UM earthquake expert Rebecca Bendick enjoys some tea in the Pakistani portion of Kashmir.

Finding Faults

Researcher maps earthquake zones to help those at risk

By Deborah Richie

To join Rebecca Bendick in the field, plan on packing sturdy hiking boots for a trek to far horizons. Her research into the nature of interior continental earthquakes and efforts to help people survive them often takes the UM geosciences professor to the far-flung peaks of Central Asia and even into Ethiopia.

“I’ve always loved mountains,” Bendick says. She has the compact and slim build of an athlete who frequents the rarefied air of the Himalayas.  “And where do mountains come from? Faulting and other geological processes. My career has taken me to some beautiful places.”

It’s not surprising that her profession would lead to a position at UM in 2005. Missoula overflows with people similarly drawn to rocky crags. Before joining UM’s geology department, she spent two years at Cambridge University in England. Bendick earned her Ph.D. from the University of Colorado.

Choosing earthquakes within continents as a focus also has given Bendick the chance to experience life in remote villages of Tibet, Nepal and other Central Asian countries. She’s shared meals, small talk and laughter with the people who are most at risk of losing their lives to catastrophic earthquakes. Her personal ties shows up on her UM website, which is replete with their images:

A woman with a radiant smile and dressed in a magenta flowered robe squats next to her outdoor cooking pot. An elderly woman sells wild mushrooms arranged on platter-sized leaves. And two small girls with their arms around each other gaze earnestly into the camera. One wears a red plaid headscarf, and the other sports a flower in her windblown hair.

Then there are the photos, too, of devastation in Pakistan after the 2005 earthquake – as three men in rags walk past the rubble of a three-story building. An abandoned military tank in the arid mountains of Afghanistan serves as a reminder that natural disasters are not the only dangers of the region.

In April 2011, Bendick joined a select number of scientists invited as delegates to a high-level exchange between the Chinese and U. S. governments in Chengdu, China, 50 miles from the epicenter of the 2008 Wenchuan earthquake.  She co-chaired a workshop and spoke on where and why interior earthquakes are more difficult to forecast and simulate then on coastal tectonic plate boundaries, such as this year’s earthquake and tsunami in Japan.

“Most of the places I work are so remote and obscure that people haven’t noticed the big faults,” she says. “As a result, hundreds of thousands of people have died in the last decade alone.”

China’s 7.9-magnitude Wenchuan earthquake in precipitous Sichuan Province killed more than 90,000 people. Schools and hospitals collapsed. Many children died. In Pakistan the 7.6-magnitude Kashmir earthquake of October 2005 led to the deaths of 73,000 people.

To investigate the forces responsible for destructive earthquakes, Bendick and her graduate students team up with local scientists to gather field data that can be translated into hazard maps.

“Surprising earthquakes come in two flavors,” she says. “There are those that scientists genuinely don’t understand and could never forecast and those that are not theoretically surprising but a problem of lack of access and study.”

Bendick and her crew use precise global positioning system instruments to measure how the solid earth moves around and changes shape. They can plot these changes as vectors — or arrows showing speed and direction. The longer the arrow, the faster the movement. When speed or direction of the rocks in a continent varies in space, the result is storage of energy to build mountains and cause earthquakes.

She explains it this way: Suppose you did the same experiment, not with rocks, but with one car stopped at a light and another one speeding up behind. The stopped car would have a vector of zero length; the speeding car would have a long vector. The difference in their speed tells you how much energy goes into a crash if the fast one doesn’t pay attention. It’s the same thing in a continent —different speeds or directions forecast a car crash in the making.

The mapping from 10 years worth of data also serves a practical humanitarian purpose that is gratifying to Bendick.

“While it’s nice to know more than we did yesterday, after going to these places time and time again after humongous earthquakes, it slowly became obvious that there is a break in the chain of communication that keeps scientific results from getting to the people who need them,” she says.

Tribal leaders have little use for complex scientific papers, she points out. What they need instead is practical information that tells them where an earthquake might happen and how to prepare for a disaster.
 
Bendick spent the early summer in Central Asia conferring with the Aga Khan Development Network, a group of development agencies dedicated to improving the lives of impoverished people in Asia and Africa.

The nonprofit group employs 80,000 people and has an annual budget of $625 million.  The network recently added earthquake-resistant construction as a high priority.

By the end of 2011, Bendick will complete a Central Asia earthquake hazard map for the network. The high-risk areas on the map will identify top priority areas to spend funds that will shore up schools, hospitals and homes, and assure a ready stock of emergency supplies.

Microfinance loans will incorporate risks as well. For instance, if an Afghan villager applies for a $100 loan to add a room, the network would give him an additional $30 to pay for sturdier construction. Bendick believes the loans are the most powerful part of the program, because they engage villagers directly in the process of earthquake preparedness.

“We have the potential to positively impact millions of people,” she says. When an earthquake hits an unprepared remote area with shaky buildings, one-third of the deaths take place immediately, but two-thirds happen over the next week from thirst, starvation and disease.

“Fortifying key buildings and preparing rapid response would save more than half the people,” she says.

Closer to home, Bendick recently began a five-year project in southwest Montana near Dillon, a region that includes the site of the 1959 Hebgen Lake earthquake and the 1983 Borah Peak earthquake. The data collected will produce a picture of the size and scale of the tectonics, yielding key information for determining the underlying physics.

Every time she heads to her new field site, sometimes with her 2-year-old daughter in tow, Bendick also mentally prepares herself for an emergency call that might take her to Asia. She’s part of a team of scientists who will rush to the scene of an earthquake to learn and apply that knowledge — ultimately to save lives.

For more information email bendick@mso.umt.edu.

Bendick (left) and her team set up instrumentation to track earthquakes in Central Asia.

This National Oceanic and Atmospheric Administration graphic shows the radiation of energy from a tsunami originating in Chile in February 2010. The graphic is a plot of estimated deep-water wave height.

Mapping Tsunami Pathways

When Mark Lorang looks at boulders shoved inland by ocean waves, he wants to know how they got there. Was it a big tropical storm? A tsunami?  The answer lies in the nature of the boulder deposits.

The UM research associate professor in geomorphology has come up with a physics equation that may allow scientists to better differentiate between the two forces.

“The problem today arises when a tsunami hazard map is made from mapping boulder deposits that are assumed to be from tsunamis,” he explains. The better the mapping, the better the planning can be to avoid building in potential tsunami pathways.

While based far inland at the Flathead Lake Biological Station, Lorang is no stranger to coastlines. His doctoral dissertation in oceanography from Oregon State University in 1997 delved into how boulder and gravel beaches behave under the force of incoming waves.

Lorang looked not only at the height and velocity of waves, but at the wave period (the intervals between waves). That investigation of wave period applies to his new equation.

“The period for a hurricane storm waves is on the order of 30 seconds maximum, while the wave period for tsunami waves is on the order of 10 to 15 minutes and much longer,” he says. “The longer the wave period, the more time each wave has to push and shove boulders farther inland and higher up the slopes.”

Lorang published the new equation in the May 2011 issue of Marine Geology. This fall, Lorang will travel to France to work with researcher Raphaël Paris to test the equation more fully.

“This paper puts The University of Montana on the map in an area most people would not expect,” Lorang says.

For more information email mark.lorang@umontana.edu.

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