Summit County Citizens Voice

A major rock avalanche in the Bregaglia after Christmas 2011 could be a result of temperature rise in permafrost areas. PHOTO COURTESY HELI BERNINA.

New mapping tool to help land-use planners and public safety officials locate potential trouble spots

By Summit Voice

SUMMIT COUNTY — While permafrost is most often associated with the Arctic north, it’s also an important component of alpine ecosystems, serving as a sort of glue that holds otherwise crumbly mountains together.

As the Earth warms rapidly due to the buildup of greenhouse gases in the atmosphere, some alpine countries have already had first-hand experience with thawing permafrost as a result of climate change. In some mountain locations, cable-car and powerline pylons have become unstable, and f temperatures continue to rise, the problem will intensify in many places.

To try and anticipate problems that could have  far-reaching ramifications for populated areas, infrastructure and ecosystems,  geographer from the University of Zurich shows where it is important to confront the issue based on new permafrost maps — the most precise global maps to-date. They depict the global distribution of permafrost in high-resolution images and are available on Google Earth.

“As a result of climate change, areas with permafrost have great potential for unpleasant surprises,” said University of Zürich glaciologist Stefan Gruber. “That is why it is all the more important for politics and the public to be aware of the problem of thawing permafrost. My maps visualize the otherwise barely visible phenomenon of permafrost.”

Permafrost is rock or soil that maintains sub-freezing temperature for at least two years. Since it occurs below the surface, it can’t be mapped directly. Existing maps are fraught with major uncertainties that have barely been studied or formulated. Furthermore, due to the different modeling methods used the maps are difficult to compare.

But land-use planner and safety officials are getting some help from Gruber, who modeled the global permafrost zones for the first time in high resolution and using a consistent method.

In his study, recently published in The Cryosphere, Guber estimates the global permafrost regions at 22 million square kilometers – a sixth of the world’s exposed land surface. With a grid resolution of one square kilometer, Gruber’s maps are the most precise permafrost maps in the world..

Part of the challenge of mapping permafrost zones is that the spatial distribution resembles a patchwork quilt. This is where Gruber’s innovative permafrost maps come in: They are based on high-resolution air temperature and elevation data. Moreover, they reveal an index that indicates the probability of permafrost.

The permafrost areas are depicted in grades – from dark blue for near-continuous permafrost to yellow for areas with little permafrost. In contrast to previous permafrost maps, which show clearly defined zones, Gruber’s maps also illustrate the uncertainty of the state of research.

Filed under: climate and weather, Environment, global warming, Summit County news Tagged: | climate change, cryosphere, Environment, global warming, permafrost, University of Zurich