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!

After being cut, the halves are split up. The working half is placed in marked trays that are labeled 1-7 and CC for the core catcher. They are identical to the trays on the description table, but these are where the scientists get their hands dirty and really go to work. Each site (and each hole for that matter) is different. Depending on the areas of interest for the scientists or possible information we might find at a particular site and depth various requests are made. It is the job of the Staff Scientist to assemble all of those requests with the input of the sampling committee which includes the Staff Scientist, the Co-Chiefs and the Curator. The finished product is the sampling plan.

The sampling plan is the blue print for what the scientists take from the working half of a core.

Posted near the sampling table, this plan is the blue print for what the scientists take from the working halves. Samples range from toothpick scrapes, plugs, wedges, scrapes to mini cores. Microbiologists often take whole round samples (these are taken on the catwalk before the properties have a chance to change). In hard rock they can take what are called slabs. Drop stones can be taken directly out of the working half.

A variety of tools are used to remove the samples, from spatulas to syringes.

The samples are sealed in various containers and some are kept in freezers or cold rooms to keep any chemical changes from occurring. Some of the samples are tested or studied on board, but many are sent to the scientists at their home labs.

Sealing samples.

After the samples are taken, the spots disturbed by sampling are marked with either foam inserts or plastic dividers marked for the science they are used for (ex: PAL for Paleo, PP for Physical Properties). The remaining core material is packaged and labeled in special “D” tubes just like the archive halves in case more detailed sampling is requested post cruise. The “D” tubes are packed into boxes to eventually be shipped to College Station where they are hermetically sealed and eventually stored by the shore based curators.

Here is a quick clip of me sampling with David Scholl, one of the physical properties scientists in Expedition 323:

Hopefully that gives you some insight into the sampling on board the JR. Soon I’ll show you some specific sampling and testing that is done with the core material.

But for tonight let me leave you with a few more links to some videos I’ve made:

Another video tour of the JR. During the filming of the prior clip of the F-deck, we spotted a cargo ship off the port side. This is what happens any time something different happens, be it whale, seal, porpoise, cargo ship, sunset… anything.

A walking tour to the bridge deck from the F-deck. We had to ask a question of Captain Alex, and I’ll see if you can guess the answer: How far can you see out on the horizon from the main deck? From the Bridge deck? Maybe I’ll get the Captain to explain how he arrives at his answer to this question on video later! He got called away to important business. You may notice there is a lot of magic on this ship…

This is the place where the cores first enter the labs. Lots of testing, imaging, poking, prodding and sampling take place on this deck. I’ll get into more detail soon, and show some of the indigenous scientists in their natural habitat.

A quick interview with Ivano Aiello, one of the sedimentologists on board the JOIDES Resolution for Expedition 323. He explains a bit about one of the things we are looking at (micro fossils in the sediments), and how they help us understand paleoclimate.

Sedimentologist Beth Caissie shows off the Core imaging camera and explains a bit about cleaning up the cores before making these images. Taken on the JOIDES Resolution during Expedition 323 to the Bering Sea.

Step four: The technicians cut the whole core into halves. They have a neat device designed specifically for this process with two razors that cut the core tube which houses the mud. There is a thin wire like a cheese slicer that cuts through the mud, and usually a quick tap on the table separates the core into two even halves. Occasionally rock or tough deposits require a turn with the circular saw to divide them up neatly.

The core cutter.

Step five: The core halves at this point are sent in two directions

* Core description – The “archive” halves of a complete core are sent to a table where each is sent to be imaged. During this process the surface that was cut is scraped clear of any material that may have been moved during the cutting process. The revealed surfaces are visually described by sedimentologists as the imaging station takes detailed digital images of the cores. The magnetic properties are often measured at this point. After this each core section is wrapped in plastic, stored in containers called “D tubes” (because they hold the half cylinder D shaped cores), boxed for storage and taken to be refrigerated.

Sedminentologists visually describe the core.

The imaging station takes detailed digital images of the cores.

Sampling – The “working” half of each section is placed on a table where those scientists working on a sampling shift collect the predetermined samples from areas designated for testing. Spot samples can be taken for interesting or potentially fragile zones that appear. These samples will eventually be tested for physical properties, sorting by sediment size and composition, microbiology (what life is in them, or byproducts of living things), paleontologists (those who study microfossils and remains of organisms such as forams, radiolarans, dinoflagellates and ostracods). If any testing is done at this point it is minimalistic so that the cores can be better characterized for later detailed sampling.

Sampling a core.

Step six: As soon as data starts coming in about the cores the Stratigraphic Correlators kick into gear. They use any and all data that is collected to create a best fit composite image of the area from the various holes drilled. Along the way they give input into future drilling so that core section breaks don’t overlap, and problem areas are recovered in as pristine a fashion as possible.

That’s a lot of stuff to digest. Learning it on site took a while to comprehend, and there are still many places where I could expand my knowledge, but hopefully we all have a basic understanding of what happens to cores on the JR. Any questions? I hope so. Check back soon!