Sensitivity of ice-cemented Antarctic slopes to increases in summer thaw

• Main Authors: Kate M. Swanger, David R. Marchant
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; McMurdo Dry Valleys; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.516.3855; http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea039.pdf

Summary We employed a Mohr-Coulomb safety factor equation to assess the response of ice-cemented slopes in the stable upland zone of the McMurdo Dry Valleys (MDV) to artificial increases in mean summertime soil surface temperatures (MSSST). Results show that ice-rich, silty tills on slopes 20 ° could fail by planar sliding with an in-crease in MSSST of ~5º to 9ºC. This change corresponds to an atmospheric increase of ~5º to 9ºC, which lies just outside the envelope of warming predicted to occur in this region over the next century. If we assume that current soil-moisture conditions can be applied to slope deposits in the distant past, and that these slope deposits have re-mained physically stable for millions of years, then our results suggest that MSSST in the upland zone did not in-crease by more than ~5º to 9ºC since deposition of most deposits, perhaps as much as 10 million years ago.