December 11, 1999 - BBC
Analysis of an Antarctic ice core taken from just above the under-ice Lake Vostok suggests that bacteria may live in it. "The subglacial lakes of East Antarctica may be among the most isolated ecosystems on Earth and could serve as terrestrial analogues to guide the design of samplers and experiments for life probe missions to the ice-covered ocean of Jupiter's moon Europa," says Dr David Karl of the University of Hawaii. The scientists were examining the ice below Vostok Station, a Russian scientific outpost in the centre of the Antarctic. Lake Vostok was discovered in 1974 using airborne radio-echo soundings and other techniques. It is one of the world's 10 deepest bodies of water and one of about 70 lakes underneath the glaciers of central Antarctica. Roughly the size of Lake Ontario, Lake Vostok is the largest and deepest of the lakes, whose fresh water is kept liquid by the pressure of the overlying ice and, perhaps, by geothermal heating. US, French and Russian scientists have studied fragments taken from an ice core drilled 3,600 meters (11,700 feet) into the ice covering the lake. Drilling was halted roughly 120 meters (393 feet) above where the ice and liquid water meet, to prevent contamination.
The bacteria, commonly associated with soils, are related to microbes called proteobacteria and actinomycetes. They could have reached Antarctica on bits of soil blown by winds from the Patagonian deserts onto the ice sheet and then buried. If so, the microbes could be more than half a million years old. "This lake and others like it, may contain previously undescribed relic populations of microorganisms that are adapted for life in these presumably oligotrophic (low-nutrient, low-biomass and low-energy flux) habitats," says Karl. Scientists at Montana State University have found bacteria within "accreted" ice, which is believed to have refrozen from the lake's waters, suggesting that it can support life. Although the bacteria are similar to other known bacteria scientists wonder whether it may contain larger, more diverse populations. In addition, the Antarctic ice cores provide a continuous climate record stretching back more than 400,000 years. Obtaining sediment samples from the bottom of Lake Vostok could extend the climate record to cover millions of years. "From a biologist's perspective, this is the Holy Grail of lake biology," Dr John Priscu of Montana State University said before leaving for another field season on the frozen continent. "Our findings indicate that the microbial world has few limits on our planet."
East Antarctic ice streams pour ice into the oceans
The first high-resolution radar map of Antarctica has revealed the frozen continent in such detail that even research huts sat on icebergs can be spotted.
The radar map covers the whole continent
This map is truly a new window
on the Antarctic continent,
providing new beginnings in our
Earth science studies there," said
Dr Ghassem Asrar, Associate
Administrator for Earth Science at
Nasa Headquarters.
Radasat, a Nasa-launched
Canadian satellite, spent 18 days in
spring 1997 bouncing radar signals
from the Earth's surface and
analysing the echoes.
Antarctica looks almost featureless
with the images from
low-resolution satellites that
previously mapped the frozen
landscape. With the new Radarsat
map, however, the continent comes to life.
A vehicle track over Lake Vostok is visible
Even the tracks of snow tractors
on their way to inland stations are
visible, as is the road that runs
over the flat ice-cap that overlies
Lake Vostok, the largest under-ice
sea in the world.
The new map has answered
scientists' questions about the icy
continent, but it has also left them
wondering what to make of
strange and fascinating features
never seen before.
"We have a new view of the entire
southern continent," said Kenneth
Jezek, a glaciologist from the Byrd
Polar Research Centre at Ohio
State University. "It shows us an
extraordinary part of our world and how humans may be changing
it - on both local and global scales."
Some scientists believe that the most amazing features that can be
seen in Radasat's images are twisted patterns of ice flowing from
the ice sheet into the ocean.
Snow dunes captured by satellite camera
"We were surprised to see a
complex network of ice streams
reaching deep into the heart of
East Antarctica," said Dr Jezek.
"There are some extraordinary ice
streams that extend almost 500
miles." Ice streams are vast rivers of ice
that flow up to 100 times faster
than the ice they channel through,
with speeds up to 900 metres
(3,000 feet) per year.
It is believed that ice streams form
in the most energetic parts of the
Antarctic ice sheet, and scientists
believe that they are quite
susceptible to environmental
change. They are important to the long-term stability of the Antarctic
ice sheet as they transport most of the snow that falls on the
continent's interior back to the ocean.
"We've recently used Radarsat and other satellite data to estimate
that one ice stream system sends over 78 cubic kilometres of ice to
the sea every year - an amount equivalent to burying Washington
DC, in 520 m (1,700 ft) of ice every 12 months," said Dr Jezek.
October 6, 1999 - Discovery Online
Lake Vostok is the largest of the lakes that lie beneath the
four-kilometre-thick Antarctic ice sheet. After scientists
stopped drilling in the ice in 1996 (to avoid contaminating the
lake water), scientists were excited to find micro-organisms
from 200,000 years ago and there was excited speculation
that the lake would hold equally ancient organisms ³seeded²
from the ice when the lake formed underneath it. But new data
shows Lake Vostok may have existed long before the ice
sheet and that the microbes that inhabit its waters may be
unchanged since they were first trapped beneath the glaciers,
40 million years ago.
It's making the researchers with the British Antarctica Survey (BAS), sound a lot like explorers
venturing into outer space.
Lake Vostok is circled
"Is there life down there? It's a fascinating question," says Dr.
Cynan Ellis-Evans, a microbiologist with the BAS. ³What kind of
microbes could survive in this dark, nutritionally-deprived
environment?"The presence of water underneath the Antarctic ice sheet was
first recognized in the 1970s. Using satellite radar and drilling,
researchers have shown that Lake Vostok is 500 metres deep
and covers an area of 10,000 square kilometres. That makes it
one of the largest freshwater bodies in the world - in fact it's
comparable in size to Lake Ontario. It is the largest of the 70 or
so sub-glacial lakes in Antarctica, and lies under the ice sheet of
Eastern Antarctica near the Russian Vostok Station.
But while scientists originally thought that these lakes
developed after the ice sheet had reached its present
thickness of four kilometres a few million years ago, that figure
is being revised markedly. And that makes for a whole new
scenario.
This is the largest sub-glacial lake in Antarctica - the size of Lake Ontario
Drilling in Lake Vostok
If Lake Vostok was there before the glaciers moved in, says
Ellis-Evans, its sediments scoured from the bedrock could
provide a record of the glaciation of that continent, a
geological record of Antarctica and its climate change. But
even more amazingly, there is the possibility that life still
exists under the ice life existing in an environment unique
among the planetıs ecosystems both unforgiving for its lack
of nutrients, and pristine.
"Once the lake began to freeze over, there would have been
a decline in biodiversity to just microbes," explains Ellis Evans.
"[These microbes] would never have been exposed to
modern pressures like pollution, antibiotics, climate change,
under four kilometres of insulating ice. Usually microbes are forced to change. What happens
when an environment is stable for millions of years? There are no references for that!"
At least no references on this planet. One of the moons of
Jupiter, Europa, has some interesting similarities.
"On Europa you've got a body of water ice-covered for a very
long time," Ellis-Evans points out. "That immediately poses
restrictions on the types of life forms and the interaction
between ice and water. Thatıs analogous to Vostok."
As a result, NASA has taken a keen interest in Lake Vostok.
Their Jet Propulsion Laboratory in Pasadena is planning a
Vostok exploration mission within five years, using radar and
melting probes, while exploration of Europa is set to start in 2003.
But according to Ellis-Evans, there are more differences than similarities between the two icy environs.
NASA sees Lake Vostok as an analog for the ice-covered ocean of Europa -
a satellite of Juliter.
Europa is likely to be salt water, and the ice is unstable, always breaking up.
It's more like sea ice, while Vostok has a glacial ice sheet. Europa would have a more
dramatic interaction between water and ice, with the bedrock being constantly pulled and
pushed by gravity. It's possible it's a volcanic hydrothermal environment. It's not that dramatic
in Vostok there's far less energy inputs."
However, Lake Vostok may show Antarctica to be more active than originally thought. While
Eastern Antarctica has been regarded as inactive, stable rock for a long period of time, there
is now the suggestion that Vostok is sitting in a rift valley: a valley created when tectonic
plates split and drift apart (some of worldıs biggest lakes, such as Lake Malawi, sit in rift valleys.)
"Vostok may lie in between two geologically distinct areas of Antarctica,"Ellis-Evans
hypothesizes. "If Vostok is sitting in a rift valley, there's a possibility that [Eastern Antarctica]
is still active."
New lifeforms are believed to live 4km beneath the Antarctic ice Scientists meeting in Cambridge are discussing whether to drill into
a lake beneath the Antarctic ice which may reveal clues to whether
life exists on a moon of Jupiter.
Lake Vostok, one of the largest freshwater
bodies in the world lies four kilometres below
the surface of Antarctica. It is believed by
scientists to contain a host of undiscovered
lifeforms. It is also thought that the 10,000
square-kilometre lake may have similarities
with the sub-glacial oceans that are believed to exist on the Jovian
moon, Europa.
If lifeforms can survive in the
extreme conditions of Lake Vostok,
scientists believe they may also be
able to survive on Europa.
But drilling through the ice into the
lake was stopped because of
fears that the work would cause
contamination.
Now, 70 scientists from 14
countries, are meeting to set the
scientific priorities for the next
steps in its exploration.
Dr Cynan Ellis-Evans, of the British Antarctic Survey, said: "It has
an air of mystery about it which ranks with a lot of the space
science.
"We know quite a lot in terms of the ice and the bedrock around the
place, but the lake itself is still an enormous mystery to us,
especially what sort of lifeforms might be in there.
"This is a very old lake and the
lifeforms that are going to be in
there could be very interesting to
us."
When Nasa'a Galileo space probe
passed Europa, it discovered the
moon had similarities to Antarctica.
The moon is covered with an ice
sheet which hides a vast ocean.
"Europa is, from our current
calculations, the largest ocean in
the solar system."
Lake Vostok could provide a unique technology test-bed and
provide an opportunity for Nasa to apply its technical expertise to
investigate a novel environment here on Earth.
The lake is situated beneath the ice sheet of Eastern Antarctica in
the vicinity of the Russian Vostok Station.
Estimates of the age of Lake Vostok range from hundreds of
thousands to millions of years.
Ottawa Citizen Online - July 9, 1999
Two groups of scientists
whose worksites are
located as far apart as
Antarctica and Jupiter's
moon Europa are
developing a joint
research project to
examine a huge freshwater
lake beneath Antarctica's
ice sheet. They hope to
find early life forms in both
places.
The Antarctic lake -- the
largest known in the
frozen continent -- is
almost as large as Lake
Ontario, and twice as
deep. Sandwiched
between the continent's
bedrock and the overlying
ice sheet, it lies partly
beneath Vostok Station,
established by the Soviet
Union in 1957. The
desolate station was
known as the coldest
outpost of the Cold War.
A strange reflection in a
single seismic record through the ice sheet in 1964 was first
interpreted by scientists as a reflection from loose deposits
under the ice. During the 1970s, radio-echo soundings showed
the area to be large and flat, and the soundings were correctly
interpreted as a sub-glacial lake. By 1994, the presence of a lake
had been confirmed beyond reasonable doubt.
When scientists at NASA's Jet Propulsion Laboratory heard about
the lake, they became intrigued because the surface of Europa is
believed to be ice -- beneath which there could be water.
The notion that liquid water might be trapped below the ice of one
of the moons of Jupiter was the basis for Arthur C. Clarke's 1984
science-fiction novel 2010: Odyssey Two.
NASA proposed using Lake Vostok as an experimental test site.
But at this point, biologists intervened because they feared
drilling through the four-kilometre ice layer would lead to
contamination of the ancient waters beneath. The ice has sealed
the water off from the outer world for at least one million years.
Peter Clarkson, executive secretary of the Scientific Committee on
Antarctic Research at the Scott Polar Research Institute in
Cambridge, England, which is coordinating the venture, says Lake
Vostok "represents one of the most exciting multidisciplinary
research opportunities in Antarctica today. ... The potential gains
for both Antarctic and planetary science, by successfully sampling
the lake and the sediment using contamination-free methods, are
enormous."
Sampling the water could reveal micro-organisms in lake
sediments, since Lake Vostok is presumed to have been
biologically active before glaciation occurred millions of years ago.
Elsewhere on ocean floors, previously unknown life forms have
been found around volcanic vents. Similar conditions might be
present both in Lake Vostok and on Europa.
Scientists seek to answer a question that has critical implications
for the existence of life elsewhere in the universe: can life actually
originate under these conditions? Both the planetary and Antarctic projects require similar technical
developments: an ice-probing vehicle, or Cryobot, miniature
instruments for measuring chemical concentrations, and an oceanic
robotic submersible, or Hydrobot, and its communication system.
The Cryobot is likely to be a version of the Philberth probe used
in terrestrial ice since the 1960s. Heated by hot water, the probe
melts through the ice, while its path is sealed behind it as new ice
forms. (On Europa, the probe would be heated by radioisotope
thermal generators, rather than hot water.) Once the Cryobot got
through the ice into the water below, it would release the
Hydrobot, which could take continuous measurements, possibly for
years.
Despite difficulties, if funding can be obtained from NSF and
NASA, along with what Dr. Ellis-Evans has obtained from the
European Science Foundation for the next workshop, he says
"we'd stand a chance of getting into the lake within the next five
years.
"It's going to be a major undertaking. When you're working at
minus-30 and minus-40-degree air temperatures, it's quite an
exercise."
Canada has no direct involvement in the project, but Canadian
scientists are doing Antarctic research, including Ottawa's Olav
Loken, who is Canada's delegate to the Scientific Committee on
Antarctic Research. It's even possible the Canadian Arctic might
serve as a test site, according to Dr. Carsey: "One place we're
thinking of is the Ward-Hunt ice shelf. It sits on fresh water which
has very salty water underneath. We need places to try things
out, and it's pricey to go to Antarctica."
September 16, 1999 - Reuters - London
Evidence of a 'lost' supernova that exploded some 700 years ago has turned up in the snows of Antarctica, New Scientist magazine said today. X-rays from the German-US orbiting Rosat satellite have shown a glowing supernova remnant just 640 light years away, suggesting the star's explosion lit
up our skies at the beginning of the fourteenth century, making it by far the closest supernova in our past. But unlike other supernovas which astronomers recorded, scientists found no historical reference to this event. Then 20 years ago, analysis of an ice core in the South Pole showed four concentrations of nitrates in the snow. Dating revealed that three of them coincided with bright supernova explosions in 1181, 1572 and 1604, which were all recorded. Now scientists say the fourth ``spike'' or concentration is the sign of the explosion pinpointed by Rosat. Its depth in the ice core corresponds to a date of around 1320, very close to the date roughly estimated from Rosat observations using theories of how supernova remnants evolve. "This fourth spike corresponds precisely with the time when light...from the recently discovered supernova would have been arriving at the Earth,'' said Kai Zuber of Dortmund University, who, along with Clifford Burgess of Montreal's McGill University, has reached the new conclusions from the evidence. The evidence from the ice core points to what astronomers call a type II supernova -- the obliteration of a colossal star 15 times as heavy as the sun.
July 13, 1999 - Reuters - Wellington
Geologists have discovered the
fossilized remains of massive dinosaurs in Antarctica, signs that
many prehistoric "eating machines" were spread over a much
broader territory than previously believed.
An expedition to the remote Antarctica Peninsula and nearby
islands has unearthed large deposits of dinosaur fossils,
including remains of two types of large marine reptile --
mosasaurs and plesiosaurus.
The leader of the expedition which unearthed them in January,
Dr Jim Martin from the Museum of Geology in South Dakota,
presented the group's findings at a symposium on Antarctica
Earth Sciences in Wellington this week.
Martin said the big surprises had been the concentration of
remains found as well as evidence of great diversity of species
and a much warmer climate in the polar region.
The number of mosasaurs was especially striking.
"Mosasaurs were just fantastic animals, some of them were up
to 10 meters long, maybe more, they were armed with teeth
that were three or four inches long. The skulls would easily be a
meter long.
"They were eating machines, that were designed to eat
anything and they did."
To have revealed remains of at least four different species
among the complete vertebrae, partial skeletons, whole jaws
and teeth in the find was unexpected in such a remote locality.
"To find a whole bunch of them like this is really surprising. We
were expecting to find maybe one little bone fragment, but
here were at least four different kinds of mosasaurs," he said.
One type, Plioplatecarpus, is believed to have been adapted to
relatively shallow water and its discovery in Antarctica
suggests the continental masses were once much closer, with
connecting marine corridors.
"We also found a duck-billed dinosaur known as a hadrosaur on
Vega Island. This was even more of a surprise.
"We had always thought of them as a North American dinosaur.
This suggests that North America, South America and
Antarctica were connected at the end of the Age of
Dinosaurs."
Martin said the creatures probably came to Antarctica in the
late Cretaceous period, some 75 to 80 million years ago.
He said his colleagues on the expedition, Judd Case and Mike
Woodburne, had hypothesized that marsupials now found in
Australia actually got there from North America by travelling
the length of South America, across Antarctica, and into
Australia before the continents split up.
BBC Online - April 16, 1999
Icebergs crashing against the sea floor could be the most
devastating natural disaster that any living community on Earth
experiences.
Scientists from the British Antarctic Survey have discovered
that over 99.5% of all visible sea-bed dwellers are massacred
when the bergs collide with the ocean bottom.
Floods, earthquakes and even meteorite impacts cannot claim
such total destruction. The project leader, Professor Lloyd
Peck, told BBC News Online: "In biological terms it is outrageous
- it's almost a sterile environment."
Up to 20% of the world's oceans are prone to catastrophic ice
berg impacts. Even ocean floor as deep as 500m is at risk.
The bergs float in and gouge and trample the communities as
they rock back and forth in the tide. It is their immense weight
that causes the damage.
"The biggest icebergs are the size of Oxfordshire and weigh
two billion tonnes. The impact force is greater than that of
cruise missiles - it's immense," says Professor Peck.
His team, including colleagues from Gent University, Belgium,
set up three underwater test sites near Signy Island,
Antarctica. All were destroyed within 18 months.
They dived beneath the sea and used vacuum pumps to suck
up the animals living on the sea bed both before and
immediately after the berg impact.
They were shocked by the totality of the death toll. In some
cases, literally everything had been ground to a fine powder.
"For animals bigger than one millimetre, there were eight really
common groups and six disappeared completely," explained
Professor Peck. "The removal of the other two species was
over 99.5%.
"Animals smaller than one millimetre, like nematodes, went down
from two million per square metre to a few hundred."
Rising from the ashes -- For the first time, the scientists also tracked the recovery of
the obliterated sites. It had been thought this would take
years.
But the first arrivals re-colonised within a few days, simply by
walking back in. The smaller creatures needed the assistance of
a major storm to be swept back in. This occurred within four
months, with a 150 km/h gale.
And this revealed a surprise - the berg impacts actually
revitalise the sea floor communities in the same way that forest
fires clear "dead wood" and allow new trees to flourish.
"The icebergs actually help to maintain the population with a
larger number of young animals because it's clearing areas for
settlement," says Professor Peck. "So the ice bergs do have
positive effects as well."
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