ANSMET meteorite hunting 2012-2013 season draws to an close

Happy New Year! This is a continuation of my two earlier University of Manchester Earth and Solar System blogs here and here about being part of the Antarctic Search for Meteorites (ANSMET) meteorite hunting team in Antarctica. The ANSMET program, run by the Polar Office of the US National Science Foundation, NASA and the Smithsonian, and lead by PI Dr. Ralph Harvey at Case Western Reserve University , has been running since 1976 exploring the ice of Antarctica for meteorites.

The full ANSMET blog for the 2012-2013 team can be found at http://artscilabs.case.edu/ansmet/

End of 2012-2013 ANSMET recon team season at the geographic South Pole (Image: Antarctic Search for Meteorites Program / Katherine Joy)

I am currently at the Amundsen-Scott South Pole Station, which is a US research station located adjacent to the geographic South Pole at 90 degrees latitude south. The station has only been built in the last few years and currently houses 158 people including the four members of the ANSMET reconnaissance team. We had been camping in the remote field from the 14^th December 2012 until the 19^th January 2013 searching for meteorites. We left our field camp in the Transantarctic Mountains on the 19^th Jan, and after a two hour flight in a small plane called a Twin Otter, we landed at the South Pole. Being at the Pole wasn’t part of our original plan – we supposed to head back from the field to the much bigger McMurdo Station, but due to weather issues our plans had to change. In fact weather was the dominating factor in our lives over the last five weeks.

ANSMET 2012-2013 recon team in the field at Szabo Bluff (Image: Antarctic Search for Meteorites Program / Katherine Joy)

There are normally four people on an ANSMET reconnaissance team. The recon team’s job is to investigate new icefields that have not been visited before to see if there are any meteorite concentrations (where we find lots of meteorites in close proximity to each other). If the recon team finds lots of meteorites then a larger (typically 8 person) systematic team will return when they can to collect as many samples as possible. The recon team may also return to small icefields that have been previously visited by ANSMET teams to sweep up any last remaining samples that were missed the first time around (for example, they might have been buried by snow when the last team visited). We search for meteorites by either driving around on snowmobiles and finding black rocks sitting on blue ice (areas of ice that is moving incredibly slowly), or we walk around in areas where there are lots of rocks in places called glacial moraines (rocky debris left behind by glaciers) and try and pick out any meteorites hiding among the terrestrial rock.

LC-130 plane bringing the 2012-2013 ANSMET recon team into the field (Image: Antarctic Search for Meteorites Program / Katherine Joy)

Our 2012-2013 ANSMET recon field season started at Klein Glacier in the Transantarctic Mountains. We flew there from McMurdo Station in a US military LC-130 aircraft (a Hercules with skis). We set up our camp consisting of two large pyramid shaped yellow Scott tents where two people live per tent, and a smaller orange tent that housed a rudimentary toilet (basically a bucket with a seat – life is not glamorous in the field!). We also set up all of our gear into cargo lines so that they won’t get easily covered with snow, and parked our four snowmobiles around the camp.

ANSMET 2012-2013 recon team camp at Klein Glacier in the Transantarctic Mountains (Image: Antarctic Search for Meteorites Program / Katherine Joy)

Over two glorious days of weather (sunshine and low winds) we searched for meteorites in two different ice fields where ANSMET has previously collected samples. We found seven meteorites in all and then moved by Twin Otter plane about twenty miles to a site known as South Graves icefield, which is more remote and surrounded by ice – mountains can only just be seen in the distance. We had mixed fortunes at South Graves – we found meteorites but the wind was often very strong and blowing lots of snow which made searching for meteorites challenging as it was hard to see the ground because of ice particles moving fast over the ground.

Twin Otter plane helping the ANSMET 2012-2013 team move camp (Image: Antarctic Search for Meteorites Program / Katherine Joy)

We left the South Graves icefield at the end of December 2012 and flew to a beautiful site on a glacier in the middle of the mountains close to a granite peak called Szabo Bluff. We had two amazing days of good weather where we explored the region and collected meteorites, and then a few days of bad weather followed by three more search days. Then, around the 7^th January, just as we were about ready to move to our next planned camp dreadful weather set in.  We had days of high winds, followed by calm days when it snowed or the cloud level was too low to give us good light to safely see the ground (when it is cloudy all the shadows and surface definition is removed which makes it unsafe to travel as you can’t easily see crevasses and steep slopes). When the weather is bad like this all you can do is sit in your tent and wait for things to improve. Well, we had to sit and wait for 13 days as the poor weather continued for too long. We were not able to search for meteorites or move camp. It was incredibly frustrating to be immobilised and not be able to work. The weather finally let up enough on the 19^th January 2013 for a plane to come and pick us up and bring us to the South Pole Station, signalling the end of our field season. We are now planning to fly back to McMurdo today and will start the process of cleaning up our equipment and preparing to head home in a week or so.

ANSMET 2012-2013 team collecting a meteorite sample (Image: Antarctic Search for Meteorites Program / Katherine Joy)

We collected 63 meteorites in all during our field campaign. We won’t know exactly what types of meteorites we found until they have been classified by the staff at NASA’s Johnson Space Center and the Smithsonian Institute in Washington. However, we suspect that out of the 63 we found about a few may be rarer types of meteorites known as carbonaceous chondrites. These types of meteorites were formed ~4.5 billion years ago and hopefully will provide scientists with insights to the early history of the Solar System. It will be exciting to find out exactly what types of meteorites we collected later in the year. Details of these samples will be announced via the Antarctic Meteorite Newsletter which can be found at http://curator.jsc.nasa.gov/antmet/amn/amn.cfm#352 .

Meteorite on blue ice found by the ANSMET 2012-2013 recon team (Image: Antarctic Search for Meteorites Program / Katherine Joy)

Thanks to the ANSMET PI Ralph Harvey for asking me to be an ANSMET team member. Thank you to Tomoko Arai my tent mate for the season who managed to put up with me for all those tent days, and with whom I had many interesting conversations. Thanks also to Joe Boyce for his good sense of humour and being a champion ice chipper. And special thanks to John Schutt who was our group’s mountaineer and all round star for keeping us all safe and leading us so well through the season.

All photos are credited to Antarctic Search for Meteorites Program / Katherine Joy