Katie Joy, South Graves Icefield, 22nd December 2012
Hope that you are all still there as I think yesterday was earmarked to be the end of the world according to the Mayans. I didn’t put it my diary though so not sure if the date has passed or not. I should really remember to bookmark these sorts of events. Anyway, if the end of the world happened here in the Graves Icefields we are about as far from a burning hell you can get… it is a freezing -25degC + extra windchill and the katabatic wind is absolutely howling outside at about 40 knots blowing in from the south. It has got a lot worse than when Tomoko uploaded the blog from yesterday (see photo), and we are in a complete white out with snow being whipped along the ground and gusts of winds that could knock you off your feet. There is no blue sky or Sun to be seen. I wish could post a photo of today’s epic scene, but to be honest it would look like a white sheet of paper. From our tent entrance we can no longer see the poo tent clearly, and the snowmobiles, which have been parked a bit further away to stop them from being covered in the drifting snow, are completely lost in the icy mist. I ventured out this morning to tighten up our tent’s guy ropes and visit the ladies room, and came back looking like a walking snowwoman. Tomoko had to de-ice me. The tent is creaking, groaning and flapping around like a wild animal wanting to be set free. This is the real Antarctica, and it is pretty exciting and incredible noisy. Thank goodness for our nice warm propane stove and thick sleeping bags that are keeping us cosy and warm. We will be staying inside all day, and are keeping our fingers crossed that the wind will drop soon. We hope that the systematic team are having better weather and are out gathering lots of good meteorites.
As there is little to report on our searching efforts, I thought that instead I would talk briefly about some of the meteorites that I am really hoping we find over the coming week, and the ones that I study in the lab – those that have come here from the Moon. Lunar meteorites are fragments of rock that were thrown off the Moon when it was struck by asteroid or comet debris (i.e., in an impact event), and then entered an Earth crossing orbit. Like other types of meteorites they have an exterior fusion crust generated when the rock enters through the Earth’s atmosphere and, as such, we can identify them as being extra-terrestrial in origin. We further recognise them as being from the Moon as they have a similar chemistry, mineralogy, age and noble gas content to samples returned by the Apollo (USA) and Luna (Soviet Union) missions.
Lunar meteorites have been found in Antarctica, Oman, the deserts of North West Africa, and a few from deserts in Australia and Botswana. These are very rare meteorite samples compared to most types that are collected. To date, there have been ~150 individual (named) lunar meteorite stones found, collectively weighing ~61 kg (~16% of the mass returned by the Apollo and Luna missions). Some of the samples are fragments of volcanic lavas (known as mare basalts) and others are from the Moon’s white highlands. We do not know the exact location where they were launched from the lunar surface, but it is thought that they represent a random sampling of lunar rocks. This is their key scientific importance: in contrast to the Apollo and Luna mission samples, which were all returned from the central and eastern regions of the nearside of the Moon, lunar meteorites represent global geological sampling of our nearest neighbour. Therefore, studies of these important meteorites are helping to advance lunar science by providing new insights to the Moon’s geological diversity and history.
For more information, and a full list of lunar meteorites please see the NASA Meteorite Curator’s Lunar Meteorite Compendium at http://www-curator.jsc.nasa.gov/curator/..%5Cantmet/lmc/index.cfm and Randy Korotev’s Lunar Meteorite list at http://meteorites.wustl.edu/lunar/moon_meteorites_list_alumina.htm . Hopefully we will be able to add a few more to these numbers this season if the weather improves!
PS – ANSMET 2011 team – I am very much hoping that our sledges and flags haven’t been drifted in like last year… remember the fun that was had digging them out at Miller Range camp 2! Attached is a picture of the snow drifts in camp yesterday and we will have to wait until the storm abates to see what the situation is like outside…
Tomoko Arai, 21th December, 2012, South Graves Glacier
We have had very bad weather with temperature of -25degC and strong wind of 20-30 knots both yesterday and today. We are close to the South Pole (87 degree south latitude), and are in the middle of the strong wind, the so-called Katabatic wind, which comes from the South Pole plateau towards the coast. The bad weather allowed us to go out to search for meteorites only for a couple of hours. One meteorite was found yesterday, and another today. Both are just a few cm across with a dark fusion crust. Hopefully, the weather will get better and we will go out to find more and larger meteorites tomorrow!
Recon team searching North Graves
Andrew Beck, December 20th 2012, Larkman Nunatak, Antarctica
With -15 air temperature and 13-15 knot winds, today was a rather brisk day at Larkman Nunatak. We awoke to a marginal amount of snowdrift around our equipment, but not enough to hamper the start of the day. Our first order of business was to fill black plastic trash bags with snow. These snow-filled trash bags were used to mark the runway we created in the snow the previous day, which will be used by the twin otter aircraft to bring in our resupply and Christmas goodies in a few days. The chilly weather didn’t stop the 2012/2013 ANSMET systematic team from then going out and collecting meteorites. We collected 5 samples on blue ice and another 3 in a moraine, which are areas of concentrated sediment deposition at the end or side of glacial ice. At the end of the day we came home with some interesting meteorites that are unlike those we have seen so far this year. The team tentatively classified one sample, shown in the attached picture, as a carbonaceous chondrite. Carbonaceous chondrites belong to the same family as ordinary chondrites, the only type of meteorite collected until today and described in a previous blog. However, carbonaceous chondrites are unique in a few interesting ways, one of which provides clues about the formation of solid material in our Solar System.
Like all chondrites, carbonaceous chondrites contain chondrules, or some of the earliest forming solids. Carbonaceous chondrites are distinct though in that they also contain refractory inclusions. Refractory inclusions pre-date chondrule formation and have been identified as the initial solid particles to condense from the Solar Nebula. Thus, carbonaceous chondrites are crucial in the understanding both the processes of particle formation in our Solar System and their timing.
By Tom Sharp
December 19, 2012
Today was the first day at Larkman Nunatak. Larkman is the peak of a large mountain poking its head above the thick layer of continental glacier that covers most of Antarctica. This is a very windy place. Any rough edges of the Nunatak have been smoothed over by the deposition of snow and ice. The blue ice here, forms a great crescent off the Nunatak with blue ridges of ice extending off two sides of the mountain with a large area of ice and rock in between. We are here to systematically search that ice for meteorites. The search is done by riding snowmobiles in a row across the ice. Each member of the team carefully searches their lane for rocks with the distinctive shapes and black fusion crusts of meteorites. The blue ice is not flat, but rather looks like a rough sea, frozen in place, with 10-cm scale ripples, meter-scale waves and huge swells. Riding snowmobiles across this ice is fun, but one must ride slowly and carefully. The blue ice is partially covered with hard drifted snow. This afternoon, we systematically searched a beautiful and rough patch of blue ice and snow at Larkman, riding slowly and carefully as we hunted for meteorites. This was a very successful search for the ANSMET Team. I found my first ever meteorite, an ordinary chondrite about 5 cm long and 4 cm wide. Others on the team found similar stones. However, the big find of the day was a very large meteorite that was visible from about 100 meters away. Stan, who was searching along the edge of the row, found this monster. It is about the size of a honeydew melon, and isn’t far the largest sample found this year. Meteorites are so important in planetary science because they provide the rock record from the formation of our solar system and the planets. The large meteorite found today will likely provide important clues to the early history of our solar system.
Stan with a big meteorite!
Katie Joy, Graves Icefield, 19th December 2012
Blue skies have returned and today the recon team moved from our snowy home on the Klein Glacier surrounded by mountains to the bleakness of the Graves icefield. A Twin Otter aircraft arrived from the South Pole around 9 am this morning, and after 5 short roundtrips a mere 20 miles back and forth (which was also a huge 10 degrees longitude!) we were at our new destination on the edge of the blue icefields. We have set up our new camp much like the old one with John and Joe having the westerly tent, Tomoko and I having the easterly one, the poo tent downwind to the north, and our four snowmobiles in between. I am completely wiped out after carrying gear around, banging stake posts into the hard ice and unpacking all our gear again, and have no idea how the Twin Otter pilots do this every day moving people around in Antarctica!
We are now at more than 87 degrees south, so this is the closest to Pole I have ever been. We are in what feels like the middle of nowhere with blue and white ice horizons completely surrounding us – a slightly higher rise to the south with some cracked bumpy tops, and we can just about see the peaks of two sets of mountains to the east and north east when the cloud lifts. But that is it – without the small mountain tops we would be encompassed by the deep freeze. We can hear the ice cracking and groaning underneath us.
I haven’t been anywhere like this before with so few points of geographic reference, so it will be interesting to see how I gauge a sense of scale and direction over the next few days with just ice, the Sun and our small yellow tents to look at. This will be a new type of remote reality to adjust to.
Hopefully, after the move we will all sleep well tonight before starting work in the morning hitting the blue ice to start the search for more meteorites. As we are so far from mountains it will be likely that every rock we encounter will be a meteorite so our hopes are high we will be in for a successful few days before the next move (I can feel my back creaking at the thought already!).
PS. Ian – through some wondrous means I got your message! Thanks for the news and for going to the effort of getting in touch Hope all is well.
Katie and Twin Otter
Recon team camp at Graves
Stan Love, 2012 December 17 Mt., Bumstead Icefield Camp
Astute readers will have already figured out that this photo does not show a meteorite. Or a person looking for a meteorite. Or anything even remotely related to meteorites. Those readers will be correct on the first two points, but not the third.
The photo shows a disassembled carburetor from the engine of one of our snowmobiles. Snowmobile carburetors constituted the main part of the day for Shaun and myself.
Ever since arriving on the polar plateau, our team has been plagued with snowmobile engine problems, mostly related to too much fuel in the fuel-air mixture. The result is that the machines hesitate when accelerating, or even die unexpectedly and refuse to restart. This is not a good situation. Without the snowmobiles, we would be limited to searching on foot, which would mean a search radius of only a couple of miles, versus ten or more miles with the snowmobiles. Without snowmobiles we would have no possibility of moving ourselves and our thousands of pounds of gear to other camp locations. Without snowmobiles it would be hard to get our team out of the field at the end of the season, since the big LC-130 cargo planes can’t land where we are.
Unreliable snowmobiles are a big problem, and one that had to be fixed before we leave for Larkman Nunatak, thirty miles away to the south and our next search destination. Shaun is our snowmobile expert, but he wanted a helper, and I had volunteered early in the season to learn how to fix the machines. So while the rest of the team went to the summit of Mt. Bumstead to sample the spectacular geology up there, Shaun and I stayed in camp and worked on snowmobiles. A few phone calls to the experts in the shop at Mac Town pinpointed the problem in the carburetors. One by one, we drove the snowmobiles to our shop: a Scott tent pinned only on one side, so we could open it like a clamshell, drive the machine inside, and let it down to make a sheltered place to do engine work. We opened hoods, pulled out air boxes, unscrewed carburetor caps, and extracted from each the slender steel pin that controls the flow of fuel to its cylinder. The pin is positioned by a tiny clip ring that needed to be moved precisely one notch away from the middle of the carburetor, a job for needlenose pliers and eyes perhaps a year or two younger than Shaun’s or mine. Nevertheless, we got the first machine’s two carburetors done in an hour, and by the end of the day we could convert a machine in about 15 minutes. Skill comes from practice. I missed some great geology and wonderful views today, but now I know how to adjust a snowmobile carburetor.
Testing the adjusted machines shows them to operate much better, so we think we’re all set for tomorrow’s long drive to Larkman, and many miles of meteorite searches for the rest of the season.
Rob Coker, December 16th, Mt. Bumstead
Today we found some meteorites! So I thought I’d spell out what we do when we find one (besides the obvious jumping up and down in joy). Once we sort of agree that it is a meteorite (we don’t *have* to agree actually), we give it a number and take pictures of it with a counter and a scale-bar in the image. Then we measure the meteorite’s dimensions and estimate the amount of fusion crust coverage and maybe what type of meteorite it is. Next we bag it, being careful to avoid any contamination; so we use sterlized tongs and a teflon bag. We must even be careful to keep runny noses away from the meteorite! Finally, we get a GPS reading and mark the spot with a flag (in case the GPS fails; it is picked up later when the GPS data is uploaded). Then it is off to the next space rock! A picture of one of the ones found today is shown — I am finding it very hard to tell them apart from the local basalt (which are also black/brown with a crust) at a distance! The ‘flat’ light due to the high cloud cover of the last few days makes seeing rocks on the ice easy, but it washes out the color, so it is that much harder to pick out the meteorites from the many many terrestrial rocks (of many types) around here.
Partly as a celebration of finding our first meteorites of this trip, we followed our mountaineer and ski-dooed and hiked up an ice and snow outcrop on the side of Mt. Bumstead. The snowmobile ride was a bit steep, but quite fun. The hike, which required pick axes to avoid the occasional soft deep snow, was up to the very peak of the outcrop at nearly 8500 feet high. The panorama is from the top, showing some of us (I’m one!) down below and, off in the distance, about 5 km away, our base camp. Try finding it in the picture! No picture can possibly do this view justice. Nor can words. One must be there to grasp it’s stark beauty. There are wind-carved ice sculptures. There is blue ice in the nearby peaks visible. Patterns of layering in the snow all around can be seen. The cloud enshrouded peaks in the distance seem to watch over all we do. The wind didn’t howl too much, but it was enough to remind us we are indeed in Antarctica: full bundeling up in many layers of clothing was required. All in all, a wonderful day of views and meteorites. I look forward to many more of the same!
Pan From Mt. Bumstead
Tomoko Arai, 18th December, 2012, Klein Glacier
The reconnaissance team did a meteorite search in Scott Glacier yesterday. It took one hour commuting drive by snowmobile to get there. The weather was just beautiful without wind. We found three meteorites in the morning and two in the afternoon. One looked liked it might be chondritic with an unusual fusion crust with lots of vesicles, but beautiful mm-sized chondrules were visible in the exposed interior. In the evening we had a Mexican delicious dinner with chilli con carne and chilli rellenos, to celebrate Katie’s birthday. It is a snowy and windy today. We have not been able to continue the meteorite search and are staying in the Scott tent. Tomorrow, we are hopefully moving to the next target site, South Graves South by Twin Otter aircraft which will fly to meet us from the South Pole station.
PS – from Katie. Thanks Byes for the Birthday card, and the Coles for the sweeties. Elliott and Alexander the photo of you in the footy shirts is up in the tent. Thanks also to the main ANSMET team for the Happy Birthday sing along!
Happy Birthday Katie
Tomoko with an alien
Tomoko Arai, 16th December, 2012, Klein Glacier
Today is the first day of the meteorite search for the reconnaissance team in Gardner Ridge. The windless, relatively warm (- 21 deg C!), beautiful weather is perfect for meteorite hunting. We left our camp in Klein glacier at 9 am, and reached the blue ice fields in the Gardner Ridge after one hour and a half snowmobile driving. There were moraines nearby, and small fragments of the local rocks were scattered on some ice field. After two hours passed since we started, we found the first meteorite which is about 6 cm across, covered by a dark chocolate brown shiny fusion crust (the first picture). All of us were excited about the recovery of the first meteorite on the very first day of our mission. In the afternoon, the second meteorite, about 8 cm across with a brown fusion crust was recovered on the different blue ice field. Both of them are likely ordinary chondrites (the most common type of asteroid meteorite fragment – see Andrew’s earlier post), although detail studies back at NASA Johnson Space Center and the Smithonian will provide the official classification. The landscape here is absolutely stunning with white snow and blue sky. The speechlessly calm and peaceful atmosphere makes me feel like being forgotten from the rest of the world, and wonder as if we were in a different planet. Now we are searching for meteorites coming from different planetary bodies or asteroids, which had been buried under the ice sheet and long waiting to be recovered by us.
Katie with a find!
Katie Joy, Klein Glacier, 15th December 2012
John, Joe, Tomoko and I reached the Klein Glacier region of the Transantarctic Mountains yesterday (Friday). We took off at about 10 am from Pegasus air strip close to McMurdo on a LC-130 US air force plane, which is a Hercules equipped with skies. The aircraft was loaded with most of our kit that we would need to set up camp and we were the human cargo. After about an hour into the flight we flew over spectacular scenes of the mountain ranges – seeing huge glaciers with rocky moraine fields, wind-whipped peaks, giant crevasses ripping across the ground, and even a few blue ice fields to get us excited about the meteorite hunting ahead. After a couple of hours we touched down at Klein and went about setting up camp of two tall yellow Scott tents (pyramid shaped with four corner poles) for sleeping, organising our cargo and setting up the solar panels and small orange coloured poo tent. We waved the plane goodbye as it fired up its engines and used rocket jets to assist in take-off. Once airborne it flew back over camp and tipped its wing in farewell. We spent the rest of the day organising cargo and settled in for a first meal and sleep. We had another LC130 visit us at midday today to drop off the rest of the cargo (fuel tanks and our two remaining snowmobiles), and so we are fully equipped for the season ahead. The weather here is just stunning – no winds and blue skies – about minus 10 C outside. We are keeping our fingers crossed that it stays this way! The views are magnificent – to the south the open expanse of ice and the polar plateau. To the north the start of the Klein Glacier surrounded by nunataks (small mountain peaks poking through the ice) and what looks like sheer cliffs, and to the west we can see more mountains where we hope to go and start the meteorite hunt tomorrow (Sunday).