Delineating shallow quick-clay structures using acoustic full-waveform inversion – case studyfrom southwest Sweden
2013 (English)Conference paper, Abstract (Refereed)
Full waveform inversion (FWI) was applied to imageshallow structures of marine-clay sediments and to provideinsight on the mechanism of a quick-clay landslide. Thedata was acquired in a high-resolution seismic surveyconducted over a known landslide scar near the Göta riverin southwest Sweden. Inversion proved to be challengingbecause of contrasted P-wave velocity structure – thevelocities ranged from 500 m/s in weathered top layer to6000 m/s in the shallow granitic bedrock (up to 30 m belowthe surface). FWI applied to 3 profiles provided highresolution2D P-wave velocity models revealing theintercalating layers of clays and coarse-grain material andthe shape of the bedrock. The multiscale approach was usedto mitigate the strong nonlinearity of the inverse problem.The models were used in pre-stack depth migration andproved significant improvement in reflector flattening andfocusing over the starting first-arrival traveltimetomography models.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:uu:diva-286462DOI: 10.1190/segam2013-0437.1OAI: oai:DiVA.org:uu-286462DiVA: diva2:921547
SEG Houston 2013 Annual Meeting