deployed on the sea floor in order to continue the transect crossing of the graben.
Jean Roux, head of the submersible team, was very eager to dive on a hydrothermal field. I found it normal that someone who had been spending so much
energy and time to direct each dive would also like to see how the sea floor looks
in this particular active spreading ridge segment. Also, this would be an opportunity for Jean to observe the high quality performance of his group in handling the
Cyana. Hence dive Cy 82-19 was made with Jean Roux as the science observer
together with Guy Sciarrone and Arnoux.
At 09:51 Cyana was in the water and ready to dive. The team reached the
bottom at 11:04 at 2,600 m depth in the axial graben near the eastern wall. The
purpose of the first part of this dive was to perform water sampling, which meant
going to pick up a bottle made of titanium/carbon that was stored in the ‘‘lift’’. So,
first the submersible had to find the basket and pick up one of the two water sample
bottles that were inside. The basket was about 80 meters from the submersible as
shown on the radar screen and by the transponder beacon beeping its signal. At
11h32, after localizing the ‘‘lift’’, Cyana went to pick up a water bottle and then
went back to the target. At 11h48 they arrived on the ‘‘black smoker’’ and started
to sample the hot fluid exiting from the chimney. Using the starboard arm to open
the small valve of the bottle that was held by the port side arm, the pilot, Guy
Sciarrone, completed this delicate operation despite the small size of the valve,
about 3 cm long.
Bottle filling required a pilot to show a great deal of skill to successfully
complete the maneuver. The submarine had to be stabilized correctly in neutral
buoyancy without moving. The observer and the co-pilot held their breath, and no
motion was allowed on board. This could jeopardize the operation and even be
dangerous for the safety of the submersible because of the high temperature of the
exiting fluid (about 300 °C). At 13h19 the bottle was on top of the chimney and the
valve was opened so the hot fluid could pour in. It took only a couple minutes to
fill the bottle, however, the time spent for the entire operation lasted about 2
hours. After taking a few more pictures of the site, they left to return the full bottle
to the ‘‘lift’’ and then followed their course at 080° towards the eastern wall at a
distance of 250 m, so they could make another visual crossing. Then, they went
back again towards the west wall of the graben where the dive terminated at 16:15
at a depth of 2,623 m.
Since the fluid sampling was successful, a geological dive (Cy82-24) was made
in the same area by the geochemist, Francis Albarede, on February 12, along with
Guy Sciaronne as pilot and Pottier as a co-pilot. As long as I have known Francis,
he has always had a mustache, with a gentle smiling face. As a young specialist in
rock geochemistry working at Institut de Physique du Globe de Paris (IPGP), he
had become very interested in hydrothermal fluid circulation.
The Cyana left the surface at 09:28 and reached the sea floor at 10h44 at
2,595 m depth. They landed on the first step of the eastern wall and they went to
the graben floor before starting their profile towards the western wall at the
hydrothermal site. The aim of this dive, in addition to doing the geological profile
of the spreading axis, was to take fluid samples on two black smokers and, if time
Cyana Dives on the EPR at 12°50
0 N
217
Jean Roux, head of the submersible team, was very eager to dive on a hydrothermal field. I found it normal that someone who had been spending so much
energy and time to direct each dive would also like to see how the sea floor looks
in this particular active spreading ridge segment. Also, this would be an opportunity for Jean to observe the high quality performance of his group in handling the
Cyana. Hence dive Cy 82-19 was made with Jean Roux as the science observer
together with Guy Sciarrone and Arnoux.
At 09:51 Cyana was in the water and ready to dive. The team reached the
bottom at 11:04 at 2,600 m depth in the axial graben near the eastern wall. The
purpose of the first part of this dive was to perform water sampling, which meant
going to pick up a bottle made of titanium/carbon that was stored in the ‘‘lift’’. So,
first the submersible had to find the basket and pick up one of the two water sample
bottles that were inside. The basket was about 80 meters from the submersible as
shown on the radar screen and by the transponder beacon beeping its signal. At
11h32, after localizing the ‘‘lift’’, Cyana went to pick up a water bottle and then
went back to the target. At 11h48 they arrived on the ‘‘black smoker’’ and started
to sample the hot fluid exiting from the chimney. Using the starboard arm to open
the small valve of the bottle that was held by the port side arm, the pilot, Guy
Sciarrone, completed this delicate operation despite the small size of the valve,
about 3 cm long.
Bottle filling required a pilot to show a great deal of skill to successfully
complete the maneuver. The submarine had to be stabilized correctly in neutral
buoyancy without moving. The observer and the co-pilot held their breath, and no
motion was allowed on board. This could jeopardize the operation and even be
dangerous for the safety of the submersible because of the high temperature of the
exiting fluid (about 300 °C). At 13h19 the bottle was on top of the chimney and the
valve was opened so the hot fluid could pour in. It took only a couple minutes to
fill the bottle, however, the time spent for the entire operation lasted about 2
hours. After taking a few more pictures of the site, they left to return the full bottle
to the ‘‘lift’’ and then followed their course at 080° towards the eastern wall at a
distance of 250 m, so they could make another visual crossing. Then, they went
back again towards the west wall of the graben where the dive terminated at 16:15
at a depth of 2,623 m.
Since the fluid sampling was successful, a geological dive (Cy82-24) was made
in the same area by the geochemist, Francis Albarede, on February 12, along with
Guy Sciaronne as pilot and Pottier as a co-pilot. As long as I have known Francis,
he has always had a mustache, with a gentle smiling face. As a young specialist in
rock geochemistry working at Institut de Physique du Globe de Paris (IPGP), he
had become very interested in hydrothermal fluid circulation.
The Cyana left the surface at 09:28 and reached the sea floor at 10h44 at
2,595 m depth. They landed on the first step of the eastern wall and they went to
the graben floor before starting their profile towards the western wall at the
hydrothermal site. The aim of this dive, in addition to doing the geological profile
of the spreading axis, was to take fluid samples on two black smokers and, if time
Cyana Dives on the EPR at 12°50
0 N
217