Google Earth Community: Global warming melts permafrost

www.geostrategis.com/p_mapm2.html

www.ecoinformatics.info

Google Earth and Climate Change: Google Earth provides a fascinating way to explore the earth remote ecosystems.
Few people would imagine that GE has the resolution and detail to monitor ecosystems, but an experienced interpreter can do remarkable
things with Google Earth.
A 2005 Google Earth visit to one of my old research sites in Manitoba, Canada, showed that Google Earth can be used to approximate the melting rates of permafrost in peat landforms. These two combined inages show a comparison of permafrost in peatplateaus just north of Lake Winnipeg. This area is within the so called southern sporadic permafrost zone, but because of its unique wetland situation permafrost is quite widespread (see for example E in 1926) and visible. Even the low resolution Google Earth images shows the melting edge clearly. The two major peat islands are aslo shown on the second image below as B and C.

The compsite figure below shows a combination of a1926 oblique aerial photo, a 1947 vertical air photo projected as oblique and a 2005 oblique Google Earth image. The permafrost around A is still present in 1947 but totally melted in 2004. The peat plateau B shows some melting (collapse holes) inside the plateau in 1947; but in 2005 they joined together and are forming a peripheral collapse. Area C is interesting because it was burned before 1926 regenerated a black spruce cover and shows still its frozen state in 2005. In fact the melting process in B and C seems very comparable. So fire does not necessarily increase the rate of permafrost melting. On the other hand, the the small peatplateau at touching the top of (A) melted within years after a fire in the late 60's.

A close up view from helicopter: Black Spruce (Picea mariana) grow on the frozen core in the middle. They are about 12-15 meters in height. The collapsing edge shows surface water and leaning trees and trunks sinking in the non-frozen wetlands. Tamarack (Larix Laricina) growth is denser around the original edge of the palsa.

Extensive collapse scars of former peat plateaus. Very little permafrost is left except for areas near (2). This area was burned a number of years ago. In these small areas of permafrost white birch and black spruce regeneration is seen. The relative recent collapse areas are marked with (1), older scar areas with (3)

Analysis page comparing 1929 and 1947 aerial photographs, and 2005 Google image and field work photos available at http://www.geostrategis.com/p_mapm2.html

website: www@geostrategis.com

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Jean Thie
Executive Director, Canadian Institute of Geomatics
www.geostrategis.com
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