ISC-GEM Global Instrumental Earthquake Catalogue (1900-2009) GEM Technical Report 2012-01 V1.0.0 Storchak D.A., D. Di Giacomo, I. Bondár, J. Harris, E.R. Engdahl, W.H.K. Lee, A. Villaseñor, P. Bormann, and G. Ferrari Geological, earthquake and geophysical data GEM GLOBAL EARTHQUAKE MODEL ISC-GEM Global Instrumental Earthquake Catalogue (1900-2009) GEM Technical Report 2012-01 Version: 1.0.0 Date: July 2012 Authors*: Storchak D.A., D. Di Giacomo, I. Bondár, J. Harris, E.R. Engdahl, W.H.K. Lee, A. Villaseñor, P. Bormann, and G. Ferrari (*) Authors’ affiliations: Dmitry Storchak, International Seismological Centre (ISC), Thatcham, UK Domenico Di Giacomo, International Seismological Centre (ISC), Thatcham, UK István Bondár, International Seismological Centre (ISC), Thatcham, UK James Harris, International Seismological Centre (ISC), Thatcham, UK Bob Engdahl, University of Colorado Boulder, USA Willie Lee, U.S. Geological Survey (USGS), Menlo Park, USA Antonio Villaseñor, Institute of Earth Sciences (IES) Jaume Almera, Barcelona, Spain Peter Bormann, Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Germany Graziano Ferrari, Istituto Nazionale di Geofisica e Vulcanologia (INGV), Bologna, Italy Rights and permissions Copyright © 2012 GEM Foundation, International Seismological Centre, Storchak D.A., D. Di Giacomo, I. Bondár, J. Harris, E.R. Engdahl, W.H.K. Lee, A. Villaseñor, P. Bormann, and G. Ferrari Except where otherwise noted, this work is licensed under a Creative Commons Attribution 3.0 Unported License. The views and interpretations in this document are those of the individual author(s) and should not be attributed to the GEM Foundation. With them also lies the responsibility for the scientific and technical data presented. The authors have taken care to ensure the accuracy of the information in this report, but accept no responsibility for the material, nor liability for any loss including consequential loss incurred through the use of the material. Citation advice Storchak D.A., D. Di Giacomo, I. Bondár, J. Harris, E.R. Engdahl, W.H.K. Lee, A. Villaseñor, P. Bormann, and G. Ferrari (2012), ISC-GEM Global Instrumental Earthquake Catalogue (1900-2009), GEM Technical Report 2012- 01 V1.0.0, 128 pp., GEM Foundation, Pavia, Italy, doi: 10.13117/GEM.GEGD.TR2012.01. Photo credits Large cover image: © Scott Haefner/ USGS. Close-up shot of the southeast area along the surface trace of the San Andreas fault in the Carrizo Plain, north of Wallace Creek, where Elkhorn Rd. meets the fault. Small cover image: © 2013 GEM Foundation and International Seismological Centre, © 2013 Google, © 2013 Geo Basis-DE/BKG, Data SIO, NOAA, U.S. Navy, NGA, GEBCO. Close-up view of the ISC-GEM Global Instrumental Earthquake Catalogue, 2013 ISC-GEM KML file overlayed on 2013 Google Earth. www.globalquakemodel.org i ACKNOWLEDGEMENTS We are grateful to the GEM Foundation for selecting our team to work on the Global Instrumental Earthquake Catalogue and for support during the work on this exciting project. We are grateful to Peter Suhadolc (University of Trieste, Italy) for leading the group of IASPEI observers that included: Roger Musson (British Geological Survey, UK) and Johannes Schweitzer (NORSAR, Norway) who provided an invaluable advice on the availability of important historical documents and bulletins, Göran Ekström (Columbia University, US) who provided analysis of uncertainties of MW values in GCMT Catalogue; Nobuo Hamada (Japan Meteorological Agency, emeritus, Japan) who provided a digital copy of JMA historical bulletin data for 1923-1970; We thank Katsuyuki Abe for making available a CD-ROM with the Catalogue of Abe and Noguchi. We wish to recognize the initiative of the late Edouard Arnold and Pat Willmore, former Directors of the ISC, for their initiative, despite the financial difficulties, in organizing the first effort of transferring a large fraction of the ISS paper bulletins onto punch-cards and preparing the Shannon tape. We also wish to acknowledge the effort of Tom Boyd, Colorado School of Mines, USA, for his contribution in correcting the data on the Shannon tape. We thank Robin Adams and David McGregor (ISC, emeritus) for providing historical information on the operations in the early years of the ISC. We are grateful to Anna Berezina (Institute of Seismology, National Academy of Sciences, Kyrgyzstan) for organizing the scanning of the original operator’s notepads of the seismic station Frunze. We thank Irina Gabsatarova, Olga Kamenskaya, Vera Babkina and Raisa Mihailova (Geophysical Survey of the Russian Academy of Sciences, Obninsk, Russia) for providing the digital archive and scanning copies of the seismological bulletins of the Unified Network of Backbone Seismic Stations of the Former Soviet Union in 1971-1977. We thank Siegfried Wendt (Universitaet Leipzig, Germany) for sending missing bulletins of the Collm Observatory; Jina Gachechiladze (Ilia State University, Tbilisi, Georgia) and Arkady Aronov and Vladislav Aronov (Centre of Geophysical Monitoring of the National Academy of Sciences, Belarus) for providing information on positions of long-serving seismic stations. We wish to thank Emile Okal for stimulating discussions on seismic moments and moment magnitudes; Yun- tai Chen and Chao Liu for providing a compilation of seismic moments published by Chinese seismologists. We are indebted to Jon DeBord and Chuck Wenger, USGS Librarians, for assistance in searching the literature and arranging inter-library loans. We are also grateful to Bill Bakun, Wang-Ping Chen, Diane Doser, Göran Ekström, Hiroo Kanamori, Hong Kao, Hitoshi Kawakatsu and Donald Wells for answering our inquires and their helpful comments. ii ABSTRACT This report describes the ISC-GEM Global Instrumental Earthquake Catalogue (1900-2009) created on the request and with sponsorship from the GEM Foundation. The ISC-GEM Global Instrumental Earthquake Catalogue (1900-2009) is a major step forward on the way to improve characterization of spatial distribution of seismicity, magnitude frequency relation and maximum magnitudes within the scope of GEM. With a few exceptions, parameters of this catalogue are the result of computations based on the original reports of seismic stations and observatories. We made every effort to use uniform location and magnitude determination procedures during the entire period of the catalogue: • In earthquake location, we used a combination of the EHB depth determination technique and the new ISC procedures that use a multitude of primary and secondary seismic phases from the IASPEI Seismic Phase List and the ak135 velocity model and take into account the correlated error structure. • In determination of earthquake magnitude, where possible, we used direct MW values from Global CMT project for the period 1976-2009. In addition, 1,127 high quality scientific papers have been processed to obtain directly measured values of M0 and MW for 970 large earthquakes during 1900-1979. In all other instances we computed MW proxy values based on our own determination of instrumental surface or body wave magnitudes using updated regression models. • It has to be noted that a computation of MW proxy values based on regressions from other types of magnitudes does not bring similarly reliable results as compared to a direct measurement of MW based on the original waveform analysis. It is, nevertheless, a necessary measure since the direct measurement of MW using historical analogue waveforms on a global scale is beyond the scope of this project. A number of important additional benefits have been achieved during this project: • The entire ISC collection of historical paper-based seismic station bulletins was reviewed, indexed and catalogued for further works. Indexes of similar collections at USGS/Berkeley were used in filling the gaps in the ISC collection. • A large number of seismic phase arrival times, body and surface wave amplitude measurements have been made electronically available on a global scale that have never been available on a global scale prior to this project. • A large number of more accurate network MS and mb magnitudes have been computed for large earthquakes that either had no magnitude estimate or the estimates were previously based on single or unreliable station data. In our work we consulted and were observed by experts from the IASPEI and, where possible, followed the IASPEI seismic standards. iii We put together an excellent team of professionals in the field and gave training to a group of technical personnel without whom the work on this project would have been impossible to complete. These personnel members are a valuable asset of this project and their experience can be used if further work was to be planned. Although the ISC-GEM Catalogue is a major accomplishment, we nevertheless believe that further work is necessary to enhance its qualities: • Firstly, neglecting to update the ISC-GEM Catalogue beyond 2009 would seriously hamper the GEM community efforts of testing and refining of the earthquake forecasting models. • Secondly, it is well known that in seismic hazard studies the effect of small to moderate size earthquakes is not negligible. This is especially the case in densely populated and industrialized areas. This calls for further improvement of completeness of the reference catalogue to be extensively used by GEM community for many years to come. • Thirdly, it has to be noted that we really have no magnitude estimates for many events in our main original source of historical