Source study of the Jan Mayen transform fault strike-slip earthquakes

• Slip models were obtained with the iterative deconvolution method.
• Sensitivity tests show stable solutions and thus reliable source parameter estimates.
• Slip models are in agreement with the observed aftershock sequences.
• The events did not present slow rupture process.

Seismic source parameters of oceanic transform zone earthquakes have been relatively poorly studied. Previous studies showed that this type of earthquakes has unique characteristics such as not only the relatively common occurrence of slow events with weak seismic radiation at high frequencies but also the occurrence of some events that have high apparent stress indicating strong high frequency radiation. We studied 5 strike-slip earthquakes in the Jan Mayen fracture zone with magnitudes in the range of 5.9 < Mw < 6.7. We determined finite-fault slip distributions with the iterative deconvolution method from teleseismic data. The slip models were characterized by determining source parameters on the asperities and background areas. We found that the areas of the asperities represent about 23–28% of the total rupture area with two different criteria based on average slip and maximum displacement. Sensitivity tests were carried out to estimate the variability of slip patterns and source parameters. We observed robust solutions and reliable source parameter estimates from the models. We also determined the radiated seismic energy and apparent stress in order to identify possible slow events. Our results suggest that the analyzed events in Jan Mayen have a regular nature in terms of apparent stress, seismic energy and centroid time delay compared to other oceanic transform fault earthquakes.