Google Earth Community: Global warming melts permafrost

This folder contains a series of aerial photos taken between 1926
( aerial obliques) , 1946, 1967, 1971 which provide a source of comparison for studying the melting of permafrost in the form of palsas and peatplateaus at the most southern limits of occurance.
For more information: www.geostrategis.com and
http://www.geostrategis.com/p_mapm2.html

Site A:
Collapsing of permafrost is regularly distribute over the area. The red areas show the location of permfrost melting between 1947 and and 1957. Most of the area was burned in 1930 (except the darker treed- black spruce islands (on permfrost), but there are no signs that the burn accelerated melting rates. For example some of these darker 'black spuce on permafrost islands' have almost completely melted away between 1967 and 2000+, the date of the GE image. use the transparency slider to compare the two dates. Maximum extent of the permafrost in this area is likely correlated with the 'little ice age'. Just outside the overlay about 1.3 km north west of the left top corner is a small area burned about 3 years before the date of the GE image.

Site B: This area is interesting because most of the permafrost has diappeared. The small dark tread areas of black spruce on permanently frozen peat plateaus were all that was left of the once extensive permafrost. At its maximum extent about 65% of this site had permfrost. In this area most of the melting actually occured before 1946. In 1967 only the small dark spots remained. They tend to occur on the edges of the former peat plateaus. Most of these have disappeared now or are significantly smaller. Barely 1% of this site still has permafrost.Aerial Photo 1967; Red marks show areas melted between 1946 and 1967. Fieldwork carried out in 1973.

Site C:This photograph was taken as part of a multi-sensor aerial flight over the study area by the Canada Centre for Remote Sensing Airborne Division for the Manitob Remote Sensing Program. The colour photo was taken towards the end of the growing season. This site is remarkable because many of the small permafrost island still exist today and show relative small rates of melting.

Site D: Significant melting occured here before 1926 and this 1926 oblique photo gives an excellent image of the collapse scars which remain after the melting of the permafrost. Melting has continued since 1926, but permafrost remains are still visible on the GE image
Approximatearea coverd by the oblique aerial photo.

Site E:
This photo compared with the underlying Google Earth image provides a 60 year time frame to study the melting of permafrost. The permafrost in the form of Black Spruce forested peat plateaus and palsas is delineated on the photo after filedwork in this area in 1969-1971. Most of the smaller bodies of permafrost have disappeared and the larger ones show slow but steady melting around the perimeter.

Edited by jean_thie (03/08/08 11:58 AM)

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