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April 17, 2001 This specific question is going to be directed to Bob Collier and Marvin Lilley. Has their been anything on this expedition so far that has been very uncommon or that made you second guess your findings? If so what were they? Stacy Misiak Excellent question, Stacy ... do you have a spy onboard? The environment continually presents us with puzzles that test and challenge our ideas about the way the ocean works. For instance, we have quite a bit of experience chasing hydrothermal plumes and we think we know what features to look for and what processes cause them. In our first few days at the 24¡N target, we looked for plumes and found clear suspended particle signals with dissolved methane, manganese, and iron. These are the signals that are derived from the original vent fluids. However, we found absolutely no temperature or salinity anomaly that we could detect. On previous expeditions, we could always detect at least some weak temperature signal in the presence of such strong chemical signals, so we were perplexed. Furthermore, the particle signals had a lot of “fine structure” - they were thinly layered with lots of variations over just a few meters distance. It looked like we must be very close to the source of those particles ... but again, no heat signature. The next few days, we found yet another particle plume nearby, and we chased this for quite a while until we finally decided that it had been caused by the resuspension of normal bottom sediments. This could have been a natural submarine mudslide or, perhaps, we even triggered the event by our own seafloor sampling studies. In any case, the water samples we collected here contained NO anomalous chemical tracers from hydrothermal vents. We still had the puzzle of the first observations and we knew, from the current meter, that the signals probably came from the north. So over the last two days, we looked at a site located 8 miles north (we know that we can usually ‘see’ hydrothermal signals that far away). We were very successful. I can’t promise that we will find the vent origin on this cruise, but we are very close (yet again, this is another hypothesis). Perhaps most satisfying was that we found all the tracers together - heat, dissolved chemicals, and particles. If this is the source of the signals we saw 8 miles to the south, we clearly do not understand how the fine structure of particles layers are maintained over such a distance. Throughout this process, we continually challenge our hypotheses - could these vents be chemically different from others we have seen? Could the currents have been coming from a different direction? What geologic formations are upstream that are the most likely origin of hydrothermal vents? Let’s hope that we can close in on the new vents in time to visit them with Jason and sample their biology and fluids! Thanks for your e-mail and for ‘tuning in’ to the cruise site. My sister suggested we were like a bunch of kids waiting around for “mail call” at summer camp. But this MUCH better than summer camp! Regards, Bob Collier Janet, What’s the best cure for an upset stomach due to seasickness, assuming that you don’t have Dramamine handy? Thanks, Dear Christy, Thank you for your question, its a good one. There are several things you can try for seasickness if you don’t have Dramamine. If your able, go out on deck (if the weather is not too rough), and look at the horizon. That helps a lot. If your stuck inside of the ship, it is better to stay in the middle of the ship and on a lower deck, because there is less motion. You should always try to keep some solid food in your stomach, even though you don’t feel like eating. Lots of people tell me they feel better if they lie down. Don’t get upset, you will get your sea legs eventually! Thanks for writing Christy, we love hearing from you. Janet Costello RN,CEN |
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