Ice Diary 4
The Hunt Begins
8 December, 2002
We finally made it to our field camp! An LC-130 operated by the New York Air National Guard dropped us off at the Beardmore South Camp a couple of days ago. The next day we took our gear and snowmobiles on a 5.5-hour traverse to our camp at Goodwin Nunatak, on the boundary of the Polar Plateau and the Trans-Antarctic Mountains.
|Heading for Beardmore! Credit: Carl Allen
Antarctic ice backs up against the mountains, flows upward, and is ablated by the wind. Meteorites are revealed in these "blue ice" areas, but meteorites are not the only rocks. Some of the blue ice contains moraines --a deposit of local rocks from a variety of areas. Some of the local rock is dark and rounded like the meteorites, so close observations are necessary. We've discovered that meteorites tend to collect with other rocks in the wind scoops that formed around boulders.
The blue ice looks like a frozen ocean. The wind carves the ice into smaller waves called "sastrugi" that almost look like whitecaps on the swell. In other areas the ice is almost flat.
Our meteorite searching was extremely successful today. Although we weren't doing any systematic searching, we still found 23 meteorites to add to the 21 we found yesterday. We had most of our success at a place unofficially named Scoraine Moraine, after Robbie Score, a former ANSMET team member. I hope we get a chance to go back. It was late in the day and I think we left a lot behind.
I can't explain the thrill at finding a meteorite. Danny compares this to an Easter Egg hunt, but I think it is more like fishing. Sometimes you can't catch them fast enough, and other times you go for hours without finding any. It's great to find several, but finding a rare variety is just as rewarding.
9 December, 2002
No searching took place today, and none was planned. If it had been a search day, it would have been miserable. It started getting windy overnight, and the temperature dropped to -14F. The wind has been gusting 10 to 20 knots all day and the high was about -5F. We figured the wind-chill was about -45F.
We thought we were ready for the wind, but drifts formed in areas we didn't expect and buried some of the equipment. We had to dig out the ski-doos and shovel additional snow around the base of the tents to insulate them. Everything is more difficult in the wind and cold. Just chipping ice for melt water or refueling stoves can be a challenge.
Carlton Allen arrived by twin otter plane today. Twin otters can land in strong winds, on short runways, and snowy surfaces. He brought us peanut butter bars from the McMurdo galley. Jaime explained before we left how important good food is to the morale of the team. He's an amazing cook and seems to enjoy it. We've already had sausages, steaks, stroganoff, and a variety of sides. Tonight, Jaime and I ate over at Danny and Dante's tent and had shrimp fajitas. I stuffed myself because they were so good. It's going to be hard to camp in the future without thinking of Jaime's cooking.
Jaime went up in the twin otter to scout out our upcoming traverse to McAlpine hills. He also transferred ski-doo fuel to this camp and our camp at McAlpine. In addition to all this, he constructed a wind turbine to provide electrical power. He is arguably the busiest guy in camp. When Jaime returned, John boarded the twin otter and left for South Pole. The reconnaissance team will join him tomorrow.
10 December, 2002
The winds picked up again last night, and Nancy came by this morning to tell us that we were going to have a "weather delay." This meant a day in the tents and no meteorite searching. Just looking outside, you couldn't tell how harsh the conditions were. The sky was blue, but the horizon was hazy from all the blowing snow. We were experiencing the full onslaught of the Katabatics.
|ANSMET team collecting one of the first meteorites of the season. It is close work, on hands and knees through the snow.
Katabatic winds are pressure-derived winds. Cold air sinks over the Antarctic continent and races over the ice toward the ocean. There is nothing to stop the wind and the mountains only funnel it. We can tell when the Katabatics are coming from the pressure change. I have a barometer on my watch that shows basic trends in barometric pressure. If we see a change toward high pressure, that generally means that windy days are ahead.
My watch uses this pressure to estimate our altitude, but this doesn't work so well in Antarctica. Due to the Earth's rotation, the atmosphere bulges a little at the equator and thins at the poles. For instance, McMurdo is at sea level, but our "pressure altitude" was about 1,500 feet above sea level. The effect is most pronounced at the South Pole, which is already at an elevation about 9,000 feet above sea level. Due to the effect of pressure altitude, it actually feels like it's over 11,000 feet! Members of our Rekki team are concerned about this because it's easy to become winded and feel ill at high altitudes. Plus they have been at McMurdo for a couple of weeks, which isn't helping with their acclimation. Our camp is just below 8,000 feet but feels like its over 9,000 feet, which is equivalent to some of the higher mountain towns back home in Colorado.
Jamie put it best yesterday when he said, "Things develop a life of their own down here." This has been very true. First of all, batteries go dead overnight from the cold. So, constant electrical power is necessary to run our satellite phone, computers, cameras, and any other electronic device. We are turning both to solar and wind generated power. We have been able to partially capture the wind to derive electrical power through a wind turbine, but like most of our technology, it has been much more complex than it sounds. Both systems ideally charge a bank of car batteries, off of which the direct current is converted to an alternating current. Unfortunately these items don't work perfectly and are entirely dependent on the weather.
To add to our technology limitations, our camp stoves have been breaking down at an alarming pace. We have already gone through six of thirteen stoves that are supposed to last us the whole six weeks. We depend on these stoves not only for cooking, but also for heat in the tent. Hopefully, we will receive an emergency shipment of them from McMurdo tomorrow.
Danny was in earlier and is reading about Shackelton's expedition and we were comparing and contrasting our situation. Despite our technology, we are in the same elements that stranded the crew of the Endurance. It's really a miracle that we can post this to the web at all.
Despite our technology limitations, we are able to get news of the outside world through a short wave radio that picks up stations from Australia. Carl Allen, who just arrived yesterday, also brought news and a poem written by Dr. Ralph Harvey, the principal investigator of the ANSMET team. Ralph usually makes it to Antarctica, but is home in Cleveland this year with his newborn son. This poem was Ralph's reaction to the images of the Rekki team spelling out ANSMET:
RAW! RAW! RAWS! THE METEORITES COME FROM MAWS! WE'LL PICK THEM UP AND WRAP THEM UP ALL DAY AND NEVER PAWS!
WE'LL SNAG EM! WE'LL BAG EM! WE'LL DO A LITTLE DANCE!
AND IF IT IS A MARTIAN, WE'RE GONNA WET OUR PANCE!
11 December, 2002
Today we were rewarded with clear skies, calm winds, and mild temperatures (5 to 20F). It looked like it was still blowing pretty well up at Goodwin Nunatak, though, so we went back to Scoraine Moraine for our systematic searching.
|Mr. Andy Caldwell preparing the daily web posting. Credit: Dante Lauretta
We picked up three meteorites on the way to Scoraine Moraine and used this as an opportunity to bring Carl up to speed on the collection procedure. We were all excited to get to Scoraine Moraine because of our earlier success, but for the first hour, we found nothing.
Then Dante brought out his metal detector. We were all skeptical about how well it would work with the low metallic content of most meteorites. But when it found a meteorite buried in the snow and another under a rock, we were all convinced. There was a tie today for meteorites found by the metal detector versus those found by people.
The metal detector helped, but it was easy to become complacent and just follow it around. Our most exciting meteorite find of the day came at the end on our way back to camp. We think it might be an achondrite, a rare type of meteorite that is thought to come from the asteroid 4 Vesta. We tried the metal detector on it and it gave no signal.
A twin otter plane made a couple of stops at our camp today to drop off replacement stoves and brought in an expert on solar power to check out our solar array. Jamie already had it working fine, but the technician brought us a new wind generator that should be more productive than the last.
12 December, 2002
This morning started out calm and downright warm. It's funny how quickly 25 degrees F feels like a warm day. This reminds me of the college students at Western State University in Gunnison, CO, who play volleyball in t-shirts and shorts when the temperature rises above 20 degrees F. By the time we reached Goodwin Nunatak, however, the temperature had dropped to -2 degrees F and the wind was blowing.
Prior to today, we would just fan out and randomly search areas that had already been searched in previous years. Today we lined up our ski-doos at equal distances apart and drove in relatively straight lines looking for meteorites in our lanes. This sounds a lot easier than it is. It seems like every time I looked up I had drifted closer to Danny or farther from Linda. It almost took more concentration to stay in formation than to watch for meteorites.
I've tried this kind of searching before with the Denver Museum Meteorite Recovery Team. We hiked a short grass prairie in eastern Colorado looking for meteorites and wound up drifting and crisscrossing each other's paths. One member of the team tested our ability to pick out a meteorite from the field by tossing a Snickers bar in the middle of our search. The Snickers was never recovered.
Despite our difficulty with staying in formation, we managed to recover 32 meteorites. That brings our total up to 91 in just four days of searching. We finished Goodwin Nunatak today, and will begin packing up camp tomorrow for our traverse to MacAlpine Hills.
|Expedition chronicler, Andrew Caldwell.
Since 1976, the Antarctic Search for Meteorites program (ANSMET), funded by the Office of Polar Programs of the National Science Foundation, has recovered more than 10,000 specimens from meteorite stranding surfaces along the Transantarctic Mountains. Dr. Ralph Harvey and John Schutt are members of each field party, serving as ANSMET continues to be one of the few Antarctic research projects that invites graduate students and senior researchers from other institutions to participate in our field work on a volunteer basis--including the Teacher Experiencing Antarctica (TEA) program. As a multi-agency collaboration, the NSF supports field operations, NASA supports storage curation, distribution and notification of recovered samples, and the Smithsonian provides long term curation facilities for the collection and assist in sample characterization.
In this multi-part Ice Diary series, all commentary are atributed to Andy Caldwell unless otherwise noted, and reprinted by permission as part of his participation in the TEA program.
Related Web Pages
Ice Diary I: Shooting Stars on Ice
Ice Diary 2: Great Scott, A Ghost
Ice Diary 3: Cheer for Team Meteorite
Ice Diary 4: The Hunt Begins
Ice Diary 5: MacAlpine Hills or Bust
Ice Diary 6: Contacting The Mother Pod
Ice Diary 7: Summer Christmas
Ice Diary 8: Where No One Has Gone Before
Antarctic Search for Meteorites (ANSMET)
Planetary Materials Curation (NASA/JSC)
Mars Meteorite Compendium (NASA/JSC)
AMLAMP: Antarctic Meteorite Location and Mapping Program (database of where meteorites have been found)
National Science Foundation (NSF) Office of Polar Programs
McMurdo Long Term Ecological Research (LTER) project
Ice Cube of Exotic Microbes
Antarctic Microbes Colonize under Mars-like Conditions
Meteorite Repository (JSC) Rock Descriptions
NIPR Meteorite Collection (Japan)