Monitoring landslide displacements with the Geocube wireless network of low-cost GPS

• The Super-Sauze landslide is monitored by a dense, low-cost and wireless GPS network.
• Precise position time series at high temporal frequency are obtained.
• The complex spatial pattern of deformation of the landslide is investigated.
• A landslide acceleration event is documented.

The analysis of landslide hazard requires continuous and high frequency surface displacement monitoring at numerous and geomorphologically relevant locations. Ground-based geodetic methods (GNSS, tacheometry) allow very accurate and high frequency temporal observations while remote sensing methods (InSAR, terrestrial and satellite photogrammetry, LIDAR) allow spatially distributed observations at high spatial resolution. A single surface deformation monitoring technique coupling all these capabilities is still missing.The Geocube system has been designed to partly overcome this pitfall by creating a low-cost, flexible, easy to install and wireless GPS receiver. Dense Geocube monitoring networks can be set easily for operational observations. Furthermore, the monitoring of other landslide properties (micro-seismicity, seismic waves) or triggering factors (meteorology, slope hydrology) is possible with the capacity of integrating additional sensors to the Geocube.This work presents the Geocube system and the results of a field campaign performed during the summer 2012 at the Super-Sauze landslide, southern French Alps, with a network of wireless low-cost GPS. The objective was to assess the performance of the Geocube system in real field monitoring conditions. Our results document the spatial and temporal evolution of the landslide during a period of 40 days. Landslide acceleration periods are detected and correlated to rainfall events.