Emmy-Noether-Projekt "Brückenschlag zwischen Geodäsie und Seismologie"

High-resolution measurement of the seismic attenuation across the Vrancea region, Romania

Sudhaus, H. and J. R. R. Ritter (2005)

Geophysical Research Letters 32(10). DOI: 10.1029/2004GL022148

Wiley online library

Abstract

We use teleseismic waveforms from a seismic refraction experiment along a N-S profile across the Vrancea region, Romania, to study seismic attenuation.

This unique data set with an average station spacing of about 2–3 km provides spatial high-resolution estimates of the variability in seismic attenuation. Time windows of the analyzed seismic phases are extracted with a multiple-taper technique and spectral ratios (δt*) are determined.

Our results from 4 teleseismic phases (P, pP, PKPdf, and PP) of two events underneath Hokkaido, Japan and New Guinea find a significant variation of the seismic attenuation along the line.

A major influence of local site effects on the values of δt* can be excluded as well as a correlation with the Vrancea slab. The variations of the δt* operators from different phases at individual stations seem to be caused by the projection of three-dimensional attenuating structures at deep lithospheric levels.

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