2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)

Paper No. 303-8
Presentation Time: 10:45 AM

ORSNET CONCEPT: A PACIFIC INTERNATIONAL COOPERATION FOR SEISMIC HAZARDS MITIGATION


LEBELLEGARD, Pierre1, GARAEBITI BULE, Esline2, TODMAN, Sylvain2, PILLET, Robert3 and ROULAND, Daniel4, (1)UMR 7329 Géoazur, IRD (Institut de Recherche pour le Développement), IRD BP A5, Noumea CEDEX, 98848, New Caledonia, (2)Geohazards Division, VMGD (Vanuatu Meteorological and Geohazards Department), Private Mail Bag 9054, Port Vila, Vanuatu, (3)UMR 7329 Géoazur, 250, rue Albert Einstein, Sophia Antipolis, Valbonne, 06560, France, (4)EOST (Ecole et Observatoire des Sciences de la Terre), 5, rue René Descartes, Strasbourg, 67084, France, Pierre.Lebellegard@ird.fr

Southwest Pacific Island countries represent a challenge in earthquake/tsunami risk mitigation: located in highly seismically active zones, with scarce seismic stations coverage (*), they often face devastating earthquakes, e.g. the 2013/02 8.0 Santa Cruz earthquake. In a particular location, subduction zone between Vanuatu and New Caledonia, seismic gap in the region between Efate and Tanna islands, associated with one of the highest convergence rates in the world, up to 12-14 cm/year, may lead to a tsunamigenic earthquake: should a tsunami occur, wave would reach coasts in not more than fifteen minutes: alert triggering quickness is therefore a critical issue.

Based on long term cooperation between Vanuatu and New Caledonia (IRD) seismic departments, and recent creation of New Caledonia seismic network, join Vanuatu/New Caledonia seismic network is now running since early 2012, with alert triggering times frequently less than two minutes for closest events.

Attention of neighbouring Southwest Pacific island countries (SWPICs) and international institutions such as CTBTO and UNESCO has been drawn and has led to the concept of data sharing and alert dissemination between SPICs participants, through ORSNET (Oceania Regional Seismic NETwork). ORSNET is currently associating PNG, Solomons, New Caledonia, Vanuatu, Fiji, Tonga, and Samoa. First ORSNET stations’ data is now collected in ORSNET data centre, located in Nouméa, New Caledonia, launched in March 2014. Upon completion, a total number of about sixty real time seismic stations is planned, and a significant reduction in seismic alert triggering time is expected.

First results will be presented, as well as future prospects, such as SWPICs warning centre of IRD centre in IRD Nouméa, New Caledonia.

(*) Cavascope : The broadband seismological network of the New Hebrides subduction zone and its associated database, R. Pillet, P. Lebellegard ; E. Garaebiti and D. Rouland, SRL, VOL. 79, NO. 4, pp. 498-503

Handouts
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