Presented by Avi Shapira. An international non-governmental scientific organization An international non-governmental scientific.

WWW.ISC.AC.UK

Presented by

Avi Shapira

WWW.ISC.AC.UK

An international non-governmental scientific An international non-governmental scientific organizationorganization.

Formed in 1964 by the initiative of UNESCO.

Successor of the International Seismological Summary (1917-1964).

A non-profit making organization that is governed and financed by its members.

Members: National Academies, Scientific institutions and non-profit making organizations.

WWW.ISC.AC.UK

Prof. J. MilneShide Circular Rept.

1900-1912

Prof. H. H. Turner ISS

1913 -1931

Prof. H. Plaskett ISS

1931 -1938

Prof. Sir. H. Jeffreys ISS

1939 -1952

Dr. R. Stonely ISS

1952 -1960

Dr. P. L. Wilmore ISS & ISC 1960 -1970

Dr. E. P. Arnold ISC

1970 -1977

Mr. A. A. Hughes ISC

1977 -1997

Dr. R. Willemann ISC

1998 -2003

Dr. A. Shapira ISC

2004 - 2007

WWW.ISC.AC.UK

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.

WWW.ISC.AC.UK

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.

WWW.ISC.AC.UK

Countries represented at ISC

WWW.ISC.AC.UK

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.

WWW.ISC.AC.UK

DATA COLLECTION

Data contributed by more than 100 agenciesData contributed by more than 100 agencies

WWW.ISC.AC.UK

DATA COLLECTION

4102 stations reported data for the ISC Bulletin of 2004

WWW.ISC.AC.UK

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 150000 ASSOCIATED READINGS ARE REVIEWED EACH MONTH

WWW.ISC.AC.UK

The ongoing growth of the ISC The ongoing growth of the ISC data basedata base

0

1000000

2000000

3000000

4000000

5000000

6000000

7000000

19

64

19

66

19

68

19

70

19

72

19

74

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

20

06

# A

ss

oc

iatio

ns/P

ha

ses

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

500000

# E

ven

ts

Associations - 59m

Phases - 81 m

Events - 2.6m

WWW.ISC.AC.UK

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 20-24 months after the events.

ALL DATA ARE AVAILABLE ON THE ISC WEB SITE AND ALL DATA ARE AVAILABLE ON THE ISC WEB SITE AND THROUGH FTPTHROUGH FTP.

WWW.ISC.AC.UK

- Epicentres of earthquakes reviewed by ISC seismologists.

- Earthquake locations not reviewed by ISC seismologists .

Earth seismicity during 2004.

WWW.ISC.AC.UK

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

WWW.ISC.AC.UK

WWW.ISC.AC.UK

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 (1977-1996)

Continuing services are outsourced to CEA

•Contact lists to seismologists and seismological institutions

WWW.ISC.AC.UK

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.

WWW.ISC.AC.UK

INTERNET DATA SERVICES

ISC Website Usage

0

20000

40000

60000

80000

100000

120000

140000

160000

2000 2001 2002 2003 2004 2005 2006

# H

its

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

# S

earc

he

s

Hits

Search

WWW.ISC.AC.UK

WWW.ISC.AC.UK

WWW.ISC.AC.UK

WWW.ISC.AC.UK

WWW.ISC.AC.UK

WWW.ISC.AC.UK

WWW.ISC.AC.UK

Nominating Seismic Events to the Database of Reference Events to ImproveLocation

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 here 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.

WWW.ISC.AC.UK

For more information

www.isc.ac.ukwww.isc.ac.uk

ftp://ftp.isc.ac.ukftp://ftp.isc.ac.uk

WWW.ISC.AC.UK

THANK YOUTHANK YOU