UMN researchers release 3-D elevation maps

They worked with universities nationwide and a supercomputer to release images that could inform climate change research

by Melissa Steinken

In the past year, a small team of University of Minnesota researchers compiled 3-D maps of Alaska to help understand and combat climate change.

The University’s Polar Geospatial Center (PCG), Ohio State University and Cornell University used satellite images to form topographical maps of the region, which they released this month — almost a year after President Obama’s call to protect the Arctic wilderness and increase scientific observations of the region.

The 3-D digital elevation models help researchers monitor erosion and water flow, and study permafrost collapse and geological mapping, said Claire Porter, Polar Geospatial Center research fellow and remote sensing scientist.

Porter said similar maps of the entire Arctic will be released in stages throughout the coming year.

“I’m not even sure what all people are going to do with this,” Porter said. “So we made it so they can be creative and come up with things.”

While photos collected from aircraft can have higher resolutions, they often cost more and are restricted to certain times of the year, said Paul Morin, director of University’s Polar Geospatial Center.

Meanwhile, satellite images offer an easy method of data collection with less shadow interference, said Joe Knight, forest resources associate professor.

“We need to be able to study the earth and… what’s on the surface of the earth and how it’s changing,” Knight said.

For example, the maps show permafrost collapse, a melting and collapsing of ice caused by releases of the greenhouse gas methane, said Mike Willis, research associate and professor at the University of Colorado Boulder.

“The temperature especially in the Arctic region is increasing much faster than the rest of the planet,” Knight said.

Stages of supercomputing

Because the University team had only six to seven people, each member was critical to the project, Morin said.

“If there had been a larger team, there’s always someone behind them to back them up,” he said.

To process the satellite images with so much data, the team used the National Center for Supercomputing Applications’ Blue Waters supercomputer at the University of Illinois at Urbana-Champaign, one of the world’s most powerful computers.

Without borrowing time from the computer online, the team wouldn’t be able to work across universities on the same scale.

Computer time replaced funding for the researchers, Morin said. Only around 30 projects are allowed on the computer at a given time.

“We think it’s the fifth fastest computer on the planet — you have to use it in a certain way. It’s very delicate,” Willis said.

Morin said the researchers will start their efforts to release images of the whole Arctic with low-resolution shots and make their way to more exact images.

Once data is collected from satellite images at eight meters, the team decides if it was a high enough quality to make a two meter image, Willis said.

Usually images of the Arctic and other regions are taken at 19 to 30 meters, but the PGC and its collaborators will be the first to map such a large area at two meters, Willis said.

He said one of the biggest challenges has been time constraints.

“The topography is beautiful to look at,” Willis said. “It’s visually striking to me and it would be great to have more time do it.”