Enhanced Earthquake Monitoring in the European Arctic

This paper presents preliminary results from a cooperative initiative between the Norwegian Seismic Array (NORSAR) institution in Norway and seismological institutions in NW Russia (Arkhangelsk and Apatity). We show that the joint processing of data from the combined seismic networks of all these institutions leads to a considerable increase in the number of located seismic events in the European Arctic compared to standard seismic bulletins such as the NORSAR reviewed regional seismic bulletin and the Reviewed Event Bulletin (REB) issued by the International Data Centre (IDC) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) organization. The increase is particularly pronounced along the Gakkel Ridge to the north of the Svalbard and Franz-Josef Land archipelagos. We also note that the vast majority of the events along the Gakkel Ridge have been located slightly to the south of the ridge. We interpret this as an effect of the lack of recording stations closer to and north of the Gakkel Ridge, and the use of a one-dimensional velocity model which is not fully representative for travel-times along observed propagation paths. We conclude that while the characteristics of earthquake activity in the European Arctic is currently poorly known, the knowledge can be expected to be significantly improved by establishing the appropriate cooperative seismic recording infrastructures.