[meteorite-list] Searching Antarctic Ice for Meteorites

From: LabNEMS <staff_at_meteoritecentral.com>
Date: Thu Apr 22 10:02:23 2004
Message-ID: <5.0.0.25.2.20020301083758.02259c10_at_popmail.xensei.com>

List:

National Geographic, February 2002

Very nice fold out map of Antarctica;
Sea Ice movement, Wind Flow, Sea Ice
Velocity, and the under-ice bedrock landscape.


National Geographic, March 2002

Natural Diamonds, localities, the harsh
Geo/Political nature of mining them. Revealing
article.


Russ K.



At 10:06 PM 02/28/2002 -0800, you wrote:


>http://www.psrd.hawaii.edu/Feb02/meteoriteSearch.html
>
>Searching Antarctic Ice for Meteorites
>Planetary Science Research Discoveries
>February 28, 2002
>
> --- Silver anniversary season:
> The vigorous life and times of
> the ANSMET team at Meteorite
> Hills resulted in a new set of
> 336 meteorites collected off the
> ice.
>
>Written by Linda M.V. Martel
>Hawaii Institute of Geophysics and Planetology
>
>For a twenty-fifth austral summer, the Antarctic Search for Meteorites
>(ANSMET) program sent a team of people from far-flung homes to the ice to
>search for meteorites. From Dec. 7, 2001 to Jan. 23, 2002 we camped at
>Meteorite Hills and traversed by snowmobiles to the surrounding ice fields
>where we searched, sometimes on foot, in systematic parallel sweeps. Led by
>Principal Investigator, Ralph Harvey of Case Western Reserve University
>(CWRU, Cleveland), the team members were: John Schutt (Co-I and mountaineer
>from Washington state), Jamie Pierce (Summit Expeditions mountaineer,
>Seattle), Nancy Chabot (ANSMET post-doc at CWRU), Cari Corrigan (CWRU),
>Matthew Genge (Natural History Museum, London), Duck Mittlefehldt (NASA
>Johnson Space Center, Houston), Juanita Ryan (NSF's Teachers Experience
>Antarctica program, San Jose), Maggie Taylor (NASA Jet Propulsion
>Laboratory, Pasadena) and me. Our efforts added 336 meteorites (from as
>small as 1-centimeter long to almost 30-centimeters long) to the world's
>collection of extraterrestrial bits and pieces. Whether these meteorites are
>collisional debris from asteroids or from high-energy impacts on the Moon or
>Mars awaits to be seen.
>
>Reference:
>
>U. S. Antarctic Search for Meteorites program.
>
> --------------------------------------------------
>
>Support
>
>ANSMET meteorites represent the materials making up the solar system. The
>unbiased and uncontaminated sampling of meteorites recovered from the
>Antarctic ice sheet provides researchers with "ground truth" about the
>materials and formation conditions of the solar nebula, asteroids, moons,
>and planets. Taking these rocks from space off the ice and into the
>laboratory is crucial to our quest to understand the history and composition
>of the solar system we live in. ANSMET makes annual expeditions to
>Antarctica to provide this much-needed continuous and readily available
>supply of extraterrestrial materials.
>
>ANSMET is funded through a partnership among the National Science
>Foundation, NASA, and the Smithsonian Institution. For the 2001-2002 season,
>ANSMET was one of twenty-six Antarctic activities supported by the Geology
>and Geophysics program of the Office of Polar Programs at the National
>Science Foundation. Our NSF program manager, Scott Borg, was in McMurdo when
>I arrived. Increased NASA funding this season, through program manager Joe
>Boyce, enabled our team to have ten members rather than the usual eight.
>
> --------------------------------------------------
>
>Logistics for a season in the sun
>
>After leaving home, our expedition team members converged in Christchurch,
>New Zealand home to the New Zealand, Italian, and U. S. Antractic programs.
>Officials at the Clothing Distribution Center briefed us on Extreme Cold
>Weather (ECW) clothing and issued about 40 pounds of it to each of us. We
>were outfitted with layers of long underwear, fleece shirt and pants, heavy
>wind pants, down-filled parka, double-insulated boots, goggles, neck
>warmers, hats, and more mittens and gloves than you could count.
>
>Flights south to McMurdo Station (77o 51' S, 166o 40' E) are handled by the
>U.S. Air National Guard or Royal New Zealand Air Force with LC130 Hercules
>cargo planes. The canvas-webbing seats, noise, and dark spaces of the plane
>were new experiences for me. It was all in stark contrast to the nearly
>blinding white snow and ice of the landing field at McMurdo.
>
>The season began with a planned staggered start allowing the two
>mountaineers, John Schutt and Jamie Pierce, to arrive first at McMurdo in
>mid-November. McMurdo is one of three U. S. year-round stations on the
>Antarctic continent. The other two stations are Amundsen-Scott South Pole
>and Palmer. All together, NSF's U. S. Antarctic Program (USAP) supported 800
>researchers in Antarctica this year participating in approximately 148
>different research projects. Over 2,000 civilian contract employees and U.S.
>military personnel supported these projects on the continent. It can't be
>over emphasized how crucial their support is for the transport and ultimate
>well being of each and every soul and piece of equipment out on the ice. Our
>team relied on the expertise of Steve Dunbar, Alana Jones, and Robbie Score
>from NSF's polar contractor, Raytheon Polar Services.
>
>In McMurdo, John Schutt and Jamie Pierce began the lengthy preparation,
>loading, and unloading of gear and supplies for the team's entire seven-week
>field season. Four meteorite collection kits, 1900 pounds of food, eight
>snowmobiles, over 5000 gallons of fuel, four Scott polar tents for
>dwellings, one old polar tent for the outhouse, one group tent, stoves, cook
>kits, sleep kits, radios, GPS units, a satellite phone, laptops, cameras,
>batteries, solar panels, wind turbine, sleds, maps, satellite images, ice
>chippers and axes, rock hammers, ropes, bungee cords, knee pads, bamboo
>poles, buckets, boxes and bags, survival gear, and personal gear comprised
>the necessities for five men and five women in the deep field of Antarctica.
>All the other team members except for me arrived in McMurdo on Nov. 30, 2001
>for training and preparations. They deployed to the remote field camp by
>Twin Otter airplane on Dec. 7. Jamie stayed longer in McMurdo in order to
>meet my arrival from Christchurch and prepare me for Meteorite Hills.
>
>Our tent camp at Meteorite Hills (79o 38' S, 155o 41' E) was organized for
>eight people at a time, so Jamie and I were geared up to swap places with
>Ralph Harvey and Juanita Ryan. The same Twin Otter plane that brought Jamie
>and me into camp on Dec. 21 also took out John Schutt and Duck Middlefehldt
>to the Finger Ridges ice fields about 55 kilometers away for a short
>reconnaissance mission. They returned to camp on Dec. 26, the same day that
>Ralph and Juanita left for home. This shifting of teammates allowed me to be
>in camp for 34 days. Six intrepid members, Cari Corrigan, Duck Middlefehldt,
>John Schutt, Maggie Taylor, Matt Genge, and Nancy Chabot, were in camp for
>the entire 48 days.
>
> --------------------------------------------------
>
>Special aspects of life on the polar plateau
>
>ANSMET camps are self-sufficient with equipment, gear, fuel, and food. Boxes
>of frozen food (meats, seafood, vegetables, fruit, cheese, rice, breads,
>chocolate bars, soups, etc.) sat outside each tent, some items needing only
>a quick thaw at the top of the stove-heated tent before cooking. A bucket of
>ice chips in each tent was not an option as thermoses and water bottles
>needed constant refilling. We required no permanent or semi-permanent
>structures, but two special tents added for the first time stand out in my
>mind: a group tent, which housed a laptop and Iridium satellite phone, and
>an outhouse tent. The Iridium's mobile phone system worked very well from
>our remote location. Voice and data from Meteorite Hills were relayed by one
>of 66 orbiting Iridium satellites to ground stations which then relayed to
>public telephone networks. In addition to the phone, we had the usual HF
>radios issued to remote field parties. The HF radios, which operate by
>bouncing high frequency signals off the ionosphere from transmitter to
>receiver, were affected more than once by solar flare activity during the
>field season. When the HF radios were inoperable, our communications with
>McMurdo were made with the satellite phone.
>
>The weather and snowmobiles seemed to dictate our every move. Bright and
>cloudless calm-wind days were interrupted by unprecedented high winds and
>overcast snowy days. Winds howled at 80 kilometers per hour and blasted up
>to 160 kilometers per hour for days at a time. I will never forget sitting
>in the tent with Nancy listening to the noisy pandemonium of those winds. We
>spent roughly 50 percent of the field season tent bound due to bad weather
>or in camp waiting for the arrival of a Twin Otter plane. And 50 percent of
>our snowmobiles (four of eight) became disabled during the last day of
>fieldwork after a season of repairs and replacements of bogie wheels, spark
>plugs, and skis.
>
> --------------------------------------------------
>
>Collection procedures
>
>During the systematic searches and sweeps we used only our eyes to scan the
>blue ice, sometimes with the aid of binoculars. Forming a line either on
>snowmobile or on foot we worked by moving in parallel transects spaced apart
>according to the terrain and concentration of meteorites. We searched back
>and forth for hours and hours with backs to the wind and faces in the wind
>to find dark objects on the ice. They turned out to be, more often than we
>liked, shadows or terrestrial rocks dumped by glaciers. The fun began when
>someone spotted a meteorite and waved his or her arms to signal the rest of
>the team to converge at the find. It had to be a big physical movement
>because we were usually too far away from each other astride noisy
>snowmobiles, buffeted by winds, to hear any voices.
>
>A snowmobile with a GPS receiver parked next to the meteorite to record
>about five minutes of location data and a collection bag was brought out. It
>held sterile Teflon bags, Teflon tape, stainless-steel tongs, number
>counter, and aluminum number tags. Each meteorite was given a unique field
>number that was logged in the notebook along with the rock's size and
>estimate of fusion crust and preliminary classification. Any outstanding
>characteristics of the meteorite or unusual collection details were also
>noted (for example, if the rock had an unusual color or was inadvertently
>touched.)
>
>Next came an official digital photograph of each meteorite with the counter
>held behind it showing the field number. Data logging during our field
>season was handled by John, Ralph, Nancy, and Jamie. We all used the sterile
>tongs to pick up the meteorites and placed them into sterile Teflon bags.
>Each bag was taped securely. A bamboo flag pole marked with the field number
>was positioned at each meteorite's location as a backup in case something
>went wrong before or during the transfer of GPS data to John's laptop back
>in camp. Workdays typically ran eight to nine hours long--painstaking work
>by motivated and persistent seekers with good senses of humor. On the best
>days, the team found 20 or more meteorites, but some days we only netted
>three or a half dozen. The finally tally of 336 meteorites came from ice
>fields around Meteorite Hills (326 specimens), Finger Ridges (6), from a
>science group at Mt. Crean (1), and from another group at Odell Glacier (3).
>
> --------------------------------------------------
>
>Clean, cold storage
>
>With superb clothing, shelter, gear, knowledgeable and experienced leaders,
>and dedicated teammates, it was almost easy for me to forget I was living in
>an extreme environment. We had ready access to calorie-packed food that was
>easy to prepare, we had email, and a phone! Then reality would hit: icy
>winds whipped up, the wind turbine roared, I had to go, I couldn't take a
>shower or it was time to drive the snowmobile over sastrugi--those dreaded
>wind-sculpted crusted snow dunes. There was no doubt I was out of my normal
>habitat. I was living in a windy freezer.
>
>It is this very environment that helps make Antarctica an ideal place to
>recover rocks from space. They are in clean, cold storage. Meteorites that
>have been falling on the surface through the millennia become buried in the
>ice moving slowly seaward. At mountains or subsurface obstructions, the
>forward movement of the ice is blocked. Old deep ice, laden with meteorites,
>is pushed up to the surface against the barriers. Dry (sometimes brutal)
>katabatic winds (winds blowing down the slopes) clear the surface of snow
>and aid sublimation and mechanical erosion which expose the meteorites on
>what we call stranding surfaces. The desert conditions of Antarctica help to
>preserve meteorites that would otherwise weather away under more humid
>settings. The blue and white background and relative lack of terrestrial
>sediments make it easier to spot dark meteorites on the stranding surfaces
>than in a forest or farmer's field.
>
>We made genuine efforts to keep every meteorite clean, by doing our best to
>collect them without touching them with hands, gloves or tools. We mostly
>towed the line, though there were a few mistakes, like the time I
>accidentally drove over one (which was duly noted in the notebook.) As for
>cold storage, the meteorites were collected frozen, stored and shipped
>frozen, and will finally be thawed under clean room conditions at the
>Antarctic Meteorite Curation labs at NASA's Johnson Space Center.
>
>The removal of rock specimens is strictly
>controlled by the Antarctic Treaty (signed by 44
>nations representing about two-thirds of the
>world's population) which says that specimens of
>any kind can only be removed for scientific
>research. The recovered ANSMET meteorites fall
>under this category and are the responsibility of
>the National Science Foundation. Under a
>three-agency agreement, NASA supports initial
>characterization, curation, and the distribution
>and notification of samples. The Smithsonian
>Institution assists in sample characterization
>and provides for long-term curation. Image
>courtesy of the National Science Foundation.
>
>After thawing, each meteorite will be examined, cracked open, and small
>pieces will be broken off for study as thin sections under a microscope.
> >From these initial characterizations, short descriptions will be written up
>and distributed in the bi-annual publication called the Antarctic Meteorite
>Newsletter. Descriptions of the 2001-2002 Meteorite Hills meteorites will
>begin appearing in the Newsletter in late summer 2002, with names beginning
>with MET01xxx. The worldwide distribution of these samples to interested
>researchers is guided by the Meteorite Working Group, a peer group of
>meteorite experts.
>
> --------------------------------------------------
>
>Post-season reflections
>
>Our collection of 336 meteorites is near the season average
>number of 350. According to ANSMET records, individual season
>totals have varied from 30 (in 1976-77) to more than 1000
>meteorites (in 1987-88, 1997-98, and 1999-2000). In all,
>roughly 11,000 Antarctic meteorites have been found by ANSMET
>teams during the past 25 years. The total reaches nearly 25,000
>when Japanese and European collections are included.
>
>The February 2002 Antarctic Meteorite Newsletter contains a
>brief description of our season written by Ralph Harvey. Of the
>336 meteorites collected from all sites this season, he reports
>from his notes that 308 are ordinary chondrites, 10 are
>achondrites, 11 are carbonaceous chondrites, 2 are irons, and 5
>are as yet unclassified. David Kring (University of Arizona)
>provides a nice on-line overview of meteorites and their
>properties.
>
>The launch of the ANSMET expedition website was a huge success
>thanks to webmaster Tim Harincar, creator of WebExpeditions.
>Our daily journal entries and photos from the field reached
>about 25,000 website visitors. Tim reports that one hundred and
>twenty-four subscribers received our journal updates via email.
>And that doesn't even count all the classrooms and offices full
>of people back home who we knew were asking, "How many did they
>find today?" Our communication links in the field were more
>than technological wonders, they were lifelines.
>
>Since returning to Honolulu, I am adding the Antarctic meteorites story to
>my usual education and public outreach activities. It is a vital
>responsibility of the scientific community to share the fascinating
>discoveries being made by planetary exploration and the research being done
>on extraterrestrial materials. Talking with students, teachers, and the
>public also lets me relive the experience of working with a group of
>wonderful people in an incredible place, one of Earth's last frontiers. I
>speak about the search and recovery of meteorites and the role these
>specimens play in shaping what we understand about the formation of our
>solar system. My stories are also about cool science careers, great
>teamwork, and how the most extraordinary dreams can come true for ordinary
>people. When the School of Ocean and Earth Science and Technology at the
>University of Hawaii has its Open House in April one thousand school kids
>will be on campus and will see our popular meteorite activities. I'll be
>there in a Scott tent mock-up with genuine Extreme Cold Weather clothes (on
>loan from Raytheon... nope, I won't be actually wearing them in this heat)
>ready to share the experience of searching for meteorites in Antarctica.
>Can't wait to see their wide eyes twinkle.
>
>
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Received on Fri 01 Mar 2002 08:57:40 AM PST