Characteristics of the Earthquake Activity in Southeast New Brunswick, an Area With Shale Gas Potential.
Previously Published Material: I have presented some preliminary results at the European Seismological Commission Meeting last September. Since then, much progress has been done in the data acquisition and analysis. The results have not been published yet, but they will be submitted to the Seismological Research Letters for a special number on Induced seismicity.
Abstract ID#: 36786
New Brunswick is a region of moderate seismicity. From 1764 to 1980, only five events have felt area magnitudes in the 5.4-6.0 range; two in the Central Highlands, two in the Passamaquoddy Bay region and one near Moncton (1855; magnitude 5.4). After 1980, earthquake activity has been monitored by the Canadian National Seismograph Network (CNSN) which provides earthquake location completeness to slightly above magnitude (mN) 2.0. Since 1980, the strongest earthquakes recorded in the sedimentary sub-basins have been two mN 3.6 events, both located just to the southwest of Moncton. A study helped define the depth distribution of earthquakes in SE NB using conversional and regional depth phase modeling (rdpm) methods. A velocity inversion was also performed.
To better monitor the Sussex Basin area, five additional seismographs with broadband sensors were installed (one in 2012 and four in 2013) to complement the permanent CNSN station LMN. Thanks to these additional stations, the area is currently monitored by a dense six-station seismograph network that can improve the monitoring of the background seismicity and allows for the calculation of focal depths within the array. Since 2010, only four seismic events in the Sussex Basin were recorded but the long period between its occurrence and hydraulic fracturing at McCully field (almost two years) makes a connection unlikely. Thanks to the new network, numerous small earthquakes have been detected in the surroundings.