E-mail reports from the Chief Scientist, Liz Sikes, on board the RV Roger Revelle:
Stories in the press:
E-mail reports from the Chief Scientist, Liz Sikes, on board the Roger Revelle:
This took a long time because we have so much stuff – and there are 24 people who are working with me… and that means a lot of stuff to check. Then we had to stow everything away so that it wouldn’t roll around or fall over and break once we leave the dock and the ship starts to roll around from the waves. So we had to put everything in the cupboards in the lab and then tie everything down. But now that is all taken care of and we are just waiting for the ship to finish fueling so we can leave.
After double checking that everything was tied down and wouldn’t fall off the tables when the ship starts rolling we had to do a fire drill – and an abandon ship drill—that’s really something you don’t have to do at school! It’s just to make sure that we know what to do if there is an emergency. Then after that I had to make sure that all the forms were up to date (like getting all the scientists’ passports to the captain). Then we left port and went out of the harbor, and I felt seasick – so I went and lay down in my bed. Being seasick is a little like having a tummy bug… I didn’t throw up… but sometimes people do. And when I lie down and close my eyes, I feel better. So, I went to bed at yesterday and I didn’t wake up until 7 this morning. I feel much better now.
Right now, we are steaming to our first station. Which means that the captain and his crew are driving the boat which has huge diesel engines out to the place in the ocean we want to take the first core. While we are steaming (they also call it sailing) we have our echo-sounders on to see how deep the ocean is and to see what the bottom looks like – the echo-sounders make a picture of the bottom of the ocean using sound – it’s kind of like looking at a cartoon of the bottom of the ocean. We use these to find the place we will sample the mud. It will take us another whole day to get to the place we want to start… boats are a lot slower than cars or planes.
Here we are
on the high seas. We steamed south and east from
So, what we are doing now is still steaming to station -- not in a straight line mind you, but with a little zig zag to get some surveying in... We have to use the echo sounder to look at and into the bottom to see where the best mud (we call it sediment) is. Right now we are coming down the south slope of the Chatham Rise, aiming to start coring when the water depth is 4000 m.
Our science plan is to get a core at different depths (every 500m of water depth). So once we start out here at the deepest point, we will then work our way up the south flank of this rise, coring every 500m water depth.... What coring means is that we have a very long and very strong pipe (called a coring barrel) with 5000 lbs (~2500 kilograms) of weight on it. We will lower that down on a long wire, then just before it reaches bottom we have a trigger that will let it drop the last few meters, and it will jam itself into the mud. Just imagine trying to jam a piece of pipe into the mud -- that's why we need so much weight. We then have to pull it out and reel the wire back into the ship. That's our plan ... now we get to see if the seas and the mud will cooperate.
As for me, I've been working hard to try and decide the best place to put our first core, and our coring team is making sure that everything is ready to go and SAFE. Even though I am feeling better, when the waves get bigger I feel a little queasy now and then. I hope to feel better enough that I can go to the gym on the ship today and use the rowing machine so that I can stay in shape-- it's a really hard thing to do on a ship because even though this is a big ship, it's still a small place -- and we are cooped up inside all the time. The food is pretty good, and they have ice-cream at every meal! So I have to be careful that I don't get fat!
Last night we finally got to our first coring location. Yesterday we did a lot of echo-sounding looking for a good place to core. We found several places where the mud is deep enough at the bottom, at the different waters depths we want, so that is good. We started with the deepest spot. Once we got there we had to rig the piston core to get it over the side so we could get the mud. That’s not such an easy thing on a ship that is rolling around. To get the samples we want we have a 40ft (12 meter) long core barrel made out of metal, which is so long we can’t lay it on the ship deck so it has to lie along the side of the boat. They put almost 5000 pounds (lbs) of weight on the top. That weight makes the pipe jam into the bottom and get a core full of mud (like pushing a straw into a slushy and pulling it out). Because the bottom is so deep you can’t just drop it from the ship, so it has to be lowered over the side on a wire, and a trigger attached to a small core releases it to fall the last distance. The way it works is the trigger core dangles below the big core, and when it hits bottom, it lets the big one go and it jams in. Some of the pictures show the coring team loading the short trigger core into its cradle, after that it’s lowered on its line down below the ship. Then the barrel of the big one is released, and then the weight stack is swung out of the cradle (you can see the cradle in the picture of the trigger core—it is the big blue tub). The whole thing is lowered into the water using the ship’s crane.
The water is so deep here it took almost 2 hours for the core to get to the bottom on the wire, and take the core. Once the core is in the mud the winch driver has to pull it back out by reeling in the wire. But you can only pull so hard or the wire will snap. On this core the technicians did such a good job of getting the core into the mud that it got stuck – we pulled as hard as we could and it wouldn’t come out so we had to wait and let the rocking of the ship ease it out. We waited about 20 minutes as the ship rocked and gently jiggled the core, but finally it let go and they could reel it back in. Getting that heavy pipe (now full of mud) onto the ship is just as hard as putting it over the side. You do everything in reverse… and you have to go slow and carefully so no one gets hurt.
The core came on board last night very late. Inside that metal pipe is a plastic pipe called the core linear that holds the mud. It had to be eased out very carefully. The core inside was 12 meters long so we had to cut it up into1.5 meter sections (that’s about 4 ft). I don’t have any pictures of that because it was my job to cut up the core. Maybe I can send some pictures next time!
want on this cruise to take some multi-cores. These are much more gentle
cores which sample just the top 3ft (1meter). So that rig has to be very
different from the piston core. So after we took the piston core, they
tried to get a multi core. But
the winds have come up -- a good southerly blowing up across the
All yesterday it was too rough to do any more coring. In fact when the coring team had time to look at the multi-core they brought back on board yesterday it was badly beaten up. Some of the metal struts were hanging loose, and when they got the net off of it they could see that many of the bolts and welds had been badly damaged. That damage is not because the multicore slammed against the side of the ship – it’s because it got rattled up and down with each wave for 4 hours as it went down and back up. The swell (which are the big rolling waves) the last 2 days have been 12 ft (3meters) high, which means the ship and the multicore were actually bouncing up and down twice that. So the multicore got pretty shaken up. We had a pinger attached to the wire above the multicore (the pinger sends out a "ping" that you can hear and we can see that on our echo-sounding trace so we can see where in the water the gear is). The batteries in the pinger go so rattled around that it stove in the tops of them! It's pretty rough. The crew spent hours fixing the multi core. See the picture of the chief engineer praying to the coring gods that we could get it fixed! The praying must have worked because they fixed it! So we are waiting still to see if the sea calms down enough so we can try for another core.
Even though we haven't gotten any more cores, that doesn't mean we don't have anything to do. We have to take the core we got, and prepare it so we can study it. When it came on board we cut the 12 meter core (that's 40 feet long!) into 1.5 meter (about 5 ft long) pieces so we can carry it around and work with it. After we run the sections through a sensor device, we then have to split those sections length wise so we can see the mud. To do that you have to cut the plastic core liner barrels with a skill saw (there is a picture of our student Matt doing that). Splitting the core barrel is messy business so that gets done out on the deck in the hanger. Now, we only use the saw to cut the barrel NOT the mud because that would stir it all up. So, after running the saw down both sides, you then have to slice the mud gently with a wire that you pull down through the mud along the slits that the saw has made. The wire we are using on this cruise is actually a cheese slicer! Then gently, very gently, so the mud won't slip out, you have to pry the 2 halves of the core apart.
We now have 2 halves of the core that we can work with. One we will work with, the other we will save so in case we need it later it's there - so we call one the working half, the other is the archive half. After the core is split, we have to clean up the surface of it so we can see what is there. This is because even though the wire cuts the mud gently, it still drags things along the surface of the core - and that stirs things up a little bit, so we even more gently clean the core by scraping the surface across the core. At last we can see what was in the core and if we got what we wanted. Next we take a picture and very carefully measure the lengths. At this stage it's very important to measure everything very carefully and carefully write everything down, so that when we go back to sample later we know what everything is. And we always have to go back again later. Some times as long as 10 years later! After that is all written down carefully, only then we can begin to sample the core.
Right now, we are waiting to see if the sea state is calm enough to try for another core - it's the Captain’s decision if it is safe enough - so we are waiting to see what he thinks.
Last night the weather calmed down enough that we managed to get a second piston core. This time when it came up on board it was still daylight so we took some pictures of people taking the core liner out of the core barrel (that's called extruding the core) and cutting it up. So once the heavy core weight is safely back in its cradle it has to be gotten back up from vertical to horizontal so we can get the mud out. The coring techs lasso a wire taped to the outside of the barrel and winch it up and lay it back down on the "sticker-outers" (those metal struts that hung so they stick out the side of the ship). Then the coring techs push on one end and the scientists pull on the other and slip the core liner out. The barrel is metal and pretty thick so that it can jam into the mud and the liner is plastic and actually holds the mud, and is thin enough to cut so we can work with it. So we pull about 20 feet out and cut it off, and cap it immediately so that the mud, which is sometimes pretty wet, can't slide out.
Then we put it on some specially designed poles to hold it, then pull out about 20 feet more and do it again. Then we go back and slice it into the shorter 1.5 meter sections that easier to work with. Those weight about 75 pounds (about 32 kilos) so you don't want to be lugging anything bigger around. When we get to the top, it’s always wet so we have to be very careful to hold it upright before we cap it so nothing falls out. I'm sending some pictures today of extruding the core and capping it.
After we do all that we have to wait a few hours to let the core warm up before we can begin processing it - the water and mud at the ocean bottom is only a few degrees above freezing. I know I explained yesterday about the splitting - but before we split it, we run the whole core sections through a multi-sensor-core-logger which has detectors that look through the core barrel -- that has to be done when it's whole and when the core has warmed up. The core we got 2 days ago we only finished processing late last night and the one we got last night we are just finishing working on now. What we discovered since the last email I sent is that the first core we got didn't have one of the important features we were looking for in it. When we looked at the core we could see lots of layers - and we don’t want that many so close together. What we were looking for was a sandy pinkish layer all by itself. This is called a tephra – a layer of ash deposited all at once from a volcanic eruption. If we find that layer we will recognize it is an ash fall from a volcano on the North Island of New Zealand. We know that the eruption occurred 25,000 years ago because other scientists have studied it before us, and we use what they have learned so we know what to look for. That is why we take our time carefully cleaning and describing the core, and looking at all the layers. When we are done describing we put the cores in labeled tubes to store them and send them back home in.
One of the things that is really different about working on a ship is that the ship runs 24 hours a day. Every job on the ship has to be taken care of all day and night. We even do the coring all night. So everyone on the ship works in shifts. On a ship that's called “standing watch”. Most of the people on the ship stand what we call split 8 hour watches - that means you work for 4 hrs then get 8 off and then you work another 4 and get 8 more hours off. There are 3 watches, the 12-4, the 4-8 and the 8-12. So, for example, I am on the 8-12 watch. That means I stand watch from 8-12 in the morning and then again from 8-12 at night. So for those 4 hours twice a day I do whatever work there is to do, whether it is helping with getting the core over or the core back, or slicing it up. There is ALMOST always something for the scientists to do. The crew is always busy because they run the ship. We the scientists are there to do science work, but we couldn't do what we need to without the work of the crew. They drive the ship, cook the food, and keep everything running. The coring and ships technicians run all the science gear and make sure it runs, and they are the ones who fix any of the gear that breaks when it goes over the side. So someone is working all the time. For the scientists, some times are more busy than others, so we get breaks and can do things like play scrabble in the lab.
mentioned in the last report, the scientists couldn't do any of the things we
do here if it weren't for the crew and the ship technicians, or techs for
short. The techs are the ones that
know how the gear and the ship works.
Because they do this sort of work much, much more often than the
scientists, they can do it faster and safer than those of us who only got to
sea every few years – so they are the ones who direct and do a lot of the
work. On this cruise we have 2
coring techs, Pete and Dale, who work hand in hand with Bob and Brent who are the ships techs or resident
techs (res techs for short) and a computer tech, Woody, who makes all the
electronic and computer gear work for us.
Pete and Dale are also training 2 more coring techs, Dan and
If you were out on deck you would notice that they are always wearing a life vest and a hard hat and steel toed boots, and usually water proof overalls or trousers. If you work on a boat you are going to get wet, so you have to dress right (here’s Dale and Brent with one of our students Jesse all suited up to go on deck). In fact wearing a hard hat and what we call a working vest is required if you are going out on deck (see one of the scientists, Hugh in his working vest and hard hat). This is because all that heavy gear swings around once you lift it off the deck, so you can easily get banged in the head, and if the ship swings when you are leaning out you could fall over. Don't worry, it doesn't often happen but in case it does we want to be prepared. If you don't have a hard hat on you must watch from inside (see Amy watching from the door). So we all suit up when working on deck.
We call them working vests, because they are big enough to keep you afloat for a little while if you fall overboard when you are working - but they are small enough so you can work. But, they aren't big enough to keep you floating for a long time. We have bigger life vests in case we have to abandon ship - these are really big, and so they will keep you afloat for a long time even if you can't swim at all. We had to all try the life vests on at our abandon ship drill earlier in the cruise (Sindia in her vest). We look and feel a bit silly in those things - but it is good to know they are there!!! Another safety thing they have on the ship is an immersion suit. This is because if you have to abandon ship, it's not just important to stay afloat, it's important to stay warm – because if the water is cold, it is the cold that will hurt you more than anything else. We have to all try them on because they are hard to get into and we need to practice (Hugh in his immersion suit). They are also pretty funny looking!!!
Last night we got another good long piston core so we are pretty happy about that. Those are the cores that we will use to look back in time to the ice age. But we are still having trouble with our multi-core. That's the coring gizmo that looks like a pyramid.
We use that to get just short cores that let us look at the surface of the mud really carefully, so we can understand what is happening right now, not in the past. The way it works is it has that pyramid shaped frame and we lower it down to set on the bottom. Then it has weights inside the frame that lower short tubes very gently into the mud just getting the top. This is very different from our huge pipe with the huge weight that slams REALLY hard into the mud. So, it's a more gentle coring device (as we call it). Even though it has gotten pretty calm for the southern ocean, the swell is pretty big and we are having trouble because it keeps doing what we call a "pre-trip" which means it closes in mid water while it's still hanging on the wire before it hits bottom. What we think is happening is, as the corer heaves up and down (that means bounces up and down) in the swell under the water, it thinks it's hit bottom and it releases and closes all it's tubes (it has 8) and so when it gets to the bottom we don't get any mud. We spent all last night trying to get one-we finally did, but we are going to try and fix the corer today so it will work better. We have the time to do that today, because we are done coring in the first location we wanted to core, and we are now going to steam for 12 hours now to get to the next place we want to core. So we have time to do that.
Well, the weather has turned rough again – we have gale warnings (that’s winds above 30 miles per hour) and we’ve been in them since last night. We managed to get another long piston core yesterday, but it was too rough to try and get a multi-core. Since we got the piston core on board (about midnight last night) we’ve been steaming north to our next coring location but also to try to get out of the weather. As I said before, even though we can’t core we still have things to do - we’ve been splitting and describing the cores we took before. It takes us about 8 hours to split them and get them described… and then we have to go back later and sample them. I will do some more sampling tonight … so there are things for us scientists to do, but it’s not frantic like it is when we are actually coring. We will finish one core today and then we have one more still to do.
scientists, the crew always has something to do. The captain is in charge and
the officers stand watches like everyone else on the ship. The captain is responsible for seeing
that everything on the ship goes well.
Our captain is always on deck whenever we put something over the side (Capt. Murline on deck). The mates steer and run
the ship (1st mate Murray on the
bridge). The seamen clean and
paint and generally keep everything “ship shape.” They have been
doing a lot of painting the last few days. (Picture of seaman Brian
all decked out in his gear for sanding the surface before he paints it).
(Picture of the
Bosun in the house for driving the crane.) The
Chief Engineer, and the engineers keep the engines running and they and the
engineering crew run the winches, and there is also an electrician with a
complete shop so they can repair anything that breaks on the ship (Manny the electrician in his shop).
The Chief (as they call him) helps us fix anything that breaks –
including our multicore that had to be fixed twice! (Chief Engineer
at work on the multicore) There is a full machine shop – if we break
anything metal the engineering officers and crew usually have the part (see a
picture of the store room) or can make it – they even welded the
multicore back together. There are of course cooks on board too. We have 2 cooks and they make everything
from homemade soup to baking fresh bread (Senior Cook Jay and scientist
Julia). We are pretty lucky,
the cooks on the Revelle are really good and so is the food. You can imagine that if the food
isn’t good people could get pretty down about it, but when it’s
good you always have something to look forward to, and we do. We have steak every Sunday… and we
Last night we had a little excitement that had nothing to do with work. Two birds landed on the ship. We don’t know if they were confused by the lights, or if they were tired and needed a rest because it was windy (blowing about miles an hour). But the first one flew right into me!
We see birds all the time out in this part of the ocean. It’s kind of neat because they keep us company, and give us something different to look at beside the water and the waves. Believe me the water and the waves get a little boring sometimes, and the birds are great to look at with their acrobatics. Some places have very few birds, but where we have been in the Southern Ocean, there are a lot. Mostly we get albatrosses. These are the biggest sea birds in the world – they look like giant seagulls with long elegant wings. The biggest of them all are the wandering albatrosses with white heads and backs, but there are also smaller ones with dark heads and dark wings called mollymawks (a Salvins Mollymawk sitting on the water). The mollymawks are still big, with a wingspan of almost 9 ft and a body is as big as a goose—but they are so graceful when they are flying you’d never think they are so big. The way they fly, especially in big winds, is amazing — they never flap their wings they just soar around the ship doing loops and zooming in front and then back (see picture of albatross on the wing). They are amazing – they get really close to the ship – clearly they are having a good curious look at us. Often, when we are stopped on station taking a core, they will set down on the water and wait to see what we bring up – and I think what they think is that we are a fishing boat bringing in our nets – and they are waiting for a free meal . Sometimes we had up to 100 of them hanging around the ship (sort of like a coring party). There are a lot of fishing vessels out and around the Chatham Rise, in the colder waters, and it would be only the fishing vessels that would stop in the middle of the ocean (lets face it, oceanographic vessels are very few and far between). So these birds have probably gotten really used to fishing boats. I keep trying to tell them they are wasting their time, but they don’t get it (either that or they don’t speak English!). The other amazing thing is how in strong winds and rough seas they just bob up and down on top of these waves like corks, while we are getting slammed around by them and breaking equipment left and right.
But we aren’t seeing many of these big birds anymore – over the last few days, we steamed over 120 miles north, and we are we are now well away from the cold water that has food for those big birds. If we see them, there are only a very few. The birds that crashed into the boat last night were much smaller petrels (petrel in hand). I’m not totally sure but we think they were Diving Petrels. We think they might have been confused by all the lights on the ship that we have to have on when we are working at night. We picked up the bird to keep them from hurting themselves and threw them back overboard over the back of the ship. But the silly thing came right back so we put them in a box to calm down and then set them free in the morning – we think they are OK because they flew off pretty happily.
That was the big excitement for last night… it was kind of a treat, because you can imagine that after 10 days of working all the time, and doing the same jobs over and over again, it’s nice to have something different to break the routine.
Last night, in fairly calm seas (that means not very big waves), we were piston coring in 3600 meters of water and we lost the piston core. Yep, we really truly did. 3600 meters is a pretty deep depth for us on this cruise – which means there is a lot wire out, and the combination of the wire (which weighs a lot when so much is wound out) and the corer itself puts a lot of tension (or pull) on the wire. We had the piston core on the bottom and there was a funny ”trip”. What I mean by this is that we watch the tension on the wire very carefully as it gets close to the bottom. We know it has reached the bottom when the tension drops quickly -- we call this the “trip”. Think about it… when the trigger core and the very heavy corer hit the bottom, then there is much less weight, on the wire, and we can see that on a meter in the lab. In a way it’s like a rope or string going slack when you stop pulling on it.
Once the core is in the bottom we have to pull pretty hard to suck it back out of the mud again, so the tension goes way, way up until the pipe gets sucked out of the mud, and we can see that too, on the meter. Once the core is free of the bottom then the tension comes back up to about where it was going down because the weight of the corer is back hanging on the wire. Well, last night there was a quick spike in the tension just on the bottom and then way too little tension, and then no pullout tension increase when we wound the wire back up. We could also see that there was much too little weight on the wire – which meant that there couldn’t be a core on the end of the wire anymore. So we new something was wrong.
Keep in mind we are trying to guess what is happening under the water, and the bottom of the ocean is a long way away (about 2 miles! or 3.6 kilometers!) so we have to make educated guesses about what’s up. It takes almost an hour and a half to reel in the wire from that deep. What the Chief Engineer could tell was that we’d lost the core, but from the tension still on the wire he could tell we had almost all the wire and the trigger core still on the end of the wire. He was absolutely right. Sure enough, when we got all the wire reeled back in that’s what was there (trigger hanging with no wire or core beneath). So, yup, we lost the core and it snapped KAPWING (!!) right where the trigger is clamped on the wire. This spot is where a lot of stress is on the wire, it is a place where the wire is more likely to snap if you’re going to be that unlucky (notice how the trigger is hanging at a funny angle in that picture).
To help you understand let’s see some pictures of what it looks like when things go right. Remember, when we put the core over the side, we put a clamp on the wire with an arm that holds the trigger core, and then loop enough wire to be the length of the core, and clamp it right above the big weight on the coring pipe (also called a bomb because it’s so big). Because that wire is looped up, the trigger clamp itself sits right above the big weight stack (see the trigger loaded and being lifted out of crutch) and the trigger weight (which is a small core) hangs below the core. The idea is that the trigger core hits bottom first which releases the trigger and the loops of wire and the piston core falls, hard, into the mud (thud!) and we get a core. When the trigger arm is down and the loops of wire set (picture of core and trigger with line over the side) the thing is loaded and ready to go down. If all goes well, when we get the core back on board the trigger arm comes up about 50 feet above the core and then we take the trigger core off the line (picture of the trigger core off the line, but the trigger still on with wire beneath), then the trigger clamp and arm (picture of recovering the trigger) and then reel up the last of the wire and recover the core (see picture of core recovery with it hanging alone on the line). So now go back and look at that picture of the trigger arm on the wire with NO wire, and so, no core hanging below. You can imagine what a sinking feeling it is to know that there is no core—but then to see that there is no wire below the trigger… well, it’s not a pretty site if you know what you are looking at.
However, we can’t get it back and I didn’t get upset. That’s because, when you are at sea, you really have to expect that this sort of thing can happen. It happens so often. There is a saying that everyone who goes to sea will tell you in their own way, which is: If you put anything over the side of the ship, sooner or later it won’t come back. They are expensive too – about $50,000 to replace the set up. We don’t like it but you have to expect that sooner or later you will loose a piece of equipment. So we always come prepared with extras of everything. Because we plan in case this ort of thing goes wrong, we have a whole spare piston core on board. You’d never go to sea with out 2 of the most important piece of equipment you need! So, as soon as we could we got on to getting the spare piston core built.
I should also point out that there was a bit of good news in this. It snapped right below the trigger -- so the trigger and the trigger core came back -- and we didn't lose much wire. Think about it… there is only so much wire on the spool – if you lose too much wire, you don’t have enough to reach the bottom.
The job at hand the next day was to get the very heavy weight from where it was bolted to the deck, across the deck and into the crutch (the big bucket that holds it on the side of the ship). The thing is so heavy that it’s kind of dangerous shifting it around on the deck while the ship is heaving around on the waves. Fortunately, we had a pretty calm day. So first they unbolted the holder it was in from the deck and moved it across the fantail (that’s what we call the flat open deck at the back of the ship) then they lifted it out of it’s holder (see picture lifting bomb into position) and up and into the bucket that it sits in on the side of the ship (see picture of bomb going into crutch). I don’t have any really great pictures of that because they had 6 people holding tag lines on it and they really wanted everyone else to stay away – but count the number of tag lines (ropes) coming off of that thing – at the end of each one is a person pulling hard so that it can’t start to swing, cause if it gets out of control it can smash things up pretty quickly. Once the bomb is in the crutch, they chain it in, and pivot the bucket to horizontal so that they can put pipes on the bottom of it (see picture of bomb with no pipes on it). Once it’s flat, they can just bolt pipe barrels onto it and we were back in business.
we got 2 cores – so everything is working fine – and we are working
our way west towards the North Island of new Zealand. We are now coring in
At sea it is amazing how fast your life and luck can seem to change. Just a week ago we were battling the rough seas and getting our multicore banged around—and not getting any mud despite the fact that we would put it over, try changing something, and then put it over again and it would still come back empty. But finally, after a lot of work, including taking the whole thing apart, and putting together the spare, and then taking parts from one and putting it on the other … the coring techs finally hit on what was wrong. They think that a part got banged up in the heavy waves, and banged in so badly that the whole gizmo that keeps the 2 parts of the corer from bouncing up and down against each other stopped working so it was bounding more than it should and pre-tripping. Pre-tripping means the whole thing thinks it’s on the bottom when actually it’s somewhere in the middle of the water column – so all the bottles close before it gets to the bottom. Then when it’s on the bottom it doesn’t get any mud of course. It was banging around so much it ripped apart a water bottle that was clamped on the frame (water bottle—it’s the grey tube strapped to the frame). The cap (or plug I suppose is a better name) from it was stuck so hard in the middle they had to take it apart to get it out! (bottle cap stuck in multicorer). Well, they finally got the multicore working by sealing up the valve in the center. They just gooed it up with stuff like silly putty or chewing gum (but stronger) so it wouldn’t leak. And I suppose there you have one of the real truths about going to sea. You have all this fancy equipment and when it gets rough you have to fix it—and sometimes it seems like the whole project is relying on chewing gum! But if it works, we go with it.
Just about the time the multicorer began to work is when we lost the piston core… and right after we got the spare piston core working is when the weather turned glorious. It couldn’t have been more calm or beautiful all day while we were coring off of Hawkes Bay (bird flying over water) We had a glorious sunrise and a beautiful sunset – which was made even more interesting because it was over land – the first land we have seen in 16 days (sunset over Bluffs). It was so calm, some of the people began feeding the albatross, so they got up quite close to the boat —and you can really see how calm it was!
We got some nice long cores, got caught up on processing them, we are getting pretty good at it—and everyone was smiling. I think that was as much the fact that it was such good weather. You have to remember, even though we get our “sea legs” after a few days at sea (which means you stop feeling seasick) that when it is rough you just get banged around a lot—everyone walks in zig-zags and it’s a lot of work to just do some of the normal things like carry those heavy core sections around. So when it’s calm everyone tries to get outside and enjoy it (Will reading on deck). So with the weather good we spent the time catching up on processing the cores, and we are getting pretty good at running them through our fancy detector that sees through the liner and measures things like the density of the mud (Tom and Amy in the MSD lab). After we split the core along its length it has to be lugged into the lab (but at least each piece only weighs one half of what it did whole (Alissa bringing split core into lab). After we split the core one of the slow and boring steps is scanning, yet Lilian was smiling while she did this most boring task (Lilian optically scanning core). We also got some nice long multicores and everyone on the multicore team was smiling as they cut up the cores into sections (Suzanne, and Lisa and Hugh slabbing mud). People were even being silly on the deck. Bob, the senior res-tech, who usually has a lot on his mind was just as cheerful (Bob and Jesse) as Dale and Brent. What a change a change a few days makes! The good weather really helps!
most of the night before last and all yesterday morning steaming up the east
coast of the
layered rocks give you a good idea of why we are out here. One of the main points of this cruise
was to get cores from the ocean floor with ash layers in them. Because mud settles on the bottom of the
ocean all the time, in our cores we see normal oceanic mud around and between
the ash layers (ash
layer marked for sampling).
Because the ash layers look a lot like those layers on
One thing most people don’t think about much is how much water that deep weighs – or rather how much pressure it puts on things that you send down that deep. For every 10 meters that you go down in the water column, the pressure on anything that is down there is another atmosphere more. What that means is if you are 10 meters deep (33 feet) you have twice as much pressure on you as you do standing at the surface. It’s the opposite to what happens when you go up in elevation. When you go up in a plane your ears pop because the pressure outside is less than inside your ears and eventually some of the air rushes out. When you go down in the ocean pressure increases quickly because water is so much heavier than air. SCUBA divers know all about this and are careful to “clear” their ears as they go down to keep the pressure balanced. Anyway, that change in pressure is something oceanographers have to think about all the time. Either the instruments we send down are very simple (like the metal pipes and the piston core) and can’t get crushed by the weight of the water – OR they are in a pressure casing that can’t get squished under all that weight. For example, we put a fancy pinger on the wire just above the multi core to help us see when it hits the bottom – that pinger is electronic and has lots of batteries in it and just like a radio or a CD player it can’t get wet or crushed or it won’t work. The pinger makes sound that bounces off the sea bottom and let’s us know how far above the seafloor our instruments are. So it has a cylindrical pressure casing on it (picture of pinger). The reason the casing is round is because a cylinder or a sphere (a ball) can’t be easily crushed if the pressure on it is the same on all sides. Think about it – if you could push on a ball from all sides at once you can’t squish it because you are pushing on all sides equally…. Anyway if you send something over the side that’s not something simple like metal pipes, or in a pressure casing, and it goes a long way down it will squish. One of the fun things we did to show how this works – and to make souvenirs for ourselves – was to put styrofoam cups into a mesh bag, attach them to the pinger, and send them down to the bottom with the multi-core. Of course, we all took a lot of time to decorate them first (decorated cups). We then put them in a mesh bag and then attached them very carefully to the pinger (attaching bag of cups to the wire) and down they go, with the instrument. At 1000 meters the pressure is 100 times what it is at the surface, and at 2000 it’s 200 times that. Well, styrofoam has lots of teeny tiny bubbles of air in it, so when it gets squished at 100 or 200 atmospheres all the gas comes out – and guess what? Those cups get REALLY small!!! Have a look back at the picture of the decorated cups getting ready to go down—see those teeny little shriveled up cups? Those are the ones that already went down and came back tiny! I guess you can tell that about this point in the cruise we are going a little crazy for something to do we have been doing the same thing every day without a real break for almost 3 weeks. We really had a great time decorating the cups and seeing how they looked when they came back—because not only does the cup shrink—so does all the writing – and most of them get a little shriveled looking too…
We have been getting a lot of cores, and most of them have been pretty good. We know that because when we open them up and look at them we can see the ashes and we can see color changes in the mud down the core that we know come from changes in climate (that’s weather) back in the past. The time that we are looking for in these cores is the last ice age – and we know it was a lot colder then and the color change goes with that change to colder weather.
But how do you get a good core??? It’s not that easy. You can’t just steam along to any old where ever in the ocean and drop that big fat pipe over the side and expect to come back with it full of mud that you can use. If the sediment is too hard it will just bend and bounce off the bottom. If the mud is too soft it will stick and get stuck. We have actually stuck the core in the bottom twice on this cruise already – and it took up to 2 hours of gently wiggling to get it out. You can’t pull too hard or the wire will break. In fact that is always a worry. We’ve already lost a corer – we can’t afford to lose another one. So, we choose our coring locations very carefully. We use 2 kinds of echo locators. We have one, called the multi-beam, which makes a picture of the bottom beneath us in a swath (picture of the multibeam readout). Sorry the pictures blurry, but you can see in the big black box on the screen that the colored part is the shape of the bottom, with the red being shallower end blue deeper. What is on there is a little sea mountain to the south of the ship (that’s the little red circle). The gold lines on that picture are the trace of where we have already been. In the little black box on the left is the same thing, but it’s drawn as if you are standing on the bottom of the ocean looking back at where we have just been. Again, you can see the bump to the right, that’s the red on the other picture. With this we can see where it’s flat and where it’s bumpy. Good, soft deep mud, is always in a flat spot. Think about it — that’s because when the little mud particles settle down to the bottom they will collect in the flat low lying places – not on the steep sides of things. It’s kind of like when snow falls — it won’t stay on the side of something steep, and even if it collects on the top of a pole or fence – that’s the first place it gets knocked off if the wind blows…. So when we are looking for mud, we look for low spots.
After we see if it’s flat down there we need to see how deep the mud is. To do this we use the 3.5 kHz locator – this uses a beam of sound that sees into the sediment – and we can see if the mud is deep and if it has layers that are good for coring (picture of the 3.5 readout). You can see on that picture, the top of the mud is to the left. So, the lines under the top of the sediment are what we call reflectors, and if there are nice even ones below the surface, that can mean that the mud is nice and deep and soft. You can see that someone has put an arrow on that trace saying possible coring site. And what you are seeing is how the bottom changes as we steam over it. If you look at the top of that chart you can see that we’ve started to steam over some bumps that are probably not good for coring. We don’t want it too hard, and we don’t want it too bumpy. We then look at the readout from the bridges to see where we have been (picture of ships track, the gold line is the ships course). Then we check all that against the charts to try and decide if it’s a good place to try (see Will and Scott plotting up the data). We work hard at this – we spend up to 6 hours looking for a good spot because we don’t want to break equipment! We do have a lot of computers to process this data and help us make sense of it – and it Woody works pretty hard to keep it all going (pic of Woody at the computer bank). Two days ago he spent 6 hrs getting the computer that runs the ships navigation fixed. During those hours we had to do it all by hand!
There are no weekends and no days off out here at sea, and sometimes it gets pretty DARNED boring. Everyone has their thing they do keep from going a little nuts. While we are on watch and working people try to keep a sense of humor… Sometimes they make sculptures of the extra mud. So far we’ve had a really good horses head (mud horse on railing) and because Pete has been coring for 30 years (wow!) they made a sculpture of him for his birthday (sculpture of Mr. Pete). Of course we tell lots and lots of silly jokes!
After we had used up some of the core tubes that were stored in the lab we had room to put up the ships ping-pong table so a lot of people play ping-pong now to burn off energy (Al and Heather). Most people like to play doubles—it’s hard to play ping –pong when the ship is moving around – the ball takes some weird dips! Sometimes people want to be quiet and relax – so they sit and read or talk (sitting and talking) or they want to be alone—and just sit and think. A couple of weeks ago the captain and crew set up a saltwater hot tub on the fan tail. You can sit and relax and soak in it when nothing big is over the side. Of course, you don’t have to relax you can be silly too (Jessie in the hot tub paddling home!). One thing the captain and crew do whenever we don’t have something over the side is put out fishing lines. We can’t fish when we have the core wire over because the fishing line might get tangled up in the wire. Just last night they caught the first fish of the cruise – and it was a beauty. A short nosed sword fish almost 5 feet long!!! (big fish). We’re having fresh fish for dinner tonight!
We are still coring away – and getting a lot of cores – we stack them up in the lab in their D-tubes for a while. Can you guess why they are called D-tubes? (picture of D-tubes). But when the rack gets full we have to put them in the refrigerator van to go back home. We also need to put them in the fridge because it keeps the cores better – and they need to last a long time – sometimes people go back to re-sample a core as long as 30 years later—so we need to take care of them! So, they get loaded into boxes (5 split halves in a box) and then stacked in the big van that’s kept cold like a fridge (picture of cores going into reefer van). That’s their last stop ‘til the van gets loaded on another ship and they get shipped home that way.
I realize that I have been telling you about how we get the cores – especially the long cores, but I haven’t taken the time to tell you why we want those multi-cores, or why there is a trigger core on the piston (rather than just a trigger weight). The reason we take 3 kinds of cores is because when you take a piston core there is a lot of weight, and it hits the ground pretty darned hard and fast. Think about what happens when you stomp your foot in soft mud—a lot of the top of the mud splats away. That often happens with the piston core – the top of the mud gets blown off when the piston core slams into the bottom. Sometimes we can tell from the mark of mud on the outside of the weight stack that the core went in “over its head” And we never know how much is missing. So we always use a trigger core… although part of its purpose is to serve as the trigger weight -- when it hits bottom it releases the piston core so it falls really fast that last little bit. The reason the trigger weight is a core, not just a bunch of lead, is that it takes a small core (Dan taking the weights off the top of the trigger core). Because it doesn’t weigh as much it hits the bottom at the speed the winch is letting out the wire (about 40 meters a minute). So it goes in slower - not as hard as the piston core. That way the trigger core doesn’t stomp the top of the mud so hard and we get the surface of the mud in the core – or I should say we hope that we get the surface of the mud. That of course doesn’t always happen. If the waves are big, sometimes the trigger core will hit the bottom twice while we are pulling the big core out of the mud and we get 2 sets of the core top in the core tube– but we don’t really know how good that is either.
Anyway, because the long cores don’t always have the top of the mud — we use the multi core. It has 8 cores in the middle supported in a frame. The frame holds the tubes off the ground when you either have it hanging by a wire (Dale attaching the wire to the top of the corer) – or you have to put big pins to hold it up, because if you don’t the lead weights in the middle push those tubes slowly, almost a meter below the frame into the mud.and when you pull back the tops and bottoms of the tubes close. So, when it goes up all the tubes are open (see picture of corer going up) and when it comes back they are all closed – and (we hope!!) full of mud (picture of corer coming in with mud). Once the corer is on board it’s way too tight inside the frame to work on the tubes (see picture of people working in frame), so they have to be taken off and put on a rack so we can work on them (2 pictures one of frame with no cores and one of cores on frame). We then have to push the mud out of those cores into ones we can slice up (the ones on the corer are really hard and really expensive) ( pushing mud into tube for cutting). For this we have a special pole that is just the right size.
If this sounds like a lot of work it is—especially because the multi-corer is much more delicate, and fiddly to get to work. Remember how much trouble we had getting it to work back when the weather was so rough???
So why do we do this? Why do you need a perfect core top? Well, if you want to study what is happening in the mud now – you need to study the little creatures that live at the top of the sediment – and you have to capture them, not blow them away. And believe me they are there (picture of worm tubes in multicore). So it’s a lot of work – but to understand how it all works now and in the past sometimes you have to use both very gentle tools – as well as big tough ones.
been getting lots and lots of multicores and piston cores here in the
We’ve been having really good weather the last few days – so nice in fact that it’s hard to remember what it was like just a few short weeks ago when we were trying to core in such rough weather in the Southern Ocean. It’s just like that out here at sea, when the weather is with you – everything seems good and when it’s rough nothing seems right.
It is hard to really explain how rough weather can really beat you up. It’s a little like being on a baby roller coaster all the time – you never quite know which direction you will get thrown next. I can try and show how much the boat can move…I took 2 pictures one at the top of a wave and then one a few seconds later at the bottom of a wave – and you can see how much the boat heaved as that wave went beneath us(see two pictures of the big swell up and down). The thing is, you expect it to be rough when the wind is blowing (like in those pictures it was blowing about 35 knots). But unless you are a surfer, people don’t think often about the fact that waves from big storms run away from the wind and end up as swell in places where it’s calm. Although we have had great weather the last week or so, several days we have had a long, low swell running under the ship – and we know that has come from storms down where we used to be, or further away. It’s hard to get a picture of that – but if you look carefully at this picture (picture of the big swell running) you can see the water is calm—but look at the long shadow running horizontally across the picture – that is the swell – about 4 feet that was running – we had even bigger swell the day before. So it was calm and warm and lovely but there was still a swell. That’s quite different to the absolute calm we had one day (see picture of bird on calm seas) or the little bit of a chop (those are small, short, waves) we almost always have around (see picture of slight chop at sunset).
The other change in weather we have had is that as we came north (that’s closer to the equator around here) it’s gotten warmer. That of course helps too. At the beginning of the cruise we were all working out on deck in all our heavy gear both to stay dry and warm (see picture of working in wet weather gear) and now it’s all T-shirts and smiles (see picture of Tom in a Tshirt and all smiles).
I think it’s a pretty good thing too that the weather is with us now… it’s been almost a month at sea and though we’re still working hard, everyone is ready to be done – and when it’s rough it’s just so much harder to work – all my bruises from the first week or so are just now healed. We have just 2 more days of work and then we head into port – and everyone is looking forward to it… me too.
has been good to great the last couple weeks of the cruise. As I said, this was really important to
all of us. We have been working
really hard and getting lots of samples.
The reason for that is partly because the
With all the great weather lots of people have been sunning themselves when they aren’t on watch, and it’s been a treat to catch glimpses of land at a distance once in a while. However, on our last night at sea as we tried to get our last cores, the wind came up. We do get weather warnings… the Captain gets a weather report several times a day and we knew the wind was going to come up, but boy oh boy, Thursday (March 24) was a real squall. The wind whipped up and the seas came up too. The weather was coming from the right direction (northeast) so that the sea state could build. What I mean by that is that not only does the wind have to blow on the water for a while to make waves—it has to blow across the water for a long distance for the waves to get big. That is called fetch. The farther the wind can blow across the water, the bigger the waves can get. So, with the wind coming from the right direction and blowing strong, there were pretty big waves. But the wind was also very intense — we even saw a water spout! A water spout is a tornado at sea — the wind sucks up water into the tornado and so you can really see it. We didn’t realize it, but there were tornados on the land too – so it was a pretty bad storm. And of course we were trying to work – then the first multicore came up pretty beaten up again. So we had to make a decision – we only had about 12 hours left to work – could we get it fixed with the weather as bad as it was? Even if we got it fixed would the weather be good enough that we would be able to take that last core? Well, with the water spouts around and things looking pretty rough – we decided that it was just too rough and time too short… so after 27 days at sea, we tucked our tail between our legs and headed into port.
Of course what that means is we got into port Friday night instead of Saturday morning – so we had a lovely ride in during daylight… with a great view of Rangitoto Island – which is a dormant “shield” volcano (notice how you can see the volcano shape really well?) and a great view of Auckland City skyline as we came in. Coming into port is always exciting – it’s hard to explain how happy you feel when you come along side dock and know that you are almost done! (Jesse happy to be in port) – they even have a name for the feeling that you just CAN’T WAIT to get off the ship – they call it “channel fever” because it’s the excitement you feel when you are steaming into the channel to the harbor. But we aren’t quite done yet. The ship has to be tied up carefully at the dock – and the lines (sea-going name for ropes) they use to do this are huge!! (tying up at the dock). But even when we are tied up we aren’t done. However, Friday night we all took the evening off – everyone was so happy to get off the ship and do and see something different. People are always so happy to get off the ship after a long cruise. But we STILL aren’t done. We have to spend the next 2 days unloading the ship of all the gear we put on it a month ago—there is still a lot of work to do! But it can wait one evening…..
spent 2 whole days packing up all the gear that was loaded onto the ship a
month before. It took every hand
working to get things packed carefully into boxes so that they wouldn’t
break on the way home… and then those boxes had to go into a
“container” is a big box that is the size of the back of a tractor
trailer truck. Just about
everything that gets shipped on a cargo ship these days goes into a container
first and then gets loaded and sent that way. All our sediment cores went in their own
refrigerator container (remember the “reefer van” we put them in
during the cruise). We had two 40
ft containers, and 2 reefer vans that had to be loaded and taken away. Most of the stuff was lifted off the
ship in slings by crane and then put into vans using a forklift. We were so busy doing this no one
thought to take pictures… but we worked late on Friday and then all day
Saturday as well – but by dinner time on Sunday we were pretty much done,
and the vans loaded and locked. All
that was left on Monday was to be sure all the paper work was in order….
And on Tuesday at 4:00 – right on schedule – the R/V Roger Revelle steamed out of
Auckland Harbor. I did get a
picture of her leaving port – and if you look closely you can see how
empty the fantail was compared to when we were onboard. I don’t know why ships are always
referred to as “she” but I can understand why you want to personify
a ship (see picture of Revelle leaving
That’s the end of my blog form the South Pacific.
Thanks for following along, Liz.