I met up with the team of researchers from the US Geological Survey who had been performing polar bear captures out of Barrow already for two weeks. That evening, after looking over our gear and getting caught up, I went over to see friends who recently moved to Barrow from Wyoming. It was great to hear about their new life in the area; moving from the mountains to the tundra is certainly a big change.

The next day I began flying in the helicopter for captures. We started in Barrow, fueled up in Deadhorse, and ended the day in Kaktovik, near the Canadian border – we covered almost the entire northern coast of Alaska. Since then we have been based out of Kaktovik, and we have had good weather and have been flying a lot.

It is great to be back out on the sea ice. Although I am out of place here, I really love this environment. In this picture we landed on a small pan of ice about twenty miles from shore; the pan was surrounded by pressure ridges and rubble from ice sheets smashing into each other.

The captures have been going well. We caught the largest bear I have seen, an adult male who weighed 1,147 lbs (I am not sure what the largest bear caught in the southern Beaufort has weighed). His neck was several times the size of my waist, and I could not fit both hands around his snout. It took several people to position him for measurements. We have caught several bears which were sampled in 2009, giving us excellent data on changes over time in the same individual.

We have also caught a lot of cubs-of-the-year, or COYs, including this litter of three. Cubs are born around January 1st. Litters of three are fairly uncommon for polar bears in Alaska, and usually include one cub that is noticeably smaller than the others – in this picture, the cub in the middle only weighed 12 lbs, nearly 10 lbs less than the other two.

Transiting back to Site U1359
Position: 64º 34’S, 140º 30’E
Water Depth: 3700 meters
The scene outside: 2 days of storms and lots of icebergs

ABOARD THE JOIDES RESOLUTION, OFF THE COAST OF WILKES LAND, ANTARCTICA– Our latest drilling target is in an area where sediments that document the transition of Antarctica from the “Hothouse” to the “Icehouse” can be easily reached at shallow depth beneath the seafloor. We drilled for 18 hours and then had to pull the drill pipe up out of the hole and reposition the ship to avoid a large iceberg that was heading straight for us. When the iceberg had passed the weather started to deteriorate. Our forecast was for 60 kt winds and big seas so we headed north out of “iceberg city” to ride the storm out in deep water away from icebergs and sea ice. The forecast was true to its word – we had waves up to 30 feet and winds over 60 kts for more than 24 hours. But we had great iceberg viewing on the way to our WOW (Waiting On Weather) point so I’ll write something about them and how they fit in with our project.

The Antarctic ice sheet is always accumulating new snow that gradually turns to ice. For the ice sheet to remain the same size it must either melt or release ice to the ocean as icebergs. In parts of Antarctica some of the ice is in fact melting but most of the ice loss that maintains the continent at its present state occurs through the calving of icebergs. Most icebergs calve off of ice tongues and ice shelves – areas of concentrated ice flow at the coast. Imagine that the ice is draining off of the high parts of the continent by flowing down small ice drainages to form mighty rivers – but rivers of ice in this case. These vast rivers move slowly, only a few 10’s to 1000’s of meters each year. When they reach the coast, the ice flows out into the ocean where it begins to float wherever the water is deep enough. In some cases, this is where the water is over 500 meters deep and the ice is over 560 meters thick. Floating ice shelves or ice tongues are influenced by winds and ocean currents. They begin to melt if the water is warm enough but they mostly breakup to form icebergs.

Many of the icebergs here off Wilkes Land came from the Ross Ice Shelf – the world’s largest ice shelf. It is over 1500 km away in the Ross Sea but icebergs travel great distances in the Southern Ocean. The water is cold and they drift with the ocean currents, for decades in some cases. As they drift, they melt a bit below the waterline and become rounded. Sometimes they flip over and this rounded part is then visible. Icebergs often collide and gouge away at each other or they list over at an angle and slowly fall apart. This means that icebergs come in all shapes, sizes, and textures.

The biggest iceberg we’ve seen was over 20 km long.

Icebergs come in all colors, from the pure white of fresh snow to the deepest blue of pure crystalline ice from far below the surface of the ice sheet.

Icebergs come in all shapes, sizes, and textures.

A penguin on a growler (a small iceberg).

The ice at the base of the ice sheet often carries sediments: boulders, gravels, cobbles, and sands. When these parts break off and begin to float they form “dirty” bergs with dark rocky layers intermixed with the clear blue ice. The debris that falls from these dirty bergs accumulates in sediments at the seabed. When we see gravels or sands in otherwise fine-grained sediments, we know this debris was transported out over the ocean by ice. In fact, the presence or absence of ice-rafted debris is something we keep close track of in the cores we are collecting on this trip – this tells us whether Antarctica was generating lots of icebergs and therefore had at least some kind of ice sheet in the past. Conversely, when we see sediments that do not contain this debris we know we are looking at a record from a time when Antarctica was much warmer.

In the foreground, a dirty iceberg.

We’ve seen over 400 icebergs in the past 2 days.

As I write, the storm has abated and we are transiting back to our drill site.

Dawn at 4:30.

See us installing a new GPS station in the video below. We previously assembled the tower, which contains solar panels and wind turbines, to charge the batteries. The batteries and the GPS hardware are in the gray cases. We use towers to keep the solar panels from being buried by accumulation and drifting snow. Note the old station in the foreground and how close it is to the snow surface. This video is played back at 15x speed.

We always have a handheld GPS on while we’re driving our snowmobiles, just in case we get lost or conditions change and we can’t see. This way we can know where we have gone and were safety lies. I compiled all of our GPS tracks and made this map.

This map our snowmobile tracks.

We have ten GPS station around the ice sheet, plus a few other locations of interest (seismic instrumentation or flag pole to re-measure) which we visited at least once each during our field season. I drove over 400 km during our 4 week field season.

Here we measure a flag pole to see how much it has moved since we measured it last (the year previous, in this case). Some times the flags were frozen into the ice and we couldn’t get them out. As a result we measure a location next to the flag and make careful notes about how far away our antenna is.

A snowmobile outfitted with a kinematic set up: simply a GPS antenna strapped to the side. We’re not moving in this picture, but are we record positions whenever we drive around.

We can use this kinematic set up to measure surface elevation and if we have multiple measurements, as in the image below, we can see changes in the ice surface topography.

In this image four kinematics GPS profiles are shown and the elevation differences between the two time periods are different. We can see that the surface of the glacier is changing rapidly. The reason for these changes are that highly pressurized water is creating a cavity below the glacier which floats the ice up. These cavities can also drain allowing the surface to deflate.

ABOARD THE JOIDES RESOLUTION, OFF THE COAST OF WILKES LAND, ANTARCTICA– So, guess what? We had to abandon our first drill hole, the one I wrote about yesterday. Turned out we had drilled into a massive body of sand, gravel, and big rocks. This came from the bulldozer effect of the ice on Antarctica. The force of the Ice Sheet as it grew to the edge of the Antarctic continental shelf scraped off all this rock and debris and bulldozed it into the deep sea – and think of a bulldozer with unlimited horsepower and a blade 2000 km wide. The power of ice to erode the hardest rock and move it great distances is unmatched by any other natural process on Earth. We just HAPPENED to be trying to drill where a deep sea canyon or channel was taking the heaviest stuff. This was unexpected from all of our pre-drill site survey work, and to be honest, very unlucky on our part – there aren’t that many channels of this type out here in the deep sea.

Our drill could only go 40 meters into the seafloor before it started to get stuck. But we described the core all night and learned some new things – like what kind of rock is under the ice. Since almost no rock sticks up above the ice, this is how we tell what is underneath. So every hole, even a short one like this one, has a story to tell.

We’ve since moved 84 nautical miles to place where we are sure there is no channel. The water is deeper but we are much more likely to achieve our main objective of seeing back into a time when Antarctica was ice free. So, we are all still excited and we are also trained as it was the first time the entire team of 30 scientists worked together with the staff and technicians on the ship to recover and describe the core.

Here are a few photos. The Albatrosses around the ship are amazing. They follow us everywhere.

Black-browed Albatross from the deck of the JR Expedition 318.

Expedition 318 scientists waiting for the first core.

Sakai-san, my roomate aboard the Joides Resolution Exp 318. He is an expert in Radiolarians, a really cool microsfossil.

We think that the dark band in this ice core is a tephra layer, or a volcanic ash deposit.

It is very rare to see such layers with the naked eye in ice cores so we all feel very lucky. Enjoy this video with our ice chemistry expert Dr. Ryan Banta as he explains more about this layer and ice core chemistry.

This one-of-a-kind airplane features an array of instruments for studying the East Antarctic Ice Sheet and the bedrock below: radar, a magnetometer, laser altimeters, and a gravity meter. Skis allow the team to land nearly anywhere in Antarctica if necessary.

The specially-quipped C-47 aircraft is designed to conduct long-range airborne surveys in Antarctica and Greenland.

The East Antarctic Ice Sheet is the sleeping giant of the cryosphere: it covers more than 95% of the Antarctic continent and locks up more than 60% of the world’s supply of fresh water. Considered much more stable than its smaller counterpart in West Antarctica, scientists are turning more attention to studying the history, structure and dynamics of this mysterious icy world. Instead of taking the stability of the ice sheet for granted, scientists from many different countries are digging into East Antarctica’s climate history to help predict how this vast ice sheet could respond in a warming world.

Graduate students Dusty Schroeder (foreground) and Jamin Greenbaum (rear) monitor instruments during a survey flight.

As a member of a research group at the University of Texas, Austin, Jack Holt participated in a multinational project called ICECAP to survey an enormous, unexplored part of the East Antarctica Ice Sheet. Building on their research experience of the last two decades, the UT team employed a ski-equipped aircraft outfitted with unique instrumentation, including an ice-penetrating radar capable of mapping the surface, internal layers, and the bottom of the ice. Other instruments revealed information about the density and type of the underlying rocks. The aircraft was also fitted with a suite of secondary instruments including specialized GPS receivers and cameras. One of the goals of ICECAP was to find the oldest ice on the continent, the site of a future ice-coring project to unlock climate records that go back a million years.

Data from the ICECAP project will help scientists understand how the East Antarctic Ice Sheet, with its enormous supply of fresh water, might react to changing environmental conditions. The ice in the target area is generally over 2 miles (3.5 km) thick and the bedrock lies mostly below sea level, making this ice potentially more likely to make a rapid contribution to sea level rise than the ice sheets in Greenland or West Antarctica. But the largely unknown continent buried beneath is also important for forecasting how the ice might respond to a warming world: The slope and roughness of the ground, the presence of water (including subglacial lakes), and the type of rocks are all factors.

ICECAP season 1 flight lines.

An ice core.

We work in shifts for the packaging because it is easy to get tired and cold in our working environment. Part of ensuring the ice cores do not get damaged, and that they maintain their utility for different chemical and physical analyses, is making sure that the ice cores get no warmer than -20°C. So, the building where the cores are stored and packaged is cooled to -25 °C! It is hard to believe but often the air temperature outside is around 10°C warmer than where we work!

The drilling and ice core handling facility at the start of the 2008/2009 field season.

As we learn the packing process (I will go into more detail in another blog), we are also learning all of the nuances of staying warm for extended periods of time at -25°C. My technique, that I learned from the veteran ice core handlers, is to keep the core of your body really warm and that way your fingers and toes get enough warm blood to not get too cold. On top I wear 2 wool tops, a wool sweater and two down jackets. On the bottom, I wear two pairs of wool longer underwear and insulated bib overalls. Thick socks and boot liners with my sturdy blue boots keep my toes warm. Surprisingly, with all of the layers keeping the core of my body warm, I can get by with some light gloves on my hands!

Heidi covered in frost after work in a -25ºC environment.

Another trick, and one that I like the best, is eating LOTS of food. Both the galley where we eat and the warming hut where we can take breaks are stocked with cookies, crackers, and candy bars! It is not uncommon to eat 3 candy bars a day! I rarely eat candy at home so it is quite a nice treat to eat so much candy and know that my body is using all of the calories just to stay warm!

I am off to work now but I hope to get more posted soon! There is so much to share! Stay tuned for how to sleep in a tent in Antarctica, the ins and outs of a hot shower at WAIS Divide and much, much more about ice cores and they story they can tell! I will do my best to get photos posted too but internet is a real luxury here and we only have 5 hours of satellite internet a day! Sending photos is against the rules but I will try to figure something out!

We began drilling the glacier ice and despite the weather conditions the day started well as we were recovering beautiful, clean, bubbly glacier ice. But soon the borehole reached a small sandy-pebbly layer within the ice and the pace of drilling came to a crawl. Drilling sediment rich ice releases enough heat to melt the ice between the sand grains. When the drill slows down the ice quickly refreezes and makes a sand ice slurry (yes, I referred to it as “crap” in the video) which adheres to the auger like cement making cleaning an arduous process.

The round depression on the top of the recovered slurry core was caused by the down-hole vacuum which assists in removing broken up rock and ice cemented debris created during drilling. Material not removed by the vacuum is hopefully recovered via use of the core barrel as shown in this video. After a few more cleaning runs with the vacuum and core barrel, we were back into clean ice once again!