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.

Geofon

SRCMOD - Database

    • Inversion modelling of geodetic (InSAR) and seismological data
    • earthquake slip complexity and co-seismic rupture history
    • Connecting earthquake models to observations
    • Kinematic earthquake source inversion

     

    In my research i am interested in how earthquakes ruptures behave and how and why earthquakes develop complex ruptures in space and time. Complex means that the earthquake ruptures e.g. across multiple fault planes with different geometries or slows down/accelerates in different areas. We know that earthquakes rupture with different degrees of complexity and we believe that larger earthquake rupture in more complex ways. This would however violate the common assumption of self-similarity of earthquakes across magnitudes. Often the choice of the modeled degree of complexity is however dependent on expert knowledge. Therefore i am looking for data driven ways to help us evaluate possibly rupture segmentation. Also I focus on small to medium sized earthquakes to investigate if we can resolve any complex ruptures from them or if they do not exhibit such behavior. I am using InSAR, GPS and seismological data.

    To asses the evolution of an earthquake rupture in time i have developed a multi-array backprojection code, which is available on github: Palantiri