Geohazards

Volcanoes Earthquakes & Faults Subsidence & Sinkholes Landslides

Geohazards present a constant and global threat to humanity and can lead to widespread risk and damage. These naturally occurring phenomena can be relatively small scale, but can create disasters on local to wider levels, impacting heavily on regional socio-economies.

Identify, Characterise and Monitor Geohazards

Geohazards can be accurately identified, characterised and monitored using InSAR – an advanced technology for processing satellite-derived radar data. By processing satellite images acquired over the same area for a period of time, the temporal evolution of a geohazard and surrounding ground instabilities can be monitored. Historical ground movement can also be determined using data archives.

Hazard Identification Residual Risk Analysis Prevention Plan

Our maps are used by Civil and Environmental Protection Agencies to identify ‘at risk’ areas, aiding the establishment of natural disaster response plans. Surface displacement rates can be detected from millimetre to centimetre range, with no ground instrumentation required. Additionally, satellite-derived surface displacement data provides a long-term solution to geohazard monitoring.

Volcano Stability Monitoring (Etna, Italy): Continuous monitoring of volcanoes can highlight flank instabilities, fault lines and subsidence & uplift due to internal pressure changes. Red measurement points indicate movement away from the satellite (typically subsidence), green indicates stability and blue is towards the satellite (typically uplift) [Img src TRE-Altamira]

Earthquake and Fault Map (L’Aquila, Italy): Image shows an interferogram of the deformation pattern associated with an earthquake. In a similar manner, movement along seismic fault lines can also be detected. The colours indicate phase change in the received radar signal, which can be equated and mapped to ground movement as the wavelength of the radar signal is known [Img src TRE-Altamira]

Ground Subsidence Monitoring (Jakarta, Indonesia): Image shows surface subsidence that occurred over a 4-year period over an urban area. Red measurement points indicate movement away from the satellite (typically subsidence), green indicates stability and blue is towards the satellite (typically uplift) [Img src TRE-Altamira]

Landslide Detection and Monitoring (Montescaglioso, Italy): Image shows a the cumulative movement of a landslide near a built-up area, where pre-cursory ground displacements were identified. Red measurement points indicate movement away from the satellite (typically subsidence), green indicates stability and blue is towards the satellite (typically uplift) [Img src TRE-Altamira]

Example InSAR ground deformation maps over geohazards (left to right): volcano flank instabilities, post-earthquake deformation analysis, urban subsidence map, landslide movement detection. Red is subsidence, blue is uplift [Img src TRE-Altamira]

Ground motion maps are used as an input to geohazard models to calculate human risk exposure and emergency response procedures. After a disaster, satellite monitoring is used to assess residual risk in the affected area and to measure the total ground deformation resulting from the event.

Single Phenomenon & Wide Area Mapping

Unlike traditional ground based surveys, our measurements are remotely acquired and cover wide areas. Additionally, our maps can focus on both single phenomenon and wide area analyses. Such an technology becomes particularly advantageous when determining long-term ground movement, or calculating risk in hard-to-access areas.

Mapping Monitoring Inventory Update

An extensive archive of satellite imagery allows the historical evolution of ground movement to be reconstructed, providing valuable insight into understanding and forecasting possible future behaviour. Displacement maps are used to delineate phenomenon boundaries and to detect changes in displacement rates, aiding the verification and update of existing geohazard inventories.

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