Finally the vessel left the port of Acapulco on January 10, 1982, at midnight
and headed out for the diving site on the EPR at 12°50
0 N. During the first leg of the
Cyatherm cruise, the scientific party included Jean Francheteau, Bob Ballard,
Vincent Renard, Jean-Luc Charlou, Pierre Choukroune, Francis Albarede and me.
The first Leg (January 9th–January 25th 1982) comprised the first 20 Cyana dives
of the cruise. The second Leg (January 28th–February 10th 1982) included 11
dives and the last dive number was Cy 82-32 (Cy = Cyana, 82 = year 1982 and
32 = dive number). The participants on the second Leg were mostly the same
scientists as the first Leg except for two new members: B. Marty, a fluid geochemist, and Jean-François Minster, a geochemist from the Institute de Physique
du Globe de Paris (IPGP), who joined the ship in Manzanillo. Jean-François
Minster later became one of the directors of IFREMER for the period of
1999–2004.
The person responsible for the submersible team was Jean Roux, a tall, thin
man who called me his cousin because he was half-Armenian in origin, on his
mother’s side. After talking about our families and their stories, we figured out that
his grandmother was probably from the same town, Kharpert, as was my mother’s
family, before the genocide of 1915–1920 perpetrated by the Ottoman government, which killed more than 1,500,000 Armenians.
The use of submersibles and deep towed bottom camera coverage had enabled
us to find more than a hundred (149 counted by Fouquet et al. 1996) hydrothermal
deposits dispersed along the strike of the EPR in the 13°N axial graben over a
distance of 31 km. These deposits vary in size between 2 and 15 m in height and
are less than 50 m in diameter. They are distributed in a sequence at a distance of
about every 150 m along the EPR axis. All the hydrothermal deposits encountered
in the axial graben consist of moderately to extremely porous zinc sulfide, iron–
zinc sulfide and copper–zinc sulfide material. Most of the active hydrothermal
venting is taking place on a narrow band of less than 50 m long, and about 25 m
wide along the en-echelon linear fissures of the axial graben. The fissures have
variable lengths and could be as long as 7 km.
Cyana Dives on the EPR at 12°50
0 N
The diving operations with Cyana on the EPR segment at 12850
0 N was the first
time we would try to use this submersible for conducting detailed geological
exploration such as contour line mapping, sampling and deploying complex
instruments such as water bottle collectors, markers for site recognition, and
baskets for biological sampling on the sea floor. The geological exploration was
mainly focused on finding and sampling hydrothermal fields. We already had some
indications about our exploration targets from previous surface ship surveys due to
hydrological water sampling data and deep-towed bottom photographic coverage.
Because of the limited space available on the Cyana’s sample storage rack, a
special system was built on board at the last minute in order to be able to store
214
7 Oceanic Spreading Ridges and Sea Floor Creation
and headed out for the diving site on the EPR at 12°50
0 N. During the first leg of the
Cyatherm cruise, the scientific party included Jean Francheteau, Bob Ballard,
Vincent Renard, Jean-Luc Charlou, Pierre Choukroune, Francis Albarede and me.
The first Leg (January 9th–January 25th 1982) comprised the first 20 Cyana dives
of the cruise. The second Leg (January 28th–February 10th 1982) included 11
dives and the last dive number was Cy 82-32 (Cy = Cyana, 82 = year 1982 and
32 = dive number). The participants on the second Leg were mostly the same
scientists as the first Leg except for two new members: B. Marty, a fluid geochemist, and Jean-François Minster, a geochemist from the Institute de Physique
du Globe de Paris (IPGP), who joined the ship in Manzanillo. Jean-François
Minster later became one of the directors of IFREMER for the period of
1999–2004.
The person responsible for the submersible team was Jean Roux, a tall, thin
man who called me his cousin because he was half-Armenian in origin, on his
mother’s side. After talking about our families and their stories, we figured out that
his grandmother was probably from the same town, Kharpert, as was my mother’s
family, before the genocide of 1915–1920 perpetrated by the Ottoman government, which killed more than 1,500,000 Armenians.
The use of submersibles and deep towed bottom camera coverage had enabled
us to find more than a hundred (149 counted by Fouquet et al. 1996) hydrothermal
deposits dispersed along the strike of the EPR in the 13°N axial graben over a
distance of 31 km. These deposits vary in size between 2 and 15 m in height and
are less than 50 m in diameter. They are distributed in a sequence at a distance of
about every 150 m along the EPR axis. All the hydrothermal deposits encountered
in the axial graben consist of moderately to extremely porous zinc sulfide, iron–
zinc sulfide and copper–zinc sulfide material. Most of the active hydrothermal
venting is taking place on a narrow band of less than 50 m long, and about 25 m
wide along the en-echelon linear fissures of the axial graben. The fissures have
variable lengths and could be as long as 7 km.
Cyana Dives on the EPR at 12°50
0 N
The diving operations with Cyana on the EPR segment at 12850
0 N was the first
time we would try to use this submersible for conducting detailed geological
exploration such as contour line mapping, sampling and deploying complex
instruments such as water bottle collectors, markers for site recognition, and
baskets for biological sampling on the sea floor. The geological exploration was
mainly focused on finding and sampling hydrothermal fields. We already had some
indications about our exploration targets from previous surface ship surveys due to
hydrological water sampling data and deep-towed bottom photographic coverage.
Because of the limited space available on the Cyana’s sample storage rack, a
special system was built on board at the last minute in order to be able to store
214
7 Oceanic Spreading Ridges and Sea Floor Creation