SCIENCE
ROUND-UP
Science season roundup By Jeff Inglis Sun staff
As summer returns to Antarctica, scientists and science support staff around the continent
gear up for the prime research season. On the U.S. research vessels Laurence M. Gould and
Nathaniel B. Palmer and at McMurdo, South Pole and Palmer stations, over 600 researchers
will work on over 130 separate science projects. Here are some of the highlights...:
ITASE
The International Trans-Antarctic Scientific Expedition will continue its journeys in East
Antarctica, looking at shallow ice cores, showing climatic data from the past 200 years or
so.
Most global climatic data shows general trends of warming and cooling through Earth's
history, according to Bernie Lettau, the NSF science representative at McMurdo Station.
But climate also includes smaller areas. Global fluctuation is punctuated by more
localized changes.
"There still have to be regional differences," Lettau said. ITASE will continue
to look at the actual data for the recent history of Antarctica.
The Crud
John Lyle is studying the McMurdo Crud, the illness that can strike McMurdo residents each
season. The viruses survive in the air as well as in the sewage outfall into McMurdo
Sound. They are not native to the area, and so they affect the water quality and the
wildlife around the station.
"What they're trying to do is see how our viruses influence the indigenous
populations," Score said.
Sea ice
John Dempsey of Clarkson University is studying the structure of sea ice, including how it
forms and how it breaks up. The group is based near the edge of the fast ice of McMurdo
Sound.
"They're cutting a floe out and they're going to start a crack and put weights on
either side," Score said.
Decoding ice cores
A team at South Pole Station is looking at how atmospheric particles end up in ice-core
sediments. Interpreting ice cores, Lettau said, requires an understanding of how the
layers form. The team, led by Doug Davis of the Georgia Institute of Technology, is
specifically targeting sulfur chemistry because of the significance of sulfur deposits in
ice.
"Sulfates in ice are a primary proxy for reconstructing the climatic history from the
core," Lettau said.
GLOBEC
The Southern Ocean Global Ocean Ecosystems Dynamics study group will spend their first
summer looking at krill as part of a summer-winter-summer set of cruises to look at the
basic element of the Antarctic food chain.
"It is intended to look at the health of these various niches in the ocean
ecosystem," Lettau said. "What do krill eat when they're under the ice in
winter? Are they happy there?"
Scott Base
Antarctica New Zealand are supporting several projects this summer season, including a
study of methods of preserving the historic huts on Hut Point, Cape Evans and Cape Royds.
Also this season, Scott Base will see a series of interviews designed to compare people's
expectations about Antarctica and their actual perceptions upon arrival, several
ecological and environmental studies and a study of Adélie penguin populations at capes
Crozier, Royds and Bird, which is one of several collaborative efforts between U.S. and
New Zealand scientists. The equipment used in the Cape Roberts drilling project, which was
stored on Cape Roberts over the winter, will be returned to Scott Base this season.
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ICEBERG
Bergs with minds of their own: Daring science mission targets giant slabs
of ice By Josh Landis Sun staff
A handful of giant icebergs are hanging out right around the corner from Ross Island. As
far as icebergs go, they haven't done a whole lot since breaking off the Ross Ice Shelf.
But a lot of people are keeping a close eye on them because of what they could teach us
about bergs and their interactions with the environment and for the impact they could have
on the entire U.S. Antarctic Program.
This summer, a team of researchers will fly by helicopter and attempt to tag two of them
with weather stations and GPS tracking devices. They're hoping the data they get will help
them decipher the slow dance of these and other super-sized icebergs.
It started with B-15.
B-15 was a tabular berg that broke off the ice shelf in March. It measured 180 miles long
and 25 miles wide more than twice the size of Delaware and was probably the largest
iceberg ever seen. The only other contender was spied in 1956, but its size could not be
confirmed.
"B-15 is simply the largest floating object we've ever witnessed," said Doug
MacAyeal, Professor of Geophysical Sciences at the University of Chicago and lead
investigator on the tagging mission. "It's like an aircraft carrier that could take
the entire air force. It's hard to imagine the size of it."
Instead of drifting north through the Ross Sea like most pieces that come off the shelf,
B-15 stayed close to home and eventually broke into several pieces, now called B-15A,
B-15B, etc.
Big bergs
ˇ Before it broke apart, B-15 was about the size of Jamaica and weighed an estimated 4
trillion tons.
ˇ If melted over all the arable land in the world, the water frozen in B-15 (now B-15A
and B-15B) would measure more than 6 inches.
ˇMost icebergs that calve off the Ross Ice Shelf are thought to be a thousand feet thick
or more, only 10 percent of which floats above the surface.
ˇA giant berg that broke off the Ross Ice Shelf in 1987 still survives after running
aground south of Australia.
MacAyeal's project will look at the different ways in which large and small bergs behave
and give clues as to how the continent would react to a warmer world.
"If we want to know how Antarctica will respond to climate warming, why not ride
along when a piece of Antarctica goes north to where it is naturally warmer," he
asked.
"This is nature's experimental opportunity to see how a chunk of ice responds to
changed environmental conditions."
The lumbering giants, named B-15A, -B, -C, and -D (see above picture), have meandered
along with a few other bergs near the edge of the ice shelf as currents, tides and winds
compete for control over their fate. Recently, B-15A collided with part of the shelf and
created a new iceberg, B-20.
Currents have had the biggest effect on their movement, according to Stan Jacobs, of
Columbia University's Lamont-Doherty Earth Observatory. He says the bergs are slowly
making their way north, but could be around for a long time.
"If they go aground on the continental shelf, they could last many years," said
Jacobs. It all depends on their course. "Once they get out into the circumpolar
current, most icebergs probably do not last more than a year."
There's one place nobody wants to see a large iceberg go: McMurdo Sound. One of the
smallest in the group, B-20, is within sight of the north side of Ross Island.
If B-20 (now named C-16A) -- or the larger B-15A -- ends up in the path of the icebreaker
and re-supply vessels, the impact on operations at McMurdo and South Pole stations would
be major. It would prevent the annual arrival of millions of gallons of heating, power and
airplane fuel, and millions of pounds of cargo.
"We'd have to make significant adjustments to our planned program activities,"
National Science Foundation representative Dave Bresnahan said.
Fortunately, the experts watching B-15A and nearby icebergs don't think there's much
chance of a worst-case scenario.
"The chances of B-20 (now named C-16A) or B-15A blocking the sound are getting
slimmer and slimmer," said MacAyeal. "Once the Ross Sea (is clear of winter
ice), everyone expects the icebergs to make more progress to the north."
When asked how concerned he was that one of the bergs might enter McMurdo's shipping
lanes, Jacobs simply replied, "Not very."
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OLDEST
LIVING CREATURE
Scientists Discover Oldest Living Creature By Patricia Reaney
LONDON (Reuters) - Scientists in the United States have revived a 250-million-year-old
bacteria that is believed to be the oldest living creature ever discovered.
The bacterium that lived millions of years before the dinosaurs was in a state of
suspended animation in an ancient salt crystal in an underground cavern near Carlsbad, New
Mexico.
``From a biological standpoint this is extremely significant because quite literally this
organism is the next best thing to having been there,'' Russell Vreeland, a microbiologist
at West Chester University in Pennsylvania, said in a telephone interview.
Hundred-million-year-old fossils and rocks give geologists clues about the Earth's past
but until now researchers have not had anything to reveal the secrets of life that long
ago.
``Now we have at least one organism that goes back that far that we can ask biological
questions of...something that we couldn't do before,'' Vreeland added.
Protective Shell Saved It From The Elements
The fact that Vreeland and his colleagues were able to bring the sleeping bacterium,
called Bacillus permians, back to life after so long opens up the possibility that
bacterial spores could live indefinitely.
``If something can survive 250 million years, what's the difference in another 250 or
longer,'' Vreeland said.
The bacterium was trapped in a tiny brine pocket in the salt from ancient rock formations.
``It was completely protected,'' said Vreeland, whose research is published in the science
journal Nature.
``It was able to shut itself down into a protective spore and once it was encased within
this particular type of rock it found itself in the most stable environment that you could
imagine.''
The scientists carefully drilled into the crystal under the most sterile conditions,
extracted fluid from it, placed the fluid in sealed test tubes and incubated it until it
grew.
The extraordinary age of the bacterium also begs the question of whether organisms can
survive long enough to travel between planets.
``If an organism were encased in a crystal and blown off a planet somewhere, or blown off
of this one due to a meteor collision, it has a reasonable probability of surviving long
enough to travel not just from planet to planet but solar system to solar system,''
Vreeland said.
The scientists are comparing the bacterium to its modern relatives and are now looking for
even older organisms.
``We are already starting to look at some 500-million-year-old and 800-million-year-old
samples and we're working on some that are even older than that,'' Vreeland added.
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RIVER ONYX
Going with the flow; By Josh Landis; The Antarctic Sun
Standing on the bank of the biggest river in Antarctica, the other side
looks little more than a running jump away. It's tempting to try to make the leap, but the
water is too cold for a slip in the stream, and nearby rocks serve as convenient
stepping-stones.
Doctoral student and researcher Mike Gooseff, however, is up to his
boot-covered ankles in the icy Onyx River. He balances a long, shiny metallic instrument
on the streambed and calls out numbers to fellow researcher Ethan Chatfield, who's perched
by the water's edge recording the data in a notebook. The instrument, which looks like a
golf club, measures the depth and velocity of the water at intervals across the stream.
When all the numbers are crunched, the stream's volume and flow will be determined.
"Listen to that raging," exclaimed Gooseff upon hearing the
river at its strongest, swiftest part. The sound of gurgling and rushing is strange for a
place where water is most often locked in place by the cold.
Gooseff and Chatfield, along with hydrologist Jon Mason, are the Stream
Team, and it's their job to monitor 18 gauges set up at numerous streams in the Dry
Valleys. Their work is part of the National Science Foundation's Long Term Ecological
Research Network. The goal of LTER is to chart ecological changes over long periods of
time and across many different environments. Eventually, it is hoped, the information will
provide a better picture of how the earth is changing.
At first glance, calling a contemporary research project "long term" in a place
where rain hasn't fallen in as many as two million years may seem oxymoronic. But the Onyx
and other Dry Valley streams are the faintest, most finicky tendrils of enormous bodies of
water flowing frozen out of the mountains. The slightest change in their behavior should,
theoretically, magnify a less detectable shift in the Earth's overall environment.
It's an idea the NSF believes in. Since 1980, 21 LTER sites have been established from the
Arctic to the Antarctic. Each one encompasses a unique ecosystem. The Dry Valleys, which
joined the network in 1993, constitute polar desert oases. Work there is focused on
microbial life, lakes, and streams. The LTER site near Palmer Station, on the other hand,
looks at polar marine life, including krill and seabirds.
The Onyx River is a unique body of water situated in a rare valley on an incomparable
continent. Its drainage pattern is the opposite of any surrounding areas. The river runs
only during the warmest months. The rest of the year it is frozen solid. And it runs into
the middle of Wright Valley, pooling at a place called Lake Vanda. The flow of the Onyx
into the dead-end Vanda is countered by the constant winds that sweep the valley,
evaporating the water and ablating the ice.
"It's been a good season," said Gooseff. "It's a little disappointing that
we have four streams that haven't flowed (much), but other than that things are going
well."
In addition to his Stream Team duties, Gooseff is exploring other aspects of the
environment. He's concentrating on the saturated areas around the flow, called hyporeic
zones. It's an area where a lot of chemistry and biology take place, but little is known
about it.
"I want to know how the water that moves in and out of the stream is influenced by
the sediments," said Gooseff. "Coupled with that is nutrient dynamics, like what
kind of transformations do you see?"
A transformation of a different kind that's being seen more and more is the increased
presence of humans in the timeless terrain. Indeed, things change more slowly in the Dry
Valleys than most anywhere on earth.
Ancient, mummified seal carcasses are still covered with skin and fur. Drainage patterns
from ice that melted hundreds or thousands of years ago furrow the ground. And footsteps
in the loose, fluffy moraine mark the place where people have been whether it was
yesterday or decades ago.
The same fragility that makes the Dry Valleys an ideal place to chart global change also
makes them extremely susceptible to those who tread there.
Like Gooseff, Chatfield is working on another project of his own. He's looking at the
re-growth rate of algae in and around the streams, as part of the assessment of human
impact in the area.
"If algae were destroyed by walking," he asks, "how long would it take to
grow back?"
It's a question that so far has no definitive answer. It's also one that needs to be
answered, for the number of people in the valleys tourists and scientists alike is on the
rise. |
DIFFERENT
COUNTRIES IN ANTARCTICA
A frozen melting pot: The world comes together in Antarctica
Compiled by Jeff Inglis
Antarctica is the second-smallest continent, home to over 100 research stations run by 29
countries. Here is a brief look at the activities of the other nations conducting research
in Antarctica.
Argentina is operating 12 stations, six year-round, and six summer-only. Its
program began in 1904, when a remote weather station was installed on Laurie Island in the
South Orkneys. Argentina participates in a number of cooperative efforts with Antarctic
Treaty members and consultative parties, including U.S. institutions. (Website:
http://www.dna.gov.ar/)
Australia has four major bases in Antarctica. The Australian program started in
1947, with the first Australian National Antarctic Research Expedition. The program
involves about 400 people each year, including 250 researchers. Wintering teams number 15
to 20 per station. Annual budget: $46 million (Website: http://www.antdiv.gov.au/)
Belgium is not currently operating any permanent stations or bases. The country
is a founding member of the Antarctic Treaty. Its scientific research program began in
1985, and has consisted of a series of three-year studies by university-based scientists.
(Website: http://www.belspo.be/antar)
Brazil operates one research station, Ferraz, on King George Island.(Website:
http://www.mar.br/~secirm/proantar.htm)
Bulgaria operates one research station, St. Kliment Ochridski, on Livingston
Island.
The first Bulgarian to visit the Antarctic went with the 13th Soviet Antarctic Expedition
in 1967-1969. Since then, several scientists have traveled to Antarctica with the British,
Soviet and Spanish programs. An ice-core drilling project is in development, as are
improvements to the base infrastructure.
Canada is not operating any bases. In 1993 the Canadian Antarctic Research
Program began to expand Canadian polar studies to the southern hemisphere. Canada
publishes a newsletter on Antarctic research and maintains a database of individuals and
organizations interested in Canadian Antarctic work.
One goal of the Canadian program is to exchange foreign access to Canadian research sites
in the Arctic for Canadian access to other countries' sites in Antarctica. (Website:
http://www.polarcom.gc.ca/)
Chile has 10 stations in Antarctica, four permanent and six summer-only. Chile
participated in the International Geophysical Year (1957-1958), but sent its first
expedition to the Antarctic in 1916. (Website: http://www.inach.cl/)
China runs two stations in the Antarctic. In January 1980 the first Chinese
scientists traveled to Antarctica to visit Australia's Casey Station. In February 1985 the
first Chinese station, Great Wall Station, was established on King George Island in the
South Shetlands. In winter, the two Chinese stations house 35 to 45 people combined, and
up to 100 during the summer.
Ecuador, though a member of COMNAP, is not currently operating any permanent
stations or bases.
Finland runs one summer-only station, Aboa in Queen Maud Land. At the site is a
year-round automated weather station. Finland's first large expedition was in 1989,
involving scientists at Aboa and on the Aranda. Finland often cooperates with Norway and
Sweden, as well as conducting long-term ozone research with Argentina. (Website:
http://www.fimr.fi/)
France has four stations, including its shared station with Italy at Dome C.
Researchers winter at two of the stations, Dumont d'Urville and Charcot in Adelie Land.
Dumont d'Urville's population varies from about 26 in the winter to 80 in the summer.
Annual budget: $9 million, plus $15 million for administration. (Website:
http://www.ifremer.fr/ifrtp/)
Germany operates two stations. Neumayer Station has a winter population of 9 or
10, and a summer contingent of about 60. A cleanup of former East German Antarctic
research stations is underway as part of the program's environmental monitoring effort.
(Website: http://www.awi-bremerhaven.de/)
India has one Antarctic research station, Maitri, in Queen Maud Land. In 1981
the first Indian Antarctic Expedition began the program. It joined the Antarctic Treaty
consultative nations in September 1983, just after the first Indians wintered on the
Prince Astrid Ice Shelf.
Italy operates two stations, including its joint station with France,
Concordia, at Dome C. It signed the Antarctic Treaty in 1981, and began Antarctic research
in 1985. The main station at present, Terra Nova Bay station, can hold 70 people.
Cooperation in logistics and science between Italy, the U.S., and New Zealand has
increased significantly. Annual budget: $35 million (Website: http://www.pnra.it/)
Japan operates four stations in Antarctica. Its first expedition was on board
the Soya in 1956. Research programs have been done every year since then. Annual budget:
$35 million (Website: http://www.nipr.ac.jp/)
Korea has one station, King Sejong, operating year-round on King George Island.
Korea has been conducting Antarctic research since 1987. King Sejong's population numbers
about 15 in the winter and up to 60 in the summer. (Website: http://www.kordi.re.kr)
Netherlands is not currently operating any stations or bases. One of the major
research policies is not constructing new research facilities, but instead using the
infrastructure of other nations in collaborative efforts. Sailors from the Dutch East
India Company sighted several sub-Antarctic islands in the 16th century. The Netherlands
has been engaged in scientific researching since the mid-1960s, when three expeditions
were developed in collaboration with Belgium. In 1990-1991, the Netherlands rented half of
the Polish Arctowski Station, rather than build their own facilities. Projects involve
collaboration with German, U.K., Australian, and New Zealand researchers, among other
nations. Annual budget: $1.8 million (Website:
http://www.nwo.nl/english/alw/programmes/antarctica)
New Zealand runs one base, Scott Base, on Ross Island, which has been occupied
since the International Geophysical Year. Scott Base has a peak summer population of 86,
which drops to 10 in the winter. The program uses Arrival Heights for some research, as
well as maintaining eight research and emergency shelters in the Ross Sea and the Dry
Valleys. Christchurch, New Zealand, is a major gateway to the Antarctic, where the U.S.,
New Zealand, and Italian research programs have offices. The New Zealand program also
supports the Antarctic Heritage Trust, which protects and maintains the historic huts and
sites of the Ross Sea area. New Zealand is heavily involved in collaborations, partnering
in the six-nation Cape Roberts Project, as well as other projects with the United States,
Italy, France, Chile, Sweden, Switzerland, South Africa, China and Australia. Annual
budget: $8 million (Website: http://www.antarcticanz.govt.nz/)
Norway runs two stations, both in Queen Maud Land. Norway participates with
Sweden and Finland in shared responsibility for Antarctic expeditions. 1996 annual budget:
$6 million (Website: http://www.npolar.no/)
Peru operates one station, Macchu Picchu, in the region of the Antarctic
Peninsula.
Poland has one station, Arctowski, on King George Island. In 1976 Poland began
research in the Antarctic with five marine expeditions to the South Shetlands. The
Arctowski station opened in 1977 and has operated continuously since then. The base houses
70 people in summer and 20 in winter. Collaborative projects join twelve Polish institutes
and universities, as well as institutions in Belgium, Brazil, Germany, and the
Netherlands.
Russia runs eight stations, three summer-only and five year-round, including
Vostok, on the polar plateau. In 1956 the Soviet Union began research in Antarctica. The
research was run primarily in institutes based in what became the Russian Republic. Russia
succeeded the U.S.S.R. in the Antarctic Treaty system. The year-round stations together
house 144 year-round personnel, while the summer season sees an increase of 162 people.
The country has economic difficulties which has made Antarctic research difficult to
maintain. International collaboration has been part of the process by which Russia has
maintained a high level of research while cutting costs significantly. 1995 annual budget:
$10.5 million
South Africa operates two stations, the larger of which is SANAE IV in Queen
Maud Land. There is also a year-round weather station on Gough Island. South African
Antarctic research began in the International Geophysical Year. South Africa was an
original signatory of the Antarctic Treaty. Annual budget: $500,000 (Website:
http://home.intekom.com/sanae/)
Spain has two stations, both in the South Shetland Islands. It also has an
ice-strengthened vessel, the Hesperides. All three operate only in the summer; the
stations can house 12 people each, while the ship can host 30 scientists, plus the crew.
Annual budget: $6 million
Sweden has two stations, both in Queen Maud Land. Sweden has long been involved
in Arctic research. In the 1980s it extended its research to the Antarctic. Sweden,
Finland and Norway have an agreement to share expedition costs and research benefits.
Collaborative efforts are also under way with the British, the U.S., and other European
Antarctic research organizations. (Website: http://www.polar.kva.se/)
Ukraine operates one research station, Vernadsky, on the Antarctic Peninsula.
United Kingdom has four stations in Antarctica. U.K. scientists have been
active in Antarctic research for over 75 years. The British Antarctic Survey has been the
primary Antarctic planning and coordination organization for the past 56 years. About 40
staff spend the winter at the four stations combined. In the summer, field parties deploy
primarily from Rothera, the largest base, which can house 120. The program has 180
scientists among its 420-person staff. Recently research collaboration has increased,
especially with Germany. Annual budget: $42 million (Website:
http://www.antarctica.ac.uk/)
United States operates three year-round stations, a number of smaller field
camps on a summer-only basis, and unattended year-round observatories. 1995 annual budget:
$197 million (Website: http://www.nsf.gov/od/opp/arctic/iarpc/start.htmstart.htm)
Uruguay has one station on the continent, Artigas, on King George Island. In
1776 the country first issued licenses for fishing in the southern seas. The first
Antarctic research began in 1975, with the first expedition to the continent in 1984. This
information is condensed from material located at www.comnap.aq, the website of the
Council of Managers of National Antarctic Programs. |
ANTARCTIC COD
Fishing for antifreeze By Aaron Spitzer The Antarctic Sun
Inside a small orange hut on the frozen surface of McMurdo Sound, a group of researchers
huddled near the rim of a gaping hole in the 10-foot-thick ice. As a gas-powered winch
reeled in a thin steel cable, the form of a giant fish appeared from the aquamarine
depths.
"This may be the largest one we've caught this year," said Kevin Hoefling,
peering down through the icy water. He slowed the winch and the group leaned in closer. A
betting pool quickly placed the creature's weight at around that of an average-sized man.
In a few seconds the seawater sloshed and the fish's head appeared enormous and
prehistoric, with protruding eyes and powerful jaws lined with inward-angled teeth. Its
massive, muscular body was wrapped in a whitish-gray skin of scales. Its fins folded and
unfolded like translucent Japanese fans.
The creature was Dissostichus mawsoni, known colloquially as the giant Antarctic cod.
A few moments after breaking the surface, the mawsoni was wrestled off the hook and laid
out and measured on a long wooden tray. Dripping with icy-cold seawater, the fish was then
hoisted onto a nearby scale.
It turned out to be smaller than expected. At 110 pounds it was hardly a record. In past
years, researchers in McMurdo Sound have reeled in cod topping twice that weight.
But the mawsoni was still the largest of the five that was caught that day. The other
slimmer versions of this motley monster were all released back into the ice hole, where,
after taking a moment to get their bearings, they quickly swam down and away.
Antarctic cod and many of their smaller cousins are the subjects of ongoing research by
the husband-and-wife team of Art DeVries and Chris Cheng-DeVries, both scientists at the
University of Illinois.
Art DeVries, a McMurdo institution himself, has been traveling to the Ice for more than
three decades, examining the mechanism by which Antarctic fish avoid freezing.
Swimming in a sea that is below 32 F, the cold-blooded creatures run the constant risk of
ice crystals forming in their blood. Once a single crystal enters, others can nucleate
around it, precipitating a potentially deadly chain reaction.
While subsurface seawater stays liquid due to its high salt content, fluids in fish don't
share the same advantage. What they do have, as Art DeVries discovered years ago, is
antifreeze.
Fish antifreeze isn't like the antifreeze in your car, explained Cheng-DeVries. It doesn't
lower the actual freezing point of the fish's blood. Instead, she said, "it inhibits
the preferred direction of growth of the ice crystals."
Ice crystals, she explained, are laid out like flat hexagons. They expand when other
hexagons interlock on their six exposed sides, forming a pattern like that on a soccer
ball.
But in the super cooled waters of the Antarctic, fish in the family notothenioid which
includes the giant mawsoni generate a substance called antifreeze glyco protein, or AFGP.
AFGP circulates in their blood and beats any ice crystals to the punch, surrounding them,
binding to their sides and thus arresting crystal growth.
This discovery has taken the DeVries' research in a range of different directions.
According to Cheng-DeVries, they're still studying how AFGP binds to ice, an odd act in
the molecular world. "Most proteins interact with other proteins," she said.
"These guys interact with ice."
In a completely different vein, the researchers are also conducting genetic studies of
AFGP to help determine when Antarctica began the dramatic cooling trend that converted it
from a mild environment to the ice continent of today.
According to Cheng-DeVries, notothenioids evolved AFGP as a response to that climatic
shift, while non-adaptive species died out. By calculating when AFGP arose, the timing of
the continental cold snap can be better determined.
A third avenue of inquiry involves the formation of AFGP in embryos. Because the fish
spawn and fertilize their eggs externally, the eggs must develop antifreeze early on, to
protect them from their frigid surroundings.
According to Cheng-DeVries, that mystery will likely bring the research team back to
McMurdo Sound during Winfly next season, so they can follow the fish eggs throughout their
developmental cycle.
As for the 110 pound mawsoni hauled in on the winch, it has come to the end of its cycle.
Giving its life to science, it goes into a long trough called the "fish coffin,"
in which it is transported from the fishing hut back to the old aquarium at the edge of
McMurdo Sound.
There, it is dissected and its blood syringed into a collection of vials. Its eyeballs,
kidneys, liver and spleen are extracted and preserved in liquid nitrogen to await
analysis. And finally, of course, from its muscular sides are carved giant white fillets,
which go to the galley for dinner. |
ADELIES
Of ice and Adelies By David Ainley Special to the Sun
Earlier this year, using annual counts of breeding pairs of Adelie penguins at capes Bird,
Crozier and Royds, plus satellite imagery of the sea ice from 1973 to 1997, we discovered
that the ice extent during winter in the Ross Sea has a major effect on Adelie penguin
colony growth.
We found that a lot of ice that extends far north from the continent during winter leads
to colony decline; but minimal ice extent leads to colony growth.
Adelie penguins that breed at sites on Ross Island spend winter near the pack-ice edge,
wherever it may lie. There, daylight is sufficient for them to see and the ice pack is
open enough to permit access to the ocean. We believe extensive ice may force the penguins
to winter well beyond food-rich waters. In such conditions, young, inexperienced penguins
apparently starve and, subsequently, their numbers are lost to the breeding population.
These findings explain about 30 percent of the annual variation in population size at
capes Bird, Crozier and Royds. Thus, other factors are important, too. A major one, we
believe, is "local" ice conditions in November when the penguins are arriving to
breed, having trekked hundreds of kilometers from the pack-ice edge where they spent the
winter.
What likely affects the ease of this journey is how large the Ross Sea polynya has been.
The polynya is the area of open water that extends north from Ross Island during the
spring, depending on how strongly the katabatic winds have been blowing. If the winds have
been strong and persistent, open water is extensive and the penguins can swim much of
their journey, at about 7-8 kilometers per hour. If they have to walk over the pack ice,
at 1-2 kilometers per hour, it takes them much longer. The longer trip uses up more of
their precious fat stores.
What does this mean? Basically, it means sea ice conditions are critical to the well-being
of Adelie penguins. Indeed, Adelies don't occur where there's no sea ice, but neither do
they occur where sea ice (especially fast ice, as in southern McMurdo Sound) persists for
most of the summer. Ultimately, sea-ice conditions on a local scale may explain why there
are 300,000 breeding penguins at Cape Crozierclosest to the polynyaand only 4,000 at Cape
Royds, farthest from the polynya. In
between are colonies at Cape Bird and Beaufort Island, with about 80,000 breeding penguins
each. But why has the colony at Royds increased in size 300 percent since the 1960s; that
at Bird about 150 percent; and that at Crozier only slightly, if at all? Why has the large
colony, seemingly, fallen out of favor?
To answer these questions, we are comparing the "quality of life" of penguins in
a "big city" (Crozier) and a "small town" (Royds). We're interested in
gathering data both in summers with little sea ice (as in 1996-97 and 1997-98) and with a
lot (as in last season and this one). We've developed a computerized scale that, before
weighing a penguin as it walks across, identifies it by reading a bar code each penguin in
our study-group wears. The penguin's identity and weight are recorded
before it feeds its chicks, then after. The difference in weight is the amount of food
delivered; the identity also tells us how often the chick was fed.
We also attach tiny radios to about 15 birds at each colony and then, using triangulation,
determine how far from the colonies the birds are feeding (as a function of sea-ice
conditions, of course). And, to another sample, we are attaching little computers that
tell us how much of foraging trips are spent traveling versus diving (and the depth to
which they dive, and how often). We also measure nesting success (number of chicks fledged
per breeding pair) and the growth of chicks (how fat they get before heading off to sea on
their own).
To gauge the effect of winter ice conditions, we band a sample of adults and chicks each
season and then look for their returns the next. The proportion that return tells us the
extent of over-winter mortality (and the satellite images tell us where the ice edge has
been and where the penguins likely have wintered).
Where is all this leading? Basically, we believe that with warmer air temperatures, which
have been documented around Ross Island over the past several decades, the patterns of sea
ice have been changing in the Ross Sea. The ice may be less compacted and less extensive
now than it was in the 1950s and 1960s. From what we observe, we can predict where the
Ross Sea Adelie penguin colonies are headed, growth-wise.
David Ainley, of H.T. Harvey & Associates, is the principal investigator of the
project entitled "Factors regulating population size and colony distribution of
Adelie penguins in the Ross Sea." |
WASTE IN
ANTARCTICA
Wasting away in Antarctica By Josh Landis Sun staff
There's a paradox of human habitation in Antarctica: The continent that has the most
brutal and forbidding environment on the planet also has one of the most fragile
ecosystems. A footstep will remain visible in the Dry Valleys for decades. A seal
population can be thrown off-kilter by the introduction of a simple, yet foreign,
microorganism.
And the refuse of a human population that's very small by U.S. standards can mar this
beautiful land for centuries.
The evolution of waste management on Ross Island has gone from no concern for the
environment in the early days of the explorers to U.S. Antarctic Program standards that
are approaching zero-impact. Days of open-pit burning and open-water dumping are long
gone. They've been replaced by a system that returns nearly four million pounds of waste
to the States each year.
And much of it gets recycled.
For example: 3.9 million pounds of waste went north last year. 651,000 of it was wood;
650,000 pounds was construction debris; 494,000 pounds was food waste (400 pound average
per person based on 1200 people!)
58% of all waste got recycled
Wednesday is America Recycles Day, but for Tom Vinson, manager of waste operations, it
will be business as usual.
"Antarctica recycles every day," he said. "It's the best option we
have."
Recycling starts at the garbage cans, as anyone who's been to McMurdo knows. Categories
range from burnables to bio-waste, clothing to construction debris. There are 19 different
varieties of solid waste here, and 18 categories of hazardous waste.
The most-recycled item by weight is heavy metal, adding up to 341,000 pounds last year.
Light metal and paper products come next.
The National Science Foundation's commitment to recycle materials such as solvents, paper
and aluminum sometimes costs more than regular disposal.
"They're commodities, and the price we get depends on what the market's paying,"
Vinson said. "It's more of an environmental decision."
Technically, recycling doesn't occur here, but the sorting ensures that once the refuse
returns to the States the process is easily handled.
Some methods of reusing waste, however, do take place at a local level. For example,
furnaces that burn waste oil and fuel to create heat account for the disposal of almost a
third of the hazardous waste stream - 341,000 pounds last season. The furnaces also
conserve new fuel that would otherwise have to be used for the same purpose.
Not all burning efforts have been successful.
In the early 1990s the NSF built a multi-million dollar incinerator to dispose of some of
its solid waste at McMurdo Station. Believing Antarctica did not fall under federal
regulations that would cover such a facility in the U.S., the foundation didn't prepare an
environmental impact statement for the project. After losing a court battle with
environmental groups, the NSF decided to abandon the incinerator approach and ship the
waste home.
It was an event that probably increased the program's recycling rate. Now waste such as
paper and cardboard that might have been burned gets turned into post-consumer products.
As the largest presence on the continent, the U.S.'s evolving approach to waste is
becoming a standard for other programs.
"Other nations are starting to look to us for guidance with their plans," said
Vinson.
The simplest Antarctic recycling method can't be beat. It's the "skua" system.
No transport, processing, manufacturing or distribution is involved. Everything from
clothing to chairs to televisions to teapots can be reused without having to go anywhere.
And the only hazard involved is looking out-of-style. |
WOMEN IN
ANTARCTICA
Women's movement, Antarctica style; World-class expeditioner makes it to
McMurdo By Beth Minneci Sun staff
It's been eight years since Anne Dal Vera made history as part of the first group of women
to ski from Antarctica's edge to the South Pole.
The monumental, 678-mile journey, however, was only a piece of their original plan to
cross the continent.
But after 67 days of skiing, upon reaching the Pole, the four women were weeks behind
schedule and one was injured and ill. They decided to stop.
"It was sad," Dal Vera said. "We had mixed feelings because we were very
excited to get to the Pole, and that was a significant accomplishment. And yet, that
wasn't the dream that we had, so we hadn't done what we set out to do."
Today, Dal Vera, 47, is in her fifth year with the U.S. Antarctic Program. She'll be here
in February to greet former teammate Ann Bancroft, who is expected to start across
Antarctica this summer, and hopefully complete the task she didn't finish in 1992.
The trip this year is especially exciting to Dal Vera and Bancroft because Bancroft
spearheaded the earlier effort and was most dissapointed by the decision not to continue.
"I think it was hardest for Ann to let go of the dream,'' Dal Vera said.
Dal Vera and Bancroft met through mutual friends in the mid-1980s. Bancroft was already a
polar pioneer, having been the first woman to reach the North Pole over land, in 1986.
The other two teammates were mountaineer Sue Giller and Sunniva Sorby, who came aboard
only six months before the Antarctic adventure, which was dubbed the American Women's
Antarctic Expedition.
One of the largest hurdles before the trip was coming up with $1 million for
transportation to and from the continent. The money was also for supplies and rescue staff
in Antarctica and at training runs in Yellowstone National Park, Canada and Greenland.
When the women approached corporations for sponsorship, company after company turned them
down."I think that's because there had not been an all-women's expedition that was
successful before us," Dal Vera said. "Corporations were skeptical whether we
could do it. We planned on making history."
Incrementally, however, donations and profits from T-shirt sales, garage sales, small
concerts and golf tournaments added up to more than half their expenses. The rest they
paid for years after the trip.
"It was an extraordinary experience to have all these people give what they
could," she said. "Some would send us a letter with a $5 bill and say,
"This is all I can give you, but I'm excited and wanted to help.'"
From St. Paul the women flew on an airplane to Punta Arenas, Chile, then to the Ronne Ice
Shelf.
On Nov. 9, 1992, they shoved off the ice edge, each pulling 185-pound sleds toward the
Pole.
In the next two months they faced 50-mph winds, put up with subzero temperatures,
confronted frostbite, heat exhaustion and weight loss.
Moreover, they dealt with each other. On the Antarctic plateau there were no distractions,
Dal Vera said. "So that means every single thing one person did was noticed or had an
impact on the rest of us. It was probably the most intense situation I've ever been
in."
On Jan. 13, while approaching the Pole, the women calculated the miles left to McMurdo
Station 882. At McMurdo, a private ship was scheduled to take them home on Feb. 15. They
didn't have enough time to get there on skis, they concluded.
"It was a tough call," she said.
Hours after Dal Vera's group reached the South Pole, two men who were also attempting to
ski across the continent also arrived.
"They had lost about one-quarter of their body weight, and they looked very, very
gaunt. They had frostbite and scars on their cheeks and their feet were all
blistered."
Still, the men went on.
"Ann went out to watch them go. She just stood there for a long time and watched
them. You could tell that she really wanted to do it, but that wasn't the year to go.
Hopefully this year is."
Dal Vera is not interested in trying to cross the continent again. The cost of the first
trip was too burdensome. Upon returning to the United States, it was five years before the
group's $385,000 debt was paid.
But for Dal Vera, the Ice does have an affinity. In 1995 she started working with the
Antarctic Program at McMurdo as a general assistant, returning for the next five austral
summers. She has worked at the South Pole, and now works with waste management in McMurdo.
In the past she has taught cross-country skiing, worked with Outward Bound and as
wilderness guide. But now, she's happy to work and live here.
"I just had quite a strong bond with the land here and the ice, so I wanted to come
back," she said. "A lot of it has to do with the great people down here. They're
just adventurous souls." |
VOSTOK
Soaring below Vostok By Kristan Hutchison Sun staff
At first glance Lake Vostok is just flat and white, but Tom Richter had three weeks to
look at it more closely.
He spent four hours a day flying back and forth over the frozen lake. The best views
weren't out the window of the Twin Otter plane, but in data from instruments that
"see" through the ice sheet, measuring the depth and altitude of the ice,
gravitational attraction, and magnetism of the earth.
"You could just look and see there was something interesting going on," Richter
said. "There's rough, regular, rocky ground and then all of a sudden you could see
some flat lake surface."
Richter was at Vostok with the rest of the SOAR team, the Support Office for
Aerogeophysical Research, to gather data for scientists trying to better understand the
hidden lake, which is the size of Lake Ontario.
"Why the lake's there nobody knows and that's why we're there," Richter said.
"I don't know if we're going to be able to find out either."
Researcher Michael Studinger thinks he will find an answer in the 30 gigabytes of data
SOAR collected in 36 flights.
"It's the first detailed image of the lake itself," Studinger said. "We are
most interested in getting the geologic setting of the lake and also the depth of the
lake."
Every second the equipment recorded the gravitational attraction, six radar readings and
10 measures on the magnetometer. The altimeter gave the altitude of the ice to within 10
to 20 centimeters. Radar showed the terrain below the flat ice changed from rolling plains
on one side of the lake to mountains on the other. The lake itself appeared to be in a
basin, below two miles (three to four km.) of ice.
The findings will help scientists decide between two theories for the creation of the
lake. One scenario is that the lake was created by erosion. The second possibility, and
the one Studinger said preliminary data supports, is that changes in the earth's crust
formed the lake.
The evidence is a huge magnetic anomaly on the east coast of the lake's shoreline. As the
first SOAR flight crossed over to the lake's east side, the magnetometer dial swung
suddenly. The readings changed almost 1,000 nanotesla from the normal 60,000 nanoteslas
around Vostok. A tesla is the standard measure of magnetism. Studinger typically finds
anomalies of 500-to-600 nanotesla in places where volcanic material has poured out of the
ground.
"When we first saw this huge magnetic anomaly, that was very exciting,"
Studinger said.
Usually magnetic anomalies are much smaller and it takes some effort to distinguish the
anomaly from normal daily changes in the magnetic field. In this case there was no
confusion.
"This anomaly is so big that it can't be caused by a daily change in the magnetic
field," Studinger said.
The anomaly was big in another way, encompassing the entire Southeast corner of the lake,
about (65 b 46 miles) 105 km by 75 km. The size and extremity of the magnetic anomaly
indicated the geological structure changes beneath the lake, and Studinger guessed it
might be a region where the earth's crust is thinner.
To create the type of topography found at Lake Vostok, the earth's crust was probably
stretched, thinning one to three percent as it pulled taut, Studinger said.
While the SOAR team flew, charting the lake from above, Studinger set up seismic stations
to study the lake through the ground. He'll learn more about the crustal structure under
the lake from the way seismic waves travel from earthquakes around the world travel
through the lake. In 22 days the sensors recorded eight earthquakes, including a 6.9
magnitude quake near Kodiak, Alaska.
Researchers are also interested in the interaction between the ice sheet and the water
beneath. The ice sheet moves over the lake at about four meters a year. As it moves, it
scrapes the ground and carries particles into the lake.
"That's a way to get nutrients into the lake, which would be important for the
ecosystem," Studinger said.
Insulated beneath the ice, the water is warmed by the earth itself. The warm water at the
bottom of the lake then rises and melts the bottom of the ice sheet in places, so small
currents circulate through the lake.
"What we observe is there are regions where there's melting going on and regions
where there's refreezing," Studinger said.
But all these observations are done through the ice. Nobody has actually sampled the lake
water itself yet, though Russian scientists have drilled to within a few hundred feet.
SOAR was really just scouting out the area for that next step, touching the water itself.
Studinger and his colleagues at Lamont-Doherty Earth Observatory of Columbia University
will spend the next two years analyzing the data SOAR collected and writing up the
results. Once fully analyzed, the data will show where the sediments are in the lake
bottom, how thick they are and where there are upwellings of water.
"One of the important things with this data is it will help to make a decision on a
drilling location," Studinger said. |
SKUA BARN
Skua (the verb) By Kristan Hutchison Sabbatini Special to the Sun
When Janet Huddleston wants a new pair of shoes, she checks the trash. That's where she
found the bright red boots she wears with jeans and a lavender shirt.
"Everything I'm wearing is skua, except my underwear and my jewelry," Huddleston
said. "I do have limits. Underwear only in the package."
Dumpster diving is a long tradition at McMurdo, going back before waste management set up
separate "skua" bins for items that can be reused. Along the way the practice
took on the name of the scavenging gull.
Here, there's none of the stigma associated with Dumpster diving in the United States.
Instead, people take pride in their ability to skua. Huddleston has a reputation as a skua
fairy.
"People will come up to me with a wish list," she said. "Within a week I'll
usually have it for them, because I'll be looking for it."
For herself, Huddleston mostly skuas clothes and stationary, though the dishes,
humidifier, shelf, hooks and chair cover in her room were all skua items. Four of her ten
pairs of shoes came from skua shopping, too.
At Skua Central, a 10 by 20 foot building where all the items are stored, a logbook
reports the treasures people have found: shirts, tablecloths, pillows, wrapping paper,
teddy bears, Christmas trees, spices, stereo speakers, maps, charts, bubble wrap.
"Last year it saved our lives," said Bess Ward, a scientist working in the Dry
Valley. Five people on her team forgot to bring towels, but found them at Skua Central.
"That was very, very useful to know about," Ward said.
General assistant Lynn Keating also skuaed some necessary equipment - a sturdy pair of
work boots.
"I've been looking 'cause the boots I brought were awful," Keating said. "I
kind of thought it was a hopeless effort. I couldn't believe it, but they were my
size."
Solid waste supervisor Bill Poulson has seen working televisions, stereo systems and
typewriters, but cheaper items are more common.
So are the seamy.
"Smut is very popular," Poulson said. "We put out probably 300 magazines at
Winfly."
Waste management staff convinced the National Science Foundation to set aside building 122
for a free exchange of used items in 1995, Poulson said. The staff painted it a bright
rainbow of purple, red, orange and yellow. Before that, waste management employees would
just hold on to stuff that seemed too good to throw away.
They still do; the best things never make it to Skua Central.
Having first dibs on castaways is definitely a perk of a janitor's job, said lead janitor
Dee Miller.
She finds items before they've even reached the trash, abandoned in empty rooms by people
who left the ice."The best that I've found was a triple down white comforter for my
bed, flannel sheets and a blow up air guitar," she said
For non-janitors, the secret to skua hunting is to know when and where to look, and then
to look often. Most of the best items are found at transition times, when seasonal workers
are leaving and others are arriving. People on their way out of McMurdo pile things they
don't want in the dorm halls. That's when Huddleston goes skua hunting every night,
wandering through the dorms. By the time stuff gets to Skua Central, it's been pretty
picked over, Huddleston said.
Jess Barr, another scavenging pro, agrees that the key is to go "straight to the
bins, because then nobody's gone through it yet. There's a whole chain of command on going
through skua."
For Barr, skua satisfies the urge to shop. At home she frequents second-hand clothing
boutiques. Last summer she depended on skua to add glamour to the utilitarian wardrobe
she'd packed.
"I just lived off it. I couldn't even go near that building without coming out with a
new wardrobe," said Barr, a field coordinator. "It's to fulfill the need for
acquiring goods."
Like Huddleston, Barr sometimes skuaed for others. When a friend needed running shoes, she
was able to bring him six pairs.
That's six pairs of shoes that might otherwise have been shipped to Washington, where the
rest of the trash is disposed. Huddleston gets satisfaction from saving items from a
wasteful demise. She even sends skuaed items home at the end of the season. Many people
put things back in skua for the next person, though, recycling the stuff yet one more
time. After traveling in third world countries and seeing how they reuse everything, even
turning soda cans into toys, Huddleston's
become more sensitive to the wastefulness of Americans and is even philosophical about her
pastime.
"People throw things away, but when you think about it there is no 'away'. It's got
to go somewhere," she said. |
WEDDELL SEAL
Beautiful and brutal The mysterious world of the Weddell seal By Josh
Landis Sun staff
Turk's Head is an eerie place. Even under the glare of a midday sun, the rocky outcrop on
Ross Island sounds haunted. The moans and bleats of Weddell seals echo off the stone
promontory as skuas hover menacingly overhead.Researcher Mike Cameron steps around a
lounging female and her pup, looking for brightly colored plastic tags attached to their
flippers. He's checking every seal in sight. He and his teammates will get the ones that
aren't tagged twice.
"Here's one," Cameron calls out to Shawn Dahle. The two of them approach the
animal, ready for a struggle.
"For an 800-pound carnivore, they're amazingly docile," he said.
But that doesn't mean they're non-resistant.
Tagging seals can be a difficult, smelly and even dangerous task. It involves one person
throwing a hood over the animal's head and jumping on its back to keep the hood in place
while another tags each of the rear flippers. Each seal responds differently to the
imposition. The more resistant ones can throw the scientists off several times before the
job is done.
But the exercise is essential to a body of work that dates back to the early 1960s. That's
when research on the population of Weddell seals in the McMurdo Sound area began. Animals
tagged then are still swimming these waters, teaching scientists more about these
mysterious mammals each year.
Nobody knows, for example, exactly how long the seals live or how many reproductive cycles
they can have. Some females that were tagged as pups in the early 1970s are still giving
birth and show no signs of slowing with age.
The violent turf battles that take place between males underwater are also largely a
mystery.
Researchers know the fights are brutal by the severity of scars and wounds they see on the
seals, but can only imagine what takes place out of sight.
"There's some conflict on the surface, but the vast majority takes place
underwater," said researcher Dan MacNulty. "The combat these males sustain is
really remarkable."
The outcome of fights like these determines the reproductive success of the Weddell males,
which is also something that is little-known. In more than 30 years of research, only one
picture has ever been taken of two Weddells breeding.
The research team at Big Razorback Island, working under veteran scientist Don Siniff, has
been trying to change that.Inside an orange, sunbathed shack next to the snow-covered
island, they monitor a television set connected to an underwater video camera. Kolene
Krysl, a member of the Teachers Experiencing Antarctica program and research assistant,
mans the camera with a small keyboard. She points it at a shaft of sunlight streaming
through an open crack in the ice. Seals swim out of the inky darkness, bob to the surface
and disappear out of view.
The camera is there to capture the underwater world most researchers rarely get to see,
with a focus."The idea is to study the interaction between males," said Dan
MacNulty. "These animals get beat to hell. They tear each other up. They're
vicious."
The camera is the only way to get a good view of the fights, and learn more about the
territorial ways of the Weddells.
"One of the big things we're looking at is male-to-male interaction as the big ones
come back to claim their territory," said Krysl.
Most large mammals, such as bears, usually presage their confrontations with bluffs, and
often avoid dangerous battle. Not the Weddells. The more researchers learn, the more they
realize how violent these animals are.
An estimated 80 percent of the 1,400 Weddells in the study area are part of a continuous
record. Each one's age, sex, location and date of birth is recorded. By tagging newborn
pups and recording which female they're with, researchers can follow the maternity line
back as many generations as are tagged.
"We can find a pup and tell you who it's great, great grandmother was," said
Cameron.
Establishing which males become fathers isn't so easy. Until recently, determining which
male sired which female was impossible, since the breeding takes place underwater and the
males aren't involved with the rearing of their offspring.Modern technology is changing
that. Now, all the adult males that turn up at Big Razorback Island are targeted for a new
monitoring project: DNA testing. By taking tissue samples from the males and comparing
them to tissue samples from pups,
scientists can determine which seals reproduce, and which ones get left out of the mating
game.
They already suspect a smaller number of males do a larger portion of the breeding.
"Most males don't get any females," said Cameron. He estimates the ones that do
get to reproduce could sire as many as seven offspring in one polygamous breeding season.
Also in the group's arsenal of scientific equipment are cameras and sensors that Katsufumi
Sato, a Japanese researcher working with the team, has been attaching to the backs of the
seals. The instruments record the depth and direction of the seals' dives as the cameras
take hundreds of pictures, looking for more information on the underwater habits of the
common, yet mysterious, Weddell seals. |
ROCKS ON THE
ICE
Searching the snows for space rocks; By Aaron Spitzer; The Antarctic Sun
With a glimmer of pride in his eye, researcher Ralph Harvey gently lifts the lid of a
wooden box, revealing a fist-sized, fractured black stone. Harvey found the rock earlier
this season in Antarctica, but it came from 200 million miles away.
The stone is a meteorite, which traveled to Earth from the vast asteroid belt between Mars
and Jupiter. And Harvey, a geology professor at Case Western Reserve University in
Cleveland, is a meteorite hunter.
Ever since he was a graduate student in 1987, Harvey has been coming south on what he
calls an "Easter egg hunt" for space rocks. Now he's the head of the project
dubbed ANSMET, the Antarctic Search for Meteorites.
According to Harvey, Antarctica is the best spot on Earth to search for meteorites. More
than 16,000 extraplanetary stones have been found here, including half of the Mars rocks
ever discovered on Earth.
It's not that more meteorites fall here than elsewhere. It's just that in Antarctica,
they're easier to find.
On the Ice, there's no soil or vegetation to hide space rocks, no running water to wear
them down, a plain white background to see them against, and few other stones to confuse
them with. In many areas of Antarctica, any rock in sight is a meteorite.
Of course, most meteorites that fall here become buried in snow, carried along by glaciers
and, after eons, discharged amid icebergs in the sea. But in certain places, especially
where the polar plateau meets the Transantarctics, ice flows into mountain cul-de-sacs
and, unable to advance further, evaporates or blows away.
In these areas of "blue ice," glaciers can be worn down by up to three inches a
day. The meteorites are left behind and, over thousands of years, they start to pile up.
The researchers don't have an elaborate system for determining where these pileups might
be. Though they use satellite images to identify areas of blue ice, "It's a rare
blue-ice spot where the meteorites are actually concentrated," Harvey said.
"You've just got to go out and look for them."
And that's what ANSMET has been doing, for the last 23 years. The program started in 1976,
shortly after a group of Japanese scientists happened upon a remarkable concentration of
meteorites near Antarctica's Yamato Mountains. Today, ANSMET is the best and cheapest
source for scientists to acquire extraterrestrial material.
Hunting for meteorites in Antarctica is less romantic than it sounds. A group of Harvey's
researchers, currently conducting a transect search in the Foggy Bottom region of the
Beardmore Glacier, has spent the last several weeks driving snow machines at a snail's
pace, back and forth in a parallel line, systematically sweeping the area.
Harvey likens the process to mowing a lawn, only with more overlap on each pass. Because
of the comprehensiveness of the hunt, he said, "You end up with a really
representative sample of what's coming down to Earth."
When a meteorite is spotted, it's assigned an identification number and its location is
recorded by GPS. Then it is placed in a sterile bag and kept frozen until it can be
shipped to the Johnson Space Center in Houston, where all of ANSMET's specimens are
collected.
The Beardmore researchers have already found several hundred meteorites this seasonmost of
them walnut-sized rocks called chondrites. According to Harvey, the stones are chemically
comparable to the sun. They are leftovers from the time when the Earth and the other
planets were formed.
Almost all meteorites found on Earth begin in the asteroid belt, where an enormous ring of
dust and debris hangs in limbo, pulled in one direction by the Sun's gravity and in the
other by Jupiter, the solar system's largest planet.
These opposing forces send the asteroids pin-balling into one another. Sometimes, one will
ricochet out of the belt, hurtling on a trajectory toward Earth.
But not all meteorites come from the asteroid belt. According to Harvey, about one in
2,000 comes from elsewhere. At least six rocks found in Antarctica have been determined to
have arrived from Mars, including one which excited a frenzy of scientific curiosity three
years ago when it appeared to bear evidence of Martian life.
According to Harvey, it's not surprising to find bits of other planets in the snows of
Antarctica. "You've got this transfer of material between the planets going on at a
fairly steady rate," he explained. "I'm sure there are bits of Earth flying
around in space."
Another story about "rock collecting" in Antarctica
Antarctica is the place to find rocks from space By Beth Minneci Sun staff
Imagine living on Mars and one day picking up a meteorite that landed from Earth. Let's
think locally and say it was a rock from Mt. Erebus.
Having never been to Earth, one might judge the whole planet by that one rock. That would
be in error, of course. The Earth is made up of lots of types of rocks with varied
histories, not just Erebus rocks from Ross Island in Antarctica.
"The same applies to meteorites found on Earth," said geologist John Schutt.
"A lot of them are coming from different parent bodies with different
histories."
Now think about how an Erebus rock is rare and considered special. So are some meteorites.
In fact, only 35 of thousands found on Earth so far are from the Moon or Mars.
The rest are mostly from what's called the asteroid belt, a suspended ring of debris and
partially-formed planets that knock about in space. The ratio makes lunar and Martian
rocks treasured finds.
For five weeks this season Schutt and five others traversed over hundreds of miles of
exposed blue ice. Their mission was to bring home lots of meteorites.
On snowmobiles about 100 feet apart they traveled in a series of parallel paths, scanning
the ice while moving across it like a farmer plowing a field, back and forth, Schutt said.
"There's some big country out there," he said. "It requires a high level of
concentration all day long."
The group worked at Meteorite Hills, an area in the Transantarctic Mountains near the
Darwin-Byrd Glacier named for numerous meteorites found there in 1978. All told 750
meteorites were taken this season, most of which are three to four centimeters in size.
"We pick up everything we find, including very small fragments," said Schutt.
Anything bigger than fist-sized is considered a large sample. The largest that U.S.
scientists have found was in 1976, at about 300 pounds. This was part of an 840-pound
meteorite broken into 40 scattered pieces.
An initial inspection of this year's catch revealed that nine meteorites appeared unusual.
Further analysis at a lab in the States will tell more.
Though meteorites fall to Earth randomly, Antarctica is by far the best place to search
for them, said Ben Bussey, who in December scouted new meteorite hunting fields with the
meteorite project's lead scientist, Ralph Harvey.
There are several reasons for this.
The likelihood of finding one here is enhanced by the continent's white background. And
the way glaciers move tends to concentrate meteorites on the surface at certain sites.
Another is that meteorites found on ice sheets are less likely than those in temperate
climates to be weathered away. And finally, in certain spots of Antarctica there is no
other terrestrial debris with which to confuse an extraterrestrial rock.
Most of the group's searching was on blue ice that has not been near any Earth rock,
Bussey said. But some areas were dense with terrestrial rocks. One way to tell the
difference between Earth and extraterrestrial rocks is by their exterior. Meteorites have
what is called a fusion crust, a glassy surface that developed as the rock came through
the atmosphere, heated up and melted.
"You develop a pretty good eye for them after a while," said Schutt, who
estimates that the team covered up to 1,200 miles on foot and snowmobile, and only
examined one-third of the territory in Meteorite Hills.
All rocks flying through space are called meteors. They are usually made up of common rock
forming minerals found on Earth.
When a meteor enters the atmosphere it glows and becomes a "shooting star." Much
of a shooting star evaporates before reaching the Earth or is crushed to dust by pressure
before it hits the planet.
"I've heard it can be 20 tons of meteorites and cosmic dust a year drifting down into
the atmosphere," Schutt said. "It may even be more."
Every meteorite on Earth is a messenger with information about the history of other
planets, asteroids and Earth's moon. Searching for meteorites on Earth is cheaper than,
say, going to the moon or Mars to take samples. So each year researchers and volunteers
scan Antarctic ice for meteorites, never knowing what might turn up.
Rare ones are prized, but even common extraterrestrial rocks are valued because they tell
a more complete story about someplace in space.
The most abundant type of meteorite has chemistry that is similar to that of the sun. They
are from the asteroid belt and are some of the solar system's oldest objects. Scientists
study them to understand the conditions present at the start of the solar system, which is
believed to have been between 4.5 and 4.6 billion years ago.
One of the rarest and most famous was found by Crary Lab supervisor Robbie Score in 1984.
Known as ALH84001, Score found it in the Allan Hills area north of the Dry Valleys.
Scientists said the meteorite contained fossilized Martian life. But other scientists have
argued that the meteorite was contaminated by its contact with Earth.
"It is still inconclusive," said Schutt.
In Score's office is a 23-pound iron meteorite, the heavies kind. It's about the size of a
super-ball.
Since 1976 the National Science Foundation has funded Harvey's group in what is called the
Antarctic Search for Meteorites program (ANSMET), which has collected specimens for study
from many spots in the Transantarctic range. Including Japanese and European efforts, more
than 20,000 have been recovered continent-wide.
The ANSMET group that hunts meteorites is actually part of a service from which scientists
around the globe can borrow space rocks for research. Field party members examine the
meteorites upon finding them in Antarctica, then send the rocks, still frozen, to the
Antarctic Meteorite Curation Facility at the Johnson Space Center in Houston. At the
center, the meteorites are freeze-dried to remove any snow and ice, then examined more.
Findings are distributed to researchers around the world twice a year.
"It's very exciting to be finding extraterrestrial material," Schutt said,
"especially if it turns out to be something unique."
|
MT EREBUS
Erebus, A Volcano with Lots of Activity By Josh Landis Sun staff
When James Clark Ross sailed through the uncharted sea in 1841 that would later bear his
name, he spied a tall, sloping mountain and called it Mt. Erebus. The smoldering peak must
have made an impression, because he named it after the lead ship in his expedition. Little
did he know that more than a century and a half later, the gold-spewing, bomb-throwing,
shimmying and shaking mountain would be the focus of a different group of explorers.
In the world of volcano research, finding a cooperative subject is difficult. Active
volcanoes can be inaccessible, temperamental, and even dangerous. Erebus is a rare find
that's well-suited to study. Its location 20 minutes from McMurdo Station is the least of
its unique points.
"It's a remarkable volcano," said Philip Kyle, an ex-Kiwi who's spent nearly
three decades studying Erebus and now works through the New Mexico Institute of Mining and
Technology. "The fact that it's in Antarctica is a red herring."
The most unique thing about it is the circulating lava lake in its crater.
"It's one of the few volcanoes in the world that doesn't plug itself up on a regular
basis," said fellow researcher Rick Aster.
Most volcanoes erupt, then cool, offering scientists little glimpse of their inner
workings. Erebus has a natural convection that continually brings new lava to the surface.
This steady circulation provides not only a fresh supply of magma, but allows gases to
escape, another attribute of the volcano that makes it ideal to study.
The characteristics of the exhaust, or plume, can reveal a lot about what's happening deep
under the surface. Jean Wardell has been taking samples of the air over Erebus for several
years, with a special focus on carbon dioxide.
Just like any liquid, magma is saturated with gases. Under the Earth's crust, at great
depth and pressure, those gases are forced into solution. When the magma makes its way to
the surface, the gasses escape much like carbon dioxide bubbles out of a bottle of soda
when it's opened. Wardell is there to catch them.
"By examining the level of CO2 escaping, I'm hoping to get a better picture of the
hydro-geological system of the volcano," she said.
Erebus is perfectly situated to study trace gases in its plume because the air that
streams past it is unpolluted. In areas closer to large populations, even the smallest
amounts of pollution can throw off measurements.
Wardell attaches a tube to the tip of a helicopter's antenna, and has the pilot fly a
precise grid pattern through the plume. GPS units record the position every second, and at
her lab she can create a detailed, three-dimensional plot of her findings.
Wardell also takes air samples inside the more dramatic formations of the volcano: the
towering ice fumaroles that dot the terrain and the labyrinth of caves carved out under
the snow. Escaping heat and gases create both, and they are as beautiful as they are
scientifically compelling. There are even tiny particles of gold in Erebus' exhaust,
according to Aster.
In addition to gas measurements, Kyle's team is mapping the surface of Erebus with
high-precision GPS units. Each time the volcano erupts, the mountain shudders. To see it
through the eyes of a seismometer is, apparently, quite fascinating and, again, quite
rare.
"This is the only volcano in the world that has this level of resonance," said
Aster, referring to the subtle ways in which Erebus shimmies and shakes. One more piece of
equipment rounds out the researcher's view. A video camera peers from the crater rim.
The camera keeps a constant eye on the lava lake, recording dramatic splashes and
eruptions 24 hours a day. A live link in Crary Lab allows scientists to watch the action
and compare it to the readings on their seismometers. Microphones also help them
distinguish between movement on the mountain and earthquakes in other parts of the world.
The recent earthquake in El Salvador, for example, showed up on instruments here, but
could be tuned out because its origin was known.
More extreme sampling methods include titanium instruments that are lowered from the
active crater rim to measure the temperature of the lava, and "dog chain"
sampling, where a chain is dropped into the lava and quickly pulled out with crystallized
magma attached.
Common sense suggests that the gases spewing out the top of a volcano would be dangerous
or even deadly, but Erebus' plume is mostly just an irritant.
It's about 95 percent water vapor, 4 to 5 percent carbon dioxide and less than one percent
sulfur dioxide. That composition makes the plume noxious, but not life-threatening, which
makes it possible for researchers to collect samples on the rim with little risk.
"Sometimes it gags us, makes us cough," said Wardell.
An eruption on Erebus can be a small pop, or as loud as a thunderclap. Regular eruptions
toss "bombs" out of the crater onto the rim. These light, glassy bombs of
varying sizes contain another rare feature of the volcano, crystals.
These crystals take years to form inside the molten stew of Erebus and are ejected inside
the bombs. Over time, the more brittle parts of the rock wear away and only the crystals
remain. There is only one other place in the world where such crystals can be found: The
volcanic system at Mount Kilimanjaro, in Tanzania, Africa. On Erebus, they are especially
abundant.
"It's just a gravel pit of crystals," said Wardell.
Eruptions in 1974 got violent enough to scare scientists away from the top of Erebus for
several months. Kyle said bombs as large as refrigerators were tossed hundreds of feet out
of the crater and landed near the research hut.
"Things got pretty interesting for a while," said Kyle.
But overall, the same qualities that make Erebus ideal for research keep it gentle enough
not to pose a threat.
"As long as it's convecting and degassing, it's going to stay happy," said
Wardell.
"It's the Old Faithful of volcanoes," added Aster. |
KATABATIC WINDS
Where the wind blows By Kristan Hutchison Sun Staff
Life at the very bottom of the ocean depends on the fierce winds blowing from some of the
highest elevations of Antarctica.
Strong katabatic winds play a vital role in the creation of what is called Antarctic
bottom water, cold dense water that slowly sinks to the depths of the ocean, bringing
oxygen with it.
If you could dive to the seafloor anywhere in the world, from the Caribbean to the north
Atlantic, you'd find water from the coast of Antarctica, said Gerd Wendler, a Fairbanks
professor who studies the connection between the cold wind and the cold water.
"Seventy five percent of all the bottom water, wherever you are, comes from
Antarctica," Wendler said in his thick, German accent. "It's a very small area
of Antarctica and it's directly connected with these katabatic winds and the sea
ice."
Wendler works with scientists from France and Australia to predict katabatic winds,
particularly when the winds speed past 90 mph. This year he traveled to McMurdo Station on
the Polar Sea icebreaker. As they cruised he measured the transfer of energy between the
ocean and the air. The data will indicate how much katabatic winds cool the water.
But the process starts high above, around 10,000 feet higher, on the Antarctic Plateau. As
air moves over the continent the layer nearest to the ice is chilled, creating a 10 to 20
degree difference in temperature between air traveling on top of it. The colder air
descends to a lower elevation, the same way cold air drops to the floor in a warm room.
Winds pulled downhill by gravity like this are called katabatic winds.
Since Antarctica is a smooth slope with no trees or mountains, the wind gains tremendous
speed as it slides over more than 500 miles to the shore. Along the Adelie and George V
coasts west of the Ross Sea the katabatic winds roar by at a mean speed of 60 mph.
The highest wind speeds ever recorded at sea level anywhere in the world were at Cape
Denison in Adelie Land. Ninety years ago Sir Douglas Mawson landed there and dubbed the
area "Home of the Blizzard" because the winds blew men off their feet. Peak
gusts have been clocked moving faster than 100 mph.
Studying katabatic winds is difficult, not only because they are so strong, because the
wind carries ice crystals from the high plateau to the sea. Wendler found that more than
10,000 ice particles per second pass through a square inch when the katabatic winds are
very strong. Working at a camp on the ice, Wendler once had to string rope to guide him
between the huts 100 ft. (30 meters) apart.
"It's highly dangerous because you can lose your way," Wendler said. "You
always held on with one hand to the rope that you never want to lose."
Most of the time Wendler and his co-researchers track the katabatic winds through a series
of remote weather stations, ranging from Dome C at 10,000 feet elevation on the East
Antarctic Ice Sheet to sea-level. They are particularly interested with what occurs when
the roaring wind meets the frozen sea.
"These winds are so strong that they can drive the sea ice away from the coast any
time of year," Wendler said.
The wind pushes away the sea ice and cools the exposed ice until new ice forms. As new sea
ice forms it leaves behind most of the salt, making the water below the ice the saltiest,
densest in the ocean. The temperature is 31 F (-0.5C). Like cold air, dense water drops
slowly down, sliding in 10 to 100 years the 2.5 miles (4 km) to the ocean bottom.
Called Antarctic Bottom Water, this cold water carries nutrients and oxygen with it, which
supports sea life thousands of miles away, said Donal Manahan, who studies species living
in the deep ocean.
"It pulls down nutrients down into the deep ocean and when those nutrients come to
the surface again they stimulate plant growth," Manahan said.
The movement of Antarctic bottom water is part of the system of global ocean currents,
which transport water, heat and salt around the world.
"It's very cold and very dense seawater that helps drive the ocean circulation by a
'conveyor belt' mechanism," Manahan said.
Those currents impact weather patterns and climates, but the impacts go two ways. While
bottom water influences the climate, changes in the climate can also influence the
Antarctic katabatic winds that create bottom water. There is concern among some scientists
that because polar regions are warming faster than the rest of the world, at a rate of 7F
(4C) in the last century, Wendler said, the wind pattern will be altered.
In the end, the wind carries a simple lesson, Wendler said.
"Everything is interconnected." |
ICEBERGS
MOTION OF MASSIVE ANTARCTIC ICE BERG CAUSES ANOTHER IMMENSE BERG TO
"CALVE"
The gyrations of an enormous iceberg that broke free of the Ross Ice Shelf in Antarctica
last week appear to have loosened another large iceberg, and the "calving" of
additional bergs may continue in coming weeks due to the ebb and flow of ocean tides.
Satellite images of the new berg indicate dimensions of about 130 kilometers (80 miles) by
20 kilometers (12 miles). The new berg is considerably smaller at 2480 square kilometers
(960 square miles) than the piece of ice -- now designated as iceberg B-15 -- which broke
off the Ross Ice Shelf earlier in March. Satellite images also indicate that the newest
berg appears already to be breaking into several smaller pieces.
B-15 broke off the Ross Ice Shelf roughly 200 miles east of McMurdo Station, the largest
of the National Science's Foundation's Antarctic Research Stations, and measured about 273
kilometers (170 miles) long by 40 kilometers (25 miles) wide. Its area of approximately
11,007 square kilometers (4,250 square miles) is roughly equivalent to the state of
Connecticut's.
NSF-supported researcher Douglas MacAyeal, of the University of Chicago, said that his
models of iceberg behavior, based on the calving of previous large icebergs in other areas
of Antarctica, led him to conclude correctly that B-15 was likely to collide repeatedly
with the Ross Ice Shelf and cause other large bergs to split off.
"The tides are constantly trying to move a new iceberg in a circular orbit,"
said MacAyeal. "The effect of that motion is that the iceberg that has just calved is
like a bull in a china shop and that causes anything else that is ready to calve to come
off too."
MacAyeal said that tides and currents around Antarctica aren't well understood, making it
difficult to predict the fate of B-15 and the newer berg that it has spawned. But, he
added, tidal motion may cause collisions that will calve other large bergs over the next
several weeks before these two big icebergs begin to drift away from the Ross Ice Shelf.
"The appearance of this new iceberg confirms this dynamic," he said, "The
fact is that we could be in for more calving."
Large icebergs, similar in size to B-15 have calved from the Ross Ice Shelf before,
notably in 1956. But MacAyeal noted that today's ability to watch the calving of these
icebergs almost as it happens through satellite imagery is very exciting to scientists.
Matthew Lazarra, a researcher at the NSF-funded Antarctic Meteorological Center at the
University of Wisconsin, first noticed the calving of the new iceberg while scanning
satellite photographs of B-15 and a smaller fragment of that berg, dubbed B-16. Both B-15
and B-16 had been obscured by cloud cover for a period of several hours.
Lazarra said that the latest satellite images indicate that the newest berg already
appears to have broken into as many as four smaller pieces.
|
NUCLEAR TESTING
Nuclear test ban sensors going online By Josh Landis Sun staff
On a quiet stretch of snow off the southern slope of Ross Island, engineers from the
University of Alaska are setting up a device that will listen for explosions on the other
side of the world.
With its tentacles of plastic tubing, the instrument looks like a space-age Hydra. But
this super-sensitive creation will be the nemesis of anyone who tries to test a nuclear
weapon. It's an infrasound sensor, and it's the newest addition to a global monitoring
network aimed at keeping tabs on any new weapons of mass destruction.
The Comprehensive Test Ban Treaty Organization (CTBTO) is extending its reach onto the Ice
by including Antarctica in its vast network of sensors. CTBTO is an international
organization with the goal of monitoring, and eventually eliminating, the testing of all
nuclear weapons.
Based in Vienna, the treaty has been signed by 160 countries since it came into existence
in 1996. President Clinton signed it in '96 but Congress has not yet approved it. So far,
30 of the 44 key countries that must ratify the treaty before it can enter into full force
have done so.
Central in the effort to eliminate large-scale, nuclear weapons testing is the ability to
detect explosions wherever they may happen. To this end, CTBTO monitors hundreds of
sensors around the world.
In all, there are 170 seismometers to measure subsurface explosions, 80 radionuclide
detectors to sniff minute amounts of fallout in the air, 11 hydroacoustic units that can
detect underwater blasts, and 60 infrasound sensors able to sense subtle pressure waves
that result from explosions on or near the surface of the Earth.
Until recently, the network was lacking in the southernmost reaches.
"Antarctica was a big hole in the global coverage," said Brian Stone, National
Science Foundation representative and CTBTO program manager. "So having (monitoring)
stations here is advantageous."
Dan Osborne heads the University of Alaska team that's installing the new infrasound
detector at Windless Bight. Hurrying around his makeshift office in Bldg. 165, the
bearded, brown-haired, bespectacled engineer spliced various computer wires to get his
laptop to communicate with a sensor on the floor.
Jagged lines leapt across the screen each time a door somewhere in the building was
opened.
"It's just like a barometer," explained Osborne. "It reacts to changes in
atmospheric pressure."
The array of infrasound detectors on the ice shelf just off Ross Island will be able to
sense a one-kiloton blast that goes off above-ground or just under the surface. Osborne
said the technology is so sensitive that when Mount St. Helens erupted in Washington in
1980, similar sensors here on the Ice detected the blast each time its shock wave
encircled the Earth. After a while, he lost count.
It's that kind of sensitivity the CTBTO relies upon. In addition to the infrasound station
at Windless Bight, there is one at Palmer Station. Traditional seismometers will be
listening to the ground at the Dry Valleys, South Pole and Palmer, where a radionuclide
detector will also be on line.
The CTBTO had to make some concessions when installing a device in Antarctica. For
starters, sensors on the network are normally required to have a near-perfect performance
record. The "up-time requirements" only allow a sensor to be off-line for about
three days a year. There is no way to guarantee that kind of reliability in Antarctica. If
the system would go down in the middle of the winter, for example, it could potentially
take more than a day just for someone to go check it out.
It's not the ideal scenario for CTBTO, but Stone says the organization will mostly likely
accept the Antarctic standards, because that's the only way they will get the data.
"There was nobody in that group who had experience in Antarctica," said Stone.
"They wanted to make it happen, but there was a lot of reality-checking. The
specifications for station up-time were not written with Antarctica in mind."
The organization also had to allow someone else to transmit the data from the sensor site.
Normally the link goes through a satellite uplink CTBTO supplies. That wasn't feasible
here, so they agreed to let Raytheon carry the data back to the States, where it will be
redistributed to the rest of the world.
"We convinced them it's better to consolidate things in Denver," said Mitch
Lasky, Raytheon point-of-contact for the project.
The sensors are all now either in the installation or testing phase. If they pass muster
they will be officially incorporated into the CTBTO monitoring network. It's an ideal
scenario and fits well with the overriding philosophy of science in Antarctica: share the
data. CTBTO is conveniently, and efficiently, co-opting the same instruments that would be
used for scientific purposes.
Still, monitoring nuclear weapons testing around the world from Antarctica is an odd twist
on the continent's position as an area of peaceful, scientific pursuit. Antarctica has
drawn researchers and explorers from the most powerful countries in the world.
"Now the science really is being used for a peaceful purpose," said Osborne.
"It's a perfect fit." |
UNIVERSE
EXPLORATION
On the cusp By Beth Minneci Sun staff
For decades astronomers struggled to prove the geometry of the universe. So when images
captured from a balloon over Antarctica last year confirmed that the cosmos was flat, the
news provided splashy headlines around the world.
In the United States, "Science Snags Front-Row Seat to Infant Universe," read
The Washington Post. "Baby pictures of universe show it's flat," said the
Baltimore Sun.
"Just last year there was no consensus with geometry of the universe," said
astronomer Erik Leitch. "Now we know with good certainty that it is flat."
The balloon project, called BOOMERanG, was the first experiment to provide evidence of the
universe's geometry with high-resolution maps of the big bang's afterglow. The radiation
is called the cosmic microwave background, and it is the closest astronomers have come to
a visual image of cosmic history.
Technological developments in the last few years indicate that history and news will be
made again, soon.
The cosmic microwave background is radiation that scientists use to trace the universe's
history to 300,000 years after the big bang, which is believed to have happened 15 billion
years ago. Just after the big bang, particles in the universe were scattered through the
cosmos like snow in a blizzard that light could not penetrate. But about 300,000 years
later, scientists believe, the universe cooled. Its particles had altered to a state that
allowed light, or radiation, to pass between them. The particles left an imprint on the
radiation that scientists are able to detect in finer detail than ever before.
"It's like a fossil of an earlier universe," said Leitch, who works with the
South Pole station radiation telescope project Degree Angular Scale Interferometer, or
DASI. "It's the oldest fossil around."
The cosmic microwave background's potential as a learning tool is far-reaching for
astronomers seeking answers to fundamental questions: Is the universe expanding? If so,
how fast? What is it made of? And most recently, is the universe's geometry flat, in which
two parallel lines will never meet? Or does it curve in on itself like a sphere, or expand
outward, like a saddle?
Since the 1960s scientists have known that the cosmic microwave background existed.
In 1991 they were first able to see temperature fluctuations in it. They say this is key
because the distribution and sizes of hot and cold spots tell of the early universe's
density of matter. Their new telescopes make maps that show the variations. As astronomer
Kim Coble put it: "The distribution of the spot sizes tells you everything you want
to know about the universe."
As evidenced by the balloon's message, prodding past our galaxy into the microwave
background is a way to churn out relatively quick answers to long-standing questions about
the universe's origin and fate.
But there is a side effect.
The more precise technology has fueled a race among academics to make the most efficient
telescopes and radio receivers and to come up with earth-shattering conclusions. The
scientists are exhilarated to quickly synthesize their data and publish their findings.
But they're also feeling pressure from the scientific community to rush to conclusions.
"We are working on questions that are so fundamental they really want to know the
answers," Leitch said. "They're just beating down your door."
Impressions from the cosmic microwave background are widely accepted as reliable paths for
tracing cosmic history. But astronomer John Ruhl takes the race in stride: "If you
look at the history of science, there's always people on the forefront of knowledge, and
there are times when the rate of knowledge accelerates until a standard is turned over.
This is a fantastic time to be doing cosmic background work. The 1970s weren't."
In Europe and Russia scientists are pursing the answers to astrophysical questions via the
cosmic microwave background.
In Antarctica, at the South Pole, new multi-million dollar telescopes and radio frequency
receivers are cropping up.
The DASI project is actually 13 telescopes aimed to detect temperature fluctuations in the
early universe. DASI is designed to record high-resolution images of the cosmic microwave
background.
A NASA satellite MAP, Microwave Anisotropy Probe, is scheduled to be deployed this year.
The long duration balloon TOPHAT launched from Williams Field early in January circled
Antarctica recording radiation and recently returned home.
At the South Pole this season, a high-frequency radio receiver was deployed with the Viper
telescope. Ruhl and Coble work on the receiver, called ACBAR, an acronym for Arcminute
Cosmology Bolometer Array Receiver, which extends Viper's observations to higher
frequencies.Together the telescopes, balloons and satellite are hunting for answers to the
origin and fate of the universe.
"We'll have answers to the big questions in, I would say, five years," Leitch
said.
But Ruhl is more cautious: "I'm more of a wait-and-see type."
|
VOSTOK
Vostok: A search starts for other life By Teri McLain Special to the Sun
On Europa, one of Jupiter's frozen moons, a thin skin of ice hides what may be a liquid
sea. If so, it would be the only known place in the solar system besides Earth where water
exists in significant quantities. It is there scientists believe we might discover our
first aliens a nation of microbes.
But the training ground for this interplanetary exploration is Vostok in Antarctica.
Engineers from NASA, Woods Hole Oceanographic Institution and the University of Nebraska
are designing a pair of robots to penetrate the sea ice of Europa and sample the putative
ocean. The cryobot, a device that melts a route through the ice, and the hydrobot, a small
submarine that explores the sea below, may see real action for the first time in Earth's
largest known subglacial body of water: Lake Vostok.
Just one of almost 80 known lakes beneath Antarctic ice sheets, Lake Vostok has recently
captured the attention of glaciologists and microbiologists alike. A pristine body of
water cut off from the outside world for a million years or more, the lake has the
potential for supporting previously undiscovered microbial life forms, as well as holding
clues to ancient climates. It is a time capsule of sorts, buried under four kilometers of
ice.
When the Russians opened Vostok Station near the geomagnetic pole in 1957, they had no
idea that it was situated over an ancient body of water more than 1,640 feet (500 m) deep
and 243 miles (230 km) long. And when they started drilling the world's deepest ice core
in an attempt to understand recent global warming in relation to the climactic cycles of
the last 500,000 years, they would not have predicted that they would be stopped at 11,886
feet (3,623 m) by a group of scientists
concerned with contamination of the lake's pure water.
This season, the National Science Foundation is setting up a camp near the Russian station
to explore subsurface features of the lake.
Although early seismic surveys in the 1960's and 70's indicated that water might exist
under the ice cap, it wasn't until drilling was well under way in the early 1990s that
satellite, seismic, and airborne radar data were put together to map the buried lake.
"It was a 'Eureka!' moment," said Martin Seigert, a University of Bristol
glaciologist.
In 1995, the Scientific Committee on Antarctic Research recommended that drilling be
stopped 400 feet from the lake's surface, until a sterile method could be found to tap
into one of the oldest ecosystems on earth. Last year, microbiologist John Priscu of
Montana State University examined bits of ice from the deepest part of the core and found
bacteria.
It is still unclear whether these microbes were deposited by ancient winds, or if they are
indicative of bacteria living in the lake below. But it is tantalizing to astrobiologists,
who speculate that if life can exist in Lake Vostok, it may also be present on Europa.
A multinational team of scientists and funding agencies is assembling to devise a method
for drilling into Lake Vostok without contaminating it with drilling fluids or foreign
bacteria. The first step will commence this week with test flights of the SOAR Twin Otter.
Equipped with instruments for an aerogeophysical survey, the team plans to conduct 69
flights this season and produce a data set that will aid scientists in understanding the
lake's physical properties and geologic origins.
The next phase could involve NASA tests of the robots. The cryobot would melt its way down
to the lake where it would eject the hydrobot to explore the depths and send back pictures
and data to the surface via a cable. The final stage would involve deep coring to retrieve
sediment and water samples. The details of probing the lake without introducing
contaminants are still being worked out.
It is a complex and ambitious effort that with the help of NASA technology will
potentially answer some fundamental questions about the evolution of life here on Earth.
And by giving scientists a testing ground for the cryobot and the hydrobot, something may
someday be discovered about the evolution of life on other planets.
|
| Penguin Plight
Nature vs. nature: The plight of the penguin By Melanie
Conner Sun staff
Mother Nature gave desperate Ross Island penguin colonies a small break in
the form of a four-day, blasting windstorm last month.
In mid-December, strong katabatic winds altered the fate of the penguin
colonies when they swept the winter's accumulated ice out to sea and provided the birds
with access to their summer breeding grounds. The event was key to the survival of some
Ross Island penguin colonies, reported scientist David Ainley, of H.T. Harvey &
Associates, ecological consultants based in San Jose, Calif. Before the storm, it was
predicted that some colonies would not survive at all.
"Cape Royds colony is going to fail," said Ainley, in an
interview in early December before the storm. "If the ice remains, it will disappear
as a penguin colony."
Troubled penguins of the Ross Sea made headline news around the U.S. last
week when the National Science Foundation released results of studies in conjunction with
satellite images from NASA that show iceberg movements. The NSF reported one penguin
colony - Cape Royds - was "in danger of extinction" while others would
experience a "significant reduction" because of abnormally extensive sea ice and
the movement of massive icebergs, one the size of Delaware.
"Enormous Icebergs Imperil Penguins," read one headline from the
Los Angeles Times last week, where it was reported the two icebergs that broke off in
March of 2000, combined with sea ice, have "choked" some coastal areas.
This year emperor and Adelie penguins have had difficulty traveling to and
from their breeding grounds, usually located at the sea's edge, because of ice conditions
in the Ross Sea. According to Ainley the birds' normal walking speed is 0.5 miles per
hour, while their swimming speed averages 4 to 5 miles per hour.
Long, difficult over-ice journeys discouraged penguins from breeding this
year. Usually, the birds migrate inland to their breeding grounds from the pack ice in the
eastern Ross Sea, where the female penguin lays eggs in pebble-lined nests, then travels
to the sea for food while her mate incubates them. This year, the foraging parent has
often returned too late, if at all, causing the incubating birds to abandon the eggs in
search of food.
"Males take the first turn on the eggs, for about 12 days," said
Ainley. "But now males sit and wait but the females don't return."
Their fate seemed a cruel act by Mother Nature until the mid-December
storm originating on the polar plateau, blew 20 miles (32k) of ice out to sea and cleared
the way for penguins. Ainley's team and other scientists were studying the birds at Cape
Crozier, Cape Bird and Cape Royds when the storm hit and they witnessed the immediate
effects of the removed sea ice.
"When we ventured forth, we found that the colony population had
tripled and more penguins continued to stream in," wrote Ainley in an e-mail.
"It appears that the big wind expanded the Ross Sea polynya sufficiently enough to
encourage all these birds to show up."
The storm could have saved the colonies had it not arrived two months too
late. The four-day storm that should have occurred during the early austral spring hit
Ross Island one week before summer solstice on Dec. 14.
What is left of theAntarctic summer is not long enough to raise chicks
before winter arrives.
"If they don't lay eggs by Nov. 20, it's too late," said Ainley.
For the penguins, Mother Nature is fickle. In many ways, the timing of the
storm couldn't have been worse, as it occurred during the peak-hatching season. The winds
carried away more than sea ice - it also stole eggs and chicks.
"Apparently, whenever a parent rose to switch position or give over
nest duty to its partner the eggs or hatchlings departed, swept away by the wind,"
wrote Ainley.
About 500 adults were blown down the hillside and killed at the Cape
Crozier Adelie colony. Hundreds of remaining penguins were buried in snowdrifts 5 to 15
feet (1.6 to 4.9 m) deep.
"A bunch wiggled their way to the surface, but likely hundreds are
still buried," wrote Ainley.
After the storm only 2 percent of the Adelie breeding population at Cape
Crozier, the sixth largest Adelie colony in the world, has chicks.
Beforehand,emperor penguins at Cape Crozier failed to produce chicks,
according to Gerald Kooyman of Scripps Institution of Oceanography. The problem with the
emperor colony is that the largest iceberg (called B15 based on the location from which it
broke) may have bumped up against Cape Crozier during the winter, which is when they lay
eggs and incubate.
"It is unclear as to the timing of the iceberg's movement in relation
to the coming and going of emperors during the winter," said Paul Ponganis of the
University of California in San Diego.
"But the end result was that we could not find any live emperor
chicks at the usual Cape Crozier emperor colony location."
The exact fate of the birds remains a puzzle.
"We do not know if most of the emperors abandoned the site and left,
if they were trapped there and died, or if they may have moved to another site,"
Ponganis said.
On the other side of Ross Island, before the four-day, mid-December storm,
the Adelie penguin colony at Cape Royds and the southernmost Adelie penguin colony in the
world was headed for extinction. The outlook remains grim. While the storm blew out 30 to
75 km (18 to 45 miles) of ice, the population increased only slightly. The birds' journey
has been shortened from a 120-km (72-mile) round-trip walk to a 60-km (36-mile) round-trip
walk - still too far for an over-ice journey. If the sea ice can break up more the colony
will be fine, Ainley said.
Just north of Cape Royds the wind worked miracles for the Cape Bird colony
that was expected to suffer the same fate as its neighbor to the south. However, Cape Bird
is located slightly farther north and closer to open water than Cape Royds. "It now
takes a day for the penguins to go out and back," said Ainley. "That's their
'normal' feeding trip duration."
According to Ainley, about 30 percent of the Cape Bird breeding population
has chicks, compared with 2 percent at other colonies.
The ice as a culprit
Just as penguins are a part of Antarctic ecology, so are ice movement and
the constant calving of icebergs. The irony is that penguins need coastline and shores
upon which they can breed; yet this terrain is provided by the retreat of ice shelf
through the calving of bergs. Colonies around Ross Island are very vulnerable to ice
calving and they are now living through the effects of a giant iceberg that calved-off
almost two years ago.
The trouble began for the penguins in March of 2000, when the B15 iceberg
broke away from the Ross Ice Shelf and eventually migrated toward Cape Crozier on the east
side of Ross Island. The iceberg measures 100 miles long (160k), 22 to 32 miles wide
(33-50 miles), 150 feet (46m) above water and 800 feet (246m) deep. The berg has split in
two, shifted, drifted, pivoted and cracked in the last two years, and harbors the
potential to block sea access to McMurdo Station.
On the west side of the island, the effects of accumulated sea further
increased the isolation of the island. This year, for the second consecutive season, the
sea ice in the McMurdo Sound did not break up as it usually does in the late austral
spring. Usually, strong, southerly winds send newly-formed sea ice on its way and out of
the area. Researchers say that perhaps the absence of the wind this year prevented the sea
ice and from escaping McMurdo Sound. Others are exploring the possibility that persistence
of the sea ice is caused by the B15 iceberg.
"There is also some argument now as to whether the sea ice is caused
by B15a or that the fact that B15a didn't get blown away last winter is due to an
unusually windless winter that also caused the sea ice," wrote Doug MacAyeal of the
University of Chicago, in an e-mail.
Along with the annual breakup of the sea ice comes the U.S. Coast Guard
vessel, the Polar Star, an icebreaker used to cut a channel through remaining ice to allow
safe passage of re-supply ships.
However, this year the NSF has contracted two icebreakers to clear a path
in the extra-thick ice.
The breakers helped the Cape Royds birds by collapsing the integrity of
the ice, which created enough cracks to allow open water to reach the colony when strong
winds blew the ice out on Wednesday and Thursday.
"The breaker cuts a swath down the middle about 100 yards wide,"
said Ainley. "The ice becomes two big ice sheets that can break apart.
Meanwhile, researchers at Cape Bird and Crozier will use radio telemetry
to track the birds and find out where penguins are feeding. They will track their progress
in the coming years and study as much of the penguin colonies as possible.
According to the NSF, "The penguins response to the icebergs likely
will provide major new insights into the biology, resolve and resilience of this
species." |