Seismicity of the Nordland area, Norway
Jan Michalek
University of Bergen
ABSTRACT: The Nordland area (65-70N; 8-18E) is tectonically active part of Norway. Enhanced seismicity may reflect on off-shore subsidence combined with the uplift of landmasses usually attributed to glacial isostatic adjustment (related to Pleistocene unloading). Detailed monitoring of seismic activity in the Nordland area started in 2013 as a part of the NEONOR2 project and information obtained from analysis of earthquakes together with geodetic data should be the key inputs for modeling of deformation and uplift patterns and their mechanisms in the region.
Local/regional network of 26 broad-band stations were deployed which together with the permanent NNSN stations consist 32 stations within span 350 x 200 km. About 330 earthquakes of M>1.0were recorded between Sep 2013 and Sep 2015 (ca 900 M>-0.4 events). The main aim of the project is to reveal the stress field in that particular region. Therefore the detailed analysis of individual events was performed including precise relative location (using hypoDD program) and space-time migration analysis. The project is ongoing and results are therefore preliminary.