Presented by Avi Shapira

An international non-governmental scientific organization An international non-governmental scientific organization. Formed in 1964 by the initiative of UNESCO. Successor of the International Seismological Summary ( ). A non-profit making organization that is governed and financed by its members. Members: National Academies, Scientific institutions and non-profit making organizations.

Prof. J. Milne Shide Circular Rept Prof. H. H. Turner ISS Prof. H. Plaskett ISS Prof. Sir. H. Jeffreys ISS Dr. R. Stonely ISS Dr. P. L. Wilmore ISS & ISC Dr. E. P. Arnold ISC Mr. A. A. Hughes ISC Dr. R. Willemann ISC Dr. A. Shapira ISC

Main Objectives 1.Final collection, analysis and publication of standard earthquake information from all over the world. 2.Re-determine earthquake locations making use of all available information. 3.Re-determine earthquake magnitudes mb and Ms. 4.Search for new earthquakes, previously unidentified by individual agencies.

Main Objectives 5. Provide the most comprehensive catalogue of global seismicity. 6. Provide the most complete list of associated arrival times of seismic waves. 7. Maintain the International Seismic Station Registry. 8. Serve as a depository of global seismological data.

Countries represented at ISC

DATA COLLECTION Measurements: Associated and non associated readings of seismic wave arrival times, measured amplitudes and periods, Array processing results (Slowness and Azimuth). Evaluations: Event locations, Seismic Moments and Moment tensors, Fault Plane Solutions, Magnitudes. Other data: Macroseimic observations, Event Classification.

DATA COLLECTION Data contributed by more than 100 agencies

DATA COLLECTION 4102 stations reported data for the ISC Bulletin of 2004

Data Processing and Analysis ISC analysts manually review every event that complies with one of the following conditions: The reported magnitude is higher than 3 The event was reported by at least 2 agencies with M>2.5 The event was recorded at a distance greater than ~1000 km. An ISC solution is provided when: There are more than 4 phase readings (P and/or S) The solution converges successfully. MORE THAN 3500 EVENTS WITH MORE THAN ASSOCIATED READINGS ARE REVIEWED EACH MONTH

The ongoing growth of the ISC data base

ISC main products: Catalogue and Bulletin Catalogue – Listings of source parameters of seismic events. Regional Catalogue – Catalogue of seismic events sorted by region and by type (earthquakes, explosions, felt, destructive … ) Bulletin – Chronologically listed events with their associated station measurements. ISC Comprehensive Bulletin – An UP TODATE bulletin comprising all seismic events in the ISC data base. ISC Reviewed Bulletin – A bulletin comprising all seismic events reviewed by ISC seismologists. Available months after the events. ALL DATA ARE AVAILABLE ON THE ISC WEB SITE AND THROUGH FTP ALL DATA ARE AVAILABLE ON THE ISC WEB SITE AND THROUGH FTP.

- Epicentres of earthquakes reviewed by ISC seismologists. - Earthquake locations not reviewed by ISC seismologists. Earth seismicity during 2004.

Earth Seismicity

Distribution of ISC Catalogue and Bulletin Every 4 months: 1.A 4-month printed Bulletin including only source parameters of edited events. 2. An attached CD-ROM with 1.A Comprehensive Catalogue (FFB and ISF files). 2.A Comprehensive Bulletin (FFB and ISF files). 3.A PDF file of a complete 4-month Bulletin. THESE FILES ARE ALSO AVAILABLE FROM THE ISC WEBSITE AND FROM THE FTP SERVER THESE FILES ARE ALSO AVAILABLE FROM THE ISC WEBSITE AND FROM THE FTP SERVER.

Distribution of ISC Catalogue and Bulletin 1. A CD-ROM with: A Comprehensive Catalogue 1904-recent (FFB and ISF files). A Regional Catalogue (PDF file) of the last year edited events. PDF files of format descriptions, programs to read and view data. 2. A CD- ROM with: 12 Comprehensive monthly Bulletins (compressed FFB and ISF files) PDF files of 12 monthly Bulletins (edited events only). THESE FILES ARE ALSO AVAILABLE FROM THE ISC WEBSITE AND FROM THE FTP SERVER Annual

Adopt and Implement IASPEI’s recommendations Nomenclature of Seismic Phases (implemented in 2003). Regionalization of Seismic Epicentres (implemented in 2004). Magnitude determinations (collecting data – starting Jan.2007) AK-135 TT models (expected in 2008). Seismic stations code names (under discussions ): Agency.Deployment.Station.Location.Epoch,Channel

IASPEI RECOMMENDATIONS FOR MAGNITUDE DETERMINATIONS AVI SHAPIRA, JAMES W. DEWEY, PETER BORMANN Working Group on Magnitudes IASPEI) Commission on Seismological Observation and Interpretation (CoSOI) The Working Group on Magnitudes (Magnitude WG) of the International Association of Seismology and Physics of the Earth’s Interior (IASPEI) Commission on Seismological Observation and Interpretation (CoSOI) recommended standard procedures for making measurements from digital data to be used in calculating several widely used types of earthquake magnitude. The recommended procedures from the Working Group have been approved by the IASPEI Commission on Seismological Observations and Interpretations and are expected to be implemented by all seismological centres. MS(20) Teleseismic surface-wave magnitudes at period of ~ 20 sec. MS(20)= log10(A/T) log10Δ A = vertical-component ground amplitude in μm measured from the maximum trace-amplitude of a surface-wave phase. 18s  T  22s on a waveform that has been filtered so that the frequency response of the seismograph/filter system replicates that of a World-Wide Standardized Seismograph Network; Δ = epicentral distance in degrees, 20˚    160  ; Focal-depth of less than 50 km. Amplitudes to be reported to ISC as MS(BB) Surface-wave magnitudes from Broad Band instruments. MS(BB) = log10(A/T)max log10Δ (A/T )max = (Vmax/2  ), where Vmax = ground velocity in μm/s associated with the maximum trace-amplitude in the surface-wave train as recorded on vertical-component seismogram that is proportional to velocity, and where the period T, 3s < T < 60s, should be preserved together with A or Vmax in bulletin data-bases; Δ = epicentral distance in degrees, 2˚    160  ; focal depth less than 80 km. mb – short-period body-wave magnitude mb = log10(A/T) + Q( , h) A = P-wave ground amplitude in μm calculated from the maximum trace-amplitude in the entire P-phase train (time spanned by P, pP, sP, and possibly PcP and their codas, and ending preferably before PP); T = period in seconds, T < 3s ; A and T are measured on output from a vertical- component instrument that is filtered so that the frequency response of the seismograph/filter system replicates that of a WWSSN short-period seismograph; Q( , h) = attenuation function for PZ (P-waves recorded on vertical component seismographs) established by Gutenberg and Richter (1956);  = epicentral distance in degrees, 21˚    100  ;h = focal depth. mB – intermediate-period/broadband body-wave magnitude mB = log10(A/T)max + Q( , h) (A/T )max = (Vmax/2  ), where Vmax = ground velocity in μm/s associated with the maximum trace-amplitude in the entire P-phase train (time spanned by P, pP, sP, and possibly PcP and their codas, but ending preferably before PP) as recorded on a vertical-component seismogram that is proportional to velocity in the period-range 0.2s < T < 30s, and where T should be preserved together with A or Vmax in bulletin data-bases; Q( , h) = attenuation function for PZ established by Gutenberg and Richter (1956), as discussed above with respect to mb;  = epicentral distance in degrees, 21˚    100  ; h = focal depth.

On-line information and services Comprehensive facilities to query ISC data base International registry of seismic stations Station book Agency codes Standards & procedures Bibliography of Seismology ( ) Continuing services are outsourced to CEA Contact lists to seismologists and seismological institutions

On-line information and services Analysis of contributed data. Preliminary assessments of seismicity parameters. ISC Reports and Documentation Practice of magnitude determinations. Reference events to improve location Automated S/SKS splitting analysis Links to rapid information about strong earthquakes. Link to ISS data. IASPEI WS on Modernizing ISC location procedures. Link to IASPEI WG on Network and Station Codes.

INTERNET DATA SERVICES

Distribution of entries to the ISC website

Nominating Seismic Events to the Database of Reference Events to Improve Location The International Seismological Centre prepares and maintains a database of a set of earthquakes and explosions for which epicentre information (Latitude, Longitude) is known with high confidence (to 5km or better (GT5)) and whose seismic signals have been recorded at regional and/or teleseismic distances. We want to facilitate and accelerate a global effort to build and validate a significantly large set of reference events that, in turn, will be used for better visualization of the structure of the Earth, better modelling of velocities of seismic waves, more accurate travel time determinations and increased accuracy of hypocentre locations. A catalogue of reference events can be found in herehere This web page is designed to receive information about candidate seismic events to be included in the database of reference events. The information will be reviewed by members of the IASPEI Working Group on Reference Events to Improve Location -WG-REIL.

Agency Codes The following is a compiled list of agency codes used in the ISC Bulletin since the turn of the 20th century. Also shown are: Equivalent codes used by NEIC and EMSC (real time data). Acronym used by the agency, if known Other code names which refer to the same agency (under Alias header). Agency Codes Unassociated Agency Codes Other "Agency" codes Please inform us about corrections to be made and updates to the agency names and acronyms. Agency Codes Country or RegionAliasAbbreviationFull nameEMSCNEICISC KazakhstanAlma-Ata-KAZKAAA KazakhstanAAAFormer name of TalgarAAB EthiopiaGeophysical Observatory, Adis Abeba University-AAE USAUniversity of Michigan, Department of Geological Sciences, Ann Arbor-AAM AlgeriaALGABA ItalyUniversita di Calabria, Cosenza-ACI AustraliaPrimary Industries and Resources South Australia, Adelaide-ADE Azores Isl.Observatorio Afonso Chaves, Ponta Delgada, AcoresPDA ADH AlaskaAlaska Earthquake Information Center. Geophysical Institute, Uni.of Alaska Fairbanks-GIAAEIC Western SamoaApia ObservatoryAFI USAAlaska Seismic Project. USGS-AGS

Unassociated Agency Codes Listed below are Agency Codes that appear mainly in the early ISC Bulletin (1913 up to 1936). At those days, the codes refer mainly to the seismic station rather than to an agency. Any correction or information about the agencies behind the code name is welcome. Country or RegionAssociated locationCode GermanyAachenAAC AzerbaijianyBakuBAK PanamaBalboa HeightsBHP IndiaBombaiBOM U.S.A.BozemanBOZ KazakhstanTchimkentCHM SwitzerlandChurCHU PortugalCoimbraCOI DenmarkCopenhagenCOP UkraineCernowitzCRA ScotlandEskdalemuirESK HukokaFKK New YorkFordhamFOR

Abbreviations of Projects, Special Studies or Network Deployments Some of the data in the ISC Bulletin were special contributions from certain projects and special studies. These were associated with a project/study code rather than with the contributing agency. These codes are: Country or RegionAliasAbbreviationFull nameEMSCNEICISC IsraelGIIAfar Depression study, GIIAFAR GermanyAndean Continental Research Project, GFZ PotsdamGFZGEANCORP USABroadband ANdean JOint Experiment, Univ. of ArizonaBANJO Data in a paper by Berkheimer H.BERK USABhuj Aftershock Study, Cent.Earthquake Research and Information,Uni. of Memphis-CERIBHUJ JapanHirosaki University Study of Aftershocks of the Bhuj EarthquakeBHUJ2

For more information ftp://ftp.isc.ac.uk

THANK YOU