Pressure gradients and earthquake rates in Groningen

A report with a statistical analysis of the relationship between gas pressure, and gradients in gas pressure, within the Groningen reservoir immediately prior to earthquakes, commissioned by State Supervision of Mines.
In this research the particular focus is on the relationship between reservoir gas pressure variations and the earthquakes in Groningen. From the analysis it is clear that there is a correlation, in the sense that prior to earthquakes there is an enhanced signal in the reservoir gas pressure at the location of the earthquake. This is a re-analysis which is carried out because of the availability of improved, daily cadence, time series for the reservoir gas pressure. Also, use is made of improved localisation of a subset of earthquakes in the KNMI catalogue after re-analysis of the relevant seismometer traces.