Historical Seismograms - Evidence from the AD 2000 Izu Islands ...

In t e r na tio n a1 Se is mo logical Ce n t re 1116. SeismogramsISC has never acted as a collecting agency for the storage of seismograms, andthere are no present plans for this.7. Future ActivitiesThe ISC will continue to carry out its primary function of the collection of earthquakephase readings and the relocation of earthquakes for the compilation of thedefinitive catalogue of world seismicity.In the late 1970’s there was much discussion, fostered by both the InternationalAssociation of Seismology and Physics of the Earth’s Interior (IASPEI) and Unesco,about the possibility of a Global Seismic Data Bank being attached to ISC. Adetailed feasibility study for this was drawn up by Dr. V. Karnik for Unesco in1980. This ambitious plan included the collection of catalogues, bibliographies andhistorical data, and the revision and upgrading of early origin estimates, includingwhere possible the assigning of magnitudes. In this way a master file of worldearthquakes would be built up, that would be as complete and accurate as possible.No agency has yet been willing to fund this project, however. This proposal did notinclude any provision for the storing of seismograms or wave forms in computerreadableform, as it was then considered that this need was best met by nationalagencies.A further suggestion that has been proposed is for the ISC to act as a StrongMotion Information Centre and Data Bank. This has also been the subject of afeasibility study undertaken by Unesco in 1975. The more widespread use of digitalrecording for strong ground motion now increases the need for such a centre.The other major international sources of seismological information are the WorldData Centers established by ICSU at Boulder and Moscow. These hold informationfrom 40 major and 55 minor catalogues, as well as collections of analogue anddigital seismograms. The ISC differs from these bodies, however, in that it isprimarily an analysis centre for providing refined data. Any expansion or changein its activities would naturally have to be subject to the provision of adequatefunding and the approval of the Centre’s Governing Council of representatives ofcontributing Members.For any such projects, the ISC has one great advantage. It remains an independentseismological agency fully operated and funded by international control, and italready has close and friendly links with the seismological community world-wide.The Centre particularly values its contacts with many smaller countries, which areoften in areas of high earthquake activity, and whose contributions are vital to afull study of world seismicity.REFERENCESAdams, R.D., A.A. Hughes, and D.M. McGregor (1982). Analysis procedures at theInternational Seismological Centre, Phys. Earth. Planet. Int., 30, 85-93.Flinn, E. A. and E. R. Engdahl (1965). A proposed basis for geographic and seismicregionalization, Rev. Geophys., 3, 123.