Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


An SwRI-led remote-sensing study quantifies permafrost degradation in Arctic Alaskan wetlands

A team of geoscientists from Southwest Research Institute (SwRI) using newly available remote-sensing technology has achieved unprecedented detail in quantifying subtle, long-period changes in the water levels of shallow lakes and ponds in hard-to-reach Arctic wetlands.

Analysis comparing time-lapsed, high-resolution satellite imagery of the Ahnewetut Wetlands in Kobuk Valley National Park, Alaska, revealed an accelerated loss of surface water in shallow thaw lakes and ponds over a recent 27-year period compared to the preceding 27-year timespan. Those periods generally coincide with a well-known cooling and warming cycle known as the Pacific Decadal Oscillation, whose period is about five decades.

The analysis compared historical high-resolution aerial photography with more recent satellite imagery to quantify the evolution of 22 shallow lakes and surrounding permafrost in the park over 54 years between 1951 and 2005.

"Total water-body surface area decreased by only 0.4 percent during the first 27 years, but decreased by 5.5 percent during the second 27-year interval," said Dr. Marius Necsoiu, principal investigator for the study and a principal scientist in SwRI's Geosciences and Engineering Division. Water body surface area was relatively stable during the early, cooler time interval, with large relative losses in small ponds balanced by small relative gains in large lakes. More significant decreases in surface area occurred during the latter, warmer timespan, including complete drainage of two ponds.

Meanwhile, ice-wedge "polygons" in the soil between the water bodies (so-named because of their geometric shapes when viewed from above), transformed from having relatively low centers to relatively high centers during the more recent interval after little change was detected during the first 27 years. The change can be explained by the melting away of ice wedges that had formed the elevated rims of the polygons, leaving the rims depressed in comparison to the polygon centers.

"This project showed that semi-automated analysis of remote-sensing data can yield important information about wetland lake dynamics and permafrost degradation in remote areas where limited funding and staff shortages prevent detailed inspections on the ground," Necsoiu said.

The SwRI-funded study was published under the title, "Multi-temporal image analysis of historical aerial photographs and recent satellite imagery reveals evolution of water body surface area and polygonal terrain morphology in Kobuk Valley National Park, Alaska," by Necsoiu, Dinwiddie, Walter, Larsen, and Stothoff in the journal Environmental Research Letters.

For more information, contact Joe Fohn at (210) 522-4630, Communications Department, PO Drawer 28510, San Antonio, TX 78228-0510.

Joe Fohn | EurekAlert!
Further information:

More articles from Earth Sciences:

nachricht Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union

nachricht Enormous dome in central Andes driven by huge magma body beneath it
25.10.2016 | University of California - Santa Cruz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>