VANUATU SEISMIC AND VOLCANO MONITORING NETWORK Esline Garaebiti

VANUATU SEISMIC AND VOLCANO MONITORING NETWORK Esline Garaebiti, Vanuatu Meteorology and Geohazards Department (VMGD) Sylvain Todman, Vanuatu Meteorology and Geohazards Department (VMGD) IRIS Metadata Workshop, 9 th to 13 th of January 2011, Bangkok, Thailand “MANAGING WAVEFORM DATA AND RELATED METADATA FOR SEISMIC NETWORKS”

Geographical location Vanuatu Extracted from one DGMWR report - Located in the south west Pacific, east of Australia

TECTONIC SETTING AND SEISMIC ACTIVITY IN THE REGION v Two subduction Zones: Pacific plate • • Indo-Australian Plate • • Western subduction belt from PNG to Vanuatu The Eastern subduction Belt from Tonga down to NZ The Vanuatu trench limiting 2 subducting the indo-Australian plate in the west and the Pacific Plate on the east side of the trench Converging velocities of plates 12 cm/year in North and South, 3, 5 cm/year in central v. High seismic activity in the area with depth ranging from 0 to 500 km. v. Tsunami-genic earthquake and volcanoes Zones v. Historical tsunami occurrences with casualties (PNG in 1998, Vanuatu 1999, Solomon 2007, Tonga and Samoa, 2009 …. )

Seismicity in Vanuatu (USGS) -Strong earthquakes Torres 7. 9 (1997) 7. 8 (2009) 7. 3, (2009) Nord • Torres, Magnitude 7. 9 in 1997, 7. 8 in 2009 • Ambrym, Magnitude 7. 5 in 1999, casualties Santo 7. 0 (2000, 2007) • Santo, Magnitude 7. 0 in 2000 and in 2007 Central Ambrym 7. 5 (1999) • Port Vila, Magnitude 7. 3 in 2002, and 7. 5 in 2010, 7. 2 in 2011 • Torres, M 7. 8, 7. 3 in 2009 Port Vila 7. 2 (2002) 7. 5 (2010) 7. 2, 2011 • South Vanuatu, Magnitude 7. 3 in 2010 and 2011 Sud Tanna 7. 3 (2010) Est Loyauté 7. 2 (2003/07) -Seismic gap at central and south Vanuau Extrème sud

VANUATU VOLCANO AND SEISMIC MONITORING NETWORK v Volcano monitoring network v 1 permanent , CMG-40, Q 330 v 4 in temporary stations v 2 CMG-40, Q 330 v 4 trillium 120 s v 1 CMG-6 TD v MINISEED format v Data still to be transmitted in RT, stations still to be integrated into SEISCOMP 3

VANUATU VOLCANO AND SEISMIC MONITORING NETWORK (CONT. ) v Local seismic network on Efate, with 3 stations up and running, 1 yet to be installed. v 3 seismic stations v v v 2 SP stations 1 Hz station L 4 D 3 1 Episensor Data format SEED VLF telemetry system Data processing and analysis by SEISSAN and SEISCOMP 3

VANUATU VOLCANO AND SEISMIC MONITORING NETWORK (CONT. ) v 1 Geoscope station in Santo v v v 1 STS 2 1 Quanterra Q 330 1 Episensor Transfer of data through ADS 4 stations for research purposes Guralp CMG_40 DM 24 v NDC of CTBTO installed in the VMGD head office in may 2011 v Geohazards Observatory operates SEISCOMP 3 since March 2011

COMMON NETWORK WITH NEW CALEDONIA v 3 SP and 1 BB stations in Vanuatu Spread along the Island arc Vanuatu New Caledonia v 7 BB stations in New caledonia v Data are shared through a seedlink, server donc, redistributed by the IRIS server in real time (rtserve. iris. washin gton. edu) v Each network operates SEISCOMP 3

AUTOMATIC SEISMIC DETECTION IN VMGD

EXAMPLE OF LOCAL SEISMIC EVENT Seismic event of 2012/01/08 at 21: 51: 47. 6 UTC , Local time : 2012/01/09 at 08: 51: 47 in Vanuatu Islands Magnitude : M 5. 1 Depth : 12 km Latitude : 17. 43 S Longitude : 167. 99 E Detected in : 2 min 27 sec

INFORMATION DISSEMINATION Volcano Alert Bulletins Earthquake information bulletins Tsunami advisory bulletins Dissemination by Email Website: www. geohazards. vanuatu. gov. vu

EARTHQUAKE & TSUNAMI ALERT SYSTEM International Alert System: USGS (Internet web service) & PTWC (CISN Display, Tide tool) Internal Alert System with SEISCOMP 3: Step 1: Seiscomp 3 earthquake automatic detection Step 2: Internal earthquake Alert system Local earthquake (Vanuatu – NC) : Magnitude > 4. 5 Regional earthquake (SWP region): Magnitude > 6. 2 International earthquake: Magnitude > 7. 2 Step 3: Email and SMS notification to on-duty staff Step 4: Confirmation by Geohazards on-duty officer Decisions taken by earthquakes threshold, M 7, 5 for regional and distant tsunami, M 7, 1 for local tsunami Step 5: Tsunami Advisory produced by Forecast on-duty officer

FUTURE PLANS FOR VANUATU AND THE PACIFIC REGION Existing seismic network Volcano monitoring network Future seismic stations Fiji Vanuatu New Caledonia v Vanuatu network • Automatize Tsunami Warning and earthquake alerts • Integration of all existing monitoring stations in Vanuatu (Volcano and seismic) into SEISCOMP • Add other future stations into the system v Merge of Vanuatu-New Caledonia network (> 10 stations , quick determination ) v Repeat networking pattern with other networks, Fiji/Tonga, Samoa, PNG and Solomon networks

Thank you for your attention