Last night instead of heading east to begin out four-day transit to Costa Rica, we headed south. Word had reached the ATLANTIS that a new hydrothermal vent field may have been born and we were uniquely positioned to find out if this were the case. Geophysicists had recovered a deep-sea acoustic data recorder that listens for and records sounds from deep in the earth, including those characteristic of lava eruptions and origins of new vent fields. Data from the recently recovered recorder suggested that fairly close to us was a new vent field and we were asked to investigate. It wasn't on the way home, and "near" is a word that means something entirely different on a ship with a cruising speed of 12 knots rather than in a car on the interstate.

We saw additional problems posed by this request as being that 1) none of us on board knew much about the exploratory methods used to detect a vent field (other than going to look for it with ALVIN); 2) the required work would take hours and we, after all, wanted to go home for Christmas after having worked without a day off for weeks; 3) the work would take all night and require someone to be up and paying attention every minute; 4) if there were no vent field (which we figured was as likely as there being one), we could look for hours and never know if in fact it was absent, or if we simply missed it; and 5) only the equipment that happened to already be on board the ship was available - no one packed to do this type of research on this cruise. The advantages of saying yes to this request were that 1) we were comparatively close to the site; 2) we are on among the best-equipped ships to do this type of work; 3) our SSSG technicians, Chrissy van Hilst and Robbie Laird, know how to operate the equipment (which was onboard, no thanks to us) and were willing to do so; 4) it was a great opportunity to explore and discover; and 5) if we said no, we would refute the existence of cooperation among sea-going scientists; no one wanted to risk that. We talked it over and agreed to go for it. We all dug through our remaining supplies and came up with pretty much everything we needed. Our SSSG's trained volunteers to do what had to be done and we have to face facts, the students on board were the true altruists in this operation.

To see if a new vent field existed, we couldn't use ALVIN; although the geophysicists told us where to look, the target area was huge. Instead we searched the water column for vent fluid using a CTD. This high-tech piece of equipment senses the Conductivity (or salinity), Temperature and Depth (among other things) of the water surrounding it and relays that information to a computer onboard the ship. The CTD is mounted on a round apparatus (rosette) that carries open bottles and the whole thing is lowered from the ship to 50 m above the bottom. The bottles are rigged so that when the CTD data suggest that vent fluid is present, the person watching the computer recognizes it and hits a button to close individual bottles and sample exactly that water and return it uncontaminated to the ship. The samples are then preserved for sophisticated shore-based analyses. It's a cool set-up, but other than getting the apparatus off and on the deck, you just sit and monitor the computer screen - All Night.