ABOARD THE JOIDES RESOLUTION, IN TRANSIT TO HOBART, TASMANIA– The work of the ship ended as quickly as it started nearly two months ago. We finished drilling Site 1361 and logged the hole. The drillers tripped 3500 meters of pipe and prepped it for storage as the ship will not drill again until July – off the coast of British Columbia. Everyone on board is absolutely brain dead from the non-stop grind of 12-hour shifts day after day. But all are happy as well. We’ve completed most of our objectives and made some exciting discoveries. When we did not meet with complete success it was always because of weather and ice, either encroaching sea ice or fields of icebergs so thick that we had no chance to pass.

Relaxing with some music after the work is done.

Now we have some days in transit. These days are filled with meetings to design our post-cruise research. We will all spend much more time at home working on the cores than our actual days at sea on this expedition. Some of the methods we will employ are expensive and difficult and we have recovered nearly 2000 meters of core. This means that we must carefully select the intervals we will study, so that we can answer the most important questions about Antarctic climate change as quickly as we can. For some of us, the analytical work will extend over the next 4 years. Then other scientists will work on these cores for decades to come. They will be stored in a vast library of ocean cores in College Station, Texas, at the IODP core repository where they are available to scientists from all over the world.

What I like most about these days in transit is going off shift. I no longer set my alarm to awake at 11PM. The two shifts mingle at meals and in the labs, almost as strangers at first as they have not seen much of each other for more than 7 weeks.

The whole team for Expedition 318. Photo courtesy of John Beck, IODP.

Working groups between the shifts assemble to design research strategies and timetables. I will lead a group that will make oxygen isotopic measurements of the small shells of amoeba-like organisms called foraminifera. Forams, as we call them, live for about 4 weeks during the brief Antarctic summer. They build their tiny shells out of calcium carbonate, the main mineral that makes up limestone. By measuring the ratios of two types of oxygen in the carbonate we can tell the temperature of the water in which the forams grew. We will make these analyses on forams that were living in Antarctic surface waters hundreds, thousands, and even millions of years ago to see how warm the water was next to the Wilkes Land coast. We already know from our microscope work on board that this part of Antarctica has been very warm at times, maybe 10 to 15 degrees centigrade warmer when we go back 35 million years. The foram work will help tell us exactly how warm the waters may have been during more recent periods when we know the ice sheet became much smaller. The results will help us predict the behavior of Antarctic ice in the future.

What a trip it’s been! I hope you’ve enjoyed these blogs. If you live in the Bay Area, please look for a notice about a talk I’ll likely give on this expedition in 6 months or so, after we’ve had a chance to start the shore-based part of the work. As we pull ever closer to Hobart we are very much aware that we are simply reaching the end of the beginning.

Christina and Joerg at the bow at sunset. Photo courtesy of John Beck, IODP.

Music by Synthhead. Courtesy of Beatpick.com.

Drilling at Site U1361
Position: 64º 24.6’S, 143º 53.2’E
Water Depth: 3470 meters
11 more days!

ABOARD THE JOIDES RESOLUTION, OFF THE COAST OF WILKES LAND, ANTARCTICA– Hi folks! We’ve been busy the past 9 days. We are coming to the end of our work window here in Antarctic. Summer has ended, the nights are much longer, and next Tuesday we must begin our transit back to Hobart, Australia.

We made our last attempt to get into one of our continental shelf drilling sites but were stopped once more by sea ice. All of the ice here is frozen seawater as opposed to glacial ice.

The sea ice is porous and inside the pores are salty brines that support plant and bacterial life. Here we are trying to collect so ice, but it’s a long way down to the water for this little bucket, especially when working from a moving ship.

We finished drilling deep into the seabed at Site U1359, encountering sediments and rocks that span much of the last 13 million years. For several hundred meters we found layers of rock that alternated between green and brown over distances of 2 to 4 meters. The green parts of the cycle showed evidence of intense mixing of the sediments by animals living at the seafloor while the brown parts showed something quite different – very well-developed laminations that could not have survived if the sediments were mixed. There were different materials in the layers too – some contain more shells of diatoms, the main plant in the surface waters of the ocean. We don’t yet know what these cycles of green and brown represent but we think they reflect the continued glacial-interglacial cycling of the Earth’s climate many millions of years ago.

Today we are in a very cold period in the long-term history of the Earth, and have been for most of the past several million years. Because the Earth is already quite cold, when we have glacial-interglacial cycles, we see large ice sheets coming and going at both poles – in Antarctica, Greenland, and over large parts of North America and Scandinavia. This waxing and waning of polar ice is driven by small changes in the shape of the Earth’s orbit around the sun (it changes from an ellipse to more circular and back again over about 120,000 years), the tilt of the Earth’s axis (it wobbles a bit over 40,000 years), and the exact seasonal timing of when the Earth is at its closest approach to the sun. All of these “orbital” changes impact how much sunlight reaches the Earth as well as when and where it warms the Earth seasonally. Sometimes, the Earth is in an orbital configuration that produces warm winters and cool summers – a combination that usually allows ice sheets to form and grow. Some 10’s of thousands of years later, the opposite occurs – warm summers and cool winters – which can cause ice sheets to rapidly melt. In today’s cold world, these small changes have big effects as the Polar Regions are cold enough to allow large ice sheets to form and last through the warmer periods. Antarctica has been covered in a large ice sheet for many millions of years because of this overall cooling. It still waxes and wanes along its margins but it is always present in the continent’s interior. But prior to about 2.5 million years ago, there was no permanent ice sheet in the north polar regions – it was simply too warm. Further back in time, the Antarctic ice sheet was much smaller than it is today but it was still dancing to the rhythms set by the Earth’s orbit.

What we were seeing at our last drill site and what we are looking for at our latest site is evidence of how these glacial-interglacial cycles affected the Southern Ocean and how they in turn may have been different because the planet was a little bit warmer than today. By studying this we can learn more about how small changes in the planet’s temperature can affect things like ice volume, sea ice extent, and the productivity of the ocean. This is directly relevant to understanding our Greenhouse future. Although all the climate variability that occurred millions of years ago was “natural” (in other words, not caused by people), the strength of the signal that caused these past changes (the orbital changes in this case) is not very different from the strength of the signal we expect from the man-induced increase in carbon dioxide levels in the atmosphere.

The poles are a great place to study both natural and man-induced changes in Earth’s climate because of a phenomenon called polar amplification. We know from many hundreds of studies of the past 50 million years of climate change that whenever the Earth warms up, the poles warm up more than the planet’s average. The converse is true for times of cooling. We don’t yet fully understand the reasons why but based on these studies of the past we shouldn’t be surprised that the poles are warming up very quickly today, at a rate greater than what we see in the tropics or the temperate belts. The cores we collect on this trip have the potential to tell us more about when and why polar amplification occurs.

I’ll send one more blog from this trip once we have cleared our last hole and are heading for Hobart. Sixty days is a long time to be as sea and working every day for 14 hours or more. We are all excited to get home.

I had a chance to get off the JOIDES Resolution a couple of days ago when we were running a “man overboard” drill. We recovered the dummy and then I was able to take these shots. It was our warmest, sunniest, calmest day by far. You’d never know we were in Antarctic waters.

We’ve been seeing lots of whales at our continental rise sites. The whales come to Antarctic waters in summer because of the abundance of food.

At dawn one day, we had more than 35 Humpback whales around the ship. From a distance you usually first see their spout, which you can make out here.

More storms and more icebergs. This seems to be the story around here now. Once each week we get a major blow and the seas kick up.

Then when we are near the continental shelf we see more icebergs…..

Position: 66º 33’ 39’’S, 136º 59’E
Water Depth: 1000 meters
Exact Location: The Antarctic Circle

ABOARD THE JOIDES RESOLUTION, OFF THE COAST OF WILKES LAND, ANTARCTICA– Yes, we crossed the Antarctic Circle today! It is perhaps only the 3rd time this ship has ever done so. All points south of the Antarctic Circle experience at least one day every year of total darkness and likewise one day every year when the sun never completely sets. We are now in early February so the sun does set but only for 4 hours and it never gets really dark. As a member of the night shift out here, I love this…I get up at 11PM, come on shift at midnight. The sun sets around 1 AM and rises again around 5 AM. I get to see both and when the weather is good, the colors are spectacular.

Moon set behind our drilling derrick.

Dawn at 0330 in the AM.

We are now working at one of our shallow continental shelf sites, called U1358. We just finished the major site for which I am the lead scientist. This site was cored very successfully. The water is a 1000 meters deep and the spot we cored is like a big dish at the seafloor, with lots of small sediment particles drifting into it.

Here you can see the annual layers in the sediment cores we collected.

The sediments accumulate at a rate of 2 cm every year and leave an annual layer – a summer deposit made up of microscopic plants and a winter layer made up of dust and silts carried by the wind and the ice. We can see each layer and each layer represents one year. It looks as though we can count these layers back over 10,000 years. The record may not be perfectly continuous, we don’t know yet, but we do know that we have 470 meters of layered mud to work on and that it will tell how the sea ice and temperature of Antarctic surface and deep waters has changed on a year-to-year basis for many thousands of years…..

The core sampling table where this bag holds the last of more than 2300 samples taken from one Hole.

We save EVERYTHING There are more boxes on this ship than you would believe.

Everyone on board worked long hours to get this site completed, many for 18 to 20 hours each day. So, when we have a transit day to another site we get to rest, but we also have a chance to cross the Antarctic Circle. Everyone is excited and a bit relaxed, both at the same time! The weather is sunny and warm today but tonight we expect a big storm to begin, one with winds gusting to over 60 kts and waves as high as 25 feet. It might last 2 to 3 days, a problem for us as it is difficult to work in such stormy conditions. I’ll let you know how it turns out!

This is mainly the night shift at the bow of the Joides Resolution as we cross the Antarctic Circle.

Your correspondents Rob and Christina on the Antarctic Circle.

At Site U1356, Hole U1356A,
Position: 63º 18.6139’S, 135º 59.9397’E
Water Depth: 4003 meters
Core Depth (penetration into the seabed): 1004 meters
Total weight of over 3 miles of pipe hanging from the ship: >650,000 pounds!

ABOARD THE JOIDES RESOLUTION, OFF THE COAST OF WILKES LAND, ANTARCTICA– Wow! What a week! We just finished retrieving our final core from the bottom of a drill hole more than 1 km in length. We’ve now recovered and described sediments that range in age from a few million to more than 36 million years old, all in the span of about 9 days.

The first sediments that came up told us what Antarctica was like when the ice sheet was like it is today. Then we saw evidence of a much warmer time and then a colder time before that – a time when flotillas of icebergs carried rocks and debris from the Antarctic continent out over our drill site, dropping this debris as they slowly melted. Even further back in time, more than 30 million years ago, we began to find evidence of much warmer waters…and for the first time no evidence of large ice sheets.

Yours truly wearing a shirt to match the core: muds from Tasmania. Photo by Christina Riesselman.

We also began to see sediments that may have come from Tasmania or other parts of Australia. Even though we are now thousands of kilometers away from Australia, back in time, 30 million years ago, Tasmania and Antarctica were much closer, perhaps only 100’s of kilometers apart. Plate tectonics since that time has carried Australia to the north while Antarctica has remained more or less anchored at the South Pole. So, not only do our sediment cores tell us tales of past warm climates (and perhaps give us hints as to what lies ahead in our greenhouse future), they also tell us new things about the science of plate tectonics.

The weather here changes fast! Yesterday, we had a warm (well…..maybe 4°C) and sunny day – our first sunshine in over 3 weeks. After shift, EVERYONE went outside to feel the warmth of the sun and to see blue skies and blue water.

Our first sunny day on Leg 318. Vitamin D the natural way.

I was up for shift at midnight. It was calm and cloudy with snow at 4AM but by 9 AM it was blowing 35 kts and we now have waves over 20 feet high. The change in weather happened while we were retrieving our very last core.

The night shift sedimentology team working on 30 million year old sediments.

Moon set on the JOIDES Resolution, 31 Jan 2010.

Now we will spend another 2 days here doing something called “logging”. Logging the hole is when we send instruments down to the very bottom of the drill hole after we remove the metal pipe that now supports it. These instruments measure the properties of the rocks we drilled through. By doing so we can piece together the sections of sediment we actually saw and described, even across breaks in our core that may have been caused by problems with the drilling. Altogether, we usually recover about 50% of the rocks we drill through. Some of the softer or stony units just can’t be cored and recovered very easily so this kind of work, logging, is very important for us.

So, back to writing up our results and making a short video clip for you about the work in the lab – I’ll send that off tomorrow. It’s great fun out here and the time is going by very quickly, just about as fast as the short Antarctic summer…..

At Site U1356, Hole U1356A,
Position: 63º 18.6139’S, 135º 59.9397’E
Water Depth: 4003 meters

ABOARD THE JOIDES RESOLUTION, OFF THE COAST OF WILKES LAND, ANTARCTICA– Here we are on the 29th of January, 20 days out of Wellington, New Zealand, and exactly 1/3 of the way through our expedition to the coast of Antarctica. It’s been a fantastic week for everyone aboard. We have now drilled over 750 meters into the seabed off of the Wilkes Land Coast of Antarctica. We are operating far enough offshore that we are in deep water – over 4,000 meters deep. This means that we have 4750 meters of drill pipe hanging from beneath the ship. The entire length of pipe rotates a drill bit and we bring up sediment cores in 10 m sections about every two hours.

Core on deck – 8AM on Jan 29 2010. This core is from 750 meters below the seafloor and will be worked on for the next 10 hours by the shipboard technicians and scientists.

Cutting the Core from IODP Expedition 318 Site 1356 in Antarctica. This core contains rocks about 25 million years old.

The cores get run through a variety of tests on the ship. We measure how much magnetism they have and how much natural radiation they emit (all rocks and minerals on Earth emit very low levels of natural radiation). This tells us how old the cores might be. We then split them using a diamond saw (we are so deep it is real rock coming up now) and run more tests.

Core from 730 meters beneath the seafloor. It’s hard rock but used to be mud that fell down on the seabed 25 million years ago. There is about 7 meters of sediment here.

I am a specialist in sedimentology which means that I describe the sediment – is it mud? Sand? Does it have fossils? Are there features that tell us of past submarine landslides? The sedimentologists get to see all of the sediment cores that come up so it is very exciting. We have seen long intervals when icebergs were dropping off bits of the Antarctic continent as they floated by and melted. We’ve also seen periods when there wasn’t much ice at all.

A close up view of some of the rock we are collecting. Here you can see ancient worm burrows from small animals that lived that the seafloor. The sediment changes color when the oxygen content of the deep sea changes.

Another section of the core. These stones fell out of icebergs that melted and dropped to the seafloor. The scale is in centimeters.

Cathy Stickley, one of our micropaleontologists who tell us how old the rocks are. She is English but lives now in Norway.

The sediment core that just came up 10 minutes ago (photos above) contains sediments that are something like 20 to 30 million years old. We won’t know for sure until our micropaleontologists have a look but we are approaching a horizon beneath the seafloor where we expect to start seeing evidence that it was much warmer here – maybe 10 to 15 degree centigrade warmer than it is now and a time of no or little ice on Antarctica. We should be done drilling here in 2 more days. Then it’s on to the next site. I’ll keep you posted!

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.