Institute for the Study of Earth, Oceans and Space

Follow UNH professor and researcher, Karen Von Damm, and her crew on leg 6 of voyage 7 on the R/V Atlantis, a Woods Hole Research Vessel. The following log is Karen Von Damm's e-mail from the R/V Atlantis . . . Click on the images for a full view.

Research Log
East Pacific Rise; 9-10°N latitude

Tuesday, January 22, 2002
Alvin dive 3759 is back to 9 33.5°N, to finish the objectives we were unable to accomplish on dive 3757 because of the mechanical problems. This is another PIT dive. As the site is found and sampled, the two transponders that we placed in order to have navigation here, are released, and recovered by Atlantis, before Alvin leaves the seafloor. This way if they fail to release, Alvin can go over and break the cord holding the transponder to a weight, as we did on dive 3751.

Wednesday, 23 January 2002
North of A vent that we visited on dive 3753, we know of several active vents, we also know of areas here that were active before the 1991/2 eruptions, but at which we did not find vents and animal communities in 1991 or 1992. This looked to be a very active area in 1989, but we haven't really had time to get back in and explore it. Today we'll do a little exploring, as well as sample a known vent in the area. To our delight, just after landing on the seafloor, we find a vent site with an active animal community which we did not know about. We note its location, sample some animals including tubeworms and mussels for genetic studies (to see if these animals are related to the ones we know of about 5 km further north). As we leave this area, after about another 200m, we find two more vents. The surface controller on Atlantis thinks we are very lucky indeed! We sample one of these other two vents. We'll have to come back for the 3rd on another day, because we've filled all the water bottles and bioboxes we have on Alvin today. The 2nd vent may be the one we were expecting to find - later we'll check more records we have on Atlantis and contact colleagues via email to see if they left markers at V vent - which this may be. We then drive another 1.5km north. While we don't find any more vents, we see enough animals in the water column and on the seafloor to suggest that there must be warm water coming out of the seafloor not too far away. Our visibility seems to be less than the usual 15m or so from the Alvin viewports, again suggesting we are near something. Tantalizing, but frustrating, but with 2 vents seen and sampled today - at least one of them unexpected - its been a good day overall on the seafloor!

Thursday, 24 January 2002
Today, dive 3761 is back in the 9 50'N area. It starts in the Transect, sampling some diffuse flow hydrothermal sites that were previously a rich tubeworm community, but since the last time we were here several years ago, the mussels have moved in in force, and most of the tubeworms are now gone. Today is also a PIT dive. Towards the end of the dive, the sub goes out of the Transect area to the north, and a couple of black smokers are also sampled. When we collect water from the chimneys, we also collect part of the sulfide chimney itself. This is a high energy environment, and in addition to the tubeworms, etc., there are also diverse microbiological communities living in the structures. We know little of these life forms, so the chimneys are important samples that are brought back to the Atlantis protected from the water column, so culturing studies can be done on them. This is also "Hump Day", or the half way point of the cruise. Once the sub is back on board, we all have a bar-be-que, which is a chance for all to relax a little.

Friday, 25 January 2002
We have known for a few days that there is a serious electrical problem with the submarine, and we planned a few days ago that today would be spent repairing it. So, while Alvin is being worked on in its hangar in Atlantis, we travel down to 9 17'N latitude, the most southerly vent area know at "9 North"and drop transponders so we can dive here tomorrow. We also use Atlantis to "rock core". Using a wire and winch on Atlantis, we drop a specially designed weight (otherwise known as "Mighty Mo") with waxed covered heads on it to the seafloor, in order to get samples of the basalt (seafloor rock) for chemical analysis. This will help several of our collaborators to better understand how the oceanic crust is formed. The scientists on Atlantis also use this day to catch up on analyses, sleep and laundry.

Saturday, 26 January 2002
Today on Alvin dive 3762, we are off to look for F vent at 9 17. Alvin dives are numbered sequentially, so Alvin has made over 3700 dives in its over 30 years of existence. We have not been to F vent since 1994, so we don't know what we'll find - an extinct vent? Lush animal community? We just don't know. F vent is in an area that is more complex geologically, making it more difficult to find than some of the others. Within hour of landing on the seafloor we are at F vent! We know we are here because we see the marker we put here in 1991, next to a small field of 10s of chimneys. Many are now extinct, and the only animals are anemones, crabs, a few alvinellid worms, and a big white fish. However, there is a lot of rusty looking material, some of which is bacterial mat. This place is a little difficult to work in, because if we stir up the rusty material with Alvin's props, we end up in a cloud of orange, and have to wait for it to settle. We find a few areas of active venting, with water coming out at almost 300C, so we sample these, and also measure their chemistry with the chemical sensor we have on Alvin.

Sunday, 27 January 2001
Today its back to the 9 46-47'N area to sample one of the vents we saw, and left a marker at, on dive 3760. This is another PIT dive. Before arriving at the vent where we left our Marker 21, the people in Alvin look for other vents where we have seen them before. An active vent we found in 1991, is now only a small pile of hydrothermal sediment. We know this, because we find one of our markers there. Then its on to this other vent to collect water and animal samples.

Monday, 28 January 2001
The plan for today was to go to another area of venting at 9 38.8'N. In order to do this, we put out transponders here 2 days ago. The weather, however, is not cooperating. High winds blowing since yesterday continue - although the skies are sunny. The A-frame on Atlantis has been having some problems, and we decide because of the wind and resulting waves, that it is not safe to launch Alvin today. The divers for today are disappointed - hopefully the weather will be better tomorrow.