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April 2002

News about Science, Technology and Engineering at Iowa State University

ISU geologist leads team under a glacier
Neal Iverson, associate professor of geology and atmospheric sciences at Iowa State University, led a team of seven researchers to a spot 700-feet under ice to get a first-hand look at how glaciers move across rock and sediment and how they shape the landscape. The team is the only one that lives and works beneath a thick glacier to do their research. For three weeks (April 3-24) they worked at Norway's Svartisen Subglacial Laboratory, located in a tunnel excavated in rock beneath the Svartisen Ice Cap. Inside the tunnel, the temperature was a constant 35 F, and humidity was near 100 percent.

"We're trying to learn more about the mechanics of what's going on at the bottom of the glacier, where ice meets rock or sediment," Iverson said. Although the data are preliminary, Iverson said the team did find that friction caused by sediment in the ice -- the debris in the base of the glacier -- could play a dominant role in limiting glacier movement. "Resistance to slip at the glacier-bedrock interface may be more similar to slip resistance along a fault line than the more classical idea of ice slipping with near-zero friction over bedrock. We found that the sediment in the ice may be providing up to 20 times more friction between the glacier and bedrock than predicted by models," he said.

For their experiments, the team melted a 10-foot x 10-foot tunnel through the ice for about 100 feet to a spot on the glacier bed where there was a trough cut in the rock. They filled the trough with sediment and instruments for measuring stresses on the sediment and its deformation beneath the ice. They also placed instruments flush with the rock surface to measure the friction between the ice and rock. The instruments (load cells, extensometers and thermistors) recorded stresses on the rock, and the speed and temperature of the ice as it slipped across the glacier's bed.

While they did this they had to continually "blast" away at the ice, using hot water to cut and re-cut tunnels into the glacier. Because of the extreme forces put on ice at these depths, it acts like toothpaste and flows into any cavity it can find. With their instruments in place, the researchers retreated back under the rock and let the tunnels fill up with ice. They then measured the stresses on the bed and rates of glacier movement.

"Glaciers can move very rapidly," Iverson said. "Surging glaciers can slip over their beds as fast as 50 meters per day, more than half the length of a football field. Understanding how glaciers move, and what causes them to sometimes greatly increase their speed, will ultimately lead to a better understanding of how they impact Earth's climate and shaped landscapes." For more information, contact Iverson at (515) 294-8048, or Skip Derra, ISU News Service, (515) 294-4917. A downloadable photograph of Iverson is available at http://www.public.iastate.edu/~nscentral/photos.html.

Virtual tornado brings storms, and students, in from the cold
Students and professors from Iowa State University have been trapped inside a tornado and lived to talk about it. Bill Gallus, associate professor of geological and atmospheric sciences, and a meteorologist with 15 years of experience in storm chasing and severe weather research, has developed a simulated tornado for Iowa State's C6 virtual reality facility.

This virtual storm allows students to navigate around and through the storm as though they were either flying in a small plane or driving around it, Gallus said. The storm shows various features of a thunderstorm containing a tornado, such as a large region of rain. With a $75,000 grant from the National Science Foundation, Gallus; Carolina Cruz-Neira, associate director of Iowa State's Virtual Reality Applications Center; and their students are planning to improve some of the realism of the storm by allowing it to move across the landscape and by adding audio effects. They've identified sounds of various rain intensities, hail, thunder, and the tornado roar to be added to the simulation. Most importantly, Gallus said, is the addition of data sampling capabilities.

"We plan to allow students to overlay data such as wind arrows to help them understand what is causing the tornadic storm and its various features," Gallus said. "In addition, we plan to allow more advanced students to collect data themselves."

Gallus said students would position themselves in different locations around the storm and gather data as though they were meteorological researchers releasing weather balloons. Students would then interpret the data and develop theories about the causes of the storm features and tornado -- all without setting a foot outside. Gallus said they will also be adjusting the software application so that it can be run on any computer system, which should allow widespread use nationwide.

The group hopes to make the virtual storm easily downloadable from the Internet and compatible to any computer, Gallus added. When the public is able to access the application directly, they will be able to "virtually" participate in a meteorological field program without leaving the comforts of their home. For more information, contact Gallus at (515) 294-2270, or Bridget Bailey, ISU News Service, (515) 294-6881.

New lab to create microanalytical instrumentation
A new laboratory at Iowa State University is helping researchers shrink scientific instruments to microscopic size. The W.M. Keck Laboratory for the Fabrication of Microminiaturized Analytical Instrumentation, funded in part by a $1.2 million grant from the W.M. Keck Foundation, Los Angeles, is now operational. This "clean room," part of Iowa State's Microanalytical Instrumentation Center (MIC), is being used to create a new generation of portable instruments that are more reliable and less costly than their much larger predecessors.

"This may be the only clean room for microfabrication in the country designed by and for chemists," said Marc Porter, an ISU chemistry professor and MIC director, noting that most clean rooms are designed for making electronic devices. "Its main purpose is to help us build microanalytical instrumentation." He adds that the lab is open to use by researchers from other universities and industry. "We support all phases of microfabrication and its use in fields ranging from chemistry and biology to zoology and genetics," Porter said.

Rather than just making miniaturized components, however, researchers in the Keck lab are working on analytical instruments and entire systems, such as dime-sized chromatography systems. "This field is now transitioning from 'what can you miniaturize' to 'what can you do with it,' and we're focused on the latter," Porter said. Applications for this technology range from entire analytical systems made for spacecraft to lab equipment that requires much smaller samples than traditional instruments. For more information, contact Porter at (515) 294-6433, or Robert Mills, IPRT Public Affairs, (515) 294-1113.


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