WOVO.org

World Organization of Volcanic Observatories

0507 - 04 - 10
Department of Geology, Mines and Water Resources
P.O. Box 001
Port-Vila
Vanuatu

Staff:

Esline Garae – Geo-Hazard Manager

Douglas Charley - Geology, geophysics: IRD Technician
Michel Lardy - Geophysics: responsible for the monitoring network (IRD)
Janette Tabbagh - Remote observation: responsible for the CTVI* data bank (CNRS)
Sandrine Wallez - Volcanology

In collaboration with:

CFR* Geochemical analysis of gases: Marie-Françoise Le Cloarec

CNET* Technical support: C. Archambault, J. Gautier and geochemical analysis of water

CRG* Heat flow: Alain Tabbagh

CRV* Seismology: Jacques Dorel

IPGP* Technical support: Claude Pambrun

Glossary of French organisations involved:

CFR Low radioactivity centre (GIF)

CLS Satellite collection and localisation of data (Toulouse)

CNET National Centre for telecommunications studies. Environnement Department(Lannion)

CNUSC Academic National Centre for calculations and statistics

CRG Geophysics Research Centre (Garchy)

CRV Volcanology Research Centre (Clermont Ferrand)

CTIV Centre for computerized remote observation of volcanoes (Garchy-Clermont)

IPGP Institut de Physique du Globe de Paris

Remote observation of Benbow and Marum volcanoes on the island of Ambrym and Yasur volcano on the island of Tanna in the Republic of Vanuatu (S.W. Pacific) by Argos Satellite.

The Ambrym and Tanna monitoring stations are the three seismo-meteo-volcanological observatories set up along the New Hebrides (Vanuatu) island arc and was installed with the assistance of the French Ministry of Foreign Affairs.

The purpose of these stations is to contribute to scientific research in volcanology whilst at the same provide a warning system for the protection of the population.

MEASUREMENTS RECORDED

Meteorological:

- temperature
- atmospheric pressure
- relative humidity
- rainfall
- speed wind
- direction of wind

Geophysical:

- heatflow (temperature measurements on shallow vertical profiles)
- temperature in the ground 90 cm
- temperature in the ground 60 cm
- temperature in the ground 30 cm
- seismological data (seismic event counting)
- thresholds:

(1) - 96 µm/s
(2) - 4,8 µm/s
(3) - 12 µm/s
(4) - 60 µm/s
(5) - 300 µm/s

ADDITIONAL MEASUREMENTS

Rainfall measurements associated with geochemical analysis of the rain (chlorydes, sulfates, pH, etc…) are carried out in the Yasur area.

The radio nuclide composition of the gases is monitored for the purpose of studying the mechanisms of eruptions and understanding magma dynamics.

TRANSMISSION - RECEPTION - REGISTRATION

The data transmitted by ARGOS beacon are both retrieved by a direct channel (received in Port Vila) and transmitted through the ORSTOM information network to the volcanological data bank at the CNUSC in Montpellier. Data recovery is also effected by the CTIV at the CLS in Toulouse and stored in the data bank at the CNUSC after processing.

The whole of the data can be made available through the information networks or the Minitel in Montpellier.

SIMPLIFIED DESCRIPTION OF THE SYNOPSIS :

a. An Argos message receiver has been set up in Port-Vila (at the ORSTOM Centre) and collects the data from the beacons which are located within a 3000 km range of Port-Vila (Latitude 17°44’09"S - Longitude 168°18’47"E).

b. A micro-processor provides for the management of data received by transferring them on to a work station. An additional computer programme enables us to draw up graphs required for prompt response control and interpretation.

c. The bulk data is compiled in the work station at the ORSTOM Centre which then transfers the information to Montpellier through the information link system (RIO).

d. A project (yet to be confirmed) for the establishment of a PC data server (retrieval system).

e. The whole of the processed data can also be retrieved by the VIAPAC network (Port-Vila) through the volcanology data bank in Montpellier, France.

f. CTIV selects the data both through the CLS ARGOS (standard mode) and through the ORSTOM Centre in Montpellier (back-up mode). Once processed, the data is then made available to users at the CNUSC in Montpellier.

Contact Information updated April 2004;

Other information is older.