Compilation of Composite Alberta Seismicity Catalog (CASC) for Earthquake Hazard from Induced Seismicity in Alberta

English Abstract:

The compilation of a comprehensive, high-quality and easy-to-use catalog of earthquake events in Alberta and the surrounding region is a fundamental step for the evaluation of the impact of industrial activity on the seismicity in the region. For this purpose, we have developed the Composite Alberta Seismicity Catalog (CASC) by combining the information from several national and international data sources: TransAlta/Nanometrics Network (NMX catalog), the Geological Survey of Canada (GSC catalog), the Alberta Geological Survey (AGS catalog), the Canadian Composite Seismicity Catalog (CCSC), and the Advanced National Seismic System catalog from the US Geological Survey (ANSS catalog). The CASC catalog covers the region of 48°- 59° N latitude, 110°- 121° W longitude, and currently includes events through December 2014. For each event, the CASC lists the occurrence time in Universal Coordinate Time (UTC), hypocentral location, the set of all available magnitude types, and an assigned preferred magnitude. We applied a semi-automatic procedure to identify and remove duplicate information from the alternative source catalogs, while retaining information on alternative estimates of locations and magnitudes from different sources. The magnitudes of all events to the end of 2013 have been converted to moment magnitude where required (i.e. if no estimate of moment magnitude is available in any of the original sources), using the empirical equations in Fereidoni et al (2012). The output files for pre-2014 and post-2014 events are available for download at http://www.inducedseismicity.ca, along with their documentations. Updated files will be available on the website on monthly basis. This compiled catalog provides a useful baseline for studying earthquake hazard due to the induced seismicity in Alberta.