An overview of high spatial resolution geophysical methods for landslide characterisation and monitoring:25th European Meeting of Environmental and Engineering Geophysics, Held at Near Surface Geoscience Conference and Exhibition 2019, NSG 2019

Abstract

Combining geophysical methods allows for the characterisation and monitoring of subsurface processes in landslide systems at unprecedented spatiotemporal resolutions. For high spatial resolution characterisation and monitoring of the subsurface, methods that provide maps, cross-sections and three-dimensional volumes of data are preferred. An overview of the results of various long-term monitoring campaigns using such geophysical methods at the Hollin Hill Landslide Observatory in the UK are presented. These methods include electrical resistivity and seismic tomography, self-potential mapping and cross-sections of horizontal-to-vertical ratio measurements of ambient seismic noise. Repeating these surveys over time results in the production of time-lapse data, making these approaches effective monitoring tools. Variations in these measurements show relationships to changes in environmental conditions, for example, decreases in seismic velocity and resistivity values associated with decreases in soil moisture content. Critically, the use of geotechnical-geophysical relationships can provide information between, and beyond the depth of, shallow geotechnical and surface environmental sensors. Using such time-series of high resolution spatial data can help achieve a better understanding of the moisture and kinematic dynamics of unstable slopes, and provides subsurface information for incorporation in to local landslide early warning systems. © 2019 25th European Meeting of Environmental and Engineering Geophysics, Held at Near Surface Geoscience Conference and Exhibition 2019, NSG 2019. All rights reserved