Ground motion in the Vale of Pickering

BGS monitored surface ground motion (subsidence, uplift or stability) in the Vale of Pickering using line of slight (LOS) interferometric synthetic aperture radar (InSAR). This is an ideal technique for ground motion monitoring because:

archive radar data (acquired by satellites since 1992) are available and can be used to ascertain a baseline of motion or lack of motion prior to any gas exploration/production

the analysis produces data over a region rather than at a point location

Satellite data

The archive radar data were acquired by the ERS–1/2 and ENVISAT satellites for the periods 1992–2000 and 2002–2009 respectively. There is no satellite coverage in the region between 2009 and 2014 due to the orbital decay of ENVISAT. Nonetheless, the period 1992–2009 was sufficient to provide a meaningful baseline assessment of ground motion prior to unconventional gas operations.

For the Vale of Pickering, ESA's archives include two data stacks of ERS–1/2 and ENVISAT scenes that cover a standard satellite frame extending 100 by 100 km. 75 ERS–1/2 SAR scenes for 1992–2000 and 25 ENVISAT ASAR scenes for 2002–2009 are available. These data (1992–2000 and 2002–2009) were provided by the European Space Agency (ESA) under grant id. 31573, and analysed by BGS.

A new ESA radar satellite, Sentinel–1A, was launched in April 2014. However, at the time of analysis, a sufficient stack of data had not been acquired by the satellite to carry out high–precision InSAR analysis.