GPS Instrumentation and Remote Sensing Study of Slow Moving Landslides in the Eastern San Francisco Bay Hills, California, USA
Abstract
The objective of this study is to characterize slope deformation as a result of static and dynamic forces, using the most current geodetic technologies that measure active ground surface displacement. Recent advances in geodetic and remote data collection, such as with continuous GPS and Interferometric Synthetic Aperture Radar (InSAR) allow for a level of primary site characterization and eventual risk assessment due to landsliding that was previously not possible. Active landsliding across the Lawrence Berkeley National Laboratory (LBNL) site and the greater Berkeley Hills region, in the Eastern San Francisco Bay, California, has been the object of many investigations over recent decades, though the mechanisms of currently mobile slides are still poorly understood. Previous studies suggest a trend in landslide mobility is closely associated with precipitation and regional active tectonic conditions in addition to the geologic setting (Alan Kropp and Associates, 2002). InSAR time-series analysis has been shown to successfully track creeping landslides in the Berkeley Hills with millimeter scale accuracy (Hilley et al., 2004) and documents displacement primarily during periods of high precipitation (Quigley et al., 2010). However, displacement of creeping landslides due to seismic activity has yet to be measured. A first focus of this project is therefore to study the spatial and temporal distribution of active Berkeley Hills landsliding in relation to local precipitation and ground shaking events by a careful observational program. This program includes the instrumentation of individual landslides with permanent continuously streaming GPS stations (beginning 2012), and regional monitoring of slope surface deformation by InSAR time series analysis (beginning 1992). To date, continuous GPS tracking of select landslides has recorded up to 2 cm of total surface deformation driven by the onset of precipitation, with displacement response times of less than 5 days. Though continuous GPS tracking also spanned two Mw ≈ 4 earthquakes along the Hayward Fault with epicenters from 2 to 10 km of the instrumented sites, no immediate response could be discerned due to shaking. Our analysis of recent InSAR time series of TerraSAR-X data processed with the Tele-Rilevamento Europa (TRE) SqueeSARTM method also shows changes in the spatial and temporal distribution of surficial landslide expressions during the relatively dry and wet Winter seasons of 2010 and 2011, respectively.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMNH11D..06C
- Keywords:
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- 1240 GEODESY AND GRAVITY / Satellite geodesy: results;
- 1810 HYDROLOGY / Debris flow and landslides;
- 4315 NATURAL HAZARDS / Monitoring;
- forecasting;
- prediction;
- 4337 NATURAL HAZARDS / Remote sensing and disasters