Shortcomings of InSAR for studying megathrust earthquakes: The case of the M w 9.0 Tohoku-Oki earthquake

Handle URI:
http://hdl.handle.net/10754/552116
Title:
Shortcomings of InSAR for studying megathrust earthquakes: The case of the M w 9.0 Tohoku-Oki earthquake
Authors:
Feng, Guangcai; Jonsson, Sigurjon ( 0000-0001-5378-7079 )
Abstract:
Interferometric Synthetic Aperture Radar (InSAR) observations are sometimes the only geodetic data of large subduction-zone earthquakes. However, these data usually suffer from spatially long-wavelength orbital and atmospheric errors that can be difficult to distinguish from the coseismic deformation and may therefore result in biased fault-slip inversions. To study how well InSAR constrains fault-slip of large subduction zone earthquakes, we use data of the 11 March 2011 Tohoku-Oki earthquake (Mw9.0) and test InSAR-derived fault-slip models against models constrained by GPS data from the extensive nationwide network in Japan. The coseismic deformation field was mapped using InSAR data acquired from multiple ascending and descending passes of the ALOS and Envisat satellites. We then estimated several fault-slip distribution models that were constrained using the InSAR data alone, onland and seafloor GPS/acoustic data, or combinations of the different data sets. Based on comparisons of the slip models, we find that there is no real gain by including InSAR observations for determining the fault slip distribution of this earthquake. That said, however, some of the main fault-slip patterns can be retrieved using the InSAR data alone when estimating long wavelength orbital/atmospheric ramps as a part of the modeling. Our final preferred fault-slip solution of the Tohoku-Oki earthquake is based only on the GPS data and has maximum reverse- and strike-slip of 36.0 m and 6.0 m, respectively, located northeast of the epicenter at a depth of 6 km, and has a total geodetic moment is 3.6 × 1022 Nm (Mw 9.01), similar to seismological estimates.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Shortcomings of InSAR for studying megathrust earthquakes: The case of the M w 9.0 Tohoku-Oki earthquake 2012, 39 (10):n/a Geophysical Research Letters
Publisher:
Wiley-Blackwell
Journal:
Geophysical Research Letters
Issue Date:
28-May-2012
DOI:
10.1029/2012GL051628
Type:
Article
ISSN:
00948276
Additional Links:
http://doi.wiley.com/10.1029/2012GL051628
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorFeng, Guangcaien
dc.contributor.authorJonsson, Sigurjonen
dc.date.accessioned2015-05-03T13:26:59Zen
dc.date.available2015-05-03T13:26:59Zen
dc.date.issued2012-05-28en
dc.identifier.citationShortcomings of InSAR for studying megathrust earthquakes: The case of the M w 9.0 Tohoku-Oki earthquake 2012, 39 (10):n/a Geophysical Research Lettersen
dc.identifier.issn00948276en
dc.identifier.doi10.1029/2012GL051628en
dc.identifier.urihttp://hdl.handle.net/10754/552116en
dc.description.abstractInterferometric Synthetic Aperture Radar (InSAR) observations are sometimes the only geodetic data of large subduction-zone earthquakes. However, these data usually suffer from spatially long-wavelength orbital and atmospheric errors that can be difficult to distinguish from the coseismic deformation and may therefore result in biased fault-slip inversions. To study how well InSAR constrains fault-slip of large subduction zone earthquakes, we use data of the 11 March 2011 Tohoku-Oki earthquake (Mw9.0) and test InSAR-derived fault-slip models against models constrained by GPS data from the extensive nationwide network in Japan. The coseismic deformation field was mapped using InSAR data acquired from multiple ascending and descending passes of the ALOS and Envisat satellites. We then estimated several fault-slip distribution models that were constrained using the InSAR data alone, onland and seafloor GPS/acoustic data, or combinations of the different data sets. Based on comparisons of the slip models, we find that there is no real gain by including InSAR observations for determining the fault slip distribution of this earthquake. That said, however, some of the main fault-slip patterns can be retrieved using the InSAR data alone when estimating long wavelength orbital/atmospheric ramps as a part of the modeling. Our final preferred fault-slip solution of the Tohoku-Oki earthquake is based only on the GPS data and has maximum reverse- and strike-slip of 36.0 m and 6.0 m, respectively, located northeast of the epicenter at a depth of 6 km, and has a total geodetic moment is 3.6 × 1022 Nm (Mw 9.01), similar to seismological estimates.en
dc.publisherWiley-Blackwellen
dc.relation.urlhttp://doi.wiley.com/10.1029/2012GL051628en
dc.rightsArchived with thanks to Geophysical Research Lettersen
dc.titleShortcomings of InSAR for studying megathrust earthquakes: The case of the M w 9.0 Tohoku-Oki earthquakeen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalGeophysical Research Lettersen
dc.eprint.versionPublisher's Version/PDFen
kaust.authorFeng, Guangcaien
kaust.authorJonsson, Sigurjonen
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