Friday, February 15, 2013

What we are learning about thermokarsts

Tremendous stores of organic carbon have been frozen in permafrost soils for thousands of years. A thermokarst failure is generated when these ice-rich, permanently-frozen soils are warmed and thawed, the ice melts, and the soil collapses and either creates an erosional hole in the tundra or a landslide if the slope is sufficient. An environmental chemist at UNC-Chapel Hill, Dr. Rose Cory, is studying thermokarsts in the Alaskan Arctic. Specifically, she is investigating the role of sunlight in stimulating carbon dioxide release from permafrost soil carbon. Dr. Cory's findings have revealed that thermokarsts produce significant amounts of carbon dioxide and represent a previously unrecognized store of carbon that is currently not included in future climate predictions.

Rose Cory, Ph.D. standing at a gully erosion thermokarst (hand on soil ice and thermokarst water sampled at bottom of picture).
Dr. Cory's research provides the first evidence that the respiration of previously frozen soil carbon will be amplified by reactions with sunlight (photochemical processes) and their effects on bacteria.  

To learn more about her latest research findings visit:
Surface exposure to sunlight stimulates CO2 release from permafrost soil carbon in the Arctic. Proceedings of the National Academies of Science. Feb 11, 2013.

Also available is a 5 minute video describing Dr. Cory's research and showing life in the field in the Alaskan Arctic  – this video features graduate students conducting research as well.

Trouble in the Tundra (article about Thermokarsts)
Video showing a Thermokarst (35 second video)
Walking in a thermokarst (29 second video)

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