SPRINGER BRIEFS IN EARTH SCIENCES Zhongliang Wu Changsheng Jiang Xiaojun Li Guangjun Li Zhifeng Ding Earthquake Phenomenology from the Field The April 20, 2013, Lushan Earthquake SpringerBriefs in Earth Sciences For further volumes: http://www.springer.com/series/8897 Zhongliang Wu · Changsheng Jiang · Xiaojun Li Guangjun Li · Zhifeng Ding Earthquake Phenomenology from the Field The April 20, 2013, Lushan Earthquake 1 3 Zhongliang Wu Guangjun Li Changsheng Jiang Earthquake Administration of Sichuan Xiaojun Li Province Zhifeng Ding Chengdu China Earthquake Administration China Institute of Geophysics Beijing China ISSN 2191-5369 ISSN 2191-5377 (electronic) ISBN 978-981-4585-13-2 ISBN 978-981-4585-15-6 (eBook) DOI 10.1007/978-981-4585-15-6 Springer Singapore Heidelberg New York Dordrecht London Library of Congress Control Number: 2014939941 © The Author(s) 2014 This work is subject to copyright. 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Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) Dedicated to Jiayong He (1962–2014) one of the active team members of the Field Investigation of the 2013 Lushan Earthquake Contents 1 The April 20, 2013, Lushan, Sichuan, China, Earthquake: An Overview .................................... 1 1.1 Parameters of the Earthquake ............................... 1 1.2 Disasters of the Earthquake and Timeliness of the Emergency Response ................................ 6 1.2.1 Emergency Response to the Earthquake ................ 6 1.2.2 Disasters of the Lushan Earthquake Testing the Wenchuan Reconstruction ........................ 9 1.3 Studies on the Earthquake ................................. 10 1.4 Summary .............................................. 11 References .................................................. 11 2 The Field Investigation of the Earthquake ....................... 13 2.1 Scientific Issues Related to the Field Investigation .............. 13 2.2 The Field Investigation of the 2013 Lushan Earthquake .......... 16 2.2.1 Field Investigation in the Stage of Earthquake Emergency ........................... 16 2.2.2 Post-Earthquake Field Investigation and Studies .......... 18 2.3 Concluding Remarks ..................................... 21 References .................................................. 21 3 Tectonic Setting of the Earthquake ............................. 23 3.1 Geodynamic Background .................................. 23 3.2 The Seismo-Tectonics of the Lushan Earthquake: Different Views, and Their Evidences ........................ 24 3.2.1 Surface Rupture and Active Faults ..................... 24 3.2.2 Deep Structure of the Vicinity of the Seismic Source ...... 26 3.2.3 The Lushan Puzzle ................................. 28 3.3 Summary and Discussion .................................. 28 3.3.1 The Blind-Lame Combination of Seismology and Tectonics ......................... 28 3.3.2 The Role of the ‘Missing Earthquakes’ in Seismic Hazard Assessment ........................ 30 References .................................................. 30 vii viii Contents 4 Aftershock Sequence: Monitoring and Analysis .................. 33 4.1 Introduction ............................................ 33 4.2 Aftershock Monitoring .................................... 34 4.3 Relocation of the Aftershocks .............................. 36 4.4 Statistical Analysis of Sequence Parameters by Fitting the ETAS Model ................................ 37 4.4.1 The Epidemic-Type Aftershock Sequence Model ......... 37 4.4.2 ETAS Parameters in the Early Stage of the Lushan Earthquake Sequence ................... 39 4.5 Summary and Discussion .................................. 40 References .................................................. 44 5 An Aftershock of the 2008 Wenchuan Earthquake? ............... 47 5.1 Introduction: Pros and Cons Regarding to Whether the Lushan Earthquake is One of the Late Aftershocks of the Wenchuan Earthquake ............................... 47 5.1.1 The Lushan Earthquake is an Aftershock of the Wenchuan Earthquake ......................... 48 5.1.2 The Lushan Earthquake is Not an Aftershock of the Wenchuan Earthquake ......................... 48 5.1.3 The Lushan Earthquake is a ‘New’ Mainshock ........... 48 5.1.4 The Lushan Earthquake is Not a New Mainshock ......... 49 5.2 The 2008 Wenchuan Earthquake, and Its Aftershocks ............ 49 5.2.1 The May 12, 2008, Wenchuan Earthquake ............... 49 5.2.2 The Aftershocks of the Wenchuan Earthquake ............ 50 5.3 The Relationship Between the Lushan Earthquake and the Wenchuan Earthquake from a Statistical Viewpoint ....... 54 5.3.1 Space-Time Epidemic Type Aftershock Sequence Model and Stochastic Declustering Method ............. 54 5.3.2 Probability for the Lushan Earthquake as an Aftershock, and Contribution of the Wenchuan Earthquake to the Occurrence of the Lushan Earthquake ............. 55 5.4 Discussion without Conclusion ............................. 55 References .................................................. 56 6 Scientific Products Serving the Earthquake Emergency ............ 59 6.1 Introduction ............................................ 59 6.2 Timeliness and Contents of the Scientific Products .............. 61 6.2.1 Quickly Determined Parameters ...................... 61 6.2.2 Timeliness of the Scientific Products and On-going Modification .......................... 62 6.3 Maintenance and Quality Control of the Scientific Products ....... 63 6.3.1 Development of the Information Service System ......... 63 6.3.2 The Infrastructure and Organization Bases for the Seismological Information Service ............... 64 Contents ix 6.4 Discussion: From Basic Science to Application— The Technology Readiness Level Related to the Seismological Information Service .......................... 65 6.5 Summary .............................................. 69 References .................................................. 69 7 An Earthquake Occurred in the Time of the Internet and the Microblog/Twitter .................................... 71 7.1 The Microblog (Weibo) ................................... 71 7.1.1 Introduction ...................................... 71 7.1.2 The Performance of the Microblogs in Reporting the Lushan Earthquake ................... 72 7.1.3 Discussion ....................................... 74 7.2 Death Toll Message from the Internet ........................ 74 7.2.1 Introduction ...................................... 74 7.2.2 Death Toll Message and Its Time Dependence ........... 75 7.2.3 Result and Discussion .............................. 75 7.3 Classroom Evacuation Recordings ........................... 77 7.3.1 Introduction ...................................... 77 7.3.2 Observation ...................................... 78 7.3.3 Discussion ....................................... 80 7.4 Summary .............................................. 80 References .................................................. 81 8 Locally Characterized Seismic Destruction Phenomenology ........ 83 8.1 Seismic Intensity and Strong Ground Motion .................. 83 8.2 Destruction Phenomenology ............................... 84 8.2.1 Residential Buildings ............................... 85 8.2.2 Public Buildings ................................... 88 8.3 Lifeline Systems ......................................... 91 8.3.1 Transportation. 92 8.3.2 Electricity, Telecommunication, Water Supply and Sewage ........................... 94 References .................................................. 96 9 Time-Dependent Seismic Hazard of the Southern Longmenshan Fault Zone and the Sichuan-Yunnan Region: Earthquake Predictability and Its Limit ................................... 99 9.1 The Lushan Earthquake in a CSEP Testing Region .............. 99 9.2 Predictive Assessments of Time-Dependent Seismic Hazard Priori to the Lushan Earthquake