Upper-mantle structure in southern Norway from beamforming of Rayleigh wave data presenting multipathing

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

2

Inverse Theory, Mantle Processes, Surface Waves And Free Oscillations, Wave Scattering And Diffraction, Cratons, Europe

Scientific paper

A model for the upper mantle SV-wave velocity under southern Norway is obtained by depth inversion of the average phase velocity of the Rayleigh wave fundamental mode in the area. The average dispersion curve is obtained in the period range 22-200 s by beamforming of 190 Rayleigh waves recorded by the MAGNUS network, a temporary regional network of 41 broad-band stations. Resolution of the beamforming procedure is increased by deconvolving the original beams from the array response function using the Lucy-Richardson algorithm. In addition to an average phase velocity, beamforming gives us some information concerning the nature of the incoming wavefield. We detect deviations of the wave propagation direction from the great-circle paths which commonly reach 10° at a period of 25 s for the teleseismic events. The amplitude of the deviations decreases with increasing period and with decreasing epicentral distance, as expected. The phase velocity measured by beamforming does not show any correlation with the deviation from great circle path, suggesting that deviation does not bias phase velocity measurements. We detect also significant multipathing with characteristics that vary rapidly with frequency. The obtained SV-wave velocity profile clearly shows that southern Norway is underlain by a low-velocity zone in the upper mantle and does not have shield-like characteristics, despite its location in the Baltic shield. These findings support the hypothesis that the high topography of southern Norway is sustained by anomalous upper-mantle material.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Upper-mantle structure in southern Norway from beamforming of Rayleigh wave data presenting multipathing does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Upper-mantle structure in southern Norway from beamforming of Rayleigh wave data presenting multipathing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Upper-mantle structure in southern Norway from beamforming of Rayleigh wave data presenting multipathing will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-926665

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.