We have now reached the ice margin where the pack ice gradually gives way to more and more open leads. The open waters between the ice floes are perfect feeding ground for seals and we see a lot of them playfully jumping in the water in front of Oden. Of course, seals attract polar bears and so we got to see yet one more of these magnificent creatures before we leave their world and enter the open sea. The boundary between ice floes and open water is surprisingly sharp, and suddenly, after about six weeks in the pack ice we are out on open waters again. Now we have about two days of transit along the rugged coast of Svalbard before we reach Longyearbyen again.

The ice margin. Photo: Richard Gyllencreutz

The last polar bear sighting of LOMROG III. Photo: Ludvig Löwemark

Although 2012 is likely to be the year in which a new record low in Arctic sea ice extent is measured, we can not see any evidence of it because we are in the middle of the pack ice, where it is thickest. Changes in areal extent are impossible to judge from our perspective – only satellite imagery can do this properly. Even as we go south, we have to take us through enormous pressure ridges. Quite often, Oden has to go back and forth a few times until we manage to break through the thickest ice ridges. Standing on the fore deck, one can listen to the sounds of breaking ice, watch greenish icy cold water welling up through new cracks, and see ice floes the size of small parking lots rising next to the boat after Oden's ice knife has split them and pushed them aside along her track. The sun is a seldom guest here, we have mostly foggy weather, and winter is in the foremarch with light snowfall. This morning, the hovercraft Sabvaabaa materialized out of the fog again: we have our second rendezvous with Yngve and Gaute here at about 84 N at the Gakkel Ridge. After Oden has docked at a large ice flow, and Saabvabaa is positioned right beside Oden, the hovercraft is refueled by Oden's crew. Yngve and Gaute join us for lunch: for Yngve, it is just a lunch, for Gaute, it is the beginning of his journey on Oden as he will stay onboard all the way to Longyearbyen. We are celebrating the arrival of our new guest with an exceptional dinner in the evening, and wish all the best of luck to Yngve, who continues through the icy white on his own.

The Hovercraft in the arctic fog. Photos: Ludvig Löwemark

The Hovercraft in the arctic fog. Photos: Ludvig Löwemark

Polar bear tracks. Photo by Ludvig Löwemark

Today is the last day of seismic profiling before we start the transit back to Longyearbyen. While working in the lab the daily routine was suddenly interrupted when bear tracks were discovered along the edge of the lead that Oden has broken in the pack ice for the seismic survey. Because it was snowing this morning, we realized that the tracks were fresh and that the polar bear may be close to the ship. Only minutes later the bear was spotted and the bridge called out “polar bear on the port side!” on the loudspeakers. Soon a large crowd gathered on deck to watch the polar bear walk side by side with Oden for twenty minutes or so, resulting in thousands of photos being taken.

Photo by Richard Gyllencreutz

2012-08-31 One month at sea!
by Richard Gyllencreutz

It is now exactly one month since we departed from Longyearbyen. The Danish team is collecting seismic profiles in the Amundsen basin. This is done by towing a 200 m long streamer with hydrophones behind the ship at twenty metres depth, while an airgun makes loud booms under water every fifteen seconds or so. The sound waves travel down through the water and deep into the sediment layers, and their echoes are recorded by the hydrophones. After a lot of processing, the seismic profile shows a section of the seafloor, where sedimentary rock layers can be distinguished. This requires as ice-free conditions as possible, because the hydrophone streamer contains very delicate electronic sensors, which easily can be destroyed by tumbling ice floes. Therefore, Oden needs to break a wide lead by sailing back-and-forth in the same track a couple of times before the actual measurement begins.

In the meantime, our Stockholm University coring team continue to open and describe the sediment cores we retrieved earlier. The mighty booms from the explosions of compressed air under water are efficiently led by the steel hull and can be heard almost everywhere on the ship.

View from the aft deck of Oden during seismic profiling. In the upper part of the image, the rising bubbles from two airgun shots can be seen as beautiful turquoise clouds beneath the water surface. Two technicians are closely watching that the ice movements aren't lifting the streamer above the surface. Photo: Richard Gyllencreutz

"Wait, did you say 'turn starboard' there?" Oden crossing its own lead while breaking ice for a new seismic profile. Photo: Thomas Funck

Our master student Jerker Eriksson is happy to point out the base of this hopefully very long Holocene climate archive. Photo: Ludvig Löwemark

Today a lot of time was spent on taking care of the equipment on the aft deck. Since the coring program is now completed, the piston corer needed to be disassembled and secured on deck. This is no small task as the weights on the head of the corer weighs 1360 kg, separated into 30 round pieces of lead, each weighing 45 kg. Still this is easier to handle than on the old piston corer where the lead weights weighed almost 70 kg each. After putting all the weights, the steel pipes, the plastic liners, and all the other equipment back in their boxes we went back to the main lab to split another core. Today’s core bears the name PC06 because it is a piston core and it was our sixths attempt at taking a core. This particular one was taken in small valley on the slope of the Lomonosov Ridge at about 2900 m water depth. We start by splitting the top section which consists of very lose and sticky sediment, making it particularly difficult to cut into two halves. As we clean up the 58 cm long top section excitement spreads in the lab. The top 45 cm consist of sticky, chocolate brown sediment typical for the Holocene period in the Arctic. The Holocene is the latest warm period in which we now live, covering the last 10.000 years or so. Usually this interval is only 5–10 cm, so with our 45 cm long record we may have struck a gold mine for the reconstruction of climate variations during this important interval in Earth’s history!

On August 22 at 23h47 Swedish time, Icebreaker Oden reached the North Pole. It is notoriously difficult to position a ship exactly over the pole, because the thick ice is constantly moving, and Oden has to break through plenty of criss-crossing ridges. But we were lucky, and managed to get within about 20 meters! All onboard gathered on the bridge to toast with Champagne or Pommac, and the Master Erik Andersson and the Chief Scientist Christian Marcussen held speeches. Everyone, especially Oden’s crew, was thanked for the very successful cruise so far. After this brief celebration, we went out onto the pack ice for a sausage barbecue and the traditional group picture. The weather was perfect: sunny and -2°C temperature, which gave a fantastic view over the vast icy landscape.

This was the seventh time Oden visited the pole. Previous visits were 1991 (as the first non-nuclear surface vessel), 1996, 2001, 2004, 2005 and 2009. Interestingly, yeasterday’s visit was exactly, on the hour, 3 years after the previous one!

Many took the opportunity to do something special while the Earth was spinning around them. Examples include practicing yoga standing upside down, shaving your head, or, like Ludvig, Richard and four others; taking a bath in the 4200 m deep and -1.2°C cold water. Researchers also took samples of sea ice and made gravity observations, and our Stockholm University coring-team successfully retrieved a 6.3 meter long piston core before we left the northernmost position on Earth. We now continue our transit to the eastern parts of the Lomonosov Ridge for further mapping and data collection.

Eager people on the bridge, some aiming their cameras at the increasing latitude numbers on the navigation panel as we approached 90 degrees. Photo: Richard Gyllencreutz

Crew and scientists disembarking Oden for the first time since we left Svalbard (for all except those who make measurements on the ice), to celebrate on the North Pole. Photo: Richard Gyllencreutz

Richard Gyllencreutz standing by the "pole", with Oden parked in the pack ice in the background. Photo: Ludvig Löwemark

Today, the Danish team successfully retrieved several hundred kilos of rock samples from the steep slopes of the Lomonosov Ridge by dredging from the aft deck. Dredging means to scrape off whatever is on the sea floor using a scoop with a chain net. Because the winch-system was occupied for dredging, coring had to wait. This gave an opportunity for our coring team to start splitting and describing the cores we retrieved earlier. The cores' plastic liners are opened using a circular saw, and the sediment is cut using a steel wire. Then the two core halves can be separated, and all the layers of sediment become visible.

Split core. Photo: Richard Gyllencreutz

Dredge. Photo: Richard Gyllencreutz

During the last couple of days, we have sailed back and forth along 88N, mapping the seafloor of the Lomonosov Ridge with our multibeam echo sounder and the subbottom profiler. The Lomonosov Ridge rises to about 1500 m below sea level. This is about 2500 m higher than the surrounding seafloor, making the Lomonosov Ridge higher than Sweden's highest mountains!

Ice conditions along 88 N have been tough, and the constant ice breaking gives rise to a lot of noise in the data we collect, sometimes even making data acquisition impossible. However, where good data is crucial we use the so-called Pirouette technique, which was invented during the previous LOMROG I expedition. To do a pirouette, we first break the pack-ice to get a sufficiently large circular ice-free opening. Then, Oden is placed in the center of this circle, where it rotates slowly around its own axis while measuring with the multibeam echo sounder until good data coverage is obtained. When one pirouette is completed (this make take up to 2 hours), we sail a short distance, and prepare for the next pirouette, ideally partially overlapping. We have now completed an upslope dance to the top of the ridge, and back down again a bit further east, yielding excellent data.

Finally, even icebreaker pirouettes take two to tango: a helmsman and a multibeam technician. The neat pirouette in the picture is the dancing footprints from multibeam technician Nina Kirchner and 2:nd Officer Karl Herlin.

Sediment! After almost two weeks of sailing through the ice and mapping out the sea floor we stopped to take the first sediment samples using our new coring equipment. Quickly we realized that the nice blue paint on the new corer is too thick and we had to scrape it off from all the moving parts of the piston corer; before even entering the water it looks used. However, not only the coring equipment is new. The old hydraulic winch has been replaced by a brand new electrical high-tech one. With this winch we are able control the length of the wire holding the 1500 kg heavy piston corer by the centimeter. But of course, new things don’t always work smoothly from the beginning. After launching our first coring attempt, a strange sound alerted us to a possible problem with the winch, and after inspecting the cable winder we realized that the cable is not being spooled on correctly. This worried us quite a bit, having one and a half tons of steel hanging 3 km under the ship and not being able to move it is no fun situation, especially since the old corer was lost in Antarctica due to winch failure. However, thanks to an arduous effort by the Oden crew and the Swedish Polar Research Secretariat we were able to retrieve three piston cores from a previously unsampled region of the Lomonosov Ridge.

In the picture we see Markus Karasti (red helmet) hosing off the mud from the hanging piston corer together with Jack Schilling. Photo: Jerker Eriksson

Today we finalized the preparations for the coring operation. While Lillen and his crew put the new 300-kg wheel in place in the A-frame (the middle one in the picture), we rigged the first gravity corer on the aft deck. Almost everything is new; the winch is a brand new digitally controlled system featuring a synthetic rope that has no weight of its own in the water, thus giving us complete control over the coring device when it hits the sea floor 3000 m below the ship. However, also the gravity corer is new and we are all eager to see it in action. Will it perform as expected? We are now waiting to reach the crest of the Lomonosov Ridge where we will take our first core.

Despite all this new equipment, the highlight of the day, as every Thursday, was the pea soup and the pancakes served for dinner. Unofficial record today was one bowl of soup and eight pancakes.

Photo: Ludvig Löwemark

On our way to the first coring station on the flank of the Lomonosov Ridge, we are now crossing the Amundsen Basin. The Lomonosov Ridge is an underwater mountain range that rises from the abyssal plain at about 4 km water depth up to only 1000 m below the surface. This ridge is actually a part of the Siberian shelf that was rifted from the continent by the formation of the Gakkel Ridge some 55 million years ago. Now the Lomonosov Ridge separates the Arctic Basin into two halves, the Eurasian Basin and the Amerasian Basin. On the ridge we hope to encounter undisturbed sediments that can tell us about the environmental history of the Arctic Ocean.

However, to be able to take the sediments we need, the equipment on the aft deck must be changed from the seismic gear used by the Danish team to our piston and gravity coring equipment. Therefore today was spent moving lots of heavy stuff around. The lead weights on the corer weigh one and a half tons.

Photo: Jerker Eriksson

Our position is 85 N, 5 E, and we are going across the Gakkel Ridge, from the Nansen Basin into the Amundsen Basin. We have hard ice conditions, and light snowfall. All is white in white. Looking at the seafloor with our multibeam echo sounder, we get a more colorful picture, at least on the computer screen. Towards the evening, the sun is breaking through – the 'plan of the day' is adapted immediately and the helicopter crew prepares for a take-off and some work out on the ice. From the multibeam office on the bridge, one is always on the pulse of what is going on. And a splendid view from 30 meters above sea level is included – watching  the helicopter depart, we spotted the track of a polar bear.

Photo: Nina Kirchner

Today Icebreaker Oden had a visitor; Yngve Kristoffersen from the University of Bergen and his PhD-student showed up at 84°North, 13°East in his hovercraft to refuel and pick up some supplies. Yngve and his student are out on a two-month expedition during which they will measure a number geophysical parameters from instruments mounted on the hovercraft named “Sabvabaa”, meaning “soaring” in the inuit language.

Photo: Ludvig Löwemark

For most of us, the whole day was a 'transit leg', meaning that we are on our way to those areas on the Lomonosov Ridge where we will hopefully get sediment cores in 5–6 days. Transit legs are usually filled with many 'small', but nevertheless important, activities, such as unpacking, checking and preparing equipment on deck, and getting all computer systems and programs up and running with which we monitor the seafloor and its sediment structure. We have been going through ice all day, but are advancing smoothly. Our current position is around 83 N, 15 E and is available from www.polar.se. As it is Thursday, the traditional pea-soup-and-pancake-dinner was a much appreciated event on board!

Satellite image showing Oden's track through the ice.

On August 1st we reached the ice-margin, first just isolated patches of sea ice, but then gradually thicker ice cover. After just a few hours work on deck we heard some shouting from the port side of the ship; “polar bear, polar bear!”. In the water just about 50 m from the ship a polar bear was swimming in the sea.

Photo: Ludvig Löwemark

Photo: Richard Gyllencreutz

Finally, after years of planning we are on our way to the central Arctic Ocean. On Monday July 30th 2012 the team from Stockholm University flew in to Longyearbyen on Svalbard. There we joined the other teams who will take part in this year’s expedition. After spending a night in Longyearbyen, a city where anti-polar bear fences surround the kindergardens and guns and rifles are a must once you leave the city limits, we boarded the Icebreaker Oden and sailed west out through Isfjorden.