Study of Snowmelt-Induced Landslides in the Western US

Hazardous landslides triggered by snowmelt or a combination of snowmelt and rainfall are common during the spring in many mountainous areas of the western US. In the spring of 1996 a landslide mass at Keno Gulch near Aspen, Colorado spawned snowmelt-induced debris flows that threatened lives and caused extensive property damage at the Aspen Country Day School.

In early May of this year, members of the USGS Geologic Hazards Team instrumented the landslide with a remote monitoring system that records and maintains a history of landslide movement, precipitation, and air temperature. A previously identified temperature threshold for the onset of snowmelt induced landslides was used to time the deployment of the instrumentation.

The remote monitoring system utilizes cellular telephone telemetry for remote computer dial-in to obtain present status, retrieve stored data history, and modify setup parameters. The system also monitors data inputs and reports user defined alarm conditions by dialing user pager numbers. The purpose of the research is two-fold: (1) to further develop a snowmelt-induced landslide forcasting capability, and (2) to further develop and test the remote monitoring system.

The Pitkin County emergency preparedness office has been given access to the data and is using it to help develop hazard warning and mitigation strategies during the critical spring snowmelt period.