Seismicity in the Labrador-Baffin Seaway and surrounding onshore regions

Abstract

Studying earthquakes in Baffin Bay and the surrounding regions is challenging. There is no knowledge of earthquake activity in this region prior to 1933 when a moment magnitude (MW) 7.4 earthquake occurred in Baffin Bay. With improved instrumentation, increased seismograph coverage in the north, and modern analysis techniques, knowledge and understanding of earthquakes in the Baffin region is improving. Active seismic zones include Baffin Bay, the east coast of Baffin Island, and the Labrador Sea, separated by areas of low seismicity. Focal-mechanism solutions show a mix of faulting styles, predominantly strike-slip and thrust. Regional stress-axes orientations show more consistency, which suggests that activity is occurring on previously existing structures in response to the current stress field. There is little correlation between earthquake epicentres in Baffin Bay and mapped structures. Glacial isostatic adjustment may be a triggering mechanism for earthquakes in the Baffin region, but modelling efforts have yielded equivocal results.