Western Washington grad creates new way to monitor volcanoes
A 26-year-old Western Washington University graduate has come up with a cheaper, faster way to make three-dimensional models that monitor volcanic activity.Angie Diefenbach calls her creation the "poor volcanoligist's toolkit."Her tools: a digital camera, her laptop and software that's typically used for computer animation and forensic analysis.Her test subject: a dome of lava that's been steadily growing inside the blasted-out crater of Mount St. Helens since October 2004.Diefenbach's models of Mount St. Helens cost less to make and are 95 percent as accurate as those obtained through traditional methods. That could make the new technique more readily available to agencies that don't have huge budgets.Dan Dzurisin, a geologist at the U.S. Geological Survey's Cascades Volcano Observatory in Vancouver, Wash., and Diefenbach told The Bellingham Herald the new method costs a fraction of the traditional technique, but could not say exactly how much cheaper it is."It's another tool that we can use to study Pacific Northwest erupting volcanoes," said Dzurisin, who worked with Diefenbach on the project. "It might be that it's a tool that can be used more widely around the world."Diefenbach, who got her master's degree in geology at Western, is about to start working for the Cascades Volcano Observatory.Mount St. Helens' last big blast occurred on May 18, 1980, sending a towering plume of volcanic ash into the air, decimating forests for miles, and killing 57 people.In the latest round of much tamer volcanic activity, which began September 2004, lava has come from beneath the Earth, cooled into rock as it came through the Earth's surface and collected to build a dome.The USGS contracts with a company that uses a plane to fly over Mount St. Helens to take numerous vertical photos with a special camera. Those photos are sent to a lab in Denver for analysis. Software turns the photos into 3-D images for comparison with past images.The USGS could afford the flyovers just once a month and the 3-D images, known as digital elevation models, every two months, Dzurisin said.The photos Diefenbach used to create her models were taken in a helicopter with a regular digital single-lens reflex camera. By comparison, vertical aerial cameras can cost as much as $250,000. And flyovers in airplanes are much more expensive then they are in helicopters.Software traditionally used in photogrammetry - the science of obtaining measurements by using photographs and maps - can cost tens of thousands of dollars, Dzurisin said.Diefenbach said she spent $800 on software she installed onto her laptop.Traditional photogrammetry software picks out points in photos and plots them into 3-D images. Diefenbach had to find the points herself.She combed through at least 1,000 photos, picking physical characteristics - a rock here, a crag there - that could be seen from different angles. She plotted those points with the software to turn the data into a 3-D model."Some of these models have over a thousand points that I choose manually," Diefenbach said. "It took a lot of coffee and a lot of hours."Diefenbach said she can now create a 3-D model in about four hours, while the traditional method can take a month or more.Through her research, she found that the new lava dome in Mount St. Helens was growing at more than twice the rate of another dome that's just to the south, which grew from 1980-86. Recent findings from the USGS back up her results.Diefenbach notes the findings are no cause for alarm, because they don't necessarily indicate another major eruption is imminent.