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Investigation of the Moho Discontinuity Beneath the Chinese Mainland Using Deep Seismic Sounding Profiles
Tectonophysics 609 (2013) 202–216 Contents lists available at ScienceDirect Tectonophysics journal homepage: www.elsevier.com/locate/tecto Review Article Investigation of the Moho discontinuity beneath the Chinese mainland using deep seismic sounding profiles Jiwen Teng a,⁎, Zhongjie Zhang a, Xiankang Zhang b, Chunyong Wang c, Rui Gao d, Baojun Yang e, Yonghu Qiao a, Yangfan Deng f a State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China b Center of Geophysical Exploration, China Earthquake Administration, Zhengzhou 450002, Henan Province, China c Institute of Geophysics, China Earthquake Administration, Beijing 100081, China d Institute of Geology, Chinese Academy of Geology Science, Ministry of the Land and Resources, Beijing 100037, China e Department of Geophysics, Jilin University, Changchun, Jilin Province, 130026, China f Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China article info abstract Article history: We herein describe the depth distribution of the Moho beneath the Chinese mainland, determined via compila- Received 4 March 2012 tion and resampling of the interpreted results of crustal P-wave velocity structures obtained from deep seismic Received in revised form 5 November 2012 soundings (DSSs) performed since the pioneering DSS work carried out in the Qaidam basin in 1958. For the Accepted 22 November 2012 present study, 114 wide-angle seismic profiles acquired over the last 50 years were collated; we included results Available online 2 December 2012 for crustal structures from several profiles in Japan and South Korea, to improve the reliability of the interpolation of the Moho depth distribution. Our final Moho map shows that the depth of the Moho ranges from 10 to 85 km. -
Effects of the 25 April 2015 Nepal Great Earthquake on The
1 Damages induced by the 25 April 2015 Nepal earthquake in the 2 Tibetan border region of China and increased post-seismic 3 hazards 4 5 Zhonghai Wu a Guanghao Haa, Patrick J. Barosh b, Xin Yao a, Yongqiang Xu c and Jie 6 Liu d 7 8 a Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 9 100081, China 10 b P.J. Barosh and Associates, 103 Aaron Avenue, Bristol, RI 02809, USA and Visiting 11 Research Fellow, Chinese Academy of Geological Sciences, Beijing 100081 12 China 13 c China Institute of Geo-environment Monitoring, Beijing 100081, China 14 d College of Resource Environment and Tourism, Capital Normal University, Beijing 15 100048, China 16 17 Abstract: The seismic effects in Nyalam, Gyirong, Tingri and Dinggye counties along 18 the southern border of Tibet were investigated during 2-8 May, 2015, a week after the 19 great Nepal earthquake along the Main Himalaya Thrust. The intensity was VIII in the 20 region and reached IX at two towns on the Nepal border; resulting in the destruction of 21 2,700 buildings, seriously damaging over 40,000 others, while killing 27 people and 22 injuring 856 in this sparsely populated region. The main geologic effects in this steep 23 rugged region are collapses, landslides, rockfalls, and ground fissures; many of which 24 are reactivations of older land slips. These did great damage to the buildings, roads and 25 bridges in the region. Most of the effects are along four incised valleys which are 26 controlled by N-trending rifts and contain rivers that pass through the Himalaya 27 Mountains and flow into Nepal; at least two of the larger aftershocks occurred along the 28 normal faults. -
Active and Passive Seismic Investigation of Structure of Orogenic Lithosphere in Asia and South America
ACTIVE AND PASSIVE SEISMIC INVESTIGATION OF STRUCTURE OF OROGENIC LITHOSPHERE IN ASIA AND SOUTH AMERICA A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Chen Chen January 2015 © 2015 Chen Chen ACTIVE AND PASSIVE SEISMIC INVESTIGATION OF STRUCTURE OF OROGENIC LITHOSPHERE IN ASIA AND SOUTH AMERICA Chen Chen, Ph. D. Cornell University 2015 Asia and South America possess the two iconic orogenic belts – Himalayas and Andes and two largest and highest plateaus – Tibetan Plateau and Puna Plateau on the earth. Their lithospheres were formed under continental-continental collision and ocean-continent subduction regimes respectively. Seismic images of their current lithospheric structure provide key insights into the current stage in their evolutionary process. Lithospheric structure beneath the Tibetan Plateau has been studied using deep seismic reflection profiling since the beginning of the INDEPTH project in 1992. This international effort led by consortium of Chinese and western academic institutions, continued over 25 years in four different phases. Key features spanned by this megatransect include the Main Himalaya Thrust (MHT) at the southern margin of the plateau, crustal seismic bright spots in the south and central part of the plateau, Moho topography across the plateau and especially an abrupt step in the Moho beneath the northeastern margin of the Plateau beneath the Qaidam Basin. A recent reflection profile by the SINOPROBE Project across the Sichuan Basin located at the southeast edge of the Tibetan Plateau, reveals sub-crustal dipping reflectors which are very likely to result from Neo-Proterozoic subduction beneath the Sichuan Basin. -
China National Report on Geodesy
2007-2010 China National Report on Geodesy For The XXV General Assembly of IUGG Melbourne, Australia, 27 June - 8 July 2011 By Chinese National Committee for The International Union of Geodesy and Geophysics Beijing, China June, 2011 2007-2010 China National Report on Geodesy by Chinese National Committee for IAG CONTENTS 1. Preface CHENG Pengfei and DANG Yamin 2. Modernization of China Geodetic Datum (2000-2010) CHEN Junyong, ZHANG Peng, ZHANG Yanping and DANG Yamin 3. The development of Compass/Beidou Satellite Navigation System TANG Jing, GE Xia, GAO Weiguang and YANG Yuanxi 4. Chinese Geodetic Coordinate System 2000 CHENG Pengfei, YANG Yuanxi, CHENG Yingyan, WEN Hanjiang, BEI Jinzhong and WANG Hua 5. The Data Processing and Analysis of National GNSS CORS Network in China DANG Yamin, ZHANG Peng, JIANG Zhihao and BEI Jinzhong 6. Progress in the Research on Earth Gravity Field of China NING Jinsheng, LI Jiancheng,CHAO Dingbo,JIN Taoyong and SHEN Wenbin 7. Progress in Geoid Determination Research Areas in China LI Jiancheng,CHAO Dingbo,SHEN Wenbin,ZHANG Shoujian,ZOU Xiancai,JIANG Weiping and YAO Yibin 8. National Report on Absolute and Superconducting Gravimetry SUN Heping, WANG Yong, XU Jianqiao, ZHANG Weimin and ZHOU Jiangcun 9. Progress of Underwater Gravity-aided Inertial Navigation WU Xiaoping and LI Shanshan 10. Crustal Deformation Monitoring and Geodynamic Mechanism Study in China XU Caijun and WEN Yangmao 11. Progress of Geodetic Data Processing Theory and Method in China ZHANG Liping and YANG Yuanxi 12. Some Activities of Astro-Geodynamics in China during 2007-2010 HUANG Chengli, WANG Guangli, WANG Xiaoya, WU Bin and ZHOU Yonghong 13. -
Sino-Tibetan Relations 1990-2000: the Internationalisation of the Tibetan Issue
Sino-Tibetan Relations 1990-2000: the Internationalisation of the Tibetan Issue Inauguraldissertation zur Erlangung des Grades eines Doktors der Philosophie dem Fachbereich Gesellschaftswissenschaften und Philosophie der Philipps-Universität Marburg vorgelegt von Tsetan Dolkar aus Dharamsala, Indien 29 Februar 2008 Erstgutachter: Prof. Dr. Dirk Berg-Schlosser Zweitgutachter: Prof. Dr. Wilfried von Bredow Sino-Tibetan Relations 1990-2000: the Internationalisation of the Tibetan Issue Submitted by Tsetan Dolkar Political Science Department, Philipps University First Advisor: Professor Dr. Dirk Berg-Schlosser Second Advisor: Professor Dr. Wilfried von Bredow A dissertation submitted to the Faculty of the Social Sciences and Philosophy of Philipps University in partial fulfillment of requirements for the degree of Doctor of Philosophy Department of Political Science Philipps University, Marburg 29 February 2008 TABLE OF CONTENTS Acknowledgement vi Maps viii List of Abbreviations xi PART I A GLIMPSE INTO TIBET’S PAST Chapter 1 Tibet: A Brief Historical Background 1 1.1.1 Introduction 1 1.1.2 Brief Historical Background 4 1.1.2.1 Tibetan Kings (624-842 AD) and Tang China (618-756 AD) 4 1.1.2.2 The Buddhist Revolution in Tibet (842-1247) and the Song Dynasty (960-1126) 8 1.1.2.3 The Sakya Lamas of Tibet (1244-1358) and the Mongol Empire (1207-1368) 10 1.1.2.4 The Post-Sakya Tibet (1337-1565) and the Ming China (1368-1644) 11 1.1.2.5 The Gelugpa’s Rule (1642-1950) and the Manchu Empire (1662-1912) 13 1.1.2.6 Tibet in the Twentieth Century 19 -
Earthquake Cycle Deformation and the Moho: Implications for the Rheology of Continental Lithosphere
Tectonophysics 609 (2013) 504–523 Contents lists available at ScienceDirect Tectonophysics journal homepage: www.elsevier.com/locate/tecto Review Article Earthquake cycle deformation and the Moho: Implications for the rheology of continental lithosphere Tim J. Wright a,⁎,JohnR.Elliottb, Hua Wang c, Isabelle Ryder d a COMET+, School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK b COMET+, Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, UK c Department of Surveying Engineering, Guangdong University of Technology, Guangzhou, China d School of Environmental Sciences, 4 Brownlow St, University of Liverpool, L69 3GP, UK article info abstract Article history: The last 20 years has seen a dramatic improvement in the quantity and quality of geodetic measurements of the Received 18 June 2012 earthquake loading cycle. In this paper we compile and review these observations and test whether crustal thick- Received in revised form 20 July 2013 ness exerts any control. We found 78 earthquake source mechanisms for continental earthquakes derived from Accepted 22 July 2013 satellite geodesy, 187 estimates of interseismic “locking depth”, and 23 earthquakes (or sequences) for which Available online 6 August 2013 postseismic deformation has been observed. Globally we estimate seismogenic thickness to be 14 ± 5 and 14 ± 7 km from coseismic and interseismic observations respectively. We find that there is no global relation- Keywords: Moho ship between Moho depth and the seismogenic layer thickness determined geodetically. We also found no Crustal deformation clear global relationship between seismogenic thickness and proxies for the temperature structure of the crust. Geodesy This suggests that the effect of temperature, so clear in oceanic lithosphere, is masked in the continents by consid- Continental rheology erable variation in lithology, strain-rate, and/or grain size. -
Normal Faulting Movement During the 2020 Mw 6.4 Yutian Earthquake: a Shallow Rupture in NW Tibet Revealed by Geodetic Measurements
Normal Faulting Movement During the 2020 Mw 6.4 Yutian Earthquake: A Shallow Rupture in NW Tibet Revealed by Geodetic Measurements Jiansheng Yu Institute of Seismology China Earthquake Administration https://orcid.org/0000-0002-4483-8695 Dongzhen Wang Institute of Seismology China Earthquake Administration Bin Zhao ( [email protected] ) China Earthquake Administration https://orcid.org/0000-0002-0484-592X Li Qi Institute of Seismology China Earthquake Administration Full paper Keywords: The 2020 Yutian earthquake, Normal faulting, Bayesian approach, slip distributionCoulomb stress changes, NW Tibetan Plateau Posted Date: December 4th, 2020 DOI: https://doi.org/10.21203/rs.3.rs-120305/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Page 1/24 Abstract The ENE striking Longmu Co fault and the North Altyn Tagh left-lateral slip fault have led to the complex regional structure in the northwestern Tibetan Plateau, resulting in a series of normal faulting and strike slip faulting earthquakes. Using both the ascending and descending Sentinel-1A/B radar images, we depict the coseismic deformation caused by the 2020 Yutian Mw 6.4 earthquake with a peak subsidence of ~20 cm. We determine the seismogenic fault geometry by applying the Bayesian approach with a Markov Chain Monte Carlo sampling method, which enables us to nd the posterior probability density functions of the source model parameters. The estimation results reveal that the earthquake have dominantly by normal slip with moderate strike slip component. Based on the optimal fault geometry model, we extend the fault plane and invert for the nite fault model dislocation, which indicate that the slip is mainly concentrated at a shallow focal depth of 3–10 km with a maximum slip of ~1.0 m. -
Tracking the Steel Dragon
TRACKING THE STEEL DRAGON How China’s economic policies and the railway are transforming Tibet A report by the International Campaign for Tibet Washington, DC l Amsterdam l Berlin l Brussels www.savetibet.org Acknowledgements We are indebted to a number of individuals who contributed original material, infor- mation and advice, and without whom this report would not have been possible. Due to the political environment in Tibet and the restrictions placed on information gathering and the expression of views, it is not possible to name many of our sources and advisors. In addition, in some places in the report, ICT has deliberately changed names and other information which could be used to identify sources. Even though their names are not listed here, ICT wishes to acknowledge their invaluable contributions and their gen- erosity — in particular, some Tibetan friends for sharing their in-depth knowledge and understanding of the current situation on the plateau — their insights were invaluable. A special thanks to our Tibetan field team in India and Nepal for their dedication under often difficult circumstances, determination and high quality research. This report was written in-house at ICT’s DC office and indispensable groundwork was laid by Gabriel Lafitte in the provision of sources, analysis, and notably, original material for the section on environmental impacts of the railroad. We are immensely grateful to Gabriel for his research, writing, and attention to detail. For their invalu- able comments on drafts of the report and provision of material, we’d like to thank the following: Andrew Clark, Susette Cooke, Steven D. -
PDF (Complete Thesis)
Defining the Relationship between Seismicity and Deformation at Regional and Local Scales Thesis by Nneka Njeri Akosua Williams In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy California Institute of Technology Pasadena, California 2013 (Defended August 14, 2012) ii c 2013 Nneka Njeri Akosua Williams All Rights Reserved iii Acknowledgements There are a whole lot of people I need to thank for helping me make it through Caltech. I would like to start off with my advisor Professor Brian Wernicke. He has always been incredibly supportive and understanding. I want to thank him for being tolerant of my flaws and being a generally fun person to be around. I also want to thank Professor Don Helmberger for posing brilliant questions that keep me thinking for weeks (and sometimes months!). He also has a great sense of humor that has always kept me at ease. Professor Joann Stock has always been had door open for me, whether I want to talk about science or life, and I am very thankful for that as well. I would also like to thank Professor Paul Asimow for asking tough questions that make me squirm but also make me think. I truly feel that he has helped me to become a better scientist. Lastly, I like to thank Professor Tom Heaton for helping me to improve my knowledge of seismology when I needed it most. As for folks who are not professors, I would like to thank Shengji Wei for putting up with me and my incessant questions when I did not know how to code my way out of a paper bag and for helping me figure out why my microseismic data refused to run with CAP. -
Relation Between the Characteristics of Strong Earthquake Activities in Chinese Mainland and the Wenchuan Earthquake∗
Earthq Sci (2009)22: 505−518 505 Doi: 10.1007/s11589-009-0505-4 Relation between the characteristics of strong earthquake activities in Chinese mainland ∗ and the Wenchuan earthquake Xiaodong Zhang 1, Guohua Yang 2 Xian Lu 1 Mingxiao Li 1 and Zhigao Yang 1 1 China Earthquake Networks Center, Beijing 100045, China 2 First Crustal Deformation Monitor and Observation Center, China Earthquake Administration, Tianjin 300180, China Abstract This paper studies the relations between the great Wenchuan earthquake and the active-quiet periodic character- istics of strong earthquakes, the rhythmic feature of great earthquakes, and the grouped spatial distribution of MS8.0 earthquakes in Chinese mainland. We also studied the relation between the Wenchuan earthquake and the stepwise migration characteristics of MS≥7.0 earthquakes on the North-South seismic belt, the features of the energy releasing acceleration in the active crustal blocks related to the Wenchuan earthquake and the relation between the Wenchuan earthquake and the so called second-arc fault zone. The results can be summarized as follows: 1 the occurrence of the Wenchuan earthquake was consistent with the active- quiet periodic characteristics of strong earthquakes; 2 its occurrence is consistent with the features of grouped occurrence of MS8.0 earthquakes and follows the 25 years rhythm (each circulation experiences the same time) of great earthquakes; 3 the Wenchuan MS8.0 earthquake follows the well known stepwise migration feature of strong earthquakes on the North-South seismic -
Effects of the 25 April 2015 Nepal Great Earthquake on the Tibetan
1 Effects of the 25 April 2015 Nepal earthquake in the Tibetan 2 border region of China and increased post-seismic hazards 3 4 Zhonghai Wu a* Patrick J. Barosh b, Xin Yao a, Yongqiang Xu c, Guanghao Ha a and Jie 5 Liu d 6 7 a Key Laboratory of Neotectonic Movement & Geohazard, Ministry of Natural 8 Resources, Institute of Geomechanics, Chinese Academy of Geological Sciences, 9 Beijing 100081, China 10 b P.J. Barosh and Associates, 103 Aaron Avenue, Bristol, RI 02809, USA and Visiting 11 Research Fellow, Chinese Academy of Geological Sciences, Beijing 100081 12 China 13 c China Institute of Geo-environment Monitoring, Beijing 100081, China 14 d College of Resource Environment and Tourism, Capital Normal University, Beijing 15 100048, China 16 17 Abstract: The seismic effects in Nyalam, Gyirong, Tingri and Dinggye counties along 18 the southern border of Tibet were investigated during 2-8 May, 2015, a week after the 19 great Nepal earthquake along the Main Himalaya Thrust. The intensity was VIII in the 20 region and reached IX at two towns on the Nepal border; resulting in the destruction of 21 2,700 buildings, seriously damaging over 40,000 others, while killing 27 people and 22 injuring 856 in this sparsely populated region. The main geologic effects in this steep 23 rugged region are collapses, landslides, rockfalls, and ground fissures; many of which 24 are reactivations of older land slips. These did great damage to the buildings, roads and 25 bridges in the region. Most of the effects are along four incised valleys which are 26 controlled by N-S trending rifts and contain rivers that pass through the Himalaya 27 Mountains and flow into Nepal; at least two of the larger aftershocks occurred along the 28 normal faults. -
Investigating the Earthquake Cycle of Normal Faults
Department of Earth, Ocean and Ecological Sciences School of Environmental Sciences University of Liverpool Investigating the earthquake cycle of normal faults Thesis submitted in accordance with the requirements of the University of Liverpool for the degree of Doctor in Philosophy by Lidong Bie August 2015 Supervised by Dr Isabelle Ryder and Prof. Andreas Rietbrock To my grandparents, for their love and wisdom Investigating the earthquake cycle of normal faults Lidong Bie Geodetic observations of crustal deformation through the earthquake cycle provide unique opportunities to gain essential knowledge of faulting mechanisms, lithospheric rheology, and fault interaction. Normal faults, an integral geologic unit responsible for crustal deformation, are specifically investigated in this thesis, via three case studies in two significantly different tectonic environments: the 2008 Mw 6.3 Damxung and Mw 7.1 Yutian earthquakes on the Tibetan Plateau, and the 2005 Mw 7.8 Tarapaca earthquake in the northern Chile subduction zone. To move toward realistic slip models, I consider crustal layering for the Damxung earthquake, and non-planar rupture for the Yutian earthquake. The Damxung study shows that assuming a homogeneous crust underestimates the depth of slip and overestimates the magnitude, in comparison to a crustal model with a weak sedimentary lid. A curved fault model composed of triangular dislocation elements (TDEs) for the Yutian earthquake recovers the geodetic observation better than rectangular fault segments. Normal faulting earthquakes are characterized by shallow slip deficit, which is partially compensated by patchy afterslip around, but no deeper than, the coseismic rupture. The complementary and partially-overlapping relationship between coseismic slip and afterslip implies complexity of frictional properties in both down-dip and along- strike directions.