Aloha again from the Atlantic Ocean! The cruise is wrapping up, we’re getting near the end! The Rappé lab representatives have finished up our last dive. We managed to collect more crustal fluid from the deep sea CORKs we’ve been sampling. As was the case every time we sent our equipment down to ~4,500 meters, we were anxious to see our bags filled and on deck, definitely wanted to end the expedition on a high note.
The transit to North Pond took just about a week, we arrived Monday afternoon at our sampling site. We had spent the transit cleaning and prepping our gear. Monday morning was filled with a little bit of anticipation and plenty of preparation for sending our sampling equipment down to the seafloor.
Clarisse and I are here to collect fluid from borehole observatories installed previously called Circulation Obviation Retrofit Kits (CORKs). These CORKs allow us to access the fluid under the seafloor. We essentially hook a hose up to the CORK and fill specially designed bags with the crustal fluid. The bags are held on Jason in one large box on the front of the ROV (the “front porch”) and six smaller boxes on the back. To fill the smaller boxes, we divert the water to a manifold with multiple ports. In addition to the boxes, there are ports connected to filters so that we can pass water through them while Jason is sitting on the seafloor. From the Jason control van (aka the command center), we can change which port the water is flowing through, so our routine includes filling up all the bags in the boxes and passing fluid through the filters.
Monday evening the anticipation built as we strapped our equipment onto Jason and the Jason engineers then went through their pre-dive to check that everything was ready to roll. We wrapped up yet another fantastic meal (the food has been seriously amazing), then Jason was hoisted into the air, over the side of the ship, into the rolling swells. Deploying the ROV at night made for a dramatic first dive, but…life is full of challenges, even more of them when you’re working at over 4,000 meters deep, and not long into the dive one of the hydraulic arms started leaking oil in a steady stream, the dive was definitely over.
After a 3 hour ascent, time to repair the arm, and a quick look to make sure everything was still strapped on tightly, Jason was sent back down to about 4,300 meters. Another few tasks were accomplished before yet. another. leak. Major bummer, we didn’t get to start collecting fluid samples and already two dives had met untimely ends. Jason was hauled onto the deck yet again, but this time they didn’t just do a quick fix, the whole ARM was replaced. Rough night for Jason, undergoing surgery before heading back to work.
Third time’s a charm though, and on that dive numero tres we managed to collect over 100 liters of crustal fluid. Everyone was happy to grab their bags of water, and I can’t tell you how stoked Clarisse and I were that it was a success. We might be the main people orchestrating the water collection, but these samples are key to multiple experiments for different labs on the ship.
Whew, what a relief! We unloaded our first set of boxes, and turned around to load the next set up – when working to get everyone’s samples and experiments in, time is of the essence! We had two more successful dives after that first round, this week has been a packed cycle of pulling samples off the ROV and loading everything back up to do it again. The actual fluid sampling process takes about 7 or 8 hours in the control van and as I type, equipment for our last sampling run is sitting on Jason on the deck ready to head down to the bottom.
In addition to whatever experiments and gear we have to deal with on board, all of the scientists are assigned a 4 hour block of time during the day or night to go oversee logs as well as take photos and videos of any experiments performed during the dive. The watch is only required if Jason is in the water, so we get to spend time sitting in the control van.
I was a lucky duck yesterday morning since there was some time to kill before the dive was ended and I got a few minutes to sit in the driver’s seat and fly Jason around the sea floor. Probably the coolest thing I’ve ever done, and not to be forgotten soon. More water sampling is on the way, our fingers are crossed for the next round!
The last few days before leaving port were spent on prep: securing equipment and supplies, troubleshooting (of course), and buying crucial items (chocolate and cable ties). However, Monday morning, everyone stopped to wave to a crowd waiting to see the ship off as we left port. This cruise is our captain’s last before retiring, and in his honor the ship even fired off cannonballs as we departed. The weather was beautiful, not a cloud in the sky, and the sailing has been smooth. Let’s hope this day is a sample of what will come over the next 30.
The main command center where the Jason pilot, additional engineers, and science team sit during Jason dives is called the ‘control van’. Along the front wall there are big beautiful screens to track what’s going on, a network of cables and wires that line the walls, and it is very VERY well air conditioned. We spent a few days testing communications between our equipment and the sampling gear on Jason in the control van. While we’ve checked this in the lab, going through the motions on the ship has, of course, has presented a few unexpected hurdles.
As I said in the last post, we’re heading to a deep sea observatory, but I didn’t really explain what that is. To study processes under the sea floor, equipment referred to as Circulation Obviation Retrofit Kits (CORKs) can be used. We are heading to North Pond where multiple CORKs were previously installed. This site is unique since the sediment in this basin stops seawater exchange from under the crust with the deep ocean, allowing researchers to focus exclusively on what is happening under the sea floor.
Clarisse Sullivan in the Rappé lab has been leading our group as we set up equipment to collect fluid from under the seafloor. As you might guess, we have customized sampling gear that connects to the cork, and using a manifold we can extract fluid and shunt it directly into specialized bags or pass it through filters as the ROV is stationed at each site.
We have a laptop with 3 key cables that hook into the control van, these three cables will let us (1) let us tell a pump to start and stop collecting water as well as regulate the pumping speed, (2) record data from an oxygen optode, and (3) let us switch the outlet of where the water being pumped will be sent to (e.g. either to a bag or a filter).
Sunday’s attempt to get our laptop to command the pump and sampling manifold on Jason was not completely successful, although in the evening we thought we had cleared up the problem. We ran into a similar hiccup Monday, and eventually figured out one cable needs to be replaced. The head electrical engineer for Jason also had to switch a few connections. In the end, we finally managed to get the pump pumping, data from the optode, and the manifold switching shunts, whew! It is still going to be a challenge to replace the cable but at least we know what the issue is.
On Tuesday evening, the winch that deploys Jason was tested in order to safely lower equipment into the ocean. In the meantime we have continued setting things up for our first dive at North Pond. It’s absolutely great to be out at sea with such a talented and interesting group of people, we’re looking forward to the days to come!
A few Rappé lab members, as well as representatives from Grieg Steward’s lab also at the University of Hawaii, recently made the treck from Oahu to Woods Hole Oceanographic Institute (WHOI) in Woods Hole, Massachusetts.
We are currently preparing for an expedition to the Mid-Atlantic Ridge on the WHOI research vessel (R/V) Atlantis. In just a few days, we’ll be heading to North Pond, located along the western flank of the Mid-Atlantic Ridge.
Our first day on the boat was mainly spent unpacking all of our carefully stacked and labeled boxes filled with (hopefully) everything we’ll need to deploy our sampling setup. We sorted out the contents of the pallets we had shipped to WHOI from Hawaii with everything from custom designed equipment to lab gloves, bungee cords, and cable ties (so many cable ties).
We will be deploying our sampling equipment on Jason, a remotely operated vehicle (ROV) built at WHOI. It’s key to get everything we need attached and functioning smoothly on Jason as soon as possible. We have a few more days in port to set things up, get it all running, and prepare for deployment to the deep sea.
As our expedition gets underway, we’ll post more descriptions of how and what will be sampled at North Pond with Jason on this expedition. One of our main pieces of equipment consists of a large frame containing boxes with custom designed bags inside to hold seawater collected from an existing subseafloor borehole observatory. Yesterday, while attempting to mount our gear on Jason, we realized some changes would be required if everything was going to fit. Since some modifications were made to Jason since the last deployment of this equipment, what used to slide into place snugly on the ROV is now too large. With some troubleshooting, a workshop to make changes, and some creativity, it looks like everything will work out fine, but I might knock on wood just in case.
Hopefully, there won’t be too many more bumps in the road, although it’s inevitable that there will be some challenges….but honestly, where’s the fun when everything’s easy? We look forward to keeping you posted on our progress on this exciting expedition, more to come from our journey at sea soon!