Geophysical tomography

The Geophysical Tomography (GTom) team provides leading-edge technology for non-invasive geoelectrical imaging of the shallow subsurface.

The techniques (instrumentation, software and methodologies) developed by GTom are used to underpin studies in waste management, contaminated land remediation, the protection of groundwater and soils, as well as the detection and mitigation of natural hazards.

Our ALERT technology permits complex earth systems and processes to be monitored remotely using permanent 'in situ' sensor networks and wireless telemetry.


Our cross-cutting research is undertaken in close collaboration with universities, industry, and a range of public sector clients. Research is on-going into:

  • Proactive Infrastructure Monitoring and Evaluation system (PRIME): a low-cost, low-power, geophysical imaging instrument designed to monitor infrastructure and geohazards. It provides remote operation through innovative data telemetry, web portal access and intelligent monitoring.
  • Automated time-Lapse Electrical Resistivity Tomography (ALERT): permanent in-situ instrumentation and wireless telemetry permit the monitoring of vulnerable sites 'on demand'.
  • Capacitive Resistivity Imaging (CRI): a novel, non-contacting capacitive electrode system has been designed for imaging below engineered surfaces in the built environment as well as dry or frozen ground.
  • Cross-hole Resistivity Tomography (CRT): new cross-hole survey design schemes and inversion algorithms are under development for detecting geohazards and contaminant plumes.
  • Electrical Resistivity Tomography (ERT): new algorithms and data capture schemes are being developed to optimise image reconstruction in 2D, 3D and 4D.
  • Induced Polarisation Tomography (IPT): this technique has the potential to distinguish between salinity and clay content variations in complex hydrogeological conditions.
  • Self Potential Tomography (SPT):  new survey techniques and 3D algorithms are being developed for mapping SP charge probability within the shallow subsurface.
  • Optimised survey design: new theory, algorithms and software are being developed to maximise ERT image resolution and improve survey design.


ALERT 2D and 3D resistivity images of an active landslide site, revealing the extent of slipped mudstone (Aerial Photograph © UK Perspectives UKP2006/01). Click to view video.

Our current and recently completed research projects include:

  • RAWFILL: supporting a new circular economy for RAW materials recovered from landFILLs.
  • Automated time-Lapse Electrical Resistivity Tomography for Monitoring Embankments (ALERT-ME): an early warning system for monitoring the physical integrity of vulnerable earth structures within the transport network.
  • Landslide ALERT: Development of non-invasive hydrogeophysical imaging to investigate hydraulic processes within the body of landslides that can be precursors to failure.
  • Contaminated land ALERT: Research and development of 4D geoelectrical imaging as a minimally invasive tool to monitor contaminated land and validate remediation processes.
  • Waste management ALERT: Development of geoelectrical monitoring of temporal changes in leachate distribution, fluid and gas flow, hydrochemistry and saturation levels.
  • Aggregate deposit evaluation: Research to develop 3D/4D ERT for investigating economically and strategically important onshore sand and gravel deposits and for monitoring impacts of de-watering associated with commercial quarrying.
  • ALARMS: Assessment of Landslides using Acoustic Real-time Monitoring Systems.  A low-cost acoustic device has been developed by Loughborough University and the BGS that can detect high-frequency stress waves generated by soil movement in vulnerable landslide terrains.  The device uses wireless telemetry to provide early warning of incipient landslides in real-time.
  • Permafrost-CRI : BGS has won a NERC Technology Proof of Concept research grant to adapt its Capacitive Resistivity Imaging technology for the remote spatial and temporal monitoring of permafrost.


Please go to the GTom contacts page for more information