Seismic wave attenuation from borehole and surface records in the top 2.5 km beneath the city of Basel, Switzerland

Handle URI:
http://hdl.handle.net/10754/554372
Title:
Seismic wave attenuation from borehole and surface records in the top 2.5 km beneath the city of Basel, Switzerland
Authors:
Bethmann, Falko; Deichmann, Nicholas; Mai, Paul Martin ( 0000-0002-9744-4964 )
Abstract:
We investigate attenuation (Q−1) of sediments of 2.5–3.5km thickness underneath the city of Basel, Switzerland. We use recordings of 195 induced events that were obtained during and after the stimulation of a reservoir for a Deep Heat Mining Project in 2006 and 2007. The data set is ideally suited to estimate Q as all events are confined to a small source volume and were recorded by a dense surface network as well as six borehole sensors at various depths. The deepest borehole sensor is positioned at a depth of 2.7km inside the crystalline basement at a mean hypocentral distance of 1.8km. This allows us to measure Q for frequencies between 10 and 130 Hz. We apply two different methods to estimate Q. First, we use a standard spectral ratio technique to obtain Q, and as a second measure we estimate Q in the time domain, by convolving signals recorded by the deepest sensor with a Q operator and then comparing the convolved signals to recordings at the shallower stations. Both methods deliver comparable values for Q. We also observe similar attenuation for P- and S- waves (QP∼QS). As expected, Q increases with depth, but with values around 30–50, it is low even for the consolidated Permian and Mesozoic sediments between 500 and 2700 m.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Seismic wave attenuation from borehole and surface records in the top 2.5 km beneath the city of Basel, Switzerland 2012, 190 (2):1257 Geophysical Journal International
Publisher:
Oxford University Press (OUP)
Journal:
Geophysical Journal International
Issue Date:
Aug-2012
DOI:
10.1111/j.1365-246X.2012.05555.x
Type:
Article
ISSN:
0956540X
Additional Links:
http://gji.oxfordjournals.org/cgi/doi/10.1111/j.1365-246X.2012.05555.x
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorBethmann, Falkoen
dc.contributor.authorDeichmann, Nicholasen
dc.contributor.authorMai, Paul Martinen
dc.date.accessioned2015-05-21T07:05:07Zen
dc.date.available2015-05-21T07:05:07Zen
dc.date.issued2012-08en
dc.identifier.citationSeismic wave attenuation from borehole and surface records in the top 2.5 km beneath the city of Basel, Switzerland 2012, 190 (2):1257 Geophysical Journal Internationalen
dc.identifier.issn0956540Xen
dc.identifier.doi10.1111/j.1365-246X.2012.05555.xen
dc.identifier.urihttp://hdl.handle.net/10754/554372en
dc.description.abstractWe investigate attenuation (Q−1) of sediments of 2.5–3.5km thickness underneath the city of Basel, Switzerland. We use recordings of 195 induced events that were obtained during and after the stimulation of a reservoir for a Deep Heat Mining Project in 2006 and 2007. The data set is ideally suited to estimate Q as all events are confined to a small source volume and were recorded by a dense surface network as well as six borehole sensors at various depths. The deepest borehole sensor is positioned at a depth of 2.7km inside the crystalline basement at a mean hypocentral distance of 1.8km. This allows us to measure Q for frequencies between 10 and 130 Hz. We apply two different methods to estimate Q. First, we use a standard spectral ratio technique to obtain Q, and as a second measure we estimate Q in the time domain, by convolving signals recorded by the deepest sensor with a Q operator and then comparing the convolved signals to recordings at the shallower stations. Both methods deliver comparable values for Q. We also observe similar attenuation for P- and S- waves (QP∼QS). As expected, Q increases with depth, but with values around 30–50, it is low even for the consolidated Permian and Mesozoic sediments between 500 and 2700 m.en
dc.publisherOxford University Press (OUP)en
dc.relation.urlhttp://gji.oxfordjournals.org/cgi/doi/10.1111/j.1365-246X.2012.05555.xen
dc.rightsArchived with thanks to Geophysical Journal International © 2012 The Authors Geophysical Journal International © 2012 RASen
dc.subjectFourier analysisen
dc.subjectSeismic wave attenuationen
dc.subjectWave propagationen
dc.titleSeismic wave attenuation from borehole and surface records in the top 2.5 km beneath the city of Basel, Switzerlanden
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalGeophysical Journal Internationalen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionGeo-Energie Suisse AG, Reitergasse 11, 8004 Zurich, Switzerlanden
dc.contributor.institutionInstitute of Geophysics, Swiss Seismological Service, ETH Zurich, NO, Sonneggstrasse 5, 8092 Zurich, Switzerlanden
kaust.authorMai, Paul Martinen
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.