Month: May 2016 Page 1 of 2

Hello hello,

  Well I have certainly gotten behind with the story of this journey (stupid internet) and instead of catching up with one giant novel of a blog entry I had tried to spread out the tale in several short installments.  Now I find myself in a weird situation where here in real time the cruise is ending (seriously it is 5am and we are just waiting until our 6:30am call in to the harbor for permission to move on in) and in story time I still have some science things to recap!  Ok ok so I guess I will give you an abbreviated version of the science and go from there.

One of the last major sample collection things we did on this cruise was multicoring.  This is quite similar to the box core method except instead of one giant scoop of sediment they pull up 12 smaller cylinders at a time.  The biggest challenge with the multicorer is that the weather conditions play a huge role in success or failure.  If the swells are too big (and by too big I mean if there are waves at all!) the multicorer will hit the seafloor at an angle and they will only recover a few samples or the whole contraption will get jostled around enough to either spring the trap too early or dump out the samples entirely.  It really needs to be very calm for the multicorer to be successful.  The reason the scientists were very eager to use the multicorer is that while the box corer is more reliable and delivers more sample in sheer mass, the multicorer brings up samples with the sediment/water interface still intact.  This little top layer of sediment is really important biologically and is preserved well in a multicore but not in the boxcorer.  A tricky set of pros and cons…

Anyways…the multicorer was very easy to get into the water and later recovered.  Not extra steps, no weird system or extra equipment.  Just grab it and pull it on board.  The hard part is that it moves through the water very slowly.  Only 45 meters per minute to go down and come back up and when it has to go 5000 meters (that is 3 miles for all those non-metric users)…well it takes a while. 

So for a couple of weeks we basically switched between box coring and multicoring all day.  And yes, all day really does mean 24 hours a day.  We just kept putting down corers, waiting, pulling up sediment, and putting the equipment right back in again.  It was not a bad routine at all.

Eventually we got to a point where one of the scientists was ready to collect phytoplankton samples with a big net (cleverly called a phytoplankton net).  The idea here is that the net, which is about 2 meters in diameter at the top and tapers down into a small collection cylinder at the bottom, is very light weight and goes into the water and down to 200 meters.  From there the ship moves ahead very slowly and the net is towed horizontally to collect phytoplankton.  That was the plan.  What actually happened was that the net went down 200 meters, was immediately caught in the current and pushed up against the propeller of the ship and the line was severed.  The net was lost at sea within the first 10 minutes of its first deployment.  Yikes.  I don’t even have a picture to include here because it happened during the wee hours of the morning while I was off shift so I didn’t even get to see it!  Things can happen really fast around here sometimes.

Well so mostly that is the story of the cruise.  By the end of the trip the German scientists have put equipment into the water 106 times during their working window of 21 days.  That is a very very impressive number considering how long it took for each piece of equipment to do its thing.  With the exception of the phytoplankton net, everything else was ultimately successful and the scientists were able to collect everything they wanted to and more.  Even phytoplankton was eventually collected using a different smaller net that was modified so that the scientist would be able to get some amount of sample. 

None of the equipment broke down to the extent that we couldn’t use it.  There were a few mechanical issues that cost us a few hours here and there but nothing that the engineers and deck hands couldn’t fix eventually. 

There were no medical emergencies and everyone has come back safe and whole.

Hard to ask for a whole lot more for a 44 day long voyage at sea:)

For now I have 1 more day here in Hawaii and then I am off to have a short break back home in Minnesota.  I won’t be adding another blog post until I am on my way to my next tropical destination…BERMUDA! Yay!

So with that I bid you all a farewell for now:)

Elizabeth

Hello hello,

 Things continue to move right along here.  The video sledge did its thing for a couple of days until the science team was confident that they had collected enough footage.  Once they gave the ok we hauled the thing up and began another round of musical chairs to get to the next piece of equipment.  This time it was the epibenthic sledge and, again, it took quite an effort to get the video sledge out of the way and the epibenthic sledge front and center.  This particular contraption is larger than the others and for deployment out into the water it is meant to stand vertically maybe a little over 3 meters (10 feet or so) tall.  The goal of this thing is to sink down all the way to the bottom of the seafloor until it is actually settled on the ground.  The ship will then move ahead slowly and drag it across the bottom collecting the surface layer and the very small life forms that live there in a filtered net sort of thing.  The bottom of the sledge itself has a big latch release on it that opens the nets for collection but is only OPEN if the latch is depressed (ie if the sledge is firmly settled on the bottom of the sea floor) and that way they know they aren’t collecting samples from the water column on the way down to the bottom or on the way back up to the surface.  It’s a pretty clever way to ensure they are getting samples just from the bottom. 

  So anyways the deck rearrangement completed we got the epibenthic sledge into the water without any trouble.  It is large and heavy but rectangular in shape with plenty of places for tag lines to ensure a safe and controlled entry into the water.  All in all…no problems.  But again, once it gets into the water it takes about 7 hours to complete a run.  With these ones it is mostly getting the sledge to the bottom and back up that takes the most time.  We put out over 6 kilometers of wire from the winch at a rate of between 30-45 meters a minute.  It takes about 3 hours for it to go all the way down and another 3 to get it to come back up.  Yikes. 

Once the epibenthic sledge was recovered we moved into a long long series of playing with sediment.  The scientists brought 2 main pieces of equipment to collect seafloor sediment; A box corer and a multicorer.  We started with the box corer.  This is a tall piece of equipment consisting of a large base to “land” well on the seafloor and a central core that has a big box and scoop at the bottom of it.  The corer is cocked in an open position with the scoop stretched back behind the box and it is deployed into the water and down to the bottom.  When it reaches the bottom (which is determined by the depth reading we have for that location, the length of wire we have put out through the winch, and by the eagle-eye attention of scientists watching the tension readout of the winch.  When the corer hits the bottom there is a dramatic lessening of the tension that the scientists eagerly wait for) the box sinks into the sediment and the scoop snaps over the bottom trapping the sediment in the box.  We then begin the long haul to get it back to the surface. 

The deployment of the box corer is relatively straight forward even though it is awkwardly shaped.  The recovery of it is a little more involved but still fairly basic.  When the scoop has been triggered the central core of the contraption stands almost a meter taller than when it is cocked.  This means that when we want to bring it back onto the ship it is too tall to go under the A-frame.  So to get around that we have to use the A-frame to lift the box corer out of the water and bring it close to the ship, attach a different line to the shackles, move it back away from the ship, then use the different line attached to a different winch to pull it on board.  Really it isn’t overly difficult it is just a few more steps and another piece of equipment thrown into the mix.  Keeps things interesting:)

The box corer is one of the fastest pieces of equipment the scientists are using and it takes just about 3 hours to get one in the water, down, back up, and on deck.  Then the ship moves to the next station while all of the scientists begin to process the sample and re-cock the corer.  By the time we are in position the corer is ready to go down again.  All in all the scientists want 40 box cores so we have been doing this for several days already with many more to come.

Before I let this post get to long I will cut it off here.  Next installment; the multicorer…and maybe some phytoplankton net action:)

Elizabeth

Hello all,

Another installment of the story.  Still trying to catch up from our internet lull so just stick with me here.

Finally the seafloor mapping has been finished!  Don’t get me wrong, the data that was collected was super cool and the map that they are assembling is really amazing but it wasn’t a very interactive process.  Once Homeside was in the water we really didn’t need to do anything else.  It was towed behind the ship in very specific straight line.  We got to the end of one line and the ship turned around and we towed it in another straight line the opposite direction.  Not really much to it for 8 days.  Finally the scientists confirmed that they had covered the whole area they were trying to map and we could bring the Homeside up.  Very exciting moment.  Once it was finally up on deck there was a whole new game to play in terms of rearranging equipment.  We had to get Homeside tucked away on one side of the large A-frame, bump the multi-corer and box corer forward a few feet to make some extra room, and then pull out the video sledge from the other side of the A-frame to get ready to deploy.  Now…these things all seem really straight forward until you consider a few extra details. 1) All of these pieces of equipment are large and weigh hundreds of KILOS (our scientists are German so I figured as a nod to them I would keep my figures metric) which means using cranes, winches, and cables to lift and move things.  2) We are on a moving vessel here.  Even on calm days there is still pitch, roll, and heave motion from the swell.  Ever seen a large crane in action while it is rocking back and forth?  Certainly adds a whole new layer of excitement.  3)  There isn’t a whole lot of free space on the deck.  This science team brought a bunch of large equipment that is strapped down on the deck.  It takes a fair amount of precision to maneuver anything around and so I refer you back to points 1 and 2 to see some of the difficulties that arise.  Earlier I gave a strong nod to the technician for being able to do his job very well and save the day.  Here and now I have to acknowledge the stellar group of guys working the deck.  They are really good at what they do and it is impressive to watch.  Their skillful manipulation of the gear and equipment makes even the most complicated transfers go smoothly and safely so hats off to them every single day!

Ok ok I digress.  Back to the action.  Moving the Homeside out of the way and bringing the video sledge front and center took some time but was eventually accomplished.  The video sledge is a rectangular contraption that has several different motion video cameras and one or two still cameras attached to it (See picture below!).  The idea is that it will go into the water and sink down over 4000 meters until it gets near the bottom (near…not actually touching down) and then the scientists are able to use the cameras to actually look at the seafloor while we are moving over it.  The sledge stays down for 8-10 hours at a time and the scientists monitor and document the video feed looking for the manganese nodules that are the focus of their work right now.  It was pretty easy to get into the water and then we just had to wait some more.  Personally I really enjoyed invading the lab space and watching the video.  The scientists had most of the lights off in the lab and everyone gathered around to see the “action” like it was a show at the theater.  The addition of the quotation marks there is because the video itself didn’t actually have a lot of action.  Every now and then there would be a fish, brittle star, or little sea cucumber that would make a quick appearance but mostly it was just looking at rocks on the seafloor.  But it was looking at rocks on the seafloor over 4 KILOMETERS under the sea that made it special to me…in a nerd sort of way:)

Next installment: the epibenthic sledge and sediment collection.  Oooooooooh

Elizabeth