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.