In 1986, H.W. Menard wrote The Europeans that had entered the Pacific for
more than 300 years came from an unwashed, polluted, disease ridden culture that
had passed from the Bronze Age to the Iron Age several millennia earlier. The
people they found on the tiny isolated islands were clean, healthy, and generally
friendly.
Some of these islands were visited by the scientific team during our VIP
expeditions, and several were used as a port of call for our research vessels. In
1987, during one of our stops in Tahiti (SONNE, Leg 100), we visited this island
with Jacques Talandier who was, at the time, the director of the French seismic
station in Papeete. Jacques took us on a tour to observe the volcanic landscape of
the island. The last volcanic eruption in Tahiti was about 900000 years ago and
despite the tropical vegetation, which grew abundantly, we were able to see
remnants of large lava tubes forming tunnels. The tunnels were so large that two
trucks could pass through them, side-by-side.
The submarine portion of the Society hotspot, east of Tahiti Island, was the
target of several international missions. The deep-ocean field observations were
carried out by the submersibles Cyana and Nautile, as well as by a deep-towed
television camera system Ocean Floor Observation System (OFOS), plus sidelooking sonar (GLORIA) and sea floor back-scatter imagery data collected by the
F.S. SONNE, N.O. L’ATALANTE, N.O. J. CHARCOT and HMS Charles DARWIN
of the United Kingdom, in 1988. The multichannel bathymetry coverage included
SeaBeam (N.O. J. CHARCOT, 1986), Hydrosweep (F.S. SONNE, 1987), and the
SIMRAD-EM12D systems (N.O. L’ATALANTE, 1999). However, it was during
the SONNE Leg 47, in 1987, that an extended survey was first made using the
German-constructed deep towed camera system (OFOS = Ocean floor observation system), plus dredging, plus the use of a large grab sampler equipped with a
bottom camera system (GTV = Grab, TV camera). This initial exploratory mission permitted us to obtain our first knowledge about the volcanic and hydrothermal activity that was taking place on the Society hotspot.
The various expeditions of the VIP program had the additional advantage of
obtaining information on the seismicity of the Society and Austral hotspots thanks
to information provided by the Polynesian seismic stations, which centralized all
the information on earthquakes and tsunami warnings with the Polynesian Seismic
Network (Réseau Sismique Polynésien RSP) in Tahiti. Seismic stations had been
installed on several islands such as Tahiti, Moorea, Rangiroa, Tubuai and Gambier.
These stations were first built in the 1960s and in the late 1980s, they were skillfully
being directed by Jacques Talandier from the Centre Enérgie Atomique (CEA,
France).
In addition to Tahiti, during more than 20 years of the VIP Program’s exploration of intraplate regions associated with hotspots, we made several stops at
Easter Island (Rapa Nui). This Island was able to provide refueling facilities and
had an international airport that facilitated traveling for our scientific teams and
shipboard crew.
Polynesian Hotspots
309
more than 300 years came from an unwashed, polluted, disease ridden culture that
had passed from the Bronze Age to the Iron Age several millennia earlier. The
people they found on the tiny isolated islands were clean, healthy, and generally
friendly.
Some of these islands were visited by the scientific team during our VIP
expeditions, and several were used as a port of call for our research vessels. In
1987, during one of our stops in Tahiti (SONNE, Leg 100), we visited this island
with Jacques Talandier who was, at the time, the director of the French seismic
station in Papeete. Jacques took us on a tour to observe the volcanic landscape of
the island. The last volcanic eruption in Tahiti was about 900000 years ago and
despite the tropical vegetation, which grew abundantly, we were able to see
remnants of large lava tubes forming tunnels. The tunnels were so large that two
trucks could pass through them, side-by-side.
The submarine portion of the Society hotspot, east of Tahiti Island, was the
target of several international missions. The deep-ocean field observations were
carried out by the submersibles Cyana and Nautile, as well as by a deep-towed
television camera system Ocean Floor Observation System (OFOS), plus sidelooking sonar (GLORIA) and sea floor back-scatter imagery data collected by the
F.S. SONNE, N.O. L’ATALANTE, N.O. J. CHARCOT and HMS Charles DARWIN
of the United Kingdom, in 1988. The multichannel bathymetry coverage included
SeaBeam (N.O. J. CHARCOT, 1986), Hydrosweep (F.S. SONNE, 1987), and the
SIMRAD-EM12D systems (N.O. L’ATALANTE, 1999). However, it was during
the SONNE Leg 47, in 1987, that an extended survey was first made using the
German-constructed deep towed camera system (OFOS = Ocean floor observation system), plus dredging, plus the use of a large grab sampler equipped with a
bottom camera system (GTV = Grab, TV camera). This initial exploratory mission permitted us to obtain our first knowledge about the volcanic and hydrothermal activity that was taking place on the Society hotspot.
The various expeditions of the VIP program had the additional advantage of
obtaining information on the seismicity of the Society and Austral hotspots thanks
to information provided by the Polynesian seismic stations, which centralized all
the information on earthquakes and tsunami warnings with the Polynesian Seismic
Network (Réseau Sismique Polynésien RSP) in Tahiti. Seismic stations had been
installed on several islands such as Tahiti, Moorea, Rangiroa, Tubuai and Gambier.
These stations were first built in the 1960s and in the late 1980s, they were skillfully
being directed by Jacques Talandier from the Centre Enérgie Atomique (CEA,
France).
In addition to Tahiti, during more than 20 years of the VIP Program’s exploration of intraplate regions associated with hotspots, we made several stops at
Easter Island (Rapa Nui). This Island was able to provide refueling facilities and
had an international airport that facilitated traveling for our scientific teams and
shipboard crew.
Polynesian Hotspots
309