Sunday, October 18, 2009

Running Up The Score

My fair-weather friends: Tina and Sean putting the CTD outboard in bright sunshine, Sunday morning.

There goes the neighbourhood – this is what our view is gonna be like for the next 48-72 hours. So THAT’s why so few devote their lives to deep-sea oceanography!

Welcome to the Caribbean? This is not like the Johnny Depp movies, and no, that bottle I’m holding is NOT full of rum - shame. Actually, the key to sampling in the rain is to make sure you don’t get any water in your seawater. Or, if you listen to Sean, the key to sampling in the rain is to get all your samples taken before it starts and then photograph your chief scientist who was following along behind you.
Position at 12h00 EST (CTD 33, end of our initial survey)
Lat: 17° 50’N Long: 081° 50’W
Water depth: 4650m

Come to the Caribbean, they said. Enjoy a sunshine cruise, they said. Bah humbug! In the past decade I have out-run typhoons in the southern Indian Ocean and been snowed on, out on deck in the Norwegian-Greenland Sea, in pursuit of hydrothermal activity on ultra-slow spreading ridges. Heck, I’ve even had friends go and break holes in the ice in the high Arctic. So I thought heading to the Mid Cayman Rise, by comparison, was one of the smartest scientific ideas I ever had!

Actually, I’m not sure I’m wrong, either, because while the New England Patriots were winning 59-0 (a little snippet of news that DID make it through from Woods Hole this weekend) we were busy running up our own score too. When I got out of bed this morning I knew we had found one set of hydrothermal plume signals but by breakfast, Doug, Carla and Koichi had shown me their overnight results for a 2nd source and by lunchtime, Tina, Sean and I had found evidence for a 3rd. Slow down, I can’t handle that much information in a hurry.

By the end of the day we had managed to take stock at a science meeting to coincide with the watch change and agreed that we had evidence for two high-temperature sites – one in the northern half of the ridge, the other right at the southernmost end (showed up in all 3 of our last 3 casts across the southernmost end) – as well as some kind of low-temperature wispy thing that is leaking methane into the water column at a very shallow depth near the top of the highest point on our maps, not too far from the first deep plume.

So after a quick emailed consulation ashore with the other half of our PIs who are joining us in Grand Cayman next week, we are going to set to work Monday trying to track the northern Hi-T plume to its source.

Trouble is, the weather is now against us. It is blowing hard and the seas have risen with no sign of improving enough for a Nereus launch until Wednesday and no guarantee of decent weather persisting beyond Friday. So while we have a week left to track things down we may only get one or two more dives with Nereus. Which means a bunch more use of the CTD. At least now we can get creative with that. Instead of just “parking” the ship at a certain spot and lowering the CTD down and back up again, we’re going to see how the weather is set and then attempt to drift across our target area, raising and lowering the instrument package as we go to collect data in a saw tooth pattern across the depths we’re interested in.

Of course, if we were really smart, we would design and build some kind of robotic instrument that could do that kind of work for us. Oh wait, we did!!! So now we just have to wait for what Nature will provide for us in the week ahead. Wish us luck!!!

1 comment:

  1. Good luck, guys! It'd be neat to see some data with your interpretation, if you have some down time, and if you can share.