Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Greenland Ice Sheet: Now in HD

22.12.2014

New software yields highest-resolution large-scale maps of polar ice

The Greenland Ice Sheet is ready for its close-up.


Kuparuk Watershed, Alaska

Braided Streams & Geology

The highest-resolution satellite images ever taken of that region are making their debut. And while each individual pixel represents only one moment in time, taken together they show the ice sheet as a kind of living body—flowing, crumbling and melting out to sea.

The Ohio State University has partnered with the Polar Geospatial Center at the University of Minnesota to turn images captured by DigitalGlobe’s Worldview-1 and 2 satellites into publicly available elevation maps that researchers can use to track the ice.

Ian Howat, associate professor of earth sciences at Ohio State, presented the project’s first data release in a poster session at the American Geophysical Union (AGU) meeting on Dec. 18, 2014.*

He called researchers’ access to DigitalGlobe’s imagery “one of the biggest breakthroughs for earth science satellite capabilities in decades,” adding that “it’s only been a few years since we’ve gotten access to really high-resolution imagery from government agencies, and we’re already discovering new things about the ice sheet.”

The imagery starts out at a resolution of about 0.5 meters. The researchers then turn it into digital elevation maps with a resolution of 2 meters.

With hundreds of terabytes of polar data already collected and additional surface area equivalent to the state of Missouri being collected every day, the researchers are steadily processing it all with new Ohio State software called SETSM (for Surface Extraction from TIN-based Search Minimization). Ohio State research associate Myoung-Jong Noh created the software, which builds 1-gigabyte “tiles” representing regions 7 kilometers on a side and assembles them into mosaics depicting land, sea and ice elevation.

Each tile is extracted from a pair of images acquired of the same region, but about 45 seconds apart. SETSM combines the two displaced images into a coherent whole, as our brain does when it combines images from our two eyes. SETSM uses the Worldview satellites’ sensitivity to a very wide band of the electromagnetic spectrum to show things that our eyes alone couldn’t see, including tiny changes in elevation.

As an example, Howat pointed to the portion of the mosaic showing Jakobshavn Glacier, the fastest-flowing glacier in the Greenland Ice Sheet. Icebergs that have calved off the edge of the glacier are visible floating out to sea—but so are cracks hundreds of kilometers inland from Jakobshavn, on what would otherwise be a flat expanse of ice.

The winding, parallel cracks, which resemble ridges on a fingerprint, are signs that the ice is accelerating, Howat explained. As the ice flows faster and approaches the sea, the surface gets stretched out and cracks open. Over time, the cracks widen. The situation is similar to cars on a highway, he explained: Cars may be bunched up when they first enter the highway from an on-ramp, but they gradually spread apart as they accelerate to highway speeds.

Any research that relies on measuring changes in the Earth’s surface, including studies of volcanoes and coastal erosion, would benefit from elevation data produced by the SETSM software, Howat said. Applications for SETSM outside of earth science include computer vision, astronomy and national security—any job for which very large amounts of terrain are mapped at high resolution.

The mosaics debuting at AGU show southwest Greenland and some of the North Slope of Alaska. So far, the Ohio State team has finished processing images from about one quarter of the Greenland Ice Sheet, representing a tiny portion of the data already stored at Minnesota, and about one year’s worth of work and computing for the research team.

The Greenland Survey, Asiaq, is already using SETSM to protect drinking water resources, where remote sensing specialist Eva Mätzler said it “strengthens the understanding of importance in reliable geographic data for the Greenlandic government and people.” Asiaq project manager Bo Naamansen added that the software “is the best news for several decades when it comes to mapping Greenland and the Arctic.”

Paul Morin, director the Polar Geospatial Center, offered more superlatives: He said that the work done with SETSM is truly revolutionary. “We are no longer limited by remote sensing data when producing elevation data at the poles,” Morin said. “Noh and Howat have shown that we’re really only limited by high-performance computing.”

The Worldview satellite data is collected by commercial imagery vendor DigitalGlobe and licensed for U.S. federal use by the National Geospatial-Intelligence Agency, which in turn provides it to the Polar Geospatial Center at the University of Minnesota. At any given time, a 30-terabyte data subset is being stored and processed at Ohio State via the Ohio Supercomputer Center (OSC) before returning to Minnesota for distribution via a publicly accessible website.

Of the many Ohio State projects that draw upon OSC resources, SETSM is one of the largest. The researchers hope to expand the project to NASA’s Pleiades supercomputer starting in 2015.

NASA funds this research, including the continued development of the SETSM software. The National Science Foundation Division of Polar Programs supports the map distribution through the Polar Geospatial Center. In addition, OSC provided a grant for computing resources.

Contact: Ian Howat, (614) 292-6641; Howat.4@osu.edu
Written by Pam Frost Gorder, (614) 292-9475; Gorder.1@osu.edu
Images are available from the Polar Geospatial Center or from Pam Frost Gorder

Pamela Gorder | newswise
Further information:
http://www.osu.edu

Further reports about: Geospatial Greenland OSC Ohio Polar Sheet cracks ice sheet processing remote sensing satellite tiny

More articles from Earth Sciences:

nachricht GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center

nachricht Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>