Made it back home!

After a long journey I have made it back home. The C-17 came in and brought us back to New Zealand. It was quite cold and windy when we were waiting on the sea ice to board the aircraft, but we were enjoying our last minutes on the ice. The cold is part of the experience and we certainly got used to it! While we were waiting our luggage was loaded onto the aircraft. Note the sea-ice firetruck, a track vehicle. It was a full flight with around 80 people coming back from the ice. After we took off, we were able to move around within the aircraft. It has 4 windows and I spent most of the first two hours looking at the icy landscapes below. First we traveled above the sea ice of the Ross Sea. One could see that it is Summer now and it is starting to break up. The Antarctic sea ice forms every Winter and breaks up every Summer. Later, we were flying across the front of the Transantarctic Mountains and one could see glaciers flowing through valleys and merging with the sea ice of the Ross Sea. Ice flows very slowly and it can flow uphill as well, but it eventually flows out to sea, where it breaks up into icebergs that are carried North by the ocean currents.
Now that the science team has made it home, we will all work in our labs in collaboration with students to analyze the core further. You can check this site for science updates. I will post pictures and information of our lab work once the samples have come in. They have been shipped from the ice and will arrive in the next few weeks. Happy holidays everyone!

Greetings from Miers Valley

The last few days have been extremely busy with wrapping up reports and packing up our gear. Then at the last moment yesterday, after being on hold for three days, we were put in the field by helo. Still, the weather wasn't too good, because a low pressure system kept hanging around the Ross Sea area, but the helo pilot managed to slip us in and out between snow storms. We headed for Miers Valley, a small dry valley south of McMurdo Station off Blue Glacier in the Transantarctic Mountains. The rocks in Miers Valley are basement rocks composed of metasediments, cut by mafic dykes. Granitoid intrusions also occur. Many fragments of these types of rocks were found in the ANDRILL SMS core. We landed next to the calving front of Miers Glacier, a nice example of a polar cold-based glacier. These types of glaciers only melt at the surface as you can see by the meltwater rills on the calving front behind the helo. We also found huge ventifacts: rocks that have been sculpted and blasted by wind carrying sand and gravel particles. We also made a stop at some volcanic islands to pick up scoria samples for comparison to the ones we found in the core. Finally we made a kind of emergency stop on a moraine in white-out conditions and waited out the weather a bit before heading back to McMurdo.

Last night was "Bag Drag" which is basicly checking in for the flight on the C-17 back to Christchurch, New Zealand. We will be leaving tonight, a little later than normally, because the C-17 had mechanical problems. I have been told they have been solved, but we will see. The weather is looking fine today, so the plane should be able to land. So, I will be hopeful and say: this was my last blog from Antarctica, see you back home in a few days!

Almost ready to go home

A helo trip to the Mount Discovery volcanic area has been arranged for tomorrow and I am scheduled to be on it. We are going to examine some of the source rocks that we find in the core. All depends on weather, but the forecast is looking okay at the moment. We are further getting ready to leave the ice in a few days. We are finishing up our scientific reports and are giving final presentations to the science team. We will leave from an area that is further from McMurdo Station. Last weekend the sea ice runway was moved to Pegasus and Willy Field on the ice shelf. You can see the train of vehicles pulling the buildings in the photo. The sea ice is getting too thin and too soft to land planes on it. It is no longer safe, so the runway had to be moved to thicker glacial ice. The sea ice edge with open water has progressed further south and the sea ice is breaking out. The recent satellite image at the top shows that the open water has come quite close to the station. The drill rig is also being dismantled as we speak. Although it is on multi-year thick sea ice, the ice is becoming to weak to support the weight of the rig.

Brunch at Scott Base and a walk through the pressure ridges

Yesterday we finished logging the last pile of cores down to 1038.54 meters below sea floor. Today, Sunday, we had a chance to finally take a couple of hours off and we were invited to have brunch at Scott Base. Scott Base is the New Zealand base and the green buildings of the base are just a few miles from McMurdo Station (see photo above). Behind the base you can see the pressure ridges in the sea ice. One of the mountaineers offered us a trip through the area. He had drilled several holes to estimate the ice thickness and found a save route through the area. The pressure ridges are exceptionally high now (much higher than when I first saw them 10 years ago) because the sea ice has not broken out since 1991. The floating glaciers (ice shelves) keep pushing against the sea ice and it buckles and cracks. Seals come up through the cracks to rest on the ice, and our way was blocked by one of them, so we had to return the way we came. The Antarctic Treaty does not allow people to disturb wild life, so we watched the seal from a distance. One of my Italian colleagues on the night shift, Franco Talarico, is visible here to the left. This is a project with scientists of 4 nations: the U.S., New Zealand, Italy and Germany.
We now have to finish writing our on-ice research reports and we are still making attempts to survey the Dry Valleys upstream from the drill site by helicopter drop-off in small groups. So far the weather hasn't been cooperating. It just started snowing, again... I am scheduled to leave here on Dec. 7, so time is running out. I am currently shipping over 300 samples for analysis in the lab at Montclair State University's Department of Earth and Environmental Studies. It is an exciting core and we will have a long way to go to fully understand it, but it is by far the most interesting core I have ever worked on.

Antarctic marine life and the origin of fossils

In the basement of the Crary lab where we work are several large tanks filled with water. In the water are animals that were collected by biologists from the sea floor and the waters of the McMurdo Sound. The temperature of the ocean here is only 28 F (-2 C) , which means it is below the freezing mark of fresh water. Nevertheless the ocean is teeming with life and has a quite elaborate food chain, with top predators, such as killer whales, and leopard seals and the Antarctic krill at the bottom. All these life forms have special adaptations to the cold. For example, fish, such as the Antarctic Cod, have a type of natural antifreeze in their blood which keeps it from freezing. In the photos you can see several strange-looking arthropods, star fish, bivalves and sponges.

There is a marked difference between the fossils we find in the cores and the biota of the modern McMurdo Sound. The difference is primarily caused by the fact that only skeletal body parts are preserved in the rock record. When animals die, their soft tissue decays, and only skeletal parts accumulate on the sea floor. A fossil assemblage therefore only represents a small portions of the actual fauna of the sea floor in the past. Paleontologists are aware of that and are specialists at knowing what is missing.

The last sampling party

Yesterday was the day of the last sampling party. Drilling is still progressing with a narrower bit and we do get to log it during the day, but the sampling will be done off-ice during a workshop in Florida next year. Note the little flags: they look quite used after more than a 1000 meters of core. I have collected ca. 300 samples, which will be processed in the lab at Montclair State University and measured on the laser particle sizer.
Peter Webb, my former PhD advisor is here too and you can see him in the picture below. He is being interviewed for a NOVA documentary and serves as a general advisor and guide to the project. You can watch a video about his early research in this area in the late 1950s on the website of ANDRILL. More videos about Antarctica today and Antarctic Geology can be found there as well. The link is here....

Logged 1011 m of core on the night shift!

A few hours ago we finished logging the first batch of core down to 1011 meters below sea floor. We have been logging for 5 weeks now, 12 hours a day, 7 days a week, so that is why we look so tired. The photo was taking soon after we finished logging and Chris is holding the last core section. The picture was taken by a radio journalist, who joined us this night. The core of last night was magnificent! The last part of it consisted of ripple-laminated sandstones. The ripples are made by currents and the dark mud layers between the ripples indicate that currents were periodically going faster and slower. This is very typical of a tidal environment. You can also see a bit of pyrite ("fools gold") at 85 cm and 93 cm, that formed as crystals in the sand after it was deposited. The minute we finished logging the message came in from the drill site that drilling had started again and that core had come up. We are going to have a one day break now, however, because we are transitioning to day shift.

The Turkey Trot

Yesterday was the day of the traditional McMurdo Turkey Trot. It takes place on the morning of the Thanksgiving meal and it is a 5 km running event on the sea ice. I participated 9 years ago, but this time I didn't feel up to it, but that gave me an opportunity to cheer my colleagues on and take some pictures. Here you see my nightshift buddies Phill, Josh and Chris at the start of the race. (Never mind Phill's outfit.) There was a mean cold wind coming across the peninsula, but it took them less than half hour to get back in: great job guys!

Later that night after we tried to sleep (it was very noisy in the dorm) we had our Thanksgiving dinner at midnight. The food was superb: of course with Turkey, stuffing, fresh fruit, salad, and desert. We also logged 36 meters of core. We have one more night of core logging to go and then we will revert back to the dayshift.

Happy Thanksgiving from Antarctica!

Happy Thankgiving from Antarctica. We will have our Thanksgiving dinner tonight at midnight with the nightshift from the drill site. They will come in from their little camp on the sea ice to celebrate with us: we have a lot to give thanks for with such a great core! We also need to work tonight, so perhaps a glass of wine will be okay, but not too much. Drilling will start again on Sunday. Our drill hole is now the second deepest on the continent (the deepest is the other ANDRILL drill hole of last year) and since we still have time in our schedule, an attempt is going to be made to go deeper than the 1011 m we have now. For us it means we have to keep logging.

After long sequences of mudstones, with very little evidence of ice close to this area, we saw evidence of ice sheets in the core last night. Once again: we see the ice-sheets come and go and the core tells us it continues back in time for more than 17 million years!

No helo trip, but core with calcite veins

The weather turned bad with snow across the sound so we did not get out on our helo trip. Instead, we logged more core (we still have 111 m to go to complete the 1011 m that were drilled). The core had multiple fractures and faults last night, evidence of brittle deformation associated with tectonics. The Earth's crust is spreading apart in this area: we call this a rift and that causes the fracturing and faulting in the rock, as well as the volcanism in this area. One calcite vein fill was truely spectacular: so here is the photograph. Calcite precipitates from the fluids that circulate through the rock.

Helo trip to the Dry Valleys scheduled

This is 08H or zero-eight-hotel. We received the helo schedule last night and a few of the night shift scientists are signed up for a trip with 08H to Taylor Valley in the Transantarctic Mountains this evening. The purpose of the trip is to survey the regional geology so we get a better understanding of the composition of the sediments in the core we are investigating. The plan is to be dropped off at a high point in the Dry Valleys and then walk down the valley walls of Taylor Valley to the valley floor. We will then pass through several rock units, which were eroded by outlet glaciers of the East Antarctic ice sheet. It is likely that some of that eroded rock material is what makes up the sediments in the ANDRILL SMS core. All is scheduled, of course as always weather permitting. Right now it is not looking great with more snow in the forecast.....we will have to wait and see if they let us go out.

A 1000 meters below the sea floor on the night shift!

Last night the night shift at the drill site reached 1000 meters below sea floor, our target depth. We, the core loggers in McMurdo are also on night shift and we celebrated a little bit with them. It is quite hard work, from 10 pm until 10 am every night, 12 hours a day, 7 days a week, but now with the celebrations of the project and the end in sight we are getting new energy. Last night was amazing because we logged meters and meters of core without any evidence for large ice sheets at all. There were a few rocks (clasts) that probably fell out of icebergs, but really only few. That was quite unexpected, but I like surprises better than getting what is predicted: it is the exploring that makes doing this type of research so enjoyable. We also found some fossil scallops, such as these here in the photo: the original fossil is still there, but also a mold, an imprint of the shell. These discoveries make the work worthwhile and interesting. What you see here is the half core: so the drill bit drilled partially through the scallop and then the drill core was split in half.Drilling at the drillsite has stopped and now a new team will step into action. After the drillstring has been removed from the hole, the down-hole logging team will bring their tools to the bottom of the hole and then pull them up slowly. While the tools are pulled up, they will measure the physical properties of the layers of rock and also take images of the walls of the borehole. In the mean time we will continue to describe the core until we have gone through all 1011 meters of it. There will be another phase of drilling with a narrower drillbit after the down-hole logging is completed, but we will describe that core on the dayshift towards the end of the season. The plan is that we will also take a helo trip to the Transantarctic Mountains to survey the geology there, because many of the sediments in the core are eroded by glaciers from that region. Stay tuned for a report of that trip.

Back in time and almost where we would like to be: 1000 meters below the sea floor!

This is an interesting phase of our project. The drill bit is more than 940 meters below the seafloor. The rock is getting really hard and the sediment is impregnated with hard, sometimes black, cement. So deep below the surface the pressure and the temperature are much higher than at the surface and that turns sediment (like beach sand) into rock. We are drilling such a deep hole because we would like to take a journey back in time and observe what Antarctica looked like in the past. We are also trying to find out when and how Antarctica got so cold and whether it is likely to stay that way in times of future global warming. Today, Antarctica is a frigid place, as you may have seen on this blog , but we know from previous drilling that it was not always like that. The arrow points to where I am on the image made by NASA. More than 90% of the continent is covered in ice, with only some mountain ranges sticking out above the ice surface. The photo to the right is of a biodiversity study here close to the station, but as you can see there are no plants growing here now. Previous drillholes have indicated that plants were once present in Antarctica. We are finding coaly plant debris in the core for some time now. We have been sending samples to scientists off the ice in New Zealand and the U.S. who are trying to find out what type of plant the material represents. Today we found some more coaly bits in the dark grey rock to the right. The question now is whether this material represents the vegetation on the Antarctic coast at the time of the deposition of the sediments or some older coal material. We will find out later! We know that aprox. 35 million years ago Antarctica looked very much like the coast of New Zealand (see image by I. Woodward), but when did it change? That is what we are trying to find out.

On the sea ice of the Southern McMurdo

The drill rig is situated on multi-year ice (shore-fast ice) adjacent to the Transantarctic Mountains. In the image you can just make out the drill rig in the distance. Those blue ice areas in the front are frozen meltwater pools, which developed during the last summer season and froze again during the winter (remember that the seasons are opposite here to those of the Northern Hemisphere). The surface of the sea ice can be dirty from dust and rock particles blown onto it by storms or material carried by small meltwater streams. Fresh snow gives the surface a bright and white color, but the sea ice surface is never smooth: the wind sculpts and erodes the snow into sastrugi. Most of the sea ice travel is on flagged routes, where the sastrugi have been plained off.

The sea ice is the habitat of penguins and seals. I didn't see any penguins this year, only footprints so far. I did see a seal flapping around in the distance. Most of the seals we see here are Weddell seals, who are endemic to the Antarctic region. Weddell seals primarily feed on fish. There is also a predatory seal here: the Leopard seal. Divers and biologists studying the seal and fish populations are always on the lookout for Leopard seals. They are solitary hunters and can follow their prey for a long distance without being noticed. Some close encounters have occurred, but no major injuries have been reported.

A visit to the drill site out on the sea ice

Last night we had a day off and we had a chance to visit the drill site. We were picked up by the staff scientist and he drove us per Mattrack vehicle out on the sea ice. We followed the procedures for sea ice travel: checked out with Macops by radio and delivered our estimated time of arrival at drill camp, picked up an extra survival bag, because we had one person more in the vehicle than normally, and off we went. After about two hours we arrived at the drillsite. The drillrig is covered in a white fabric to keep the rig and the people on it away from the wind. The rig is situated on 7-8 m thick multi-year sea ice (frozen ocean) and there are around 380 meters of water below it until the drill pipe reaches the sea floor. The small blue building attached to the rig is the mud room. In the mud room the drilling fluid is prepared and recovered. Drilling fluid keeps the drill hole open and lubricates the drill string. The drillers on the rig floor keep and eye on the pressure of the drill bit on the formation it is drillling. Once a core section of 6 meters is completed, the core comes up from the drill hole and is further processed and cut into one-meter long sections at the drillsite lab. The fractures and physical properties of the cores are studied and measured there too. The whole-round core sections are transported to McMurdo Station by helicopter. There the core sections get split and imaged, before we get to describe the core. Check back later for a blog on the core process here in McMurdo. Lastly: some penguin feet we discovered out on the sea ice, but unfortunately the penguins had left. There was a group of them at the drillsite not long ago and the people there enjoyed the entertainment. They have very little entertainment there so I am glad they had a chance to enjoy themselves.

A busy week for the science team and 800 meters down!

The current depth of drilling is at more than 800 meters below the sea floor. The sedimentology team has logged and decribed more than 700 meters of core and we are starting to feel a bit worn down. We are getting beautiful rocks though, like the ones in the photos below. We still see diamictites but the last few days they alternate with mudstones that are laminated or layered. In the photo the layers are at an angle, tilting, which is a sign of disturbance of the original beds. Sediments are always laid down horizontally, so if we see these tilted layers, we know that something happened to the layers after deposition. Details like these are recorded by us, the sedimentologists, in the core descriptions. We also found very flat-laminated rocks. You can see us at work in the photo above (photo by Tracy Frank). These mudstones are important to the science team because they potentially indicate conditions away from an ice sheet, although some mudstones may accumulate very close to a glacier. We will find out by analyzing their composition and the microfossils they enclose. For example: if there was vegetation on land with formation of soils, we would find pollen of plants and clay particles indicative of chemical weathering in soils in the mudstones. The pollen and soil materials were washed into the ocean from land and the particles accumulated as mudstones. So: we can analyze the composition of the mudstones and reconstruct what the environment was like on land in the past.

Yesterday I took some time to take a walk around the peninsula. The weather was very calm and I enjoyed the view across the sound and the presence of Mount Erebus, the active volcano. I also encountered two skuas, who totally ignored me so I decided to take a picture of one of them.

A forest of wormtubes and the UNDRILL 500

Last night we logged another 30 m of core and a large proportion of it consisted of mudstones with abundant fossil worm tubes made of carbonate. We are having a unique view here on an Antarctic seafloor more than 15 million years back in time. Between the worm tubes we found fragments of moss animals (bryozoa), and foraminifera, microscopic single-celled organisms that live either at the surface or at the bottom of the ocean. Serpulate worms and bryozoa make up part of the present Antarctic benthic community and were recently discovered to be living underneath a floating glacier or ice shelf (see link here). Paleontologists will now investigate the specific species and try to determine in what type of an environment these organisms were living: in open water without ice or near the ice.

The presence of foraminifera, these microscopic creatures, is good news. Diatoms (see a few blogs earlier) are apparently not really flourishing in this environment, so instead of the diatoms, the foraminifera may help us to obtain an age for these rocks. Different species of foraminifera are characterized by different shell or test morphologies and through evolution one species followed another in the past. In other words: different shell morphologies are characteristic of different times in the past. So, these microfossils can help us to find out how old these rocks are.

Yesterday we celebrated the fact that we reached 500 meters below sea floor with the UNDRILL 500. The drillbit is currently already more than 700 meters below seafloor, but we didn't have time to celebrate earlier. The traditional Antarctic way of celebration (going back to Scott's and Shackleton's times) is that you dress up with elements of underwear (or sometimes men wear womens clothes and make-up, yeah really!). We were marching around the station dressed up, with the national flags of the team, a tuba and a trombone, good fun!