools back in the toolbox. He stashes them everywhere else instead. One time, after weeks installing stations in Tonga, we drove to the airport at Nuku’alofa, to fly out of the country.

“We’re be-bopping through the airport carrying our daypacks, and we pick up our tickets and we go through security. Or I go through security and then around the corner to buy a cup of tea. After a while, I realize Doug isn’t coming after me.

“So I went back round the corner, and there were four fairly significant piles of tools, one for each time he had tried to walk through the metal detector and failed, a flustered Doug and a very annoyed Tongan.

“In the end, she made him check his daypack.”

But the best story is the one about Elephant Island, the ice-covered island off the tip of the Antarctica Peninsula where Ernest Shackleton’s crew took refuge after their ship, the Endurance, was crushed by pack ice in 1915. In 1998, Wiens and his team were nearly stranded there when heavy seas smashed the floorboards of one Zodiac, the inflatable boat that was to ferry them back to their research vessel, and broke the motor off the backup Zodiac.

“So we’re ashore with the Zodiac with no motor, and on the ship they have the Zodiac with broken floorboards,” says Stacey Robertson Maurice, a student who was stranded with him who now is a seismologist for Exxon Mobil.

“The ship’s crew took all the ropes they could find and tied them together and tied the rope to a life ring. And then our logistics guy walked out on a spit until he was past the worst of the breakers. The Zodiac with the broken floorboards drove as close to him as it could, and the driver threw him the life ring. After many, many attempts he caught the ring, and then he walked the ring, which was tied to the rope, back to the beach. We tied the rope to the Zodiac without a motor and climbed in. Then the Zodiac with the broken floorboards, which had stayed far offshore to avoid the breaking waves, towed us back to the ship.

“The next morning when I woke up,” Maurice recalls, “there were signs posted all over the boat that said, ‘Stuck on a remote Antarctic beach? Don’t forget to call 1-800-Pull-Boat, the Lawrence M. Gould towing service. We’re wet, but we’re quick.’”

Fast facts about Doug Wiens

Born: May 1, 1958, Minneapolis
Degrees: BS, physics, Wheaton College; MS, PhD, geological science, Northwestern University
Has done research in: Antarctica, Cameroon, Fiji, Tonga, South Shetland Islands, Patagonia and Mariana Islands
Puts likelihood of major New Madrid quake in 2010 at: Close to zero
Scientific question he most wants answered: What causes deep earthquakes
Body part sacrificed for science: His wisdom teeth — the extraction required to go to Antarctica
Most frustrating time on a research trip: Trying to do laundry on a Japanese research ship, with all the labels in Kanji
Professional honor he is proudest of: Becoming a fellow of the American Geophysical Union