Geohazards in Greater London: the Ground Stability Layer of the EU FP7 PanGeo project

Validated geohazard layers depicting areas of observed and potential ground instability are being generated by the EU FP7 PanGeo project for 52 of the largest towns across all 27 countries of Europe. The first product generated by the BGS covers the administrative area of Greater London, and consists of a polygon-wise Ground Stability Layer and associated Geohazard Description document. The identification of geohazards was performed through combined interpretation of geological, landuse and other geospatial layers, together with satellite Persistent Scatterers (PS) ground motion data for 1992-2010. The PanGeo product identifies ~450 km2 of observed and ~1,240 km2 of potential geohazards over London. Potential for natural ground movements (shrink-swell clays, and compressible ground) is observed for the majority of the area. Geohazards observed through the PS data include both natural processes (compaction of the River Thames sediments) and anthropogenic instability due to water abstraction and recent engineering works (e.g., Jubilee Line Extension).