 Welcome home. Nereus being lifted out of the ocean at the end of its first AUV-mode science mission. No room for error. There isn’t a lot of spare space on the deck of “the little ship that can”. From left to right: Casey, Daniel, Andy and James carefully lower Nereus into place in its cradle. We had to add the wooden uprights because otherwise, whoever is driving the crane from the deck above cannot see where Nereus is being landed. Caught in happy nerd land. Here’s me, Ko-ichi, Dana & Louis, at the very moment that Dana plotted up the Nereus data, freshly downloaded from the vehicle, confirming that what we are on the trail of a high-temperature “black smoker” vent. |
Lat: 18° 22’N Long: 081° 42’W
Water depth: 4350m
OK, so the mission did not go quite as planned and we also ran out of battery power earlier than expected (around 11am) but we don’t care too much about that because during the 20 hours that Nereus WAS submerged we made a major breakthrough.
Just around 2 miles north of where we had seen potential plume signatures during a CTD cast a few days ago, Nereus intercepted some new plume signals, at exactly the same depth, but much stronger – i.e. we’re getting closer. Not only that, but the combination of signals we got from our optical sensor, as well as Ko-ichi’s sensor that detects for chemical anomalies confirms, for the first time, that what we are on the track of must certainly be a high-temperature hydrothermal vent, also known as a “Black Smoker”.
We still have plenty to do to track the plume back to its source but at least now we have a much better clue of what it is we’re on the trail of. And we also know we now have an excellent additional tool to help us with the search.
Tonight we are back to completing our systematic survey to the southern end of the ridge, because we still don’t know if there’s anything bigger and better still waiting to be discovered. That will be completed by Monday morning and then it’ll be time to start chasing down whichever signal seems like the best bet at that point, with whatever the sea conditions will allow us to set to work with.
So, given that there's evidence of a "black smoker", how is it found? Is it a matter of narrowing the possible location to some patch, and then simply surveying it with a raster scan? Or is there something more sophisticated, like having Nereus or other device follow parallel to the gradient of greatest local concentration? I imagine undersea turbulence isn't that big of an issue, but could of course be wrong.
ReplyDeleteThanks!