Regional moisture balance control of landslide motion: Implications for landslide forecasting in a changing climate
Jeffrey A. Coe, U.S. Geological Survey, Denver Federal Center, MS 966, Denver, Colorado 80225, USA. Published online 14 Feb. 2012; doi: 10.1130/G32897.1.
The Slumgullion landslide is a thick, complex landslide in the San Juan Mountains of Colorado, USA, that has been moving for at least 300 years. Movement of landslides like Slumgullion is difficult to forecast because they incorporate a variety of materials, have many parts, and respond to long-term groundwater conditions. For Slumgullion, Jeffrey A. Coe of the U.S. Geological Survey forecasts that increased air temperatures and evapotranspiration from global warming will cause the landslide to slow in the 21st century, and that the upper part of the landslide will stop moving in the middle of the century. To make this forecast, Coe measured the movement of 18 points on the landslide for 12 years (1998-2010) and linked the observed movement to moisture balance index values from the same time period. Moisture balance index values were a measure of precipitation minus potential evapotranspiration. High moisture index values corresponded to faster landslide movement and low values corresponded to slower landslide movement. Coe used the link between movement and moisture balance, in combination with predictions of decreasing future moisture balance values, to forecast decreasing landslide movement. The moisture balance technique may be useful for forecasting the movement of thick landslides in other parts of the world.
Stress-controlled fluid flow in fractures at the site of a potential nuclear waste repository, Finland
Jussi Mattila and Eveliina Tammisto, Geological Survey of Finland, P.O. Box 96,
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Geological Society of America