30. July, 2014
Last year we (team water column) started a project under the “code name” CTD festival. This festival included three full days and 30 CTDs all along the Mohns Ridge going north. This translates to no sleep, huge amounts of coffee and even greater amounts of candy. We did all this to hunt for hydrothermal systems as well as getting a better understanding of how much volatiles are actually diffusing up through the ridge itself.
This year we were going to finish our work to the very end of the Mohns Ridge. It all seemed a very easy task, with the CTD being a very reliable instrument which rarely fails. We started out around 20:30 on the 28 of June and we were going to work all the way until midnight the 29. However, things are never as easy as it seems. On the fifth CTD there suddenly appeared to be a problem on the wire carrying all the weight of the CTD and all the expensive sensors mounted on it. The wire seemed to lose tension and started to hang lose around the winch. Needless to say, we were all a bit on edge with all the expensive equipment hanging from a broken wire 2400 meters below us. Luckily the story has a happy ending. The CTD was retrieved safely and the wire was fixed a day later by the hard working crew of the G.O. Sars. Unfortunately we would have to wait a little while longer to finish our festival
The CTD is arriving the ship from the bottom of the ocean
Desiree sampling for methane and hydrogen and Tamara is sampling for helium isotopes in the background.
Our beautiful CTD and Tamara in the background
The art of helium sampling, performed live by Tamara
A very tired face ready to inject a sample for analysis of methane and hydrogen
29. July, 2014
The “micro team” has been busy analyzing the microbes living in the sediments thousands of meters below the sea surface. One might think that there couldn’t be much life down there but despite the extreme pressure and freezing temperature (below zero) microbes thrive and can be counted in millions per gram of sediment. Their main food source is organic material produced in surface waters and after passing through the water column it eventually settles on the sea-floor. Some microbes use oxygen (as humans) when they degrade this material, others can “breath” with e.g. iron, nitrate, manganese or sulfate. Others again do not even need organic material but gain energy from catalyzing inorganic reactions such as coupling CO2 and hydrogen to produce water + methane + energy.
Anyways, enough micro nerdines, what I really wanted with this blog was to explain a bit about the way we get the sediments up on the ship in the first place. Basically we lower a long plastic tube (core liner) to the sea floor (read more about the gravity core here). It has a very heavy lead block attached at the top and a “core catcher” allowing sediment to go in but not out, in the other end. Then we penetrate the sea-floor with approximately 4 km/h and retrieve the core onto the ship with a winch. Now, in principle this is a very simple operation, especially when you are operating in regions where the sediment cover is thick and homogenous. This is NOT the case in areas close to hydrothermal/volcanic activity. Here you often find hard layers of volcanic ash within the first couple of meters and thus the core liner breaks and then forever bound to the sea. Another obstacle is “drop stones”. Drop stones are stones that are carried by glaciers during ice ages to the sea, and when the ice retreat (melt) the stones are “dropped” to the seafloor. Here they can lie undisturbed for thousands and million of years until either transported to the subduction zone and melted or hit by a scientist core liner in his or hers attempt to collect sediment samples. The result of the latter is often that the core liner brakes. As you might have guessed this has happened a time or two during this cruise. Normally a broken core liner means a lost core, however, this year the new temperature loggers have saved our core a couple of times, even though the liner broke. The reason is that a steel wire runs all the way from the lowest temperature logger and all the way up to the lead block in the top (this might become clearer if you have a glance at one of the pictures). In effect this means that although the core liner is broken we can still recover it and if we are lucky the liner might still contain sediment all the way up to the braking point.
Preparing the gravity core before deployment. Temperature loggers are fittet on top of the core liner and a steel wire runs along the length of the core liner and are attached in the “bomb” head. Photo: Michael Melcher
Gravity core being deployed from the ship hangar. Photo: Ingunn Thorseth
Broken core liner, but the steel wire connected to the temperature loggers enabled us the save both the loggers and the sediment in the lower half of the core. Photo: Michael Melcher
This was all very good and very helpful but all good things comes to an end and yesterday morning the steel wire gave up and not only the core was lost but all the tree temperature loggers have now found their final resting place at the bottom of the sea 2465 meters below the seafloor and at a temperature of -0.765 (the temperature is obviously nothing more than a qualified estimate from me side).
Retrieval of one broken core liner. The steel wires snapped and the remaining 4 meters of core liner and three temperature loggers are to be found more than 2000 meters below the ship. Photo: Michael Melcher
I must admit that this was not one of the highlights of this cruise, but it did help that we got a beautiful 3.5 meter long core 1.5 hours later at the same site. I also helped that the special group of microbes that we have been searching for was actually present in that core and in very high amounts.How do we know they are present, the alert reader might ask. Basically, we crush all the cells, extract all DNA present in the sample and then we are searching for the genes that we know belongs to this specific type of organisms. When (or if) we have found them we stain the DNA with a fluorescent dye so that we can visualize the DNA. The whole process from the core goes down until we know if we have the organisms of interest takes about 14 hours. Then starts the laborious work of trying to get them to grow in the laboratory but that’s another story.
Visual proof that the organisms of interest are actually present. The fluorescent bands are DNA fragments from the microbes we were searching for. Photo: monsieur Cedric Hamelin
This is by far the only stuff going on in the “micro” lab; Desiree is estimating sulfate reduction rates and Rui are doing both de-nitrification, anammox and nitrification rate measurements.
Michael Melchner transfering microbes from the deep ocean floor to lab cultures and hope that they will grow. Photo: Steffen L Jørgensen
Rui Zhao are preparing de-nitrification experiments inside an anaerobic (without oxygen) gloveback. Photo: Steffen L Jørgensen
Last but certainly not least the geochemist are analyzing the pore water (the water in the sediment) for geochemical composition as soon as the water is extracted from the core.
Pore water is extracted from the sediment cores by deploying rhizon samplers at regular intervals. Photo: Michael Melcher
Their data not only helps us select the right samples for further analysis but enables us to predict what the different microbes are doing in the sediment and how much and how fast they are eating. This might seem trivial and without interest for people outside academia, however, mine damen ünd herren it is of immense importance for you, human kind and all life in general. Their activity level is a key controlling factor in determining the oceans and hence also the atmosphere’s chemical composition. In other words – If these organisms for one reason or another change their activity level significantly, you and I would no be here anymore.
With these dramatic words I will end this blog.
27. July, 2014
Today, the marine biologists – better known to the rest of the science crew as the ‘guys that sample the stinky animals’ – report on their sampling nights and intriguing finds from the Kolbeinsey and Jan Mayen ridges.
While much of the daytime has been used for AUV mapping and ROV dives, the nights have been the busiest for the biologists. So far we have had two dedicated bio-nights, where we used our trawl and sled to get samples of the animals living on the seafloor. In addition the geologists have been dredging for rocks for two nights, and then we have been ready on deck to get the biological by-catch.
Sorting out the by-catch from the rock-dredge.
Sieving samples on deck.
In the sled samples we got a lot of mud that needed to be washed and sieved to find the animals within, but it was worth the effort! Especially the second bio-night, when we got many individuals of a small calcareous sponge that we were hoping to find. The sledge samples also contained a wide variety of bristle worms, crustaceans and other small animals. The trawl samples usually bring up larger animals, and in the picture below you can see the cocktail of shrimps, brittle stars, fish and various other deep-sea creatures that we got from the trawl at almost 2000 m depth close to Jan Mayen.
Sorting the sieved samples in the lab. Almost like a treasure hunt!
Megafauna-cocktail from 2000 m deep.
Baby octopus looking out from his egg.
Although the first whole night of work was hard because we had been up since breakfast, we have gotten into the rhythm of sleeping during the day, and working during the night. The midnight sun makes the arctic nights just as bright as the days, which makes is so much easier to stay awake.
Sunshine at 3 AM.
25. July, 2014
It has been a couple of days since the last update on this blog, and that has a very good reason: all of us have been very busy with the collection and analysis of samples from the hydrothermal vent field and volcanic area of the Kolbeinsey Ridge! In between labwork and processing of mapping data, we also enjoyed the first ROV dives (read more about what an ROV is here)– whilst surely setting the record for the fastest offshore popcorn consumption – and have started a 5K rowing competition in the gym, which is currently led by Ole the AUV technician. Early on Thursday morning, we got clear views of Jan Mayen island when passing by so that some of us ran to the deck to take hundreds of pictures in the cold morning air.
G.O. Sars passing by Jan Mayen island.
Well – not cold enough for socks in sandals, apparently…
Arctic air is not cold, according to Alden.
Below is an update from all the geo-groups on board. Stay tuned for an update from the biologists tomorrow!
Geochemistry (by Anne and Tamara)
At the Kolbeinsey Ridge the water column/geochemistry group got samples from 5 CTDs (a Conductivity-Temperature-Depth sensor, read more here). We took these samples to identify the hydrothermal signal in this area, and to get information about the types of volatiles emitted at the seafloor in this area. In addition, we did pore water analyses on a core taken outside the hydrothermal area that is further sampled by the microbiologists.
Although we are running up and down the stairs all day to check on the CTD, the group is not doing well in the rowing competition. Thinking about it, this might be due to the cake, Sørlandschips (favorite meal of the day) and candy in our daily diet but still, we are very enthusiastic about the rowing and are convinced that we will be champions in the end.
The CTD is coming back up with samples for the geochemists.
Ingunn and Ingeborg measuring oxygen concentrations in the sediment core.
Petrology (by Filipa and Cedric)
Ship time is precious and often one needs to make long work marathons to use the most of the time available on a specific area. We had one night to dredge the Seven Sisters volcanic system on the Kolbeinsey Ridge – focusing on the sulfide mineralization and hydrothermal alteration of rocks as well as the fresh volcanic rocks. The first two dredges were made over known active hydrothermal vent areas, previously seen by the ROV Aglantha, and the latter dredges were made on fresh lava flows near and far from the active hydrothermal areas.
Dragging a metal framed basket through the bottom of the ocean can be a tricky operation and the first two dredges got stuck to a rock. 6 000 kg tension on the cable was not enough to break the samples and we had to turn the boat around to finally get us free. Feel the dredge, see the dredge, be the dredge.
The dredge used by the petrologists to get rocks from the seafloor.
By early morning there were enough rocks on deck to make the scientists happy and eager to work on. The next step is to prepare the rocks for petrographic observations and geochemical analysis once we are back in the lab.
A happy petrologist with the result from a rock dredge.
Mapping (by Alden)
As a marine scientist working in acoustics my main goal is to see the seafloor, ideally as well or better than we can see land. For the 2014 expedition to the Kolbeinsey seafloor volcanoes, we needed the best map of the seafloor possible in order to identify small but important hot vent features. To do this we used a state of the art autonomous robot (or AUV – read more here) that acoustically maps the seafloor to a resolution of 3x3cm, covering a square kilometer per hour. At Kolbeinsey we mapped several locations, rapidly processing the sonar maps overnight to use the information for cruise operations the next day. After two days of mapping and many discoveries based on the sonar data, the robot Hugin proved itself as a capable mapping vessel and an essential element of our expedition.
The ROV Aglantha is being deployed to figure out what is there on the seafloor.
23. July, 2014
Endelig har G.O.Sars ankommet det første området som skal kartlegges, Eggvin banken på Kolbeinsey ryggen. Da vi søkte gjennom dette området i fjor sommer oppdaget vi et nytt hydrotermalt felt, som ble døpt «de syv søstre». Dette navnet ble gitt etter strukturen til feltet som består av syv vulkaner med flat topp.
Vi ankom området på mandag morgen og det første som skjedde var at vår eminente AUV, Hugin, ble sluppet ut i vannet. Hugin sitt arbeid er å kartlegge havbunnen under oss, noe den kan gjøre med utrolig nøyaktighet. I tillegg til dette har vi tatt flere CTDer, en sediment kjerne og hatt to dykk med ROVen Aglantha.
Dykkene med ROVen har vist oss underverkene som er skjult under havoverflaten. Dette er virkelig et fantastisk sted med hvite bakteriematter omgitt av rosa og oransje anemoner. Med tanke på geologien i området er det også grunn til å hoppe i taket, med vulkanske og hydrotermale strukturer i skjønn symfoni. Kort sagt er hele området unikt og forbløffer alle og enhver på båten.
Her følger noen bilder av den vakre midnattssolen og våre aktiviteter så langt
21. July, 2014
We are almost at the Kolbeinsey ridge and ready for the first ROV dive, so before all the science and excitement starts – a couple of photos that Cédric made showing the highlights of the first few days of the cruise.
Loading the AUV container onto the ship in Bergen.
Heading to Kristiansund to get spare parts for the GPS.
Steffen preparing for the sediment core sampling.
Asgeir (IMR) explaining the instruments operated from deck 5.
Scientific discussions on how to split up the sediment core between all researchers.
Calm seas all the way on our journey.
Curious about who is who on board this leg? Read more here.
19. July, 2014
With the new functional GPS module in place, yesterday afternoon, we set sail to our first destination – Kolbeinsey ridge, North of Island – two days from here. The transit time is often a painful experience, testing your patience to the absolute maximum. However, during this transit the time has not been used entirely in vein. Last night we stopped a couple of hours at the Storegga slide to retrieve a sediment core for some of our colleagues back in Bergen. The operation gave us a perfect opportunity to test the equipment used for sediment coring, including the temperature loggers that we will deploy in order to measure heat flux in the sediments. As a rule of thumb, the temperature increase with one degree Celsius per 10 meter you go down into the sediments and this was exactly what we observed in this core. However, in other places the heat flux can be significantly higher, especially along the spreading ridges, and this year we are excited (at least I) that we will be able to measure it. The work with the core finished just before the sun, after a short dip beneath the horizon, once again felt the urge to rise.
Otherwise there is not much to report; some people are in the final stages of preparing their labs making sure that everything will run smoothly (is that possible) once the samples are on deck.
Others are engaged in killing time digesting the long list of videos that are onboard the ship.
Written by: Steffen Leth Jørgensen
18. July, 2014
Slowly we have started making our way up north, but not without an unexpected journey along the beautiful Norwegian coastline and a short stop in Kristiansund (about 400 km north of Bergen) to get new parts for the GPS (navigational system) of the ship. This is one of the reasons why test runs are done before heading out to sea – if something turns out to not function as it should, it is still relatively easy to get it fixed without losing lots of time going back to the mainland or requiring an expensive helicopter to drop the stuff. Still, the piece of equipment (vital for basically all of the mapping, AUV and ROV operations) had to come from Trondheim so some patience was required, and we were happy to continue our scientific discussions and meetings on sampling strategies in a bar overlooking the Kristiansund harbor.
Just before dinner, the AUV crew started testing their equipment and launched the instrument into the fjord outside Kristiansund. Watch a video of the launch here.
AUV Hugin on the deck of the G.O. Sars
Preparing for launch
The AUV in the water. We all wondered what the fisherman in the background – just in front of the yellow house – was thinking when this bright orange torpedo look-a-like approached him…
17. July, 2014
With so many people and different research groups joining this expedition, the logistics of bringing all equipment from the university to the ship involve quite some effort. After carefully placing all the boxes and instruments onto pellets and wrapping these in plastic foil in the last couple of days – well-prepared for the Bergen weather, we started loading everything into a truck at 8:00 on Wednesday morning. It was not until lunch-time that everything had arrived on the ship and was ready to be installed in the laboratories, but where to start with that many boxes…?
Anne in between an endless stack of boxes…
Tamara checking the CTD equipment
Alden and Joakim helping out with the lab tables
In the meantime, other gear was checked and the ship moved to another port to get the AUV on board, and rumors started to spread that we would not leave Bergen until tomorrow. Not bad for those who had forgotten to pack some essential personal gear, such as their warm sweaters or toothpaste. Although everybody is keen to leave, the delayed departure was welcomed as perfect opportunity for that last beer (no alcohol is served on board) and kebab out in town.
11. July, 2014
Boxes are starting to pile up in the laboratories at the Centre for Geobiology.
They are filled with all sorts of lab equipment and hundreds of tubes, flasks, filters and tubing for the collection of geological and biological samples from the Arctic mid-ocean ridges. It is all part of our extensive preparation for the cruise, which usually starts in the spring and continues until the very last day before departure with discussions on where to go, what to sample and if we packed everything that we need. Of course, this preparation is key to a successful cruise – in the middle of the Atlantic ocean, you don’t want to find out that you forgot to pack something essential!