South Georgia Fieldwork

We left South Georgia a few days ago by now, and we are almost back at the Falkland Islands where our voyage will come to and end (we should arrive there tomorrow morning, 26th April). But I’d still like to share some pictures and stories of our last day of fieldwork on the island of South Georgia.

After several days of bad weather, during which the ship had been sheltering in Cumberland Bay, we finally woke up to a beautiful morning of clear skies. The sunrise over the snowy peaks of South Georgia was absolutely stunning, watching the first rays of sunlight hit the tops of the mountains and then creep slowly downwards, bathing everything in an orange-pinky light. There had been quite a lot of snowfall during the storm, and the whole island was now completely covered in snow.

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South Georgia at sunrise
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South Georgia at sunrise.

The JCR then sailed into King Edward Cove, where the BAS research station is located at King Edward Point (KEP). Also in this same cove is the abandoned whaling station of Grytviken. South Georgia has quite a history of whaling operations in the early 20th century. The whole northern coast of the island was dotted with whaling stations, run by the Norwegians, the British and other nations. These settlements where like small factory towns where the whales that had been captured were brought in to be processed. All that is left of them now is a mangled heap of rusty old buildings and bits of machinery, which were abandoned when the whalers left. Most of South Georgia’s whaling stations are therefore quite dangerous sites which are out of bounds due to the risk of things falling down and asbestos in the buildings. But Grytviken has been tidied up a bit and made secure so that it is possible to visit it. Once the JCR was moored securely at KEP, we went ashore and walked around the bay to have a look at it. It was quite an eerie and atmospheric place, especially under the blanket of snow.

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The RRS James Clark Ross alongside at King Edward Point.
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Grytviken whaling station in King Edward Cove.
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Abandoned whaling ships at Grytviken.
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“Blubber Cookery” at Grytviken whaling station.
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Grytviken looking eerie in the mist and snow.
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In among all the abandoned buildings, there is also a Post Office at Grytviken!

From Grytviken, we headed up into the mountains for our fieldwork. We walked up to Glacier Col, where there is a small ice field which we wanted to get an ice core from. The ice field was actually quite hard to spot, because it was covered in rocks and debris, but luckily one of the KEP base members had come along to point us in the right direction. There was also a really cool ice cave underneath the ice, which we could crawl into. Once the ice core had been drilled successfully, we headed back down towards the bay. Along the way we also collected some more water samples from Gull Lake, which is fed by the meltwater from the glacier.

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Walking up to Glacier Col. From left to right: Andrew, Wave, Rob, Erik & Ollie.
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Andrew drilling an ice core on Glacier Col.
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In the ice cave on Glacier Col.
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We collected water samples from Gull Lake on the way back down.

 

We also paid a visit to Ernest Shackleton’s grave, which is located in the graveyard at Grytviken. Shackleton was buried here after he suffered a heart attack on his last ill-fated Antarctic expedition. Apparently, his body was going to be shipped back north to the UK but then his wife sent a message saying not to bother, he would’ve preferred to be buried down there anyway! So that’s how he ended up being buried on South Georgia. For more info about Shackleton’s harrowing journey across South Georgia on foot, after the loss of the Endurance, have a look at Ollie’s blog post In the footsteps of Shackleton.

 

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Ernest Shackleton’s grave.

That evening, back at KEP, the team at the base laid on an amazing BBQ for us, which made for a lovely end to a great day visiting this beautiful island!

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Barbeque in front of the boathouse at KEP.

On departure from South Georgia the next morning, we sailed round to one of the other bays along the north coast called Leith Harbour, where there is another abandoned whaling station. This one was run by the Salvesen family, a Norwegian family who emigrated to Scotland and set up a whaling company. They were actually some distant ancestors of mine, so it was great to be able see the whaling station, even if we couldn’t go ashore.

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Team photo just before setting off from KEP. From left to right, back to front: Erik, Mike, Dan, Dave, Ollie, Rob and Andrew. The JCR and Grytviken in the background.
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The abandoned whaling station at Leith Harbour.

 

Since then, we’ve been sailing West from South Georgia back towards the Falkland Islands, where we will be arriving tomorrow morning. During the crossing, we’ve been finishing off the analysis of our salinity samples, and written a report about all the science that went on during the cruise. We’ve tidied up the labs and packed up all the kit and samples that need to be shipped back to the UK. We also went on a tour of the engine rooms yesterday which was pretty cool. It’s amazing how much more of the ship there is down below deck!

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Steve giving us a tour of the engine rooms. This is the ship’s steering gear.
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Watching the propellor shaft go round and round!
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This is where 8km of CTD winch cable is kept!
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South Georgia

It’s been a few days now since our last blog post and a lot of things have happened in the meantime. First of all, we finished the A23 hydrographic section, with the last CTD back on deck just in time for dinner on Saturday evening. We now need to process all the data collected by these CTDs, which involves running a large number of water samples through the salinometer. This machine measures the salinity in the water samples from the CTDs, which are then used to calibrate the CTDs on-board salinity measurements. The salinometer is quite laborious to run, as you need to flush the machine several times between each sample to avoid any contamination from one sample to the next. Analysing a crate of 24 samples can easily take up to 2 hours!

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Ollie at the salinometer.

During some of the last CTDs on the A23, we continued our polystyrene-object-shrinking experiments and sent our evil pirate gnome down to 3000m below the ocean surface. Originally measuring 28cm in height, he returned from the deep measuring just 11cm, i.e. 39% of his original length. We will have to add this result to those of our previous experiments. We also sent a few more polystyrene cups down to 3000m, and interestingly they came back having shrunk by the same amount as when we sent them down to 4800m previously. We tried again at another CTD station which was only 2000m deep, with the same result. So it would appear that sending the cups down deeper does not necessarily mean they shrink more. According to Mike, who has done this many times before, once the cups have gone below about 1500m they don’t shrink any further, presumably because all the air has been squeezed out of them by that point.

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The pirate gnome before and after his journey to the deep.
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The pirate gnome safely lashed to the CTD frame with a pair of tights and cable ties, along with some more polystyrene cups.

By the time we had finished the A23 on Saturday night, a big storm was brewing so we headed straight for South Georgia to seek shelter in Cumberland Bay, one of the large fjords on the northern side of the island. South Georgia is a long, narrow and very mountainous island, with peaks up to 3000m high and deep fjords cutting into it along both its northern and southern shores. An ideal place to shelter from the storm. We arrived here early on Sunday morning and had a brief rendez-vous with the SG Pharos, a ship run by the South Georgia government. South Georgia is a British Overseas Territory but has its own government which is based in the Falkland Islands. On South Georgia itself there is just a small settlement at King Edward Point (KEP), where the BAS research station is also located.

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Arrival at South Georgia with SG Pharos in the bay (Picture by Andrew Meijers)
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South Georgia Harbour Patrol comes to say hello (Picture by Mike Meredith)

As the worst of the storm hadn’t quite arrived yet, the weather was still good enough for us to do some small boat work in Cumberland Bay. Similar to what we did back at Signy, we wanted to collect water samples of the glacial outflow from Nordenskjöld Glacier, a large glacier flowing into the eastern end of Cumberland Bay. To do so, we sailed the JCR right up to within about 1km from the glacier terminus, where we launched the two Humber powerboats to get even closer to the glacier. One boat went to sample the eastern end of the glacier terminus, while the other boat went to the western end. The glacier terminus is easily 30-40 metres high, so we felt very small sailing along the front of it in our tiny motorboats. Bits of ice kept breaking of the front as well (a process called “calving”) and splashing down into the ocean. All very impressive and imposing!

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View of Nordenskjold Glacier terminus from the monkey island on the JCR
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Ollie, Rob, Erik and Carson kitted out in boat suits ready for the small boat sampling work. (Picture by Andrew Meijers)
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Heading towards Nordenskjold Glacier in the boats. (Picture by Andrew Meijers)
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Small boats, big glacier! (Picture by Andrew Meijers)
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Spot the boat! (Picture by Andrew Meijers)

After the small boat work, we did a line of CTDs along the length of the bay as well, to sample the glacial meltwater as it flows out towards the open ocean. While we were doing these, the weather started getting worse and a big snowstorm hit us. This made for some very atmospheric CTDs!

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Snowy CTD. (Picture by Mike Meredith)

On Sunday night we were called out on a little adventure to assist the South Georgia government with investigating a vessel that had been reported as behaving suspiciously, a little way out to the north of the island. They were worried it was an illegal fishing vessel, as it was not responding to any attempts to make radio contact. The seas around South Georgia are a protected marine environment with a fragile ecosystem and illegal fishing is a big problem here, so the government clamps down on it very strongly. Happy to assist them with this, we left the shelter of Cumberland Bay and sailed back out into the storm to go and find the suspicious vessel. It was all very exciting to watch from up on the bridge. The wind had picked up a lot and we were racing along at 15 knots with all 4 engines on, huge waves breaking over the bow of the ship and snow blowing horizontally through the beams of the searchlights. However, as we approached the suspicious vessel, it quickly became clear that it was actually an iceberg, which would explain the lack of radio contact! A slight anti-climax therefore, but it was an exciting chase nonetheless and the South Georgia government was very grateful of our assistance to rule out any illegal fishing activity.

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Waves breaking over the bow while we were out in the storm with the searchlights on.

Since then we’ve been back in Cumberland Bay doing some more CTDs and sitting out the bad weather until we can go ashore and collect some ice cores and more water samples from South Georgia. It’s looking like the weather will be good enough for this tomorrow, so fingers crossed we’ll get to go on land then!

Whales & Icebergs

We’re still sailing North along the A23 section, and have settled into a routine of sailing for a couple of hours until we reach a CTD station, stopping for 3-4 hours to do the CTD, and then continuing to the next CTD station and repeating the whole process again. This pattern continues 24 hours a day, so we are now working around the clock on 8 hour shifts, with 2 people per shift. A lot of the time there is not much to see outside apart from grey ocean stretching towards the horizon, but every now and then some visitors appear. Today, a Southern Right whale came to check us out while we were on a CTD station. I imagine it was probably very intrigued as to what the weird metal object on a long cable dangling down into the ocean was… It circled the ship for quite a while, and put on a nice display for us twisting and twirling at the surface and flapping its flippers and tail fin. Rob got some really great pictures of it from up on the bridge. Apparently, Southern Right whales got their name historically from being the “right” type of whales for whaling ships. That is, they are relatively easy to spot, they often hang around at the surface and, most importantly, their bodies remain afloat once they have been harpooned (in contrast to other whale species whose bodies sink). Thankfully, those kind of practices are now a thing of the past and these majestic creatures are no longer hunted.

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Yesterday, there were some beautiful icebergs around while we were doing our CTDs. The sea was really calm too and the evening light on the icebergs was quite magical. The sea has got a lot rougher in the meantime and I’ve been told there is a storm approaching in the next few days. I’ll leave you with some pictures of the icebergs, and you can also check out our new Meet the Team page to find out more about the people on this research voyage.

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Under Pressure

Aside from sampling seawater and collecting ice cores, another key scientific objective of this voyage is to examine the effect of extremely high pressure upon polystyrene objects. The classic (and highly scientific) approach to studying this phenomenon is to attach polystyrene cups to the outside of the CTD frame (carefully wrapped up in a sock or a pair of tights and strapped on with cable ties) and send them down, along with the CTD, to depths of 4000m or more below the ocean surface. At such depths, the cup is then subjected to the huge pressure of 4km of ocean water crushing down upon it, which squeezes the air bubbles out of the polystyrene. The image below shows the result of this experiment very clearly. The left-hand image shows the cups (beautifully decorated by Rob) in their original form, where they are about 10cm tall. The right-hand image shows the same cups after having been sent down to a depth of 4800m and returned to the surface. The third blank cup on the right (which is the same size as the original cups in the left-hand image) has been added for scale to show the effect of the crushing pressure at depth. As you can see, the decorated cups have reduced in size dramatically and are now around 5cm tall, a staggering 50% shorter than they were originally!

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Rob’s beautifully decorated polystyrene cups, before and after they were sent down to 4800m deep. The blank cup on the right is included for scale.

We thought we would take this science one step further and perform the same experiment on some other polystyrene objects, to see if they behave in a similar manner. Two polystyrene owls were sent down to the same depth of 4800m below the surface, to study the effect of the pressure on them. The two “before & after” images below show the result of this experiment on the owls. As you can see in the top left image, the owls originally measured in at 13cm tall. However, after travelling down to 4800m deep and returning to the surface, the owls were reduced to a mere 5cm in height, i.e. just 38% of their original size! Clearly, owls feel the increased pressure more than cups do.

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Polystyrene owl before and after it’s journey to 4800m deep. Thanks to Beth Waters for painting this one before the voyage!
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Ollie and his owl before and after traveling down to 4800m below the ocean surface (the owl that is, not Ollie).

The same experiment was performed on a polystyrene aeroplane, a polystyrene Easter egg, and a polystyrene penguin, as shown in the images below. In all cases, the objects were sent down to a depth of 4800m and had greatly reduced in size when they returned to the surface. The aeroplane shrunk from being almost the full length of a marker pen, to being only a third of the length of said marker pen (that universally accepted measurement unit), the egg shrunk from 10cm to 6cm (60% of original length), and the penguin was originally 18cm tall and returned measuring only 11cm (61% of its original height).

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Mike’s polystyrene plane before and after being crushed at 4800m deep.
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Dan with his “Deep Sea Egg”, before and after its trip to the deep ocean.
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Erik’s penguin before and after its journey to the murky depths of the Weddell Sea.

Let’s summarise these results in a table:

Object Length before Length after % of original length
Cup 10cm 5cm 50%
Owls 13cm 5cm 38%
Aeroplane One marker pen 1/3 marker pen 33%
Easter egg 10cm 6cm 60%
Penguin 18cm 11cm 61%

Clearly, the owls and the aeroplane were affected most by the increased pressure at 4800m deep, whereas the penguin and the Easter egg were least bothered by it. How can we explain these differences? Given that owls and aeroplanes are designed to be creatures of the skies, and the deep ocean is not really their natural habitat, this may explain why they suffer so badly under the increased pressure. Penguins are much more at home in the ocean which may give them the upper hand in this situation, although they tend to hang out near the surface rather than in the deep ocean. The Easter egg is harder to explain, as one would expect eggs to cope particularly badly when subjected to extremely high pressure, whereas our egg seems to have coped quite well. Clearly, more experiments will be necessary before we can draw any conclusions from this, and as such all the above hypotheses should be treated with caution and not as fact.

Next in line to be subjected to the increased pressure of the deep ocean is a polystyrene garden gnome, who is currently being lovingly decorated and prepared for his journey. We will update you once the results of this next experiment have come in.

Disclaimer: no owls, penguins, aeroplanes, easter eggs or garden gnomes were hurt during these experiments.

 

What is a CTD and how does it work?

We’ve started sailing north again, leaving the sea ice behind us, and have begun working on the A23 hydrographic section. The A23 is a line through the Southern Ocean, starting in the Weddell Sea (where we are now) and heading north towards South Georgia, as shown on the map below. This line is of particular interest because it crosses the pathways of several important ocean currents (yellow arrows on the map) which transport dense waters deep down in the ocean out from the Weddell Sea. The A23 is surveyed once every year, so that we can learn more about how these currents are changing over time.

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Map showing A23 section (red line), CTD stations (black crosses), and Weddell Sea transport pathways (yellow arrows)

 

Along the A23 there are a set of marked points, known as stations (black crosses on the map), and at each of these stations we take a set of measurements and water samples using a Conductivity-Temperature-Depth profiler, or CTD for short. I have mentioned CTDs a few times before in other blog posts, but I haven’t really explained properly what they do or how they work. Given as CTDs are a pretty important observational instrument in oceanography and they form the backbone of most of the measurements we are taking on this voyage, I thought it would be worth explaining them in a bit more detail.

A CTD consists of several highly sensitive measurement sensors, mounted at the bottom of a large circular metal frame. The sensors measure several physical properties of the water, including temperature, depth and conductivity. Conductivity is measured by firing a small electrical charge through the water, and is used to calculate the salinity. Basically, the higher the conductivity of the water, the higher its salinity (i.e. salt content). As the CTD is lowered down into the ocean, these measurements are relayed back up to ship through the cable and shown in real-time on the monitors in the control room.

The upper part of the CTD frame holds a set of 24 water sampling bottles (known as Niskin bottles after the person who invented them), mounted in a circular rosette-like fashion. These bottles can each hold 10 litres of water, and are used to “trap” water at different depths as the CTD returns back towards the surface. The plugs at the top and bottom of each Niskin bottle are connected by wires to 24 individual metal hooks in the centre of the rosette, and connected to each other by a strong spring through the centre of the bottle which holds the plugs under tension. Upon a command from the control room back up in the ship, each of the metal hooks can be released individually at a chosen depth, causing the plugs on the respective Niskin bottle to snap shut and trapping the water at that depth inside the bottle. This is called “firing” a bottle.If all goes well and the bottles behave themselves (which they don’t always do), the CTD will return to the surface with a unique water sample in each of the bottles, from 24 different depths.

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A CTD ready to be lowered into the Weddell Sea. Note the sensors in the metal cylinders at the bottom of the frame, and the Niskin bottles above. The plugs at the top and bottom of the bottles are all open, ready for deployment.

So, in practice, as we approach a station on the A23, the CTD is prepped and made ready for deployment, with all the sensors running properly and the Niskin bottles open and under tension. Once we arrive at the station, the CTD is lowered over the edge of the ship using the mid-ship gantry winch system, which is operated by one of the crew members. The CTD is then lowered right down to 10 metres above the ocean floor, which can be a very long way down depending on how deep the ocean is at that station. The CTDs we ran today were all down to depths of between 4700 and 4900 metres, so almost 5km below the ocean surface! As you can imagine, it can take quite a long time for the CTD to reach such depths. The winch system can lower the CTD at a maximum speed of 60m/min, so that’s 3600m in an hour, or 1 hour and 20 min to reach a depth of 4800m. It takes even longer to winch it back up, because you have to stop the CTD 24 times along the way in order to fire the Niskin bottles.

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CTD being lowered by the mid-ship gantry winch system.
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View from the winch control room

As the CTD goes down, the real-time measurements from the sensors start appearing on the screens in the control room, showing the temperature and salinity of the water in function of depth. We need to monitor these readings very closely, to see if everything is working properly and to decide what are the interesting depths at which we want to fire the Niskin bottles on the way back up. Examples of interesting depths are depths at which the temperature or salinity reaches a minimum or maximum value, or where there is a clear shift in one of the physical properties. As the CTD gets closer to the ocean floor, we need to be very careful that we don’t let it hit the bottom. Once it gets within 100m of the bottom, an altimeter kicks in and starts counting down the metres left to go, so at this stage we need to keep a very careful eye on things and make sure to stop the winch on time. At 10m above the ocean floor, the CTD is stopped and the first Niskin bottle is fired to capture a water sample from the deepest point of the CTD. Then we start the long ascent back up to the surface, stopping along the way to fire Niskin bottles at the interesting depths we decided on during the descent. For a deep CTD, the whole process of descent and re-ascent can easily take up to 3.5 hours!

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Mike in the CTD control room.
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This screen shows the readings from the CTD sensors: temperature in red and salinity in blue, with depth along the vertical axis. In this image the CTD is on its journey back up to the surface, and Niskin bottles 1 through to 8 have already been fired, as shown by the orange lines and numbers. Bottle 8 is currently the last bottle to have been fired at a depth of 2500m. Note also the temperature maximum at around 250m deep, where the water is noticeably warmer than at the surface.

Once the CTD reaches the surface again, it is winched back onto the deck and returned to the CTD annex, where the water sampling takes place. Each Niskin bottle now contains 10 litres of ocean water from one of 24 different depths. From every bottle, we need to decant smaller samples which can be analysed in the lab. This is done by filling small glass bottles from the spigots on the bottom of the Niskin bottles. Different types of water samples require different types and sizes of bottles. In our case, we are interested in salinity and d18O (oxygen isotope) samples, which use larger glass bottles and small glass vials respectively. The salinity samples are run through a salinometer and used to calibrate the CTD’s on-board conductivity measurements, and the d18O samples are sealed, packaged up and shipped back to the UK for analysis.

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Filling a salinity sampling bottle from one of the Niskin bottles (Picture: Rob Mulvaney)
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Erik filling a d18O sampling bottle from one of the Niskin bottles (Picture: Rob Mulvaney)

 

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Mike sealing a d18O bottle, ready to be sent to the UK for analysis. (Picture: Rob Mulvaney)

Once all the required water samples have been taken from the Niskin bottles, the CTD is prepared again, ready for its next deployment. This involves re-attaching all the wires from the plugs at the top and bottom of the Niskin bottles to the metal hooks in the centre of the rosette, and putting them under tension again. Any remaining water in the Niskin bottles that is not required for sampling is emptied out. Once all this has been done, the CTD is ready to set off again on its next trip down to the murky depths of the Southern Ocean!

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Re-attaching the wires from the Niskin bottles to the metal hooks in the centre of the rosette. (Picture: Rob Mulvaney)
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Attaching the wires is a fiddly job! (Picture: Rob Mulvaney)
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Emptying the remaining water from the Niskin bottles. (Picture: Rob Mulvaney)

 

Ice, Science & Wildlife

Just a short blog post from me today, as it’s been a very long day with lots going on, and I mainly just want to share some photos of what we’ve been up to in the ice. During the night and this morning, we kept sailing south into the Weddell Sea, in search of some sea ice that was thick enough for us to be able to get off the ship and stand on the ice safely.

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The JCR’s powerful search lights guiding us through the ice at night.
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This morning we woke up to ice and more ice everywhere, as far as the eye could see.
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Snaking our way through the ice.
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More sea ice and some icebergs too!
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Checking out the view from the “Monkey Island”, on top of the ship’s bridge.

Finally, at 68°S, we found some ice that was thick enough to stand on safely. At this point, the radio officer informed us that we were the southernmost ship in the world! To get onto the ice, we used a device called a “Wor Geordie” (don’t ask me why!), which is basically just a cylinder of netting with a ring on the bottom that you can stand on, whilst you hold on to the netting. The Geordie, with passengers on board, is then hoisted up by the crane and lowered over the edge of the ship and onto the ice. It may look a bit precarious but it was actually a pretty comfortable ride!

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Some nice thick sea ice, this should be good enough to stand on!
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Andy, Carson, Dan and Dave all geared up and ready to be lowered onto the ice!
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The “Wor Geordie” in action with Dave, Mike and Rob on board.
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The “Wor Geordie” on the ice, passengers can disembark safely.

Once safely on the ice, the science work could begin! In my previous post about Signy Island, I explained how we are measuring  d18O (oxygen isotope) in the water, and how we need to collect samples from various different locations in order to get a good calibration. After collecting glacial ice cores and glacial runoff samples at Signy, it was now time to collect some samples from the sea ice. Just like we did in Signy, this meant drilling ice cores from the sea ice, and collecting water samples. Once the ice coring and water sampling was completed, we also ran a CTD down to 1000m below the surface, to get some deeper water samples.

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Andrew and Ollie drilling an ice core on the sea ice.
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This was a second, thinner, bit of ice we sampled, but still plenty thick enough to stand on.
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The James Clark Ross in the ice. Don’t often get pictures of the ship from this perspective!
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On the ice!
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CTD about to be winched down to 1000m below the surface to collect water samples.

While the ship was lying still during the science work, a lot of the local wildlife started appearing to check out what was going on. There were some very inquisitive emperor penguins, who were really interested to see what we were doing and kept swimming around and bobbing up on one side of the ship and then diving underneath to the other side again. It was quite hard to follow them and get pictures of them before they disappeared again! A pod of minke whales also turned up and were swimming around in the leads between the ice, surfacing every now and then to breathe. The water was so clear you could see them swimming by underwater! It was amazing to see so much life in an environment that feels like a barren, icy wasteland.

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Some inquisitive emperor penguins checking out what is going on.
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Another emperor on the ice.
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The emperors are such fast swimmers, it’s really hard to keep track of where they are!
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A minke whale breaching between the ice floes.
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Minke whale underwater. The water was amazingly clear!
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Another minke breaching.

We’ve turned the ship around now and are sailing northwards again, so that was the southernmost point of our voyage! The plan is to do one more stop near the ice edge tomorrow morning, to collect some more samples there, before we head further north into the open ocean again to do the A23 hydrographic section. We will keep you posted with further blog posts, pictures and tweets as we go!

Sitting out the weather

The weather has been pretty rough for the past 24 hours, with strong winds of up to 40 knots and a very lumpy ocean. The ship was pitching a lot (rocking backwards and forwards) and also rolling from left to right, which made for an interesting night’s sleep… Although I’ve been told that it can get a lot worse than this…40 knots is “only” force 8 on the Beaufort scale! We reached the southern end of the A23 section (see map here) yesterday evening and the James Clark Ross “hove to” for the night. This means that the bow (the front) of the ship is pointed into the waves/wind and the engines are used to keep the ship as close as possible to a fixed position. The hope was that by the morning the winds would have died down enough for us to get the southernmost CTDs of the A23 section out of the way before sailing further south towards the sea ice. However, in the morning it was still far too rough to deploy a CTD so we waited here for the rest of the day in the hope that things would improve. The winds did ease off a bit and the sun even came through in the afternoon, but the conditions were still not favourable enough for a CTD. By this evening, we gave up waiting and start sailing south again towards the sea ice edge. The good news is that the weather is set to improve tomorrow so hopefully we will get some nice weather when we are in the ice!

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Very windy and big waves this morning on the “Monkey Island”
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It started clearing up a bit in the afternoon, but it was still extremely windy
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The sun trying to break through, with nothing but ocean as far as the eye can see

Even when the weather doesn’t play ball or things don’t go to plan and we can’t do any CTDs, there is still a lot of science happening on the ship at any given time. The JCR has a whole suite of “underway” instrumentation which measure a range of physical features continuously as the ship is sailing. These instruments are mostly autonomous and require little or no help to keep collecting data, but we do need to monitor them to make sure everything is running properly, and analyse the data once it has been collected. This monitoring and analysis is done in the Underway Instrumentation Control Room (or UIC for short), which is where we spend a lot of our time day-to-day.

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Ollie and Dave in the UIC (Underway Instrumentation Control Room)
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Some of the instrument screens in the UIC.

Here are a few examples of instruments you will find in the UIC. The set of 4 monitors in the picture above show several useful bits of information. The top left monitor is the ship’s navigation and meteorological summary screen, which shows the JCR’s current position (latitude/longitude), its heading (the direction we are sailing in), the wind speed (currently 27 knots) and direction, the air temperature and the sea temperature, amongst other things. Note the sea temperature is currently reading -1.4°C, i.e. pretty close to the freezing point of seawater which is at around -1.8°C! We are getting close to the sea ice…!

The screen labelled “Microplot”, in the bottom left corner underneath the nav/met screen, shows the ship position on a navigational chart of the area and also shows our planned route and how far away we are (in nautical miles, and hours sailing time) from our next waypoint. The bottom middle screen labelled “SCS” (Ship Computing System) basically gives a summary of how all the various underway instruments are running. At the moment all the boxes are green, which is good cause it means everything is happily churning away and collecting data. If one of the boxes starts flashing orange or red, it means something is not right and you need to go and check it. The screen on the bottom right labelled “ADCP”, is the ship’s Acoustic Doppler Current Profiler, which uses the scattering properties of sound waves to measure water velocities at different depths. Basically, it tells you how fast the water is moving below the ship, which is pretty cool!

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Ocean and atmosphere timeseries plots in the UIC

 

This screen shows some timeseries plots of data collected by the underway instrumentation. The top plot is all about the ocean, showing the sea temperature (magenta), salinity (blue), fluorescence (green) and transmittance (orange). Temperature and salinity are the main ones of interest to us on this voyage, and you can see how the water temperature has been decreasing and the salinity creeping up as we’ve sailed south over the past few hours. The bottom plot shows timeseries of atmospheric data, including air temperature (red) and barometric pressure (purple). It’s very clear on this plot how the temperature has dropped and the air pressure increased during the past few hours, which should be an indication of better weather on the way.

 

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The swath bathymetry system showing the depth of the ocean floor (almost 5km!)

Finally, these two screens show the data collected by the ship’s swath bathymetry system, which measures the depth of the ocean floor using sound waves. Currently it’s giving a measurement of 4993m, so the ocean is almost 5km deep where we are at the moment! This instrument is constantly mapping the ocean floor wherever the JCR sails, so over time as the ship sails along new routes it builds up a pretty good map of what the seabed looks like.

That’s just a quick run through of a few of the instruments we use on board the JCR. If all goes well, we should arrive at the sea ice tomorrow which will be really exciting and hopefully provide some good photo opportunities! Stay tuned for more updates.

PS, an update on the previous blog post: the birds pictured sitting on the glacier which I said were penguins are in fact not penguins at all, but giant petrels! I’ve corrected this now. We did see a couple of penguins but I didn’t get any photos of them, so hopefully we will still come across some more!

Signy Island

It’s been a while since our last post, so time for an update! We’ve spent the last few days at Signy Island, which is part of the South Orkney Islands archipelago. You can see the location on the map here. We arrived at Signy early on Sunday morning with the intention of heading straight onto the island for some fieldwork. However, it is not possible for the JCR to dock at Signy as it is too shallow around the island and the ship has to stay well away from the coast. The only way to get there is in small rubber powerboats which get lowered over the side of the ship to ferry passengers to the island. So we all got geared up in our boat suits and lifejackets, ready to get in the boats, but unfortunately the weather was not great and the sea was too rough to be able to use the boats safely so the decision was made to postpone the fieldwork.

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Bad weather on arrival at Signy on Sunday.
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Dave and Ollie gearing up in their boat suits, before the fieldwork was postponed.
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Part of the team in front of Sunshine glacier on Coronation Island, next to Signy. From left to right: Dave, Andrew, Rob, Erik and Dan.
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Nice iceberg near Signy.

Monday brought much better weather, with lovely sunshine, and the swell had died down enough to use the boats. A field party of six of us set off early in the morning and got dropped off at Signy Island research station. This is one of the smaller BAS bases which is only manned during the summer season, and it had been closed down for winter just a few days before we got there, so there was no one there to welcome us apart from some huge elephant seals who had set up camp on the jetty and all around the base. They looked pretty big and menacing up close, growling and baring their teeth at us as we approached, but they seemed happy enough to let us walk past. The effort required to move their huge bodies probably wasn’t worth losing their spot in the sun!

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We were greeted by this lovely elephant seal on arrival at Signy research station.
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Signy research station down by the shore and Coronation Island in the background.
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The RRS James Clark Ross out in the bay with Coronation Island in the background.

The objective of the fieldtrip was to collect some ice cores from one of the glaciers on the island and water samples from the melt pools at the foot of the glacier. These cores and samples will then be analysed for salinity (salt content) and d18O (oxygen isotope). This is all part of one of the main scientific objectives of this voyage, which is to set up an automatic oxygen isotope analyser on the JCR. Once this new piece of equipment is up and running it will be able to analyse the sea water wherever the ship sails and automatically measure its d18O content, which can be used to trace the origin of the water (whether it comes from precipitation, sea ice, glacial runoff, etc.). The new machine requires careful calibration, which is why we need to collect samples from various locations such as glaciers, glacial fjords, sea ice, etc. A more detailed post about the science behind all this will follow in due course!

To get our ice cores, we walked up Moraine Valley to Khyber Pass and the McLeod Glacier (there are some great names of features on the map of Signy, including “Shagnasty Island” and “Confusion Island”, someone clearly had fun naming these!). We carried a small handheld ice corer with us, which is basically just a 1-metre long cylinder with a screw thread around the edge and some teeth at the bottom to drill into the ice. Rob, who has over 30 years worth of experience in ice core drilling, showed us all how to use it and we took turns at drilling, which was surprisingly hard work in the tough glacial ice! We got 7 cores in total, in a line from the top of the glacier to the bottom, which was a great success.

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Walking up Moraine Valley towards the glacier. The yellow/orange tube sticking out of Andrew’s backpack is the handheld ice core drill.
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Rob showing us how to drill an ice core.
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Almost there!
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A successful ice core!
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Each ice core is packaged up and labelled (making sure to mark which end is the top!) and then stored in the -20C freezer back on the ship.
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The hole left behind by the core.
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Carrying the ice cores down off the glacier, the bag was pretty heavy!

After the ice coring we went and got water samples from some of the glacial melt pools and from the foot of the glacier where it meets the ocean. The beach where we were sampling was also covered in elephant seals, and we could smell them long before we could see them! There were some really huge males there, all jostling for space and growling at each other. The noise they make is incredible, a deep guttural growl which is pretty hard to describe! It was quite a spectacle. The female elephant seals are a lot smaller and more peaceful (and a lot prettier!) than the males. There was one female basking in the sun right next to us while we were getting our samples, but she didn’t seem to mind at all and just looked at us quizzically every now and then, before closing her eyes and dozing off again.

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Heading down to the elephant seal beach for water sampling, with the glacier terminus on the right.
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Lots more elephant seals!
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Aren’t they lovely…

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Some giant petrels chilling on the ice in the distance. Not penguins as I said initially!

We got picked up again by the boats and ferried back to the JCR, clutching our precious ice cores and water samples, but the day didn’t end there. A second party went out in the boats to collect more water samples from the bay in front of the glacier. Finally, we did a few CTDs to collect yet more samples further out into the bay and at depth. Combining all these various ice cores and water samples will give us a line of data points from the top of the glacier to where it meets the sea, into the bay and out into the open ocean. It was a very long day and we were working well into the evening to finish the CTDs but it was absolutely amazing to be able to visit this beautiful island with such stunning scenery!

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Dan and Dave getting ready to collect more water samples from the bay.
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Lowering the boats off the edge of the ship.

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Boat party heading off as the sun begins to set.
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Sunset over the bay.
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Another beautiful iceberg at sunset.

We are currently sailing south again, heading towards the sea ice. Hopefully we will find some sea ice that is thick enough to stand on, and then the plan is to get some more ice cores there, which should be pretty cool! We will keep you posted.

Hello from the JCR

It’s been a busy past 48 hours and we’ve traveled a very long way, but here is our first post from aboard the RRS James Clark Ross! The flight down from the UK was extremely long, but the whole journey went pretty smoothly in the end. We had a short stop in Ascension Island to refuel the plane as planned, and then carried on to the Falkland Islands. As we were a few days late getting there, we transferred directly from the airport to the JCR, which was moored nearby at Mare Harbour, and pretty much immediately set sail so as not to lose anymore time. We were briefed on all the safety and communications aspects of the ship, given a tour of the science labs, and had our first delicious JCR dinner, before heading to bed for our first night at sea. There was quite a big swell during the night and the ship was rolling a lot, but being so tired from the long flight I had a surprisingly good night’s sleep!

Today started off with sunshine and blue skies but also a strong wind and quite a rough sea. There were lots of albatrosses and other sea birds following the ship. I didn’t manage to get any pictures of them myself, but the communications officer Mike Gloistein has some great photos on his blog here. After breakfast we were given our BAS kit bags which contain all the specialist gear such as steel-toed boots, boiler suits and lots of warm layers that we need to be able to work on the ship. Then there was a safety drill where we all had to go to our muster stations when the alarm sounded, don our life jackets and head for the lifeboats as we would in a real emergency (which hopefully we won’t have to!).

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My cabin and BAS kit bag

We also did our first CTD trial run today. The CTD (Conductivity-Temperature-Depth profiler) is one of the main pieces of scientific equipment we will be using on this voyage, so it is really important that we all know exactly how to work it. It consists of 24 large water bottles mounted on a circular frame, and several measurement sensors in the middle. The CTD is lowered from the edge of the ship on a cable, and can be lowered right down to almost at the seafloor. Today we “only” lowered it to 1000m deep though, as this was just a test run to make sure everything is working properly. Whilst the CTD is being lowered down the 24 bottles are open, but as it is winched back up again the bottles are each “fired” at a certain depth so they trap the seawater at that depth. Once the CTD is back up on the ship, it then contains 24 water samples from different depths in each of the bottles. These samples need to be stored in small glass bottles so they can be processed in the lab. Our job is to prepare the CTD before it goes down, then to monitor its progress as it goes down and decide at what depths we want to fire the bottles on the way back up, and finally to do the sampling work after the CTD is back up on the ship.

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The CTD in the room where it is prepared and the sampling work is done.

It’s taking quite a bit of getting used to this new environment where everything is constantly moving and sliding about as the ship rocks back and forth. You can’t leave anything just sitting out on the table, everything needs to be stored away somewhere securely, especially all the expensive scientific equipment. My chair is currently also sliding from left to right in front of my desk, which makes for interesting typing!

At the moment, we are sailing towards Signy Island and we should reach that sometime on Sunday morning. We will be doing more CTD work in some of the fjords there, and we are also going ashore to get some glacial water samples for oxygen isotope analysis, so that should be very exciting. But more about that will follow! As always, you can follow where we are using the links on the right for the webcam, the ship’s track and Mike’s daily updates (he also posts a copy of the daily ship menu!)

Departure, take 2

After our first unsuccessful attempt to fly to the Falkland Islands on Sunday, we are going to try again today. Fingers crossed we will actually make it off the ground this time! Same procedure as last time: the flight departs tonight from RAF Brize Norton in Oxfordshire and flies direct to the Falklands with a refuelling stop at Ascension Island along the way. I’ve included the route map again below. Hopefully I won’t need to write this post a third time!