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A New Perspective on Fault Geometry and Slip Distribution of the 2009 Dachaidan Mw 6.3 Earthquake from InSAR Observations.

Liu Y, Xu C, Wen Y, Fok HS - Sensors (Basel) (2015)

Bottom Line: On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake.We then propose a four-segmented fault model to investigate the coseismic deformation by determining the fault parameters, followed by inverting slip distribution.The inverted geodetic moment is 3.85 × 10(18) Nm (Mw 6.36).

View Article: PubMed Central - PubMed

Affiliation: School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China. Yang.Liu@sgg.whu.edu.cn.

ABSTRACT
On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake. This study utilizes the Envisat ASAR images from descending Track 319 and ascending Track 455 for capturing the coseismic deformation resulting from this event, indicating that the earthquake fault rupture does not reach to the earth's surface. We then propose a four-segmented fault model to investigate the coseismic deformation by determining the fault parameters, followed by inverting slip distribution. The preferred fault model shows that the rupture depths for all four fault planes mainly range from 2.0 km to 7.5 km, comparatively shallower than previous results up to ~13 km, and that the slip distribution on the fault plane is complex, exhibiting three slip peaks with a maximum of 2.44 m at a depth between 4.1 km and 4.9 km. The inverted geodetic moment is 3.85 × 10(18) Nm (Mw 6.36). The 2009 event may rupture from the northwest to the southeast unilaterally, reaching the maximum at the central segment.

No MeSH data available.


Related in: MedlinePlus

Interferograms of the descending track T319 (a) and the ascending track T455 (b) for the 2009 Dachaidan Mw 6.3 earthquake. Red arrows point out the deformation boundaries with a South-East-East (SEE) direction between hanging wall and footwall, which are used to determine the fault locations in the inversion step. The deformation zone labeled as A and delimited by the black polygon in (a), isolated from the deformation zone B, may result from atmospheric errors and/or aftershocks. The dashed purple rectangle in (a) is the spatial extent of Figure 8. The dashed black polygons in (a,b) delimit the zones that mainly include contribution from atmospheric errors, DEM errors, and other unknown errors. Epicenters of the main shock from GCMT and USGS catalogues are displayed in (a).
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sensors-15-16786-f002: Interferograms of the descending track T319 (a) and the ascending track T455 (b) for the 2009 Dachaidan Mw 6.3 earthquake. Red arrows point out the deformation boundaries with a South-East-East (SEE) direction between hanging wall and footwall, which are used to determine the fault locations in the inversion step. The deformation zone labeled as A and delimited by the black polygon in (a), isolated from the deformation zone B, may result from atmospheric errors and/or aftershocks. The dashed purple rectangle in (a) is the spatial extent of Figure 8. The dashed black polygons in (a,b) delimit the zones that mainly include contribution from atmospheric errors, DEM errors, and other unknown errors. Epicenters of the main shock from GCMT and USGS catalogues are displayed in (a).

Mentions: Both descending and ascending interferograms were produced from ASAR level 0 (raw data) images using the Caltech/JPL ROI_PAC software [26]. Topographic contributions were removed from the interferograms using the 3 arc-second Digital Elevation Model (DEM) produced by the Shuttle Radar Topography Mission (SRTM) [27]. Precise orbits from European Space Agency (ESA) were used for the orbital corrections. The differential interferograms were then filtered with the power spectrum filter technique [28] and unwrapped with the branch cut method [29]. The two interferometric deformation maps were finally geocoded to geographic coordinate system (Figure 2).


A New Perspective on Fault Geometry and Slip Distribution of the 2009 Dachaidan Mw 6.3 Earthquake from InSAR Observations.

Liu Y, Xu C, Wen Y, Fok HS - Sensors (Basel) (2015)

Interferograms of the descending track T319 (a) and the ascending track T455 (b) for the 2009 Dachaidan Mw 6.3 earthquake. Red arrows point out the deformation boundaries with a South-East-East (SEE) direction between hanging wall and footwall, which are used to determine the fault locations in the inversion step. The deformation zone labeled as A and delimited by the black polygon in (a), isolated from the deformation zone B, may result from atmospheric errors and/or aftershocks. The dashed purple rectangle in (a) is the spatial extent of Figure 8. The dashed black polygons in (a,b) delimit the zones that mainly include contribution from atmospheric errors, DEM errors, and other unknown errors. Epicenters of the main shock from GCMT and USGS catalogues are displayed in (a).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541906&req=5

sensors-15-16786-f002: Interferograms of the descending track T319 (a) and the ascending track T455 (b) for the 2009 Dachaidan Mw 6.3 earthquake. Red arrows point out the deformation boundaries with a South-East-East (SEE) direction between hanging wall and footwall, which are used to determine the fault locations in the inversion step. The deformation zone labeled as A and delimited by the black polygon in (a), isolated from the deformation zone B, may result from atmospheric errors and/or aftershocks. The dashed purple rectangle in (a) is the spatial extent of Figure 8. The dashed black polygons in (a,b) delimit the zones that mainly include contribution from atmospheric errors, DEM errors, and other unknown errors. Epicenters of the main shock from GCMT and USGS catalogues are displayed in (a).
Mentions: Both descending and ascending interferograms were produced from ASAR level 0 (raw data) images using the Caltech/JPL ROI_PAC software [26]. Topographic contributions were removed from the interferograms using the 3 arc-second Digital Elevation Model (DEM) produced by the Shuttle Radar Topography Mission (SRTM) [27]. Precise orbits from European Space Agency (ESA) were used for the orbital corrections. The differential interferograms were then filtered with the power spectrum filter technique [28] and unwrapped with the branch cut method [29]. The two interferometric deformation maps were finally geocoded to geographic coordinate system (Figure 2).

Bottom Line: On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake.We then propose a four-segmented fault model to investigate the coseismic deformation by determining the fault parameters, followed by inverting slip distribution.The inverted geodetic moment is 3.85 × 10(18) Nm (Mw 6.36).

View Article: PubMed Central - PubMed

Affiliation: School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China. Yang.Liu@sgg.whu.edu.cn.

ABSTRACT
On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake. This study utilizes the Envisat ASAR images from descending Track 319 and ascending Track 455 for capturing the coseismic deformation resulting from this event, indicating that the earthquake fault rupture does not reach to the earth's surface. We then propose a four-segmented fault model to investigate the coseismic deformation by determining the fault parameters, followed by inverting slip distribution. The preferred fault model shows that the rupture depths for all four fault planes mainly range from 2.0 km to 7.5 km, comparatively shallower than previous results up to ~13 km, and that the slip distribution on the fault plane is complex, exhibiting three slip peaks with a maximum of 2.44 m at a depth between 4.1 km and 4.9 km. The inverted geodetic moment is 3.85 × 10(18) Nm (Mw 6.36). The 2009 event may rupture from the northwest to the southeast unilaterally, reaching the maximum at the central segment.

No MeSH data available.


Related in: MedlinePlus