The ILP/ICSU's Global Seismic Hazard Assessment Program is a demonstration program of the UN/International Decade for Natural Disaster Reduction. The GSHAP was implemented in the 1992-1997 period and came to conclusion in occasion of the 29th IASPEI General Assembly (Greece, 8/97). A final one-year phase is under way to allow by 1998 the publication of GSHAP products and materials and the compilation of a global map of seismic hazard. Here we review the regional results of GSHAP as presented at the closing IASPEI meeting and the ongoing activities in the 1997-1998 final phase.

Regional reports, GSHAP yearly reports, summaries and maps of seismicity, source zones and seismic hazard are now found on the GSHAP homepage on HTTP://SEISMO.ETHZ.CH/.

REGIONAL TEST AREAS

GSHAP implemented a regionalized strategy for the assessment of seismic hazard based on a mosaic of multinational test-area and regions. Following the scheduled proposed in 1992, most of these test areas produced in 1997 a preliminary or final SHA, complemented by regional earthquake catalogues and seismic source zonations, presented at the final GSHAP event, the workshop W17 at the 1997 IASPEI General Assembly in Greece (8/97).

GSHAP cooperated with several bilateral and multinational projects in different continents. Among these the "Eastern Asia Natural Hazards Mapping project" led by the GSJ, the UNESCO/USGS program "Reduction of Earthquake Losses in the Eastern Mediterranean Region", the UNESCO/IUGS International Geological Correlation Program n.382 SESAME "Seismotectonics and Seismic Hazard Assessment of the Mediterranean basin", the regional seismic hazard mapping of Mexico, Caribbeans, Central and South America supported by PAIGH/IDRC, the CIPA-CT94-0238 "Quantitative seismic zoning of the Circum-Pannonian region".

SOUTH AMERICA

The whole South American continent has been targeted as test area by CERESIS, the GSHAP Regional Centre for South America. CERESIS completed in 1996 a new SHA for the whole continent, as part of PAIGH/IDRC effort; the new map is based on an updated earthquake catalogue, extending the 1981 SISRA catalogue to 1991, and on a new seismic source zonation.

ANDES

Five Andean countries (Bolivia to Venezuela) and four European countries cooperated in the PILOTO program ("Test area for earthquake monitoring and seismic hazard assessment"), launched under GSHAP and sponsored by the European Union (Ct.94-0103) to produce in 1997 a unified SHA for the Andean region. Activities included the integration of national earthquake catalogues and source zonings in common regional databases, regional workshops held in Bogota (10/95, 1/97) and Quito (6/97) and a joint ILP/PILOTO "Training course in paleoseismology" held in Venezuela (2/97).

CENTRAL-NORTH AMERICA

A network of national and regional programs in seismic hazard assessment covers Canada, the US, Mexico, Central America and the Caribbeans. The role of GSHAP has been to promote inter-program coordination at continental scale and to connect activities in Central-North America with other regions. A GSHAP working group led by USGS is merging a unified SHA map of North America, joining the existing national and regional source zonings.

CENTRAL-NORTHERN EUROPE

The GSHAP implementation in Central-Northern Europe was coordinated by the GFZ Regional Centre in Potsdam. In 1996 the regional seismic catalogue has been completed with the addition of the database for Fennoscandia and of the SIRENE catalogue for France, for the first time released for an international program. The final SHA map, including Fennoscandia, was presented in 1997. In addition, a unified hazard assessment for the German speaking countries (Germany-Austria-Switzerland) was produced in 1996 by national teams including seismologists and engineers, under the coordination of GFZ at Potsdam, as preparatory work for the implementation of the new european seismic building construction code (EC8). DACH has also been promoted as GSHAP test area.

IBERO-MAGHREB

GSHAP has promoted the reactivation of the former ESC program. In 1996 the CNCPRST of Rabat, the regional GSHAP centre, became the "Centre Euro-Mediterraneen d'Evaluation et de Prevention du Risque Sismique or Seismic Hazard Assessment (CEPRIS)" under the Open Partial Agreement on Natural Disasters of the European Council, with the mandate of coordinating activities in the Ibero-Maghreb and Western Mediterranean areas. In addition, activities to produce a first generation of SHA for the Ibero-Maghreb area by 1997 have been coordinated by the CSIC of Barcelona. Workshops were held in Granada (5/94), Rabat (12/95) and Barcelona (12/96, 5/97), with partial support from IGCP/SESAME, the first in occasion of the UNESCO/USGS "6th Int. Forum on Seismic Zonation: First Ibero-Maghreb Region Conference".

ADRIA

This project includes all countries bordering on the Adriatic Sea, from the Alps to Greece, coordinated by OGS of Trieste. Seismic zoning map, earthquake catalogue and PGA map have been compiled during a series of regional workshops (Trieste 7/94, Athens 9/95, Ljubliana 10/95), and presented in 1997. The final event is scheduled for February 1998 in Pisa (Italy).

EASTERN MEDITERRANEAN

The UNESCO IGCP-382 SESAME and the UNESCO/USGS RELEMR are coordinating their activities, leading toward a unified hazard mapping for the whole area. In 1996 SESAME organized its first "Training workshop on seismotectonics and seismic hazard analysis in the Eastern Mediterranean countries" in Cairo (12/96); a second workshop was held again in Cairo (12/97) focussing on the compilation of the active fault map and regional SHA. RELEMR includes hazard mapping from Turkey to the Red Sea; two workshops were held in Cyprus (12/96, 12/97) to establish a common regional strategy for the production of a preliminary regional PGA map, to be completed at a technical event in Jordan (Amman, 3/98). The PGA maps for Turkey, Greece and Iran have been independently produced under national programs.

CAUCASUS

The Test Area for SHA in the Caucasus is coordinated by GSHAP with IASPEI endorsement and INTAS support (Ct.94-1644), joining seismological institutions from the Caucasian republics, Russia, Turkey and Iran. Starting in 1994, multinational working groups produced an integrated regional earthquake catalogue (historical and instrumental), a new model of seismic lineaments and seismic zoning, and comparative SHA following probabilistic, deterministic, mixed probabilistic-deterministic and areal probabilistic methodologies. The NATO-ARW "Historical and prehistorical earthquakes in the Caucasus" was held in Armenia (Ct.95-1521, 7/96) and produced a comprehensive proceedings volume published by Kluwer. Workshops were held in Tehran (1/93), Moscow (9/93), Ashgabad (10/94), Tehran (5/95), Yerevan (7/96) and Tbilisi (7/97). A comprehensive report has been distributed in 1997, summarizing the results.

AFRICAN RIFT

The "Eastern and Southern Africa Regional Seismological Working Group", with support from Sweden, Bergen University, IASPEI and GSHAP, held periodic workshops to compile the regional earthquake catalogue and SHA for the African Rift area. Workshops were held in Entebbe (8/94), Addis Abeba (1/95), Bulawayo (2/96) and Bergen (6/97), and the regional PGA map is now available; for the first time eight of the nine participating countries have a national seismic hazard map, including site-specific hazard estimates for the capital cities along the Rift. In addition, the GSHAP Regional Centre at the University of Nairobi has compiled a seismic zonation following a historical probabilistic approach and hosted the 1997 UNESCO/GFZ "International Training Course in Seismology and SHA" (9/97).

NORTHERN EURASIA

The GSHAP Regional Centre in Moscow, JIPE, is coordinating the seismic hazard mapping for the whole territory of the former USSR. This five-year program, initiated before the FSU break-up and interrupted during the period of more intense political turmoil, has been restarted, leading to the compilation of the seismic catalogue and the SHA, using for the first time a probabilistic approach. Technical workshops are held routinely in Moscow. The area has been subdivided in five blocks, and the release of regional hazard maps in MSK is expected in early 1998.

CHINA-INDIA-NEPAL

The GSHAP test area has been established in the border region of China, India, Nepal, Myanmar and Bangla-Dash, under the direction of the SSB of Beijing, the GSHAP Regional Centre, in cooperation with the NGRI of Hyderabad; it is the first time that this type of regional framework is effectively operating in the region. Activities initiated with a planning meeting in Beijing (10/93), followed by the preliminary compilation of regional catalogues and by technical workshops in Beijing (10/94) and Hyderabad (3/96), to produce the final earthquake catalogue, seismic source zoning and SHA presented at the ASC Assembly in Tangshan (8/96). In addition to the PGA map for the test area, a regional map comprising the whole continental Eastern Asia has been produced in 1997 by SSB.

OCEANIA

Activities in this vast area have progressed in independent sub-areas (Australia, New Zealand, Papua New Guinea, Tonga-Fiji, Vanuatu and Solomon Is.), with a coordinating "South-West Pacific/South-East Asia Regional Meeting" hosted by AGSO in Melbourne (11/95). AGSO is presently coordinating the integration of the national products and the inclusion of Indonesia and Philippines.

CLOSING PHASE: 1997-1998

A one-year phase of completion of the GSHAP has been planned by the Steering Committee in its closing meeting (Greece, 8/97), devoted to the publication of the GSHAP results and to the compilation of products which could be of direct use in the final years of the Decade implementation, following also the recommendations by the UN/IDNDR Scientific-Technical Committee and by the ICSU Special Committee on the IDNDR. The closing phase initiated with the 1997 IASPEI General Assembly, and is proceeding with the following schedule and goals:

GSHAP VOLUME AND CD-ROM

The regional reports, detailing the compilation of the databases and of the hazard results in the GSHAP test-areas and regions, will be collected in a special volume, prepared following common guidelines, including also a CD-ROM with the earthquake databases, the seismic source zones and the regional hazard maps. Reports and databases are to be produced by spring 1998, the volume and CD-ROM are scheduled for release in late 1998, published by Annali di Geofisica.

GLOBAL SEISMIC ASSESSMENT MAP

The GSHAP global map of seismic hazard (PGA) will be completed by the summer of 1998, integrating the results obtained in the regional areas. Four of the GSHAP centres are acting as focal points to collect and merge the existing results in four large continental areas: USGS, Colorado, for the Americas; GFZ, Potsdam, for Europe-Mediterranean-Africa-Middle East; SSB, Beijing, for Central-Eastern Asia; AGSO, Canberra, for Australia-Western Pacific margin. The final iteration of the regional products and the transmission to these four centers is under way and scheduled for completion by end of March 1998; the centres will then complete the regional integration for end of May 1998; a final phase of global reunification will then take place, to complete the map for inclusion in the GSHAP volume and for global distribution. An editorial commettee has prepared technical specifications for the final compilation of the regional reports, the databases and the hazard maps. All work is to be completed by August 1998.

INPUT FOR MEGACITIES PROGRAMS

The final years of the Decade are shifting the emphasis on the protection of megacities, moving from hazard assessment to engineering applications and risk mitigation strategies. Several UN sponsored initiatives are under way. Under request by ICSU and the IDNDR, GSHAP will include in several regional reports site-specific hazard evaluations as input for megacities programs.

Report released on January 15, 1998, by D. Giardini, GSHAP Coordinator