GMES – Terrafirma Stassfurt Case Study

Report of the project:

• GMES Terrafirma – A Pan-European Ground Motion Hazard Information Service
• GMES Terrafirma – Ein europaweiter Informationsdienst über Bodenbewegungen

Project Summary

Terrafirma is one of ten services being supported by the European Space Agency’s (ESA) GMES Service Element Programme. Terrafirma aims at providing a ground motion hazard information service, distributed throughout Europe via national geological surveys and institutions, and through utilizing the technique of Persistent Scatterer Interferometry (PSI) (www.terrafirma.eu.com).

The technique of Persistent Scatterer Interferometry (PSI) analyses series of 20 to 100 satellite SAR data (SAR: Synthetic Aperture Radar). Phase shifts detectable for persistently backscattering points over the complete series of SAR data are highly sensitive to vertical motion of the ground even if annual displacement rates amount to millimeters only.

BGR is Terrafirma project partner. BGR’s contribution was the geological evaluation of PSI-ground motion data for Berlin, Hamburg and Stassfurt (Terrafirma stages I and II). A summary of the Stassfurt results is presented. Further processing results are presented in the Terrafirma Atlas (www.terrafirma.eu.com).

Stassfurt is the site of several abandoned potash mines. The mines have been flooded causing collapse sink holes and land subsidence. The city centre is now below the groundwater table due to subsidence. The PSI-derived land subsidence features strictly follow the surface projection of mined potash horizons. The PSI data complement the levelling data collected for a few benchmark points very effectively. The PSI-derived motion rates fully agree with motion rates from levelling.

Terrafirma stage III launched in December 2009, focuses on testing and implementing a border-crossing "Wide Area Mapping Service".

GMES – Terrafirma Stassfurt Case Study: Preliminary Results (PDF, 504 KB) – Terrafirma Powerpoint-Präsentation