Moho Topography and Velocity/Density Model for the Hedmarken area, Eastern Norway, using Receiver Function Analysis and Rj-McMC

A Receiver Function Analysis was carried out in the Mjøsa area, Eastern Norway, in order to better image this tectonically complex area, understand the crustal contrasts and complement geological analysis that were made previously in the area. For this, we used seismic traces received for seven broadband stations from the NORSAR permanent array. The H-K (depth vs Vp/Vs) stacking procedure and a Reversible jump Markov chain Monte Carlo (Rj-McMC) inversion were developed independently. The first analysis allows us to obtain a model with the Mohorovicic discontinuity values under each seismic station and the average Vp/Vs crustal ratio. With the inversion, it was possible to develop a 1D local velocity model. Applying the Nafe-Drake relationship, a 2D density model was obtained and tested against observed gravity. Results indicate the presence of a low anomalous density layer that is located to the NNW of the study area, which is probably related to low-density meta-sediments in the Åsta Basin located above the basement. A main crustal fault is also indicated from the density model, spatially coinciding with faults grown during the Sveconorwegian orogenic process.