The micro‐seismicity of Co. Donegal (Ireland): Defining baseline seismicity in a region of slow lithospheric deformation

Abstract

AbstractA catalogue of precisely located micro‐seismicity is fundamental for investigating seismicity and rock physical properties in active tectonic and volcanic regions and for the definition of a ‘baseline’ seismicity, required for a safe future exploitation of georesource areas. In this study, we produce the first manually revised catalogue of micro‐seismicity for Co. Donegal region (Ireland), an area of about 50K M2 of on‐going deformation, aimed at localizing natural micro‐seismic events occurred between 2012 and 2015. We develop a stochastic method based on a Markov chain Monte Carlo (McMC) sampling approach to compute earthquake hypocentral location parameters. Our results indicates that micro‐seismicity is present with magnitudes lower than 2 (the highest magnitude is 2.8).The recorded seismicity is almost clustered along previously mapped NE‐SW trending, steeply dipping faults and confined within the upper crust (focal depth less than 10 km). We also recorded anthropogenic seismicity mostly related to quarries' activity in the study area.