Extension On The Tibetan Plateau: Recent Normal Faulting .

Transcription

submitted to Phys. Earth. Planet. Int.Extension on the Tibetan Plateau: Recent Normal Faultingmeasured by InSAR & Body-Wave SeismologyJ.R. Elliott1 , R.J. Walters1 , P.C. England1 , J.A. Jackson2 , Z. Li3 , B. Parsons11COMET, Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK.E-mail: john.elliott@earth.ox.ac.uk2COMET, Department of Earth Sciences, Bullard Laboratories, Madingley Road, Cambridge, CB3 0EZ, UK.3COMET, Department of Geographical and Earth Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.27 July 20101Supporting Information2This file contains the on-line only appendices. Appendix C contains the seismological body wave3solutions for each event. Appendix D includes the interferogram figures used in the fault modelling4of the Yutian and Zhongba 2008/2005 earthquakes that are not present in the main body of the pa-5per. Appendix E contains the SAR time coverages for each of the eight events. Appendix F presents6tables of slip distributions for the Yutian, all three Zhongba and both the Gerze earthquakes from7the InSAR distributed slip modelling.

2Elliott et al.8APPENDIX C: BODY-WAVE MODELLING9Seismological body-wave modelling is presented for each earthquake in this appendix. In each10case the model is calculated from the inversion of P and SH body-waves for a point source in a11half-space. Focal mechanisms show P (top) and SH (bottom) nodal planes in a lower hemisphere12projection. Closed and open circles represent the P - and T - axes respectively. Waveforms for each13station are plotted around the focal mechanisms in approximate azimuthal locations. Observed14waveforms are solid and synthetic waveforms are dashed, whilst the vertical ticks mark the in-15version window. The station code is to the left of each waveform, in vertical capital letters. The16vertical bar and number beside each focal sphere is the amplitude scale for the plotted seismo-17grams (in µm). The STF is the source-time function, and the scale bar below it is the horizontal18scale for the seismograms. The numbers in the header are strike, dip, rake, centroid depth (km),19and moment (Nm) for the best-fit solution. For the 2008 Yutian and Zhongba earthquakes, two20fault segment solutions are also given.

AYLdERLEdRPKAdFVWXABCDETUSQRPOFHGNMILK JRAEdSE8s STF40sAXLdPLAdFWX CUTV YA BDEFSRHGQPO INML KEdRSTVW BCPDMOQRU A ENKLJIHFGIANdK00KTEdVCJOdCOY ACXW Z BEDFUVSRTQPNOM GLK JI HTAIdXIWFRdABKVBdSMDDdJXIYCAdK8s SUUdMGAWLdEKHAdPIEERdMYCAdK16th January 2008 earthquake.Figure C.1 Body-wave minimum misfit solutions for the (left) Mw 6.4 Gerze county 9th January 2008 earthquake, (right) Mw 5.9 Gerze 0116 Tibet Gaize080109 Tibet GaizeExtension on the Tibetan Plateau: Recent Normal Faulting3

Elliott et VUdWRLEdR00RYEdSRNEdRTAIdXIACVWX YBDEFTUSRGQON HPIML KJ30s STF60sTAIdXI*VWXY ABCDEFSTURGPQOIHKJN TdAOPJSdITGAdTOKBDdAKMEDdJ080320 Tibet Yutian DdITGAdTOTPSdUMMEIdDWWIRdABITDdI080320 Tibet Yutian 95/6/8.524E18TAIdXIACVWX YBDEFTUSRGQON HPIML KJ25s STF60sTAIdXI*VWXY ABCDEFSTURGPQOIHKJN dSRNEdRKJAdPIUKGdMthose calculated from InSAR, and only centroid depth and moment were solved for in the JAdPIUKGdMsegment fault model (right) in the south (1: solid) and north (2: dashed). For the two segment model, the fault strike, dip and rake were held toFigure C.2 Body-wave minimum misfit solution for the Mw 7.1 Yutian county 20th March 2008 earthquake for a single fault (left) and a twoCMOdCO*258545d517090d258545d517090d

MPSdEYROEdRWXYABCDEVTUSGHFRQJILKPON SGHFRQJILKPON KTIdEVWRDdDVAYLdEKXBdSRMEdRTUVWXYABCDEFSRQGHPONJIM OKTIdEVWRDdDV14s STF40sKWEdAYLdEKXBdSRMEdRthose calculated from InSAR, and only centroid depth and moment were solved for in the inversion.FPUdRIASQdU25s IM MGHUdMOIFNdCNPDEdTsegment fault model in the south (1: solid) and north (2: dashed) (right). For the two segment model, the fault strike, dip and rake were held toKQMdBOTSAdMGVRdFOITDdIKXEdVYCAdK5Figure C.3 Body-wave minimum misfit solution for the Mw 6.7 Zhongba county 25th August 2008 earthquake for a single fault (left) and a 07/8/3.196E1825/46/292/8/9.379E1880143dOWBdN080825 Tibet Zhongba double080825 Tibet Zhongba80143dExtension on the Tibetan Plateau: Recent Normal Faulting

Elliott et LWVdZKXBdSIANdKAYLdEMSTdEIQSdPSXUdMGKWEdVVWXY ABRTU CDEFOQPSGHNMLKJITAIdXIAYLdEVWXY BRTU ACDEFPQSHGOMNIL WJRdABNKWdAOSTTdU8s STF40sMCAd2DUSdB00KYBdSARQdU10s STF40sLXVdZMEDdJ00DEUWXABCRQSTVGFPNOLM JIHKIANdK050407 Tibet LIQSdPPSAdBIANdKANTdDTPAdMYDSdSCDEUVWXY KNMdBOSVUdWKUIdEVMFAdJO040711 Tibet UdRIcounty 7th April 2005 earthquake ure C.4 Body-wave minimum misfit solution for the Mw 6.2 Zhongba county 11th July 2004 earthquake (left) and for the Mw 6.2 ZhongbaKMMdBOLLSdZ47590d35692d28296d28296d

KGEdG8s STF40sSNSdTHAdM00OPBdNEQSdKSNSdBOPBdNPLKONMQ A dISTUdWCAOdLTDSdKYBSdSCAOdLSUUdWEOCdHPQ A 0KWBdSVWX BSTU A CDERQPFGOMNIHL KJIANdK10s STF40sCLOdCOVWUT XABCDSRQEPOGFNM GFUdMOPHMdGMDAdJOPCEdTcounty 8th October 2008 earthquake (right).Figure C.5 Body-wave minimum misfit solution for the Mw 6.1 Nyemo county 30th July 1992 earthquake (left) and for the Mw 6.3 006 Tibet Dangxiong920730 Tibet NimuExtension on the Tibetan Plateau: Recent Normal Faulting7

8Elliott et al.21APPENDIX D: ADDITIONAL INTERFEROGRAMS USED IN FAULT MODELLING22This appendix includes the additional interferograms not shown in the main paper used in the23modelling of the Yutian, Zhongba 2008 and 2005 earthquakes.

Extension on the Tibetan Plateau: Recent Normal FaultingInterferogramALOS track 515a81.2 81.4 81.6 Model81.8 81.2 81.4 81.6 9Residuals81.8 81.2 81.4 81.6 81.8 35.6 35.6 1235.4 35.4 335.2 35.2 AzENVISAT track 427alos (i 39 )35.6 35.6 1235.4 35.4 335.2 35.2 AzENVISAT track 155alos (i 41 )35.6 35.6 1235.4 35.4 335.2 35.2 Azlos (i 41 )81.2 81.4 km0 5 1015202581.6 81.8 81.2 81.4 81.6 81.8 81.2 81.4 81.6 81.8 cm 10 8 6 4 2 0 2 4 6 8 10cm 20 1001020Figure D.1. Yutian earthquake interferograms for distributed slip with fixed rake models and residuals.Interferogram and model show range changes as fringes re-wrapped to 10 cm, with colour cycles blue tored indicating motion away from the satellite. Residuals are unwrapped values for clarity. The fault segmentis marked by a solid black line, with the black box indicating the outline of the fault at depth projected tothe surface. Satellite track azimuth (Az) and line-of-sight (LOS) with angle of incidence (i) are indicated byblack arrows.

10Elliott et al.InterferogramENVISAT track 284a80.8 81 81.2 81.4 Model81.6 80.8 81 81.2 Residuals81.4 81.6 80.8 81 81.2 81.4 81.6 35.6 35.6 1235.4 35.4 335.2 35.2 AzENVISAT track 248dlos (i 41 )35.6 35.6 1235.4 35.4 335.2 35.2 los (i 23 )Az80.8 81 81.2 km0 5 1015202581.4 81.6 80.8 81 81.2 81.4 81.6 80.8 cm 10 8 6 4 2 0 2 4 6 8 10 2081 1081.2 081.4 1081.6 cm20Figure D.2. Yutian earthquake interferograms for distributed slip with fixed rake models and residuals.Details as for Figure D.1.

Extension on the Tibetan Plateau: Recent Normal FaultingInterferogramENVISAT track 384a83.4 Model83.8 83.4 83.6 Residuals83.8 83.4 83.6 83.8 31 31 1230.8 30.6 ENVISAT track 391d83.6 1130.8 Az30.6 los (i 41 )31 31 1230.8 30.8 los (i 23 )30.6 30.6 Az83.4 83.6 km0 5 10 15 20 2583.8 83.4 83.6 83.8 cm 5 4 3 2 1 0 1 2 3 4 583.4 10 583.6 083.8 cm510Figure D.3. Zhongba 2008 earthquake interferograms for distributed slip modelling with a fixed rake. Details as for Figure D.1.

12Elliott et al.InterferogramENVISAT track 470a83.6 83.8 Model84 83.6 Residuals83.8 84 83.6 83.8 84 30.6 30.6 30.4 30.4 Az30.2 los (i 41 )83.6 30.2 83.8 84 83.6 83.8 84 83.6 0 5 10 15 20 2583.8 84 cmkm 2 1012cm 6 4 20246Figure D.4. Zhongba 2005 earthquake interferograms for distributed slip modelling with a fixed rake. Details as for Figure D.1.

Extension on the Tibetan Plateau: Recent Normal Faulting1324APPENDIX E: INTERFEROGRAM TIME SPANS25This appendix contains the time span coverage for the interferograms used in each of the eight26earthquakes studied.

14Elliott et al.92 dys, 493 m9 dys315 dys, 22 m70 dys, 8 mAJALOS 509 ASC30 dysOENVI 427 ASC IS625 dysENVI 348 DSC IS2J2007Figure E.1. Time spans for suitable SAR acquisitions for interferometry by track (black horizontal bars) andinstrument covering the coseismic period of the Mw 6.4 Gerze earthquake (black vertical line and star, 2008January 9th ) and the Mw 5.9 Gerze earthquake (black vertical dashed line and smaller star, 2008 January16th ). The time interval between acquisitions and the perpendicular baseline are also indicated in the centreor to the left of the black bar. The number of days after the earthquake on which the second SAR image wasacquired is given to the right of the black bar for each track, indicating the postseismic span covered.67 dys92 dys, 41 m92 dys, 1230 m420 dys, 21 m70 dys, 40 mALOS 515 ASC33 dysENVI 12 ASC IS643 dys175 dys, 123 m15 dys385 dys, 92 mAJ2006ENVI 284 ASC IS697 dys385 dys, 19 mJENVI 155 ASC IS252 dys665 dys, 48 mOALOS 514 ASC38 dysOENVI 248 DSC IS231 dysJA2007ENVI 427 ASC IS2ENVI 477 DSC IS2J2008Figure E.2. Time spans for suitable SAR acquisitions for interferometry by track and instrument coveringthe coseismic period of the 2008 Mw 7.1 Yutian earthquake. Caption as for Figure E.1.66 dys70 dys, 235 m41 dys770 dys, 407 m140 dys, 247 mOJ2006AJOJENVI 384 ASC IS223 dys490 dys, 67 mENVI 119 DSC IS27 dysAJ2007ENVI 241 ASC IS6ENVI 391 DSC IS2OJ2008Figure E.3. Time spans for suitable SAR acquisitions for interferometry by track and instrument coveringthe coseismic period of the 2008 Mw 6.7 Zhongba earthquake. Caption as for Figure E.1.175 dys, 61 m9 dys35 dys, 231 mAMJJASENVI 26 ASC IS620 dysOENVI 176 DSC IS2N2008Figure E.4. Time spans for suitable SAR acquisitions for interferometry by track and instrument coveringthe coseismic period of the 2008 Mw 6.3 Damxung earthquake. Caption as for Figure E.1.

Extension on the Tibetan Plateau: Recent Normal Faulting315 dys, 1176 m128 dys245 dys, 128 mENVI 470 ASC IS687 dysENVI 384 ASC IS2105 dys, 52 m 69 dys455 dys, 145 m175 dys, 70 mAJENVI 119 DSC IS2322 dysENVI 384 ASC IS259 dysO15ENVI 119 DSC IS2JA2004JO2005Figure E.5. Time spans for suitable SAR acquisitions for interferometry by track and instrument coveringthe coseismic period of the 2004 and 2005 Mw 6.2 Zhongba earthquakes. Caption as for Figure E.1.175 dys, 76 mJ133 dysOERS 1 176 DSC IS2J1992Figure E.6. Time spans for suitable SAR acquisitions for interferometry by track and instrument coveringthe coseismic period of the 1992 Mw 6.1 Nyemo earthquake. Caption as for Figure E.1.

16Elliott et al.27APPENDIX F: FAULT SLIP DISTRIBUTIONS28This appendix contains the fault slip distributions for the InSAR distributed slip models for the292008, 2005 and 2004 Zhongba, Yutian and Gerze earthquakes.

Extension on the Tibetan Plateau: Recent Normal Faulting17Table F.1. Slip values (metres) for the 2008 Mw 6.7 Zhongba earthquake from the InSAR distributed slipmodel with fixed rake. Values are presented for the two segments with increasing distance from the upperleft corner of the fault along the columns left-to-right, and depth increasing down by row. Segment headerlists fault upper-left corner easting, northing, strike, dip, rake, segment length, segment vertical width (notdown-dip width).Southern Segment — 83.2923E 30.7030N 040 41 306 1 km 1 km0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.03 0.04 0.05 0.07 0.09 0.08 0.05 0.03 0.00 0.00 0.00 0.01 0.01 0.01 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.07 0.10 0.11 0.09 0.07 0.1

Int. Extension on the Tibetan Plateau: Recent Normal Faulting measured by InSAR & Body-Wave Seismology. J.R. Elliott1, R.J. Walters , P.C. England1, J.A. Jackson2, Z. Li3, B. Parsons. 1COMET, Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK. E-mail: john.elliott@earth.ox.ac.uk.