Gemini Seamount,
New Hebrides Island Arc,
Vanuatu Islands

Update 003

From: Jean-Philippe EISSEN - ORSTOM Brest
Date:         Fri, 23 Feb 1996 07:56:57 MST
Subject:      Eastern Gemini seamount still active

Following our first report of the 21th of february, the activity of the Eastern Gemini seamount (southern New Hebrides island arc - Vanuatu - SW Pacific) was observed one more time during a flight of the New Caledonia coastguards Guardian plane on february the 22nd. A TV team of RFO New Caledonia was onboard the plane and brought back a video shown on the local TV news. The activity seems to be more important than the one observed during their first flight of 19/02/96, probably similar to that documented by the initial observations of the merchand ship OSCO STAR on the 18/02/96.

Description of the activity on the 22/02/96 : The white zone, from which steam is rising, has a diameter of about 400 m. This zone sets inside a wider ellipse brown-ochre, some 4000 m long, elongated down current.

Each 9 to 3 minutes, an explosion occurs which sends black products approximately 20 m above sea level. After each explosion, the diameter of the white area diminishes drastically to rise again until the next explosion. The black products are diluted to form the brown-ochre ellipse. The initial report of floating pumices was wrong.

Informations Contact :
Bernard Pelletier, Centre ORSTOM de Noumea, BP A5, Noumea, New Caledonia
fax (+687) 26 43 26, e-mail :
Michel Lardy, ORSTOM, BP 76, Port Vila, Vanuatu
fax (+678) 23 276, e-mail :
Michel Monzier, Claude Robin, ORSTOM, A.P. 17-11-6596 CCI, Quito, Ecuador
fax (+593) 24 48 699, e-mail :
Jean-Philippe Eissen, Centre ORSTOM de Brest, BP 70, 29280 Plouzane, France
fax (+33) 98 22 45 14, e-mail :