Thursday, October 15, 2009

Under Pressure

Not just a blogger. Here’s me (left) and Sean (right) putting the CTD outboard in mid-afternoon: our 2nd deep cast of the day.

Savour the moment. After a very heavy rain squall in late afternoon we had a beautiful evening. This photo was taken right after dinner during a 10 minute break waiting for the CTD to come back up to the surface. Pretty phenomenal view, huh?
Position at Midday EST (CTD Cast 19)
Lat: 18° 22’N Long: 081° 42’W
Water depth: 4350m

It has been a long day today and time has been on my mind. Amazing to think that we have only been working on the Mid-Cayman Rise for 4 days so far, we haven’t yet started our science missions with Nereus either, but even so I’m already worried about the days running out. This may seem bizarre because we only expected to be halfway through the CTD program by the end of Day 4. Instead, we are currently mid-way through our 22nd CTD cast, we only have about 10 more stations to complete and we already have one known target to follow up on (I wasn’t really expecting more than one). So why the hustle?

Well, there are three things trying to gain prominence in my mind: first, we have near perfect weather right now (winds down to 5 knots, seas of less than 1 foot in height) that we want to take advantage of; second, we want to build confidence in and gain experience at using Nereus in AUV (free-swimming) mode sooner rather than later; third, we want to complete the systematic search of the Mid Cayman Rise as soon as we can, because while we already found one site to follow up on, we don’t want to spend all our time there if it turns out that the southern end of the ridge has something even bigger and better to chase after.

So today we have been burning through CTD stations as fast as we can to get south sooner rather than later whilst, at the same time (in a 12 hour shift I typically only get 2 occasions when I get 1 hour of peaceful “quality time” as the CTD is being lowered to the seafloor) trying to work with the likes of Dana, Mike, James and Louis to plan out exactly what the mission should be for tomorrow’s Nereus dive.

It is now 10:45pm and we are working to a Plan A and a Plan B mission because we know we’ll be ready to launch tomorrow afternoon and we know we’ll have great weather for as long as Nereus’ batteries will last (we’re expecting a 14 hour mission or more overnight from Friday into Saturday morning) but squally weather is due to reach us on Sunday that will preclude any further Nereus work on Sunday or Monday. That’s as far as our weather forecast goes but if it is going to be lousy at that point, chances are it’ll take at least another day or two for the seas to lie back down – in the best case scenarios.

So we know we can get one good dive in, starting tomorrow, and that we can take advantage of the remaining good weather to complete all our remaining “survey” CTD casts between Saturday midday and Sunday midday while the weather remains good (this is also a key component of the Captain, Chief and 2nd mates being able to keep the ship stationary to within 100m for up to 5 hours at a time as we lower the CTD 5000m or so to the seafloor and back).

After that we’ll still have more than a week to play with and we’ll also have all the information we need to know exactly where we want to focus the rest of our efforts. But what will the weather allow? Its at times like this you just have to take a deep breath and accept that when working in the deep ocean – no matter how good your planning – you just have to accept what Nature brings your way and be ready to make the most of it… …whatever that may be.

Oh, and one last thing preying on my mind (Blog-writing as therapy?) – it’s my big brother Tim’s birthday this coming weekend (Sunday 18th) and I’ve forgotten to send him a birthday card. It was him who first got interested in Geology when I was much younger and I completely missed the opportunity to pick up on it at the time (hard for a 10 year old to see the bigger picture beyond digging fossil ferns out of Thames estuary mud-flats!). So now, to help make amends for being an ingrate back then, I want everyone reading this blog to set their alarm clocks for around 10am (UK time) on Sunday (5am East Coast USA; midnight in Hawaii?) and shout so loud that he can hear it all the way across the Atlantic “Happy Birthday, Tim!”

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