One of the most active seismic regions; the reasons behind an Oceania seismic regional network
30% of global seismicity is observed in the South West Pacific Region (Lebellegard et al., 2007) with less than 3% of seismic stations available for real time monitoring within this area (repartition based on GEVN network). The reasons to establish an Oceania seismic regional network are:
- To better and more quickly manage Tsunami Alerts for local and regional countries (more stations mean better/faster earthquake detection);
- Supporting National TWS with a Regional Alert System;
- Sharing of the resources (financial, technical, and human) for mutual support;
- Having a better standing among worldwide and regional institutes;
- Training local engineers and technicians to improve the self-resilience of these state members.
The origin behind ORSNET, the example of bilateral collaboration in the region
Collaboration between IRD (Noumea) and the Vanuatu Geohazards Observatory (Vanuatu), since 2010, helped both countries to improve tsunami and earthquake mitigation. This common network allows both observatories to manage:
- Efficient regional automatic detection (using a standard software system used by most of TWS around the globe);
- An automatic alert system (i.e. email and SMS dissemination to all national disasters risk reduction stakeholders);
- A real merged and integrated regional network with a common system shared and mutualized.
At the same time the government of Fiji and Tonga, with the support of JICA, developed a common seismic network based on the same technology with the same advantages than the NC/Vanuatu collaboration.
A regional collaboration approved and supported
The Pacific Tsunami Warning System (PTWS) of UNESCO-IOC is leading a global effort to establish ocean-based tsunami warning systems as part of an overall multi-hazard disaster reduction strategy. The IOC Tsunami Unit works with Member States to build sustainable tsunami early warning systems. The ORSNET countries are all state members of the IOC/ICG-PTWS Working Group for the South West Pacific. Following the recommendations of the IOC/PTWS Task Team on “Seismic Data Sharing in the South-west Pacific” (2009 in Vanuatu, 2011 in New Zealand) and the recent meeting of the International Federation of Digital Seismograph Networks (FDSN) community on Infrastructure for Seismology during the XXV International Federation of Digital seismograph Networks (IUGG) General assembly (July 2011 in Australia) the ORSNET members confirmed and approved the support of data sharing amongst Pacific seismic stations to better understand regional seismic activity and hazard.
The development of ORSNET
In 2014, official representatives from Papua New Guinea, Solomons Islands, Vanuatu, New Caledonia, Fiji, Tonga and Samoa agreed to share their data coming from their seismic network to mitigate the regional natural disasters (earthquake & tsunami).
Following the design of an unified regional seismic network with encouraging results coming from the Vanuatu/New Caledonia partnership, this technical solution has been used and deployed amongst all the ORSNET member countries since this date.