Daily Log

Steven Constable

On this web page I will be posting daily updates on the progress of our cruise on the R.V. Ocean Stalwart offshore Uruguay. The object of this project is study the geological structure of the continental margin and collect data that will help design future exploration programs for this area.

Diary (most recent first, so read from the bottom if you're not up to date)

Thursday 6/2/2013: All done! We picked up the last instrument around 2 pm on the 4th, and got word that we had confirmed dock space in Montevideo for the 5th. This was great - we had expected to show up and get put in anchorage. We tied up around 10 am, and then word came that our empty containers were going to show up around 1 pm. Even better! Weather forecast was for 25 mm of rain that evening. We worked like mad to stage our stuff on deck, and then when the containers showed up started craning stuff off. We were doing the last couple of lifts when the rain came pouring down, but we were down to a steel launch plate and a couple of barrels with rope and stuff, so apart from Chris, Jake, and me getting a bit wet it was no big deal. But it did pour down last night, with yet more lightning shows, and it is still raining this morning as I write this. I pity the Uruguayans their summers - the beaches are supposed to be good here, but I really haven't seen much beach weather.

We did 176 deployments and 174 recoveries, a record for our group. The two losses were about what we expected - 1% is our long term loss rate, and given the limitations of electronics and mechanical systems this is hard to beat. Every instrument came back with data, a 99% data recovery rate, and that really is pretty darn good.

Now we're looking forward to getting off the ship and having a drink or two (just two - honest). Cheers, all the best, see you next time.

Sunday 2/2/2013: Yesterday wasn't the greatest. At the end of the last SUESI tow we had about 12 hours to spare before we needed to start recovering our magnetotelluric instruments, so we decided to beach SUESI on deck and transit down the line at 4 knots with the antenna in the water, in order to re-deploy everything to carry out some tows across the main line. All looked OK, but we were only an hour into the tows when we lost output current on SUESI. I figured we had lost an electrode - they are soft copper and will break if worked back and forth at all, and we had been using them for a while, which tends to erode them (pushing 300 amps into seawater does that). But Jake bet Peter a beer that it was our antenna termination, and Jake was right. The towing at high speed must have been too much mechanically for the joint. The good news is that we had done all the work we intended to do with it, the bad news is our custom 250 metre antenna is now flooded with seawater, and since we use aluminium for its lightness that's the end of that.

Never mind. We are now recovering all 49 magnetotelluric instruments, four deployed transmitters, and a current meter. We are making good progress, with nearly half the gear on board after only one day, although the next batch are more widely spaced and in deeper water, so things will slow down. We've not seen much sea life this trip, but we were followed yesterday by a bunch of albatross (see pictures) and tonight there was a pod of small dolphin hanging out around an instrument during recovery. I had in fact heard them whistling and chirping on the acoustics when I was releasing the instrument. Reminded me of a time long ago in the Gulf of Mexico when sperm whales made so much noise that I couldn't get release commands through to the instruments and had to wait until they moved on.

Friday 31/1/2013: Has it really been nearly a week since I posted to the log? These last days have been squarely in the "boring is good" category; recover, release, rinse and repeat. We do get rinsed regularly. For mid-summer the weather has been quite cloudy and wet - at 36 degrees south we are at the same latitude as Adelaide Australia and Cape Town, but I guess this is more a maritime climate than Mediterranean. At least it is pleasantly warm.

We have now done over 300 deployments and recoveries of the seafloor instruments, with only one loss. Instrument Joey did not respond to our acoustic signals last Sunday, so it is either on its way to Argentina or it is broken on the seafloor. Normally I would say drifting is more likely, just like Roo, but given that Joey had been deployed before my guess is that a glass ball has gone bang. The stored energy under pressure is about the same as a pound of TNT, so apart from the loss of flotation they tend to destroy the instrument. They do implode very occasionally - I have seen it happen once that I know of, but the seismic group in the lab next door at Scripps has lost a lot of instruments this way. We factor in a 1% loss rate all up for all causes, so we are on target in that regard. It had to be pointed out to me that our two recalcitrant instruments were Joey and Roo. Keeping an eye on Wallaby...

We are now towing SUESI up one of our MT lines, and after that will recover all the instruments (hopefully). Weather forecast is good, and we are on track to get back into port on the 5th to unload on the 6th. Wish us luck in getting dock space.

Sunday 26/1/2013: Well, the storm came as advertised on Friday afternoon. I was debating whether to pop (release) a fifth instrument because the weather was still looking great (for once, discretion got the better of me), and two hours later by the time we were picking up the fourth instrument it was blowing 30 knots and the seas were rising rapidly. We stood down around dinner time, battened down the hatches and did our best to sleep or rest. The ship rides incredibly well; the story from the second mate is that this is the first time in two years he's been able to sleep on the boat. It has a passive roll stabilizer; a tank with baffles that is partially filled with water and gets out of phase with the ship's roll - the Revelle class ships have them and they work really well. I know this because we sailed out of Honolulu into the trades once on the Revelle without it and nearly everyone was instantly sick until they filled it and got it working. Another time on the Thompson the Captain made me stop work saying "just because it is not rolling doesn't mean it is safe to work". Anyway, to resume the story, the previous Chief Engineer on the Stalwart didn't believe they worked and refused to fill it. Bizarre... Anyway, I am glad they chose my cruise to try the thing out.

So the storm came and went in less than 24 hours; it died down as fast as it built up, and we were up and running before dinner yesterday. Today it is just about as nice as it gets. The Captain needed to do a drill, and so he decided to use the recovery of our seafloor current meter as a man-overboard exercise, and launched the rescue boat to drag the instrument alongside the ship. He asked me after what I thought of the event. I told him I was glad to see that the rescue boat worked - when we're towing SUESI it is the only way short of cutting the cable to go get people (see the "Center Barracuda Rescue" movie on the SERPENT cruise blog). The other thought was that if I ever need to be rescued, I hope the seas are this calm and that I've got an orange flag and a GPS locator beacon with me. It also reinforced the fallacy of using small boats to recover instruments. Eventually everyone has this idea, when they see an instrument drift by the ship just out of grapnel range. "Wouldn't it be good to just go and get it with a small boat." No, it wouldn't. It is really slow, and instruments don't drag through the water easily ('specially ones with 10 m arms).

Speaking of which, poor Jake wore his grapnel arm out and is having to give it a rest. We're making do with lesser mortals, but fortunately the bridge is getting the hang of instrument recoveries, so heroic throws are not as necessary as they were at the beginning of the cruise.

Fri 24/1/2013: Absolutely spectacular lightning display last night. We've been picking up instruments and dropping them again with routine monotony (we better get used to it: the plan is for 200 MT receiver drops, but with the up-front delays we will probably end up with a little less than that), and every now and then we have to stop operations because lightning is too close. This is a first for me, but where would the fun be if you didn't come across new things every now and then? Life is good. The coffee is holding out (we have an automatic grinder/drip machine and an espresso/cappuccino machine as well, and started with about 14 pounds of Peet's Coffee) and so is the lettuce (how do ship's cooks do that?).

The big news is that a significant storm is about to blow through. We are getting what work we can done in anticipation, and being diligent about tying the lab and deck down. The predictions are for peak wave heights up to 8 meters, but the average is likely to be quite a bit less than that, and prediction is an imprecise business - the start of the storm has already been pushed back about 12 hours, and right now we are recovering instruments with a 10 knot breeze and seas about as calm as they get around here (which is still a little choppy - no glassy seas this cruise, I fear).

Tues 21/1/2013: A whole day of picking instruments up from the deep end of one line, in 3,500 to over 4,000 meters of water depth. It takes three and a half hours to get to the surface from these depths (20 meters per minute is our standard rise rate), so we release instruments about 30 minutes apart and stack them up in the water column, up to five at a time. This of course means you want to recover instruments about every 30 minutes, and you don't want to have any big delays. The weather was quite rough and the winds were up to 30 knots, which makes driving a big ship up to the instruments quite challenging (and the watch on this ship is new at this game), so we often took quite a lot longer than this. Fortunately, we have nifty stray-line floats that radio back the instrument's GPS locations on the surface, so having them drift around a while on the surface isn't a disaster.

Mon 20/1/2013: We launched SUESI with her new transponder (which worked well) around breakfast time and had a nice boring day until around midnight. At that time the seismic vessel that is working our blocks arrived on the scene after being away for a while for a crew change. At first we thought that there would be no problems, but then they requested that we turn to the northwest. Since we were towing to the southeast, with about 4,500 meters of tow cable out and SUESI about 3,000 meters behind the ship, this was impossible. Unfortunately, the captain didn't know that, and made a rather sharp left-hand turn. You have to picture a cable stretched back from the ship at about 45 degrees, with SUESI about 75 meters above the seafloor. The cable angle is maintained by the lift and drag as the ship steams down the line at about 1.5 knots. When you make a turn, even though the ship is still moving, it is no longer in the direction of the cable, and so the cable sinks. Immediately. Many a novice has dropped their deep-tow onto the seafloor by making this mistake, and we've had some close shaves ourselves in the past with planned turns that became too sharp because of wind, etc. Normally the trick is to bring in enough cable that you have less than the water depth out, and then you can turn without worrying about impromptu dredging.

We started pulling in on the winch as fast as it would go, whilst increasing the ship speed again and again to try and make SUESI kite up into the water column. We had it up to at least 4.5 knots, which I think is a SUESI speed record. In spite of all this, SUESI was within 50 meters of hitting the seafloor on two occasions. It was quite nerve-wracking to say the least. The captain indeed got the ship heading northwest, but the frightening thing at that point was that SUESI was IN FRONT of the ship, still with maybe 3500 meters of cable out. How we didn't hit the seafloor I don't know, but I'm thankful that we didn't.

Sun 19/1/2013: Yet more deployments and recoveries. Fire and boat drill at noon. We do these drills once a week. We all run up to the life raft deck and don life vests. It seems trivial, and I've done these drills a hundred times now (literally), but every ship is configured slightly differently and it doesn't hurt to have the right behavior drummed in. Indeed, all my people who go to sea regularly take a one and a half day course on what to do if you actually end up in a life raft, how to flip it upright, and things like that. The odds of having to use these skills are minuscule - in all my seagoing life I have only met two people who admit to abandoning ship, and in both cases they were near shore (there are more things to hit near shore) and rescued quickly. But when panic threatens to set in past training becomes the difference between doing the right thing and doing something that might turn out to be terminally stupid.

The really interesting event of the day was the transfer of a package of stores that included some more SBL transponders, which we really need to complete our SUESI navigation. We had arranged for a vessel to bring these out to us from Montevideo. Finding each other was the first task - the internet has been pretty rotten these last few days: I'm told there's solar activity disrupting things, but I don't see any change in the magnetic field indices. We like magnetic storms a lot - they provide extra good data. We caught up with the ship a bit after midnight, and were expecting some sort of small vessel, but the ship was nearly as big as we are, and rolling a lot more. Being that close to another ship at sea is something you don't often see, and probably don't want to. The transfer was successful, however, and we quickly strapped a new transponder onto SUESI for our next tow.

Sat 18/1/2013: We deployed the instruments picked up yesterday, and then recovered some more. We are making good progress on turning the instruments around. An otherwise "boring is good" day was made a little interesting by the ship losing power just before midnight during recoveries. The ship is diesel-electric, whereby diesel powered generators make electricity to power electric propulsion motors. It is a great system - lots of flexibility and efficiency, and acoustically quiet. We have four generators, or "engines" on this ship, and have been running between two and three depending on transit speed and need for maneuvering. We had only two engines on when the watch got too enthusiastic about maneuvering to pick up an instrument, and tripped everything out. Since the generators provide power for everything, it is an eerie experience to suddenly have a pitch black, and quiet, ship. We were soon up and running again, but those without them quickly found flashlights to put into their work vests. The only other time this happened to me was on the Melville off San Onofre. Being on a blacked out ship drifting towards a nuclear power plant was slightly more interesting than today's event.

Fri 17/1/2013: A busy, but routine, day of recovering instruments. We are doing about one an hour, which is pretty good given the site spacing and the water depth. We have had our first glimpse of data, which is always exciting, and it is pretty good. Some noise from currents at the shallow end of the line, but nothing we can't process through. I was hoping to do some processing on the vessel, but we're a small team on this trip and we are keeping very busy, with almost no down time, so I think it best to concentrate on collecting the data and leave the processing for the shore.

Thur 16/1/2013: Yesterday was a reasonable example of the "boring is good" philosophy to CSEM deep-towing. The external battery pack worked, but USBL lost signal at a slant range of about 2,000 m, but we worked out a couple of ways to make our long baseline (LBL) acoustic system work for us. One was the LBL transponders hung off the stern, which we call Barracuditas, after our larger Barracuda inverted long baseline system (see the Scarborough and SERPENT cruise logs for more on the Barracudas). The other is an old idea I tried before without success, and that is using LBL ranges directly from SUESI to seafloor instruments. This time the scheme worked, so we are effectively using the seafloor instruments as an acoustic transponder network. The plan was to tow through the night until we ran out of cable on the drum (the Chief and I have agreed that leaving 1.5 wraps on the drum should hold OK).

Today was not boring. I was woken around breakfast with the news that we had an instrument on the surface. Our nifty strayline system, which radios an instrument's name and location to the ship when it is on the surface, informed us that Roo was floating about 4 km away. OK, we were nearly out of cable on the SUESI tow anyway, so we decided to pull SUESI up and then go roo hunting. Did I say Arnie likes to drive the winches? He jumped onto the antenna winch and presto! it didn't work. We poked around and could not find any obvious problem - we feared that the 3-phase motor had burnt out, but why it would do such a thing sitting between the deployment and recovery I couldn't understand.

We had to keep working, so we used a crane to help us haul the first half of the antenna back in and then did the rest of the antenna and 500 m of Vulcan (towed receiver) line by hand. Then we went and picked up Roo. Meanwhile, the Chief Engineer, Julio, was working our winch problem. He showed that the motor was OK, so the fault had to be in the controller. The controller is a micro-controlled pulse width modulator or some such thing - not something easily repaired. However, he pulled it apart anyway, polished it some, put it back together, and made it work. A real hero - the prospect of doing the rest of the antenna deployments and recoveries by hand was quite depressing.

Now we are off to the top of the line to start proper recoveries.

Tues 14/1/2013: Well, with regards to the turtle, it turns out my divining skills leave a little to be desired. The battery in the SBL transponder died at midnight after only 7 hours of operation. We continued our deep tow for a while longer using a jerry-rigged system of our own long baseline transponders, which gives distance to SUESI but not direction, but stopped the operation around mid-day. We found an underwater connector cable in the lab that would allow us to rig up external power to the SBL transponder, so we spent some time filling a spare pressure case with a gazillion batteries all wired in parallel. This is sorta against the rules, but it works. We had SUESI back in the water by midnight.

Excellent fish and chips for lunch. I discovered that sherry vinegar is a good substitute for the malt vinegar much beloved by the British.

Mon 13/1/2013: We started to deploy SUESI around 2 pm. We saw a sea turtle swimming by behind the ship, so I decided to declare this a good omen. All of SUESI's stuff went into the water really well. I should mention that the weather has generally been lovely the whole trip so far, which makes life a LOT easier at sea. We had SUESI down near the seafloor and transmitting by about 5:30 pm. We normally get a remote winch control put in the laboratory, and drive the winch up and down to keep SUESI about 75 m off the seafloor. This is not available on this vessel, but Dallas had the great idea of putting one of our laptops with the SUESI monitoring program in the winch shack. We found a serial data cable that ran from the lab to the winch shack, and before long had a monitor that allowed the tiny winch shack to become a mini-laboratory. Worked well. The real computer lab is cold as anything, to keep the computers cool I guess, so there was no shortage of volunteers to stand around in the balmy evening and run the winch. Especially Arnie. Arnie loves to drive winches.

Sun 12/1/2013: Finished deploying instruments today, another 23 for a total of 55, finishing a bit before midnight. While the main focus of this project is the magnetotelluric method (MT), a passive method that involves "listening" to Earth's magnetic and electric fields, it turned out that the ship had a winch and cable that would allow us to make a few runs with SUESI, our EM transmitter. This method is sometimes call active source (c.f. passive), but we generally call it controlled source electromagnetic sounding, or CSEM. There is some concern about how long and how deep the ship's SBL transponder will go, so we're going to start our CSEM run from the shallow end of the line (where we started to deploy the instruments).

Sat 11/1/2013: We continue to deploy instruments down the line, getting 23 in by the end of the day. We would have done a couple more, but there is a seismic vessel criss-crossing the work area at right angles to our lines, and our mandate is to stay well out of its way, and so we stopped work as it passed across our line. Seismic arrays nowadays are huge, mind-bogglingly huge: this one is 3.5 nautical miles long and half a mile wide. I once saw a promotional picture where a company had laid out a diagram of a 3D seismic array over the city of Copenhagen. (or was it Oslo? Probably Oslo.) It stretched all the way across the city.

We also lost some time because I had made a bad blunder when I wired our gear up to the ship's acoustic echo-sounder transducer. This is a big piezoelectric device mounted on the bottom of the ship and used to bounce sound off the seafloor to get water depth and some sediment properties. We use the 'ducer to talk to our instruments. The cable had 3 pins, and I knew one of them should be a shield and the other two were the 'ducer, so I poked around with the multimeter looking for a ground but couldn't find one. Turned out that the probes were not going into the sockets enough to make contact, but I didn't know that at the time. I tested the pins with a transducer tester and thought I had got the right two, and indeed it worked very well. Until we got into 2,000 m water. Then we started losing instruments on the chart recorder. A bit of a rising panic ensued, and we hatched some crazy plans to go back into port for some hardware to mount our own transducers in the ship's well (a sort of little moon-pool). Fortunately, I had the sense to email the ship's people and ask for a pin-out on the 'ducer cable, and when I got the prompt reply I immediately realized my mistake. I fixed it, and the acoustics started working well. Really well. If you followed my link on the home page you will have noticed that this ship was built as a submarine hunter during the cold war, so it is no surprise that it is acoustically quiet. I felt quite dumb, but also frustrated that even when I connected to the shield and only one cable, it still worked quite well. Must be capacitance...

Fri 10/1/2013: We spent the morning on our transit to the work area. Weather is quite nice, but the seas are "bumpy" as I'm told they mostly are around here. The ship rides well, however, and while a few of the "youngsters" (i.e. people younger than me, which accounts for pretty well everyone except Arnie) are queasy, nobody is doing the Sproul. We arrived on station around 1 pm, went through our work plan with the crew, and tested the SBL system by lowering its transducer over the side on a rope. Thankfully, it works. This is a great relief, since it is critical for our SUESI operations. We started deploying instruments on our line 3 in the middle of the work area and got 9 in by the end of the day.

Thur 9/1/2013: The plan was for the SBL technician to arrive at around 9 am and for us to push off at noon. Then we heard that the technician's taxi had broken down on the way to the airport. He eventually arrived on time but they had closed the gate 20 minutes early. He got another flight that would put him at the ship at 1 pm, so the plan was to board the pilot and stall an hour. Of course, it took a bit longer than expected, but the technician arrived and immediately started work. He speaks little English, but thankfully our Brazilian colleagues can help with translation. More delays ensued (the cook ran off to get more food), but finally we pushed off at 6:15 pm.

Wed 8/1/2013: So we all got up at 7 am again expecting to see containers arrive. No such luck. They finally arrived at 10:30 am, but we got everything aboard pretty quickly. Then the big job of tying down, unpacking, setting up the laboratory space started. Welders came and started welding our gear to the ship; on our (university) ships we have a nifty 2' x 2' bolt-hole pattern in all the decks, and all our gear is designed around this, allowing us to bolt down everything from a small table to a huge winch in minutes. Here we had to have it welded to the deck plates. Welding went on until about 4 am. The big disaster of the day was discovering that there was nobody on the ship who knew how the short baseline acoustic system (SBL), which we planned to use to track SUESI, worked. Not a clue. Arnie has been involved in this equipment before, and he set to with the manuals trying to work things out, but this was more a heroic gesture than something likely to actually succeed. These are quite complicated systems, and the ship's computer lab was a rats-nest of cabling (as these things always tend to be). It was agreed that a technician would be flown out to join us in the morning and come along to operate this system.

We hosted a quick show and tell for some of the local oil company and oceanographic people.

Tues 7/1/2013: Sitting around Montevideo waiting for port access for the ship. We were told yesterday that we'd be picked up at 8 am to be taken to the ship, so we all got up for breakfast at 7 am. I was woken around 6 by a rather fabulous lightning storm, and the view from my bedroom, on the 22nd floor of one of the largest buildings in Montevideo, was great. I was counting about 3 flashes a second.

By the end of breakfast an email arrived on my phone (thank goodness I bought a data roaming plan for this trip - I would have been in trouble without it) saying that the ship would dock at noon, so we all went back to our rooms (I took a nap, expecting to be working all night loading the ship). Then we were told 13:00. The problem was that the ship occupying the position we were going to use was delayed, maybe by the weather. Then 18:00. Finally, the ship docked at 19:30 and we were taken to the port, where we met Stephanie and Fabricio, geologist/geophysicists working at a colleague's company in Rio. At last we got to get on the ship. We expected to start loading right away but were told that because of the weather we were better off doing it in the morning. OK; we could get a night's sleep. We were promised that the containers would arrive at 7 am and we could start loading at 8 am.

Mon 6/1/2013: Sitting around Montevideo waiting for port access for the ship. Port access is only allocated a day ahead of time, and we're hoping for tomorrow. Did I mention this was a holiday weekend? Biggest holiday in Uruguay (twelfth night I assume). But one of the biggest attractions was open, an old train station converted to a restaurant market with many Parilla (barbecue) stands. We arranged to meet Keith (technician from our marine facility who is acting as the safety officer for our project) there, which we did, and had lunch at a place made famous by Alain Bourdain.

Dallas and Peter, the two students joining this project, arrived around lunchtime. Another miracle; they too managed to get upgraded on the Miami to Montevideo red-eye using my systemwide upgrades.

That evening we avoided Don Pepperoni's by eating at a Parilla place yet again. I had the octopus.

Sun 5/1/2013: Arrived in Montevideo with Arnie (trusty colleague) and Chris and Jake (trusty techs), after a fairly long, 3-connection flight. We had re-booked this flight after it was clear that we were not going to get port access for the ship on the weekend (as we had earlier been told) and Arnie gave me stern warnings about the connection time I chose in Miami (an hour). Chris and Jake followed their leader (who can blame them for that?) and the plane was indeed (only) 15 minutes late getting in. Fortunately we didn't have to transfer terminals and so we (very efficiently to my mind) walked off one plane and onto another. Miraculously, we had ALL been upgraded using Arnie's and my systemwide frequent flyer credits, and there was Arnie lounging back in his seat smirking as we got on the plane. Also miraculously, our bags all made the transfer.

When we arrived we met up with Joel (trusty tech from another group who was joining us for this project to cover for the lack of student labor) and went out for dinner. Montevideo was very quiet for the holiday weekend, with almost nowhere open, but we did find a place called "Don Pepperoni" (a pizza place, of course). Pepperoni is one of the few things I don't like, but I scored a nice number with huge chunks of bottled porcini mushrooms on it.