Friday, November 6, 2009

Passing the baton

That elusive pot of gold… Tradition has it that all cruises end with a sunset. But, just like I have kept to a promise I made myself at the start of the cruise (no matter how boring the blog is, do NOT start writing about what you had to eat). I’ve decided to skip the sunset instead and end with something I had never before seen at sea – a perfect Rainbow. This was a photo we took while riding in very rough and rocky weather back to Grand Cayman at the end of Leg 1 and came to mind today when doing exactly the same at the end of Leg 2. We were sailing right toward it as the sun went down and night fell so I like to think we passed right through its archway.

Position at 13h00 EDT – Approaching Grand Cayman
Lat: 19° 09’N Long: 081° 29’W
Water depth: <2000m

So we are on our way home. Soon after I posted my last blog yesterday the weather turned against us and rose above 20 knots where it has stayed ever since. Indeed, Steve and I even saw gusts over 40 knots at our last CTD station when we got up around 2am to do that final shift. Needless to say that meant the chance of a final Nereus dive to our vent site today never happened. Even the idea of using our small grab became a non-issue because of safety. Actually, that was probably a good thing.

When I thought of that idea last afternoon it was as a chief scientist for this particular project, wanting to get the best possible samples for my various colleagues aboard ship. But then there is the bigger picture:– working in the deep ocean, this project included, is an international collaboration that isn’t ever finished with a single cruise. Considering that what we had found at the bottom of the Mid Cayman Rise may be a quite unique habitat, what might have been more irresponsible than lowering a sampling system in amongst it, blind? Far better to wait until circumstances (e.g. funded research projects, favorable weather) will allow us (as in the collective “us” of the international research community) to do the job properly.

This is what various programs that I have been involved with in the past decade - including the Census of Marine Life and InterRidge, both of which have been very supportive of our work – strive to achieve. So while it would have been wonderful to achieve everything we hoped for in less than 4 weeks on station here, in this first program, what we have already done is prove (a) that there is actually hydrothermal activity present and waiting to be investiagted and (b) localized key target areas from the blank canvas we started with (2000 sq km) to some very precise targets on the seabed. We’ve also proven that – on the days that the weather allows – the technology now exists to send our new Nereus robot vehicle to great depths and observe the seafloor from a much smaller research ship than had ever previously been possible. We think that must already be a world record in its own right.

Of course, that does still leave some major research questions unanswered. From the seawater samples we collected yesterday we will be able to make quite accurate predictions of the types of hydrothermal venting that wait be visited on the seafloor – but nothing about their biology. Happily, it probably won’t be long before those questions, too, get answered. Informed by what we have learned here, two new research cruises will be returning to the same area in 2010, the first in just a few months from now. This time next year, Jon Copley – who will be taking over from me as InterRidge Co-Chair on Jan 1st 2010– will be leading a cruise from the National Oceanography Center, Southampton to dive to the MCR using Isis – the sister vehicle to WHOI’s better known ROV Jason. But before that, Doug Connelly (you’ll remember him from Leg 1) will be back here next April on a precursor cruise as part of that same project, picking up where we left off. You can be sure that all of us from this team will be doing all we can, whether ashore or at sea, to help support that program – just as Jon, Doug and their colleagues have been so supportive of our cruise this year. So don’t be surprised if you pick up this thread again, somewhere in the blogosphere, before too long. But before that, Jon, Doug and I will all be off on a different (but closely related) adventure – off to the Antarctic next January to dive on new vent-sites we have already tracked down on a similarly isolated stretch of mid-ocean ridge, down there.

So now, as I sign off, I just want to pay tribute to you the readers (both of you?) and, especially, everyone it has been my pleasure to sail with on this trip. Mark (Chief Enginer) paid us the great compliment this morning of telling me and Andy that he had never in his 18 years at sea enjoyed such a combination of good humored, well-motivated and professional research throughout such a long cruise. I can’t take credit for that – I’m just the chief cheerleader – but I do want to echo the sentiment. It has been a great privilege for me to come out here and (i) work with the Nereus engineers as they put their new robot through its paces, (ii) share with my international research colleagues as we have made a series of REALLY cool scientific discoveries (specially considering I thought there was only a 50:50 chance that the MCR might host any hydrothermal activity in the first place) and (iii) achieve all the above in the fantastic environment provided by Captain Dale and his crew whose support, dedication and interest in our work has made all the difference to what we have managed to get done. The RV Cape Hatteras truly has lived up to its reputation as “the little ship that can” and I hope I soon get the chance to sail with her again.

Message ends.

Thursday, November 5, 2009

Down to the wire

Not exactly fireworks (it is bonfire night back home in the UK today) – but these wiggly lines were enough to put a smile on our faces this afternoon. The green trace, whenever it plunges down the screen, is from Ko-ichi’s Eh sensor and tells us when we are closest to the plume source. The blue trace shows the depth of our instrument package as it varies with time (the axis across the bottom of the screen) as we pulled the CTD along behind the ship, lowering and raising it through the water screen. It’s not quite as exciting as watching hydrothermal vents and animals via video cameras would have been but as some of us enter our 5th week out at sea, its amazing what simple pleasures you can glean from just about anything!

Will we, won’t we??? This afternoon the wind-speed has been down in the Nereus comfort zone of 10-15 knots although not often at Andy’s favourite of less than 11 knots. So what will the next 24 hours bring? Will the weather continue to subside, or will it get worse again? Our vehicle is ready, our scientists are ready, and we know exactly where to go. But without a guaranteed 12 hour good weather window, we still won’t be able to launch Nereus and get the final job done. Sickeningly, the longer-term forecast DOES say that the weather will improve here after Sunday. But by then, most of our team will have jumped ship in the Cayman Islands and the rest of us will be on passage back to the Cape Hatteras’ home port in Beaufort, North Carolina.

Position at 11h30 EDT – CTD 56
Lat: 18° 32’N Long: 081° 44’W
Water depth: ~4850m

Funny how fast things can change at sea. We finally got the CTD working again last night after about 8 hours becalmed in vent-infested waters and have made out like bandits ever since. Actually that’s not quite exactly true. Due to a slight miscommunication error we ran a 6 hour tow-yo between suppertime and midnight last night that didn’t go right through our strongest plumes from earlier in the cruise as planned but, instead, flew past about 400m to the south and measured nothing, all the way. So we have the southern limits to where the vents can be REALLY well constrained now. Overnight we sailed back to our shallow site about 15 miles SW of here and lowered the CTD just before breakfast. The in situ sensor data didn’t look specially promising there , either, but we collected samples from each 50m up above the seafloor anyway and were duly rewarded for our persistence. Jeff and Jill measured the highest dissolved methane concentrations of the trip – by about a factor of two – in their samples from that cast and so we also collected samples for everything else we came equipped to sample for: metals, helium isotopes and microbial studies. Not bad for an early morning shift.

This afternoon the work got even better. We lined our CTD tow-yo run back up (in the correct position, this time) and ran a line that went right over the vent-site. The 30 minutes when we were right in the core of the plume not only coincide with our two previous strongest sets of anomalies (1 each from Leg 1 and Leg 2) but also coincide with when we were passing directly over a small semicircular feature that is about 200m across and 20m high, sticking out from the base of a volcanic cliff. How do we know it is sticking out from a volcanic cliff? Because it is the SAME cliff that we dived on with Nereus last weekend! Honestly – we were within 200m of the vents, twice, earlier in the cruise: on our last dive with Nereus in AUV mode on Leg 1 and our first proper dive in ROV mode earlier in Leg 2. Unfortunately, being 200m off still counts as a long way away when your mapping device can only see 40m to a side and your cameras can only see 10m or less in any direction. Call that a swing and a miss.

But there’s no point feeling sorry for ourselves and wondering “what if?”. This evening we are lowering the CTD back down, right over the site, in the hope of collecting another complete set of great samples, just like we collected at the shallow site this morning. And we’re also keeping a close eye on the weather. Our forecasts continue to be grim but this afternoon the winds have been below 15 knots when they were predicted to be closer to 20 and the waves were definitely lower than yesterday. If things continued in that trend we could still be in with a shout. Trouble is, that is NOT what is predicted and its no good launching Nereus just because the weather is good now. It is what the weather will be like 12 hours later, when we need to be able to bring the vehicle safely back aboard that matters. So we’ll remain poised and ready – like coiled springs – and optimistic right up until our time runs out:– about 36 hours from now. In the meantime, I have just remembered that we do also have one other last trick up our sleeve. Although we don’t have much variety of scientific gear aboard ship – after we had loaded Nereus and the CTD there wasn’t room for much more – we do have a small grab system that we could mount on the bottom of the CTD cable, instead of the CTD itself. So if tomorrow comes around, and we do already have all the water samples from here that we need, then even if Nereus still cannot be launched, we may yet be able to get David, Julie and Max some pretty cool samples from the seafloor.

We’re definitely not done yet - but I’ll still keep hoping for that one last Nereus dive…

Wednesday, November 4, 2009

If it wasn’t for bad luck…

Leaving it’s mark(er). When we come back here in future – and we surely will – this little marker on the seafloor will provide a “reality check” between one cruise’s navigation systems and the next – as well as a lasting testimony of some of the challenges faced, and the contributions made to deep submergence research by “the little ship that can” and all who sailed with her to get us this far along our path.
Position at 14h00 EDT – Too rough for Nereus, CTD undergoing repairs
Lat: 18° 31’N Long: 081° 44’W
Water depth: ~4850m

… we wouldn’t have any luck at all, it seems. When you’re out at sea you sometimes just have to take a few knocks and keep going. Where that becomes tough is when the knocks keep coming from various directions. Here’s yesterday’s tales of woe:-

1. Deceived by bathymetry. On Monday night we thought we had the source of a low-temperature site narrowed down because the source, based on depth, should have been on top of one of two small hills: the only places shallow enough to be responsible. Trouble was, when we landed with Nereus, the depths on our map were out by about 150m or so. This made our search area (everywhere shallower than 2150m) about 10 times bigger than anticipated. We searched hard for 10 hours and got lots of information about where the Eh signals were getting stronger and weaker in the water column, but we eventually got to the point where we couldn’t double back on our fiber. The final piece of evidence showed the source was still to the south of us, but all we could do was go north – and we were out of battery power anyway. So we left one of our markers at the seafloor to show where we left off – anchored, instead of the usual dive-weights, with a coffee mug of the RV Cape Hatteras (a ship’s tradition we were happy to help continue) and headed back up.

2. Deceived by sensors. Something else we found out during that last Nereus dive. When you are driving across the seafloor and then stop, our temperature sensor gets warmed up and, if you stay put long enough, the warming effect (because you aren’t constantly driving forward into fresh cold water, can also cause small signals on the Eh electrode. We found this out by stopping to look at some outcrops of old lava covered by sediment on this last dive. Nothing hydrothermal in site, but when we moved off, our sensor data had recorded anomalies just as big as the ones Nereus had collected at the end of Leg 1 while making a map close above the seafloor. There, the biggest anomalies coincided with when the vehicle – in autonomous mode, was having to climb the steepest terrain: across the very top of the volcanic hill and when approaching the base of, and rising up , some steep cliffs. Both locations looked attractive as potential hydrothermal sites – so the same data set had fooled three of us, each working independently to select where we should dive with the ROV to make sure we didn’t make a mistake. So how did we get that wrong? Well, steep terrain like that is also exactly where Nereus, in autonomous mode, would have been most likely to have to slow down and take time to adjust its dive plane before climbing vertically up and over the seafloor. And that slowing down process, we now know, could be just as capable of generating anomalies in temperature and Eh: signals we had mistaken for a hillside covered in weak diffuse hydrothermal flow.

3. Heart-broken by the weather. Even though we had spent two ROV dives – and had been preparing for a third - chasing after false signals in our sensor data, we still could have been in good shape for the rest of the cruise. Whatever else happened, we still knew of one high-temperature site that should be present in our search area. We don’t think it is likely to be the source of most of the plume signals we have been detecting but it is less than a mile from the deeper hill we had dived on previously. We found it rather by accident on an early Nereus dive when our compass went wrong, so we don’t have the greatest navigation data to show exactly where it is. But even so, we believe we know where to go to within 100m on the seabed because between 35 and 36 minutes past midnight, on an evening dating from about 2 weeks ago, Nereus passed through a column of hot, smokey water while driving around just 120m above the seabed. So last night we went back through what data we could salvage from that work to decide exactly where Nereus should dive next as an ROV. We got up this morning (most of the Nereus team were up at 5am) to prepare everything for launch, and then waited for the latest weather forecast. Which told us that the weather was due to turn worse today and might continue to get worse still for the rest of the week. Given the problems we had at the end of Leg 1 we had no choice. We had to postpone today’s dive until further notice and hope that, for the first time in a while, the weather forecasters will be proven wrong

4. Let down by our trusty CTD. You wonder whether your time’s up when even your best friends turn against you. Given that the sun is shining, the sea is blue, and there is a fresh breeze blowing, even the fact that we still couldn’t launch Nereus this morning didn’t have me too downhearted. There was still much to learn and interesting samples to be taken with the CTD that has been a trusty work-horse since the cruise began. But overnight last night and into today, even that has begun to get its own ideas about how many more times it wants to be deployed. Since 8am this morning we checked through everywhere we have already been in our area and where is left that the big vent-site we are after has left to hide. With another 12 hours of work we reckon we would be ready to lower the CTD right onto the site. Even if we couldn’t launch Nereus again in our last 3 days, that would still be pretty cool to achieve. But maybe the CTD has become self-aware and doesn’t want to risk getting its feet scorched? Because on 3 attempts since 10m, it has thrown up technical problems when we’ve tried to put it to work. Poor Steve is doing his best but it must be frustrating – Chris and Daniel have volunteered their help from the Nereus team (they are frustrated in a different way because they don’t have any ROV driving to do) but there is a limit to what any of the rest of us can do but sit here and wait.

As I said to Andy just before lunch: “A weaker person might begin to feel discouraged at this point.” But I’m probably just flattering myself there – weaker should probably be replaced by “smarter” or, at the very least, “less stubborn”. But we still have 60 hours left (psychological trick: sounds bigger than just 2 and a half days) so hope springs eternal - no point coming all this way and then not doing as much as you possibly can, right up to the end.

Monday, November 2, 2009

Decisions, decisions…

David and Julie H (from our ship) wave off our recent visitors – science colleagues Julie S and Cindy, flanked by Ari and Mark from National Geographic. They may have taken two of our scientists away but we traded them for Katy, their field producer, who will continue to ride the ship with us all the way back to Grand Cayman at the end of this week.

The tug boat Sand Cay as it departs for Grand Cayman - we'll see this little boat again in just a few days when we drop most of the rest of the science crew off.
Position at 16h00 EDT – End of CTD 49
Lat: 18° 21’N Long: 081° 51’W
Water depth: ~2500m

At times like this, when time is closing in on us, working out how to make use of the last few days of the cruise can prove quite tricky. Last night we finally got a good dive to the seafloor. Trouble is, the seafloor wasn’t quite so good to us. We landed on piles of lava with varying amounts of sediment and for the entire dive that is pretty much what we saw, everywhere, all the way up one side of the hill we had targeted (although we didn’t stop to look too closely, anticipating there were vents up the top) and all the way back down the other side. At around 6am it was time call things quits and bring Nereus back home. So what to do next?

Looking ahead we came up with a range of plans: (a) go back down and survey the other half of the same hill more thoroughly in the hope that it would be more rewarding than last night’s dive; (b) pursue a different set of plume signals from Leg 1 that were not so strong but might be easier to locate on the seafloor; (c) drive up a long-lived fault half-way down the ridge where hydrothermally altered rocks had previously been located or (d) dive to the top of that same shallow hill based on a hunch that the high concentrations of dissolved methane that we found at shallow depths in the southern half of the ridge on Leg 1 might be coming from their summit.

To follow up on the latter idea we conducted two more CTD stations this afternoon just off the top of that large feature (termed a detachment fault or, more poetically, a Mega-Mullion) which showed up both in the dissolved methane concentrations Jill & Jeff measured as in Ko-ichi’s Eh electrode sensor data. Gambling that we may have tracked those signals down to one of two shallow hills atop the very summit, that is what we’re going after in Nereus dive 26 tonight.

Not least in our minds when reaching this decision is the news that our good weather window may already be up – so diving to a target at 2100m rather than ~5000m means we may at least manage to get one more good complete dive in before weather issues mean we have to call Nereus back. Sad to think this might be our last Nereus dive, just a day after we got our first good one in ROV mode, but as I suspect I mentioned more than once in Leg 1, sometimes at sea you just have to accept what Nature provides and do the best you can with it.

Given that we came out of Florida 4 weeks ago not knowing if there would even be evidence of active venting anywhere on the Mid-Cayman Rise, I guess it would be churlish to do anything else but be happy with what we have already achieved, scientifically. And the fact that we successfully drove a deep diving submersible around for something like 10 hours yesterday at the bottom of a very deep ocean, from the back of a rather small research ship, is something that should make both our Nereus engineers and the Cape Hatteras crew very proud – if that doesn’t set some kind of new world record, I would be very surprised.

Our last bot of news for today is that we had more cruise members set off for home. Our friends from National Geographic TV had sailed down to meet up with us over the weekend but this morning, right after Nereus was on deck, it was time for them – plus our science colleagues Cindy and Julie S – to depart back to shore: don’t worry, they left Katy from the NatGeo team with us in case we do yet make that final “Eureka” breakthrough before the week is out.

What I have to start facing up to, however, is the worst case possibility that, having overcome the concerns that maybe we would have NO hydrothermal signals to pursue in Leg 2 we would, instead, have a multitude of interesting potential targets and yet still not get the opportunity to follow any one of them all the way back to their source at the seabed.

Saturday, October 31, 2009

Ghosts in the machine?

All clear: Here’s Andy checking for stow-aways in the tool sled prior to Nereus launch. Could that have been the cause of the excess baggage? Or was it just a Halloween haunting?

Please, please, please, let me get what I want (with apologies to Morrisey and the Smiths). Here goes Nereus, back to the seafloor late Sunday afternoon.
Position at 16h00 EST – End of CTD 48
Lat: 18° 33’N Long: 081° 44’W
Water depth: ~5000m

We had a bit of an adventure on Halloween, but not a specially fun one. The launch of Nereus went extremely well and the pay out of our depressor to 2500m went well too. We worried, briefly, whether the release of the fiber-optic tether that would be used for Nereus to get the rest of the way to the seafloor would work OK - we quickly dubbed this “separartion anxiety” - but that too went flawlessly as well.

And so we continued, over 4 hours, all the way to ~5000m, where we dropped our descent weights and aimed to put Nereus into hover-mode. But instead, we kept descending slowly. Even when Chris had the thrusters trying to drive the vehicle up as hard as they could. All the way to the seabed.

We’re still not sure quite why, but the vehicle had arrived at the seabed heavier than expected – not by much, but by enough to have us rooted just where we sat. National Geographic is out with us for a few days at present, filming, but this was NOT quite the kind of drama we had wanted to share with them.

Of course, our engineers are not easily left stumped for long and after 15 minutes or so we already had a first plan of action lined up and put in motion. We jettisoned some of our “ascent weights” (the ones we normally would only drop at the end of the dive, so Nereus would float back to the surface) and that allowed us to start to head south and explore the seafloor from our launch point on thick soft sediment toward our proposed work area (and hydrothermal vents?) about 600m distant and 150-200m shallower.

As we headed south, and began to climb quite steeply uphill, we came across fields of large boulder-sized blocks of basaltic lava and, further uphill again, intact tongues of basaltic lava that had been frozen in place as they had poured over and flowed down the rock face toward the direction Nereus was arriving from.

This already gained us useful information – we now know the hill that we are heading toward must have previously been a site of active and extensive volcanic eruptions. You might think that obvious if we’re working on a mid-ocean ridge (i.e. an underwater volcanic chain), but there was actually something like a 50:50 chance, since the Mid Cayman Rise is a very slow-spreading ridge, that at any given site the local geology would be dominated by long-lived and deep rooted faulting extending all the way down from the seafloor toward the underlying mantle. Sadly, however, that is also where the tale of our first ROV dive to the Mid-Cayman Rise ends.

After some rapid and earnest conversations among the Nereus team, Andy was able to advise us that the consensus was this: the only way to be SURE that we could get Nereus back on deck safely and ready to dive another day was to conserve power (i.e. leave the seafloor immediately) AND to also shed more weight to make sure we came all the way back and didn’t run out of buoyancy while Nereus was still submerged – i.e. never to be seen again. So, unsurprisingly, that’s what we did.

Making sure we had excellent navigational fixes, we lifted one of Jeff Seewald’s titanium vent-fluid samplers carefully off the basket and placed it on the seafloor. The moment it was released from the manipulator arm, Nereus rose up from the seabed. We released all the remaining ascent weights and the vehicle began its long flight upward and home. Happily, the rest of the recovery went smoothly and just around sunset Nereus came back up to the ocean surface where it was promptly recovered and lifted back aboard ship.

Overnight and into this morning we slotted in two more deployments of the CTD rosette, each of which measured the strongest sets of hydrothermal anomaly data we have seen all cruise confirming (surely!) that we really DO have our target narrowed down now. And tonight we are back in the water with Nereus and heading back down. Once again, we’re telling ourselves: this really COULD be the one.

Friday, October 30, 2009

Getting Ready for the Big One

Suit up! David is our chosen victim of Leg 2 who gets to don one of the immersion suits we are all issued with in case of emergency.

Getting ready. Nereus team preparing the Depressor (looks like a large missile with its covers off!) for deployment over the rear end (nautiacal speak = aft, or stern) of the ship ahead of tomorrow’s Nereus dive when it will be used for real.
Position at 16h00 EST - Testing Nereus Depressor Weight
Lat: 18° 33’N Long: 081° 44’W
Water depth: >3000m

Exciting times! We sailed slowly south overnight to arrive on station this morning to see just how bad the weather was compared to the forecast. Great news! The weather here is just fine for working in and the forward look says it will only stay the same or better for the next 4 days. So that means we can plan to launch tomorrow.

With that in mind we have taken it slow and steady today. Boat drills and safety briefings for all the newbies on board came first. Then a deep test of the depressor weight we use to carry Nereus’ optical fiber as close to the seafloor as we can reach before we pay that out – about 2500m down (i.e. halfway in this case!). Finally, a final tow-yo of the CTD across the northern limits of our target site from West to East (a line the weather has finally) allowed me to run, to confirm that the strongest plume signals do indeed coincide with where we think that vents are sat, ready to be dived on.

Final operations were done just after 10:30pm so then it was off to bed ready for a HUGE day tomorrow. Nereus pre-dives begin at 4:30am and Julie and Jeff are due up at 5am to load their science gear but happily James (chief Navigator) has told me he won’t be ready to talk through the final mission plan with me before 7am- so if I can stay asleep that long, I get a lie-in.

Thursday, October 29, 2009

Back on the road again

Here’s where we left off – running ahead of the seas into port last Monday evening.

Does this tool sled make me look big? Nereus put on a bunch of weight while we were in port – but in a good way, we reckon.

Becky (jumping) and Evan (already in the water) came by for a while this afternoon to take advantage of the wonderfully clear waters here and shoot some HD video of Nereus in action underwater.

Did I mention that Nereus is an unmanned vehicle? You couldn’t always tell that before today’s first dive. Here’s Phil (pilot) booking his space early and Jeff (geochemist) working hard to make sure he could get in there too. That only left Julie looking on – surely they could make room for a micro-biologist?
Position at 12h00 EST - Test Dive: Nereus 023
N and 81°33W
Water depth: 20+ m

Did you miss us? After a very busy two days in port we have now changed out our scientific personnel, converted Nereus from an AUV to an ROV, done a bunch of interviews with everyone from the local press to Astrobiology magazine and headed back out to sea again. Even managed time for a bottle of New Zealand Pinot Noir along the way somewhere too.

The most bittersweet moment, of course, was having to say goodbye to the folks who worked so hard on Leg 1 to get us to where we are and who now have had to head back home and leave the new guys in town take over as we head back to the seafloor. So for the record: heartfelt thanks to all.

To Dana, Louis and Mike for all their efforts in keeping Nereus running and getting us as far along in the mission as we have, and especially to Tina, Sean, Doug, Carla & Ko-ichi for their sterling and enduring work with the CTD without which we still wouldn’t have much of a clue where to look to find venting.

Dana and Louis were the first to escape to a conference in Biloxi where Dana was receiving the IEEE Oceans’ Lockheed Martin award at a dinner Wednesday night. Happily, all of the rest of the Leg 1 team were still around the ship working late yesterday when we finally got far enough along with our data processing to work out that Nereus flew through anomalously warm water on four separate occasions while making us a detailed map of our dive site last Sunday/Monday. Not bad for the last thing we managed to do on Leg 1 – we are now in REALLY good shape for Leg 2.

Today we headed back out to sea for all of a mile along the coast to a mooring in deep enough water to give Nereus a good testing in ROV mode. While Nereus has been used as an ROV before – last June it managed dives to >10,000m in Challenger Deep, Marianas Trench, the deepest point on Earth. Even so, with a new ship and a new team to work with, practice makes perfect so it was a good use of the day. Added to that, we know that the weather back in our work area isn’t super calm right now so probably won’t be ideal for Nereus for at least a day or two. So instead, we decided to take advantage of our good weather today to get some of that practice in, make sure we really could get everything we wanted to into the science basket, and check out other new things like the manipulator arm and our video cameras.

Tonight we’re off to our work area, but taking it gently so our new arrivals can get their sea-legs well before we arrive on site. We’ll be keeping busy over the next couple of days but don’t expect our first Nereus dive to the seafloor until Sunday or even Monday – but be sure we’ll keep you posted when we do!

Monday, October 26, 2009

If fools rush in, it's the wise man who heads to port - right?

Heroes of the High Seas. Medal of the day goes to all involved in the safe recovery of Nereus aboard ship in rapidly deteriorating conditions. Both our Captain, Dale, and Andy have decided that since they have now proven that they can get the vehicle back safely in bad weather, they don’t need to do so again. I’m all for that – we’d just like nice weather for Leg 2 now, please. Thank you!
Position at 16h00 EST - Headed for Grand Cayman
Lat: 18° 40’N Long: 081° 35’W
Water depth: >6000m

Late on Saturday I was reading part of Lao Tzu’s “Tao Te Ching” - I bought this after a visit to China a couple of years ago and have found it can be a good travelling companion. That probably counts as my equivalent to Ford Prefect’s recommendation to “always know where your towel’s at” in The HitchHiker’s Guide to the Galaxy (although, for the record, I also make sure I always bring my own towel on research cruises too – at least one home comfort you can take on the road).

Anyway, on Saturday night I was reading the section of the Tao Te Ching that includes one of the more well-known sayings I had heard long before I knew of its provenance: “A journey of a thousand miles starts with a single step”. Just two lines down was a couplet that struck home even more keenly:

“People on the verge of success often lose patience
And fail in their undertakings.”

I’ve been flirting with making that kind of mistake a lot these past few days. When our Nereus dive 19 didn’t go as planned last Wednesday, but we intercepted a weak buoyant plume sample, I tried to make up for lost time on Nereus 20 by focusing on a small area, near to the seafloor, rather than doing the more cautious thing and repeating what we had planned for dive 19. As a result we didn’t make much progress on Nereus 20 either, especially after the thruster fell off!

So Nereus dive 21 was exactly the right thing to do. Drop back and do the more cautious thing and wait. And presto, that decision paid off and we completed the survey I described yesterday and closed in on our biggest hydrothermal signals.

So have I learned from my mistakes? Yes, I have, and apparently given the opportunity, I can repeat them exactly! Well, not quite, but I did make a decision yesterday that 20:20 hindsight suggests could have been better.

Knowing that we could only survey a fraction of the remaining seafloor in the time left (we only had one dive left before we headed to port), I decided to focus all our attention in the southern half of the remaining area, rather than focusing on the seafloor area right under the strongest plume anomalies we had seen. Basically, I was gambling that any vent sites were sited on top of the shallowest part of our remaining search area. Nereus is now back on deck (see later) and the data suggest we have passed over some areas of diffuse chemically enriched flow but have not yet found the hot vents we’re after. But they MUST still be there because Nereus passed through two dispersing plumes of smokey, chemically enriched water on its way to the seabed on Sunday, and passed through both those plumes again, on its way back up to the surface, about half a mile farther to the south east, around 8 o’clock this morning. But wherever those vents are, it seems like they aren’t where Nereus just went :(

To add insult to injury, the weather turned against us overnight – indeed, it started getting worse almost as soon as we launched Nereus yesterday. So I was immensely relieved when we had the vehicle safely back on deck today, just before lunch. The weather today, without question, is the worst we have had all trip, so quite frankly I thought everyone involved – both the Captain and ship’s crew as well as Andy and all our Nereus deck team - were quite magnificent pulling that off. Nereus got a kiss of green paint from the ship’s hull and a piece of 4x4 timber gave its life in the cause of science but other than that we recovered unscathed with no major dramas. That is always a good thing.

This afternoon we ran ahead of the waves for an hour or two and then turned and faced into the weather for a further hour to keep the ship on a comfortable heading while evaluating whether we should try one or more further CTD stations to trawl through our search area one (or more) last times. But the weather certainly isn’t getting any better so (finally) heeding the cautions of sages down the ages, we’ve decided that (i) since we still have an intact vehicle and an intact CTD system on deck, and (ii) that we’ll expect to have at least SOME better weather on Leg 2 - at least, that’s what I ordered when I booked this cruise ;) – then discretion is the better part of valor. We’ll take what we have achieved already, thank you very much, and live to fight another day.

So we’re off to port, now, where our Leg 2 scientists and a National Geographic film crew await us. They’ll all be coming back out with us toward the end of the coming week. Since I’ll have a dozen other things to attend to in port I’m going to sign off now for a while, but will aim to be back on-line again on Thursday, when Leg 2 of the expedition gets underway. Don’t know about you guys, but I can’t wait :)

Saturday, October 24, 2009

Its good to be wrong (in moderation)

After two weeks of dives, I finally found a new vantage point to get a clear shot of Nereus being lifted outboard on the ship’s crane.

A picture that tells more than one story. On the right hand side of this map is where I had THOUGHT Nereus should search for hydrothermal activity on the seafloor on its latest dive – the dark red circles show how wrong I was – strong hydrothermal signals are coloured yellow, green and blue. At the top of the page and all down the left side are the EXTRA lines that got added. The ones at the top were ones I had pre-planned in case things didn’t start well (note to self: all those red circles show that I was wrong again!) but down the left hand side is where we finally struck gold… or sulfide… of whatever it is down there that remains to be investigated in Leg 2.. Since each of these lines is only 1600m long and spaced 600m apart we really SHOULD be getting close by now. Shouldn’t we?
Position at 08h00 EST (Launch of Nereus 021)
Lat: 18° 33’N Long: 081° 43’W
Water depth: 4650m

If you read the previous blog you’ll remember it ended: “But don't hold your breath - no part of the expedition has been quite that predicatable yet!”

When Nereus came came back Friday night, with one thruster hanging on by its cables and only a subset of the data I had hoped we would collect, I asked that we turn the vehicle around as fast as possible and send it back for a short and simple dive next day that would at least confirm we were searching in the right place.

While it was easy for me, as chief scientist, to say that’s what I wanted to happen, it was Andy and his team who had to stay up past 1am that night running repairs… …and the same guys who were up again just four hours later to conduct the extensive tests needed for Nereus prior to re-launch.

So down the vehicle went, right after breakfast, running the shortest mission possible that I thought was guaranteed to pay off. By 10am Nereus was at the seafloor and by midday it had seen some great hydrothermal signals. Wonderful!

Then it drove around in clean, hydrothermal-free ocean water for another 4 hours. Hmmmm…. And those “clean” waters were in the center of my survey areas, the strong signals were along the western-most flank i.e. not anywhere near where they “should” be. Hmmmmm again…. I went back to the map. I was SURE that I knew that the vents had to be along the ridge we were searching because, obviously, there was no way they could be even deeper, on the deep valley floor at around 5000m. Unless they were, and my judgements to that point were all wrong…

By the third Hmmmm it is always good to question whether you really know what you are talking about or whether it is time to think again. And if everything you predicted in science came out just so, how would you learn anything new? So I don’t mind being wrong too – so long as I doesn’t happen too often. Specially not if it leads to discovery of something nobody has ever seen before… But I digress….

In the “old days” of vent exploration by AUV (since we have only been doing this for about 5 years, that means any time up until about a month ago) the only thing to do when you are chief scientist in a situation like yesterday is to:

a) confess to the engineers that your interpretations were quite wrong
b) compliment them that their new machine is working quite beautifully
c) then add that, even so, since the AUV is working in quite the wrong place, you would now like them to abort the whole mission and start over, elsewhere.

(PS: I’ve found that it’s best if you do remember to say “please”, at that last point…)

But welcome to the future…

In keeping with our NASA funding (how often can a space scientist ask if they can have their rocket fetched back so they can re-program and launch again?) our Nereus team pulled off their most cunning new trick, yet, yesterday afternoon. After listening to my problem and discussing with me what the proposed mission plan SHOULD have been, they simply reprogrammed our submarine while it was driving around on the seafloor, using signals beamed down from the ship via sound waves.

No kidding!

It was during the first dive of this cruise that I had seen little snippets of data coming up from the sub via the same technique and I remember Louis remarking to me: “We think this could be extremely useful in the future… …but it may take us some time to work out how to use it to full advantage.” Make that two weeks, apparently.

During the 2nd half of yesterday’s survey (the part that was sent down AFTER the sub was launched), Nereus not only doubled the size of the area of seafloor investigated but, about an hour before its batteries finally ran out of power, it flew directly over the core of a rising hydrothermal plume some 700m up above the very deep seabed down at around 5000m depth. Our map of the plume-sensing data shows us a clear bulls-eye to aim for, with weaker signals on all sides in a survey that means we now have our source tracked to a fraction of 1 kilometer squared.
I think!

Given that I didn’t know where we would end up within 2000 square kilometers of seafloor when we started work, just two weeks ago, that’s not bad. And of course, we’re not done yet. We heard last night that our Leg 2 scientists are already in port in Grand Cayman, awaiting our arrival. But we plan one last dive, starting Sunday, before we head for dry land.

Friday, October 23, 2009

Wild Mood Swings

Home with a tale to tell. It had been predicted, before Nereus made it up from the seafloor, that there was a problem with one of its thrusters. But can you guess which one? Hint: this is NOT a trick question!!!
Position at 18h00 EST (Recovery of Nereus 020)
Lat: 18° 33’N Long: 081° 43’W
Water depth: 4650m

Where to begin with a recap of the past 2 days – including two Nereus dives and two new CTD tow-yos along the ridge axis? First, the good news: using our CTD tow-yos we are confident that we have narrowed down our search area to around 4 square kilometers. That feels pretty good, since when we arrived on the evening of Sunday 11th Oct we had a mapped area of more like 1500 square kilometers to search in.

Second – more good news. Through a very happy piece of good fortune, we are confident that Nereus flew through the rising cone of a hydrothermal plume sometime on the morning of Thursday 22nd which means we should now have all the data needed to track its source down to within less than 1 kilometer. But you may ask yourself – Well, how did we get here?

You’ll remember that on Wednesday night we deployed Nereus to the seafloor. It arrived on bottom at around 8pm local time, but its main compass failed almost immediately. So while the first part of the dive seemed fine, hovering near the seafloor and adjusting ballast, it then started out its mission heading in the wrong direction! Through acoustic communications we did have the ability to try and compensate for that but, to compound things, we also had a problem with the main foil that sits amid ships on the vehicle and controls a lot of the vehicle’s vertical motion as well as forward thrust. After about 3 hours of trying to come up with strategies that could overcome all of this we decided that it would be more effective to recover the vehicle and fix it and get it ready to go again. So just before midnight we sent down the “abort” command, acoustically, and by 2am Nereus was back on the surface.

Our CTD night watch immediately leapt into action, and through the rest of Wednesday night and into Thursday we completed two more towed surveys from South to North through the area that we originally planned for Nereus to map out to prove that there were no signals there. This in itself was significant progress – it halved our remaining search area at a single stroke. Once Nereus was on deck, Dana also took the time to look at the data that it did collect while it was at depth, however briefly.

As luck would have it, since we had programmed the vehicle to start its work by driving along the ridge that we were betting was the most likely source for the vents, Nereus had indeed intercepted a patch of chemically unsual and particle laden water while hovering close above the seafloor for a few minutes. When Dana came to find me and tell me this my immediate question was “Was it warm, too?” Sure enough – it WAS. So Nereus was sat no more than ~100m above the seafloor (400m deeper than the dispersing plume we have been mapping out with our tow-yo surveys) when it passed through chemically enriched, smokey, warm water. Following the logic of: if it walks like a duck and quacks like a duck… I think we are getting very close.

Suitably encouraged, we reprogrammed Nereus for a new mission flying close above the seafloor in our now much smaller search area and sent it back down last night. I hung around until midnight by which time the vehicle was at the seafloor driving to and fro in closely spaced lines and making a map. All seemed well so I took myself off to bed. Mistake. Apparently Nereus must have known I wasn't paying due attention, because when I woke up today things had NOT continued as planned. Instead of continuing to survey at a speed of about 1m/sec, it had slowed right down. At time of writing our engineers’ best guess is that one of the thrusters might be damaged or broken. We’ll know when we get it back on deck.

So the first decision of the day, today, was whether to continue the dive or send down the abort command right away. With the vehicle moving slowly we knew we would have trouble flying close enough to the seafloor to continue to make maps OR to complete all the rest of our planned survey. But we persevered and between 8 and 10 am we figured out how to get Nereus to fly a little higher in the water column and raster backward and forward, clear of the rough topography, and sniffing for more rising plume signals across more of our targeted ridge. I think I got full value out of our AUV brains-trust today. It's really impressive when I just ask innocent questions like, can we make it go up a little higher, can we make it go further West etc etc and either Mike, James, Dana and Louis (working in shifts but it seems there are always three or more of those 4 to hand) very quickly says: yes we can - and then make it happen.

Arthur C. Clarke once wrote something along the lines that in the future, if we were to encounter some alien culture enriched in advanced technologies, the experience should be indistinguishable from watching magic. I feel like that's the kind of privileged company I have been keeping all day!

Finally, at 4pm, we called Nereus home. With the data set currently being carried up from the seabed we expect to learn two key things. First, we will know if we have found any more places where Nereus has flown through warm, smoky water (because it is warm, it must be buoyant, which means Nereus must have passed through the rising part of a plume which can only be a few hundred meters across). Second, because we have been flying close to the seafloor, we will be able to distinguish which part of the vehicle’s motion has been due to forward progress over the ground and which has been due to currents pushing the vehicle through the water column. The latter is important to calculate because that can help us deduce which way the current was blowing, and how strong, at any time when we have flown through rising columns of smokey water. And knowing that, we should finally know where to go next, tracing those columns of smoke down toward the seabed where they came from - seafloor hydrothermal vents.

But time and weather may still be against us. First, we need to get Nereus on deck and make sure we have guessed correctly what the problem is. If it is a simple matter of replacing a thruster then we are in good shape. We have a spare on deck that has already been checked out this afternoon in preparation and is ready to be installed tonight. If all goes to plan we’ll be launching Saturday, early, and getting Nereus back on deck in late afternoon ahead of a storm that is due to pass by tomorrow night. That may yet leave us enough time later on Sunday and early into Monday for one more dive before it is time to head to port, switch out science teams, and change over to ROV mode with Nereus.

But don't hold your breath - no part of the expedition has been quite that predicatable yet!

Wednesday, October 21, 2009

Back in the Game!

AUV-ROV mind-meld. James (left, wearing ABE AUV T-shirt) and Chris (right, wearing Jason ROV T-shirt) deep in discussion during pre-dive deck-tests of the Nereus Hybrid vehicle.

Once more unto the deep. In this photo, Nereus is just visible as a green-yellow blur directly beneath the arm of the crane that it was just released from.
Position at 16h45 EST (Launch of Nereus 019)
Lat: 18° 33’N Long: 081° 42’W
Water depth: 4800m

The last thing that Andy Bowen and I discussed late yesterday was that we would take a look at the weather first thing today and consider our next Nereus launch. So when I was woken from a sound sleep by a flash of bright lightning around 6am – so bright I thought someone had come into my cabin and turned the fluorescent light on, I didn’t consider the omens specially promising.

Which was a shame, because after 36 hours of essentially groping in the dark we had had a major success around 6pm on Tuesday. Then, for the first time since we returned to this area, we managed to pick up sensor signals in the deep ocean that were comparable to what Nereus found on its first science dive here 4 days ago. Really? Was that only last Saturday afternoon? Wow – seems like ages!

Anyway, the good news is that we now think we have narrowed down what we thought was a ~10 mile by 10 mile box to an approximately 3 mile by 2 mile box: not bad for 48 hours’ work - but talk about grinding out a result!

To add to the good news, our forecasts came in on schedule this morning and all confirmed that there is nothing bad expected to happen, weather-wise, until Saturday at the earliest. The passing storm was just one of a series of squalls we are having to contend with, but in between conditions are not too bad now – certainly better than they had been last Sun/Mon/Tues. So we completed a last CTD survey around 3:30pm today and no more than an hour later, Nereus was off the hook and slipping gently down toward the seabed to track down and map out (we hope) a dispersing hydrothermal plume. We’ll hope for good things to come back tomorrow.

Finally, it’s time for you all to put your lungs to use again - Friday this week (23rd) is my wife, Romey’s birthday. This is the 2nd time I have been at sea for her birthday (bad) but the first time in 18 years (not quite so bad). For the record, I also missed each of my older children’s birthdays once each – but they were bad ones: Martin’s 18th birthday and Helen’s 16th (I was in the Antarctic for the latter). When I was growing up, my Dad always told me about his Dad (who was in the Royal Navy) being posted to China for 2 years straight in the 1920s so he didn’t see him from when he was 2 until when he was 4. At least modern day oceanographers only go to sea for a month or two at a time, tops – but even so, the families we leave behind are the ones that have to cope without us (maybe mine does better when I’m not around?). Cumulatively, over the past 23 years, I have spent between 900 and 1000 days at sea. That’s more than most spouses have to put up with so I can genuinely say that Romey takes a large chunk of the credit for any of the discoveries I have ever been involved with: this expedition included.

Monday, October 19, 2009

All we seem to do is talk about the weather

Position at 12h00 EST (CTD 38/Tow-Yo 3)
Lat: 18° 30’N Long: 081° 43’W
Water depth: 5100m

Maybe it’s the curse of being English (as well as Doug and Carla, both Andy Bowen and I are also UK passport holders) but weather seems to have become a key topic of conversation lately. Yesterday morning, after a seriously poor night's sleep, I came down from my cabin to find waves breaking over the back deck. So first order of the day was to get the tool-sled for Nereus (essential for anything we want to do in ROV mode next Leg) moved away from the very back of the ship where it was in danger of getting damaged.

Next job: talk to the Captain about what kind of direction we could move the ship while lowering the CTD (because trying to hold position in this weather was a REALLY bad idea) and agreeing that WSW-ENE was worth a try. So that’s what we did: we picked the shallowest point on the map and lined up a survey that would allow us to pass slowly directly over the top of what we take to be a young volcanic feature (not a stupid place to look for a vent-site) – pushing back the frontiers of science at about 1 mile per hour while lowering and raising the CTD as we went.

For the first 6 hours nothing happened and then, just as we passed over the top of the ridge we saw some small but significant plume signals for about 30 minutes – then back to nothing again. The whole plume cannot have been more than a mile wide and then we were back to seeing nothing else for a few more miles before we quit. By then the weather had changed and so, rather than run a 2nd parallel line, the only option was to choose a new route running from South to North. Happily, that was easy to do – we simply chose a line that ran right across the previous survey and around 10:30 last night that was just getting underway as I headed to bed. Doug, Carla and Koichi had that survey wrapped up by 7am this morning and, teasing through their data today, Dana and I have shown that the one time that THEY saw any plume signals occurred right when their survey line crossed ours – apparently we’re making progress.

But then came more good news – not. Every twelve hours we get our own dedicated weather updates from a team in New Hampshire called Commander’s Weather and this morning’s bulletin started: Must be very careful. (Uh-oh!) Apparently there’s a reasonable chance that a tropical storm could strike up in our area any time Wed-Sat this week. It might not happen but if it does then we’ll be right out of luck. During the course of the morning we also got an update via the ship’s base saying much the same thing based on an 8am dispatch from the National Hurricane Center in Miami, FL: there is an area of low pressure centered at 11N, 82W (i.e. about 700 miles south of us) that is drifting slowly North over the next few days (i.e. towards us) with a low (30%) chance of becoming a tropical cyclone in the next 48 hours. So needless to say, we’re going to be talking about the weather a lot (and checking the email updates soon as they come in) in the next day or two.

P.S. The title of today’s blog coincides with a line from a Blow Monkeys song dating from the late 1980s. It is half of a couplet that continues: “I’m just a man at the end of his tether”. Hmmmm…. Not yet, I'm not - but lets see what tomorrow brings.

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!!!

Saturday, October 17, 2009

Happy Happy Joy Joy

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.
Position at 12h00 EST (Nereus Dive 18)
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.

Friday, October 16, 2009

Riddle me this…


Optical illusion. Believe it or not, this is a picture of the CTD package already beneath the ocean surface – that’s how calm it was earlier today. Don’t believe me? Look close and you can see a “kink” in the wire where it cuts the ocean surface.

What’s BIG, cute, yellow, and currently >4000m under water?
Position at 18h00 EST (Nereus Dive 18)
Lat: 18° 22’N Long: 081° 42’W
Water depth: 4350m

Q: What’s yellow, cute, and rarely found out in the middle of the deep ocean?
A: A stowaway! I was up early this morning and Carla and I found we had a visitor as we were waiting to watch the sun come up. We think it’s a warbler but hope there might be an ornithologist out there can tell us what kind. Answers on a postcard to…. Oh no, that won’t work. Anyway, surprisingly enough, this isn’t the kind of bird you find in a book of marine life! Presumably swept here by one of the series of squalls that seem to be passing by with increasing frequency (a bit ominous!).

Anyway, after breakfast it was back to CTD stations again. Sorry if that’s getting a bit repetitive but think how it feels for us – 12 hours a day making sure that most of the ocean out here DOESN'T have a hydrothermal plume signal in it!!! Did I mention yet (the team out here are sick of hearing it) that I once did 176 stations in a row on a single cruise and didn’t see a plume for the first 150??? Now that really was quite dull. Happily we wouldn’t have time to do that many out here if we tried ;)

But getting back to the main order of the day. There’s something else out here that is also yellow and quite cute. (Which could well be a sign that I’ve already been at sea too long). Can you guess what it is yet? Correct: Nereus in full racing trim.

Today saw the launch of our first dive in pursuit of a hydrothermal target that is programmed to last well into Saturday afternoon. During that time, Nereus will survey more than 20 miles over the deep ocean floor undulating through the water column to collect data equivalent to more than 20 CTD casts and, hence, doubling our total data-set in a single day. Don’t know about cute, but you have to agree that’s quite ambitious. No doubt you’ll be hearing all about it here, soon, once the mission is complete. Just can’t wait to get back to more CTD stations after that. Hmmm….

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!”

Wednesday, October 14, 2009

Inside: Outside - You’re OK to Launch

Just say when! From nearest to farthest wearing hard hats, the “outside” half of the Nereus team (Chris – Mr Green hat; Andy - Mr Yellow; Daniel - with the pull-pin, Mr Red; Casey – Mr Orange; and last but not least, Mr Versatillity, Mike: he not only handles the lines for Nereus launches & recoveries but is also the 4th member of our AUV brains-trust. In 2004, he taught an AUV to think the same way that I do (such cruelty to a robot!) but today he’s just been busy making “phone calls” to the seafloor to interrupt Nereus and upload new mission programs on-the-fly.

Night fishing. Under the cover of darkness, Nereus PI Andy Bowen (yellow hard hat) leads the deck crew getting ready to snag Nereus and crane her back aboard ship.
Position at Midday EST (Nereus Dive 17)
Lat: 18° 24’N Long: 081° 49’W
Water depth: 2150m

In yesterday’s blog you met James, Louis and Dana: three of the core team who run Nereus’ software (hence, “brain” when it is decoupled from the ship). So now its high time I introduced you to the rest of our 8-strong team of engineers. Photo 1, here, was taken just at the moment when those working “Inside” (in the lab) had given the signal to Andy and the rest of the team “Outside” (on deck) that it was OK to go ahead and launch Nereus.

We’ve had a great day with the vehicle today which has us all set for the rest of the science program. After launching around 10:30am, Nereus descended to the seafloor (the guys don’t like it when the Captain says”sinks”!) over about 2 hours and then spent about 6-7 hours going through a series of maneuvers to test out all the different systems we might want to use for science in the next week and a half.

First it did a series of speed runs so we can calculate what its full endurance is likely to be and what will be the most efficient survey speeds for different kinds of operations. After that Nereus went through some bottom following mode operations at around 40m off the seafloor (ideal for making detailed sonar maps of areas of interest), then it ran a series of yo’yos where it will undulate up and down as it swims through the ocean – e.g. if we want to send Nereus down sniffing out new hydrothermal plumes for us. Finally, Nereus did some low-level runs, driving around just 3-3.5m above the seafloor in the mode used for taking photographs from the seafloor.

But perhaps the most interesting part of the day for me was how the mission kept getting longer! When we launched Nereus, I definitely knew that the seafloor mission was for 5.5 hours of operation on the seabed. But the little piece of masking tape across the top of the main computer that had “end of mission time” written on it kept getting updated by 20-30 minutes at a time. How do you make a mission last longer, when everything is uploaded into the vehicle’s computers before you launch it? Turns out that our engineers have found a very cool way to cheat. If they come up with better ideas while Nereus is on its way to the seafloor, or just decide they’ve seen it do enough of any one activity and want it to do something else, they just call it up and re-program it. Seriously!

They have found a new way of doing things that I have never seen done before where the vehicle can be “interrogated” via underwater acoustics and, when prompted, it sends a series of information back telling us aboard ship what is it up to: where it is, where it’s headed, how fast its moving and what its busy measuring at the moment: stuff like that. Then – and this is really VERY cool – if they have any new programs they want to send down, they can do that too! Turns out, there is only one completely untouchable “home time” sub-routine in the mission program that they can’t over-write and that cut in around 7pm. If it wasn’t for that, I think they would still have Nereus down there now. And by the twinkle in his eye, I don’t think Louis was joking when, as Nereus was finally rising back up to the seabed, he suggested that maybe they’ll be wanting to fix that, soon, too.

Tonight, our CTD system is back in action as we head further south along the ridge-crest continuing our search for stronger hydrothermal plume signals. We plan another day and a half of that so that tomorrow, while I am on CTD watch, I can also start planning our first Nereus science mission. I’m sure we haven’t even begun to think through all the ways we can make use of our acoustic communications with Nereus, but the best way to find out is to get stuck in and start working.

Tuesday, October 13, 2009

If you want to make Chicken Soup…

Dana showing off his birthday present, featuring a robot he really admires (clue – he was made in Mexico, smokes cigars, and likes bending things). Looking on are two more members of our AUV brains-trust: James Kinsey & Louis Whitcomb.
Position at Midday EST (Dana’s Birthday)
Lat: 18° 31.6’N Long: 081° 40.0’W
Water depth: 4950m

First, get a chicken”. So said Dana Yoerger today and we had to listen: it was his birthday! Dana has plenty of tales to tell, the sign of a true Grandpa, I reckon – and I should know: for this trip he is Grandpa Senior and I’m Grandpa Junior. Anyway, Dana’s more pertinent point is that we can’t use Nereus to find a vent-site until we use the CTD to first find some tell-tale signs that there is something nearby to chase after.

So this morning, Dana announced that this year, for his birthday, what he would like would be for the CTD team to find us a plume signal to chase after. And right toward the end of the afternoon, in fact just around dinner time, I think that may well be just what we found.

So while most of the team were enjoying their evening meal – complete with birthday cake, a few of us were almost completely distracted looking at traces on a computer screen from Ko-ichi’s in situ sensor that showed us a layer of water, down below 4000m, that is chemically different from everything else we had seen in our previous 10 casts. Lying that deep, just a few hundreds of meters above the seafloor and in a layer a few hundred meters deep, is exactly the kind of setting we might expect to find the effluent from a hydrothermal field. That’s not proof positive, but it is a start. And we certainly know this is something that we have not seen anywhere to the North or East of us – so now we need to continue South and West (we are only about 1/3rd of the way through our survey) to see what the rest of our exploring brings. But after 10 sets of results that showed absolutely nothing at the bottom of the ocean, this new profile is certainly encouraging. Or, to quote Tina (and returning to the message of the day): Sweet, Sweet, Chicken-Feet!

Monday, October 12, 2009

Silent Running…

A typical view of the CTD these days: all you can see is the wire descending into the depths. Because we are using it round the clock, the instrument is never going to be on deck for more than an hour at a time until Nereus is good to go again.
Position at 23h00 EST (Launch of CTD 09)
Lat: 18° 36.3’N Long: 081° 41.4’W
Water depth: 5087m

Not much to report today. With Nereus on deck our small but perfectly formed science team is running flat out running CTD casts round the clock. With only 5 miles between stations we get from one sampling site to the next faster than we can draw the samples and get ready to put the CTD back in the water, so we grab moments for things like food, drink etc when we can during the 12 hour shifts when we are on watch. Doug, Ko-ichi and Cara are doing the heroes’ watch from 8pm to 8am local (midnight to midday on Greenwich Mean Time, which we use as our time standard for recording all our science data at sea) and Tina, Sean and I are doing the day-time shift, 8am to 8pm.

We started this late Sunday and will keep going until Wednesday morning by which time we’ll be at least a third of the way down the ridge and ready for our next Nereus dive: repeating the engineering tests we first started on Sunday. That seems like a long time ago already!