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entry Mar 21 2006, 02:57 PM
Great read!!


Journey to the end of the Earth

TISHANI DOSHI

Want to know more about the planet's past, present and future? Antarctica is the place to go.

My first emotion on facing Antarctica's expansive white landscape and uninterrupted blue horizon was relief, followed by an immediate and profound wonder.


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Epiphanic moment: Within sight of a vast white landscape. Photo: Tishani Doshi

EARLY this year, I found myself aboard a Russian research vessel — the Akademik Shokalskiy — heading towards the coldest, driest, windiest continent in the world: Antarctica. My journey began 13.09 degrees north of the Equator in Madras, and involved crossing nine time zones, six checkpoints, three bodies of water, and at least as many ecospheres.

By the time I actually set foot on the Antarctic continent I had been travelling over 100 hours in combination of car, aeroplane and ship; so, my first emotion on facing Antarctica's expansive white landscape and uninterrupted blue horizon was relief, followed up with an immediate and profound wonder. Wonder at its immensity, its isolation, but mainly at how there could ever have been a time when India and Antarctica were part of the same landmass.

Part of history

Six hundred and fifty million years ago, a giant amalgamated southern supercontinent — Gondwana — did indeed exist, centred roughly around present-day Antarctica. Things were quite different then: humans hadn't arrived on the global scene, and the climate was much warmer, hosting a huge variety of flora and fauna. For 500 million years Gondwana thrived, but around the time when the dinosaurs were wiped out and the age of the mammals got under way, the landmass was forced to separate into countries, shaping the globe much as we know it today.

To visit Antarctica now is to be a part of that history; to get a grasp of where we've come from and where we could possibly be heading. It's to understand the significance of Cordilleran folds and pre-Cambrian granite shields; ozone and carbon; evolution and extinction. When you think about all that can happen in a million years, it can get pretty mind-boggling. Imagine: India pushing northwards, jamming against Asia to buckle its crust and form the Himalayas; South America drifting off to join North America, opening up the Drake Passage to create a cold circumpolar current, keeping Antarctica frigid, desolate, and at the bottom of the world.

For a sun-worshipping South Indian like myself, two weeks in a place where 90 per cent of the Earth's total ice volumes are stored is a chilling prospect (not just for circulatory and metabolic functions, but also for the imagination). It's like walking into a giant ping-pong ball devoid of any human markers — no trees, billboards, buildings. You lose all earthly sense of perspective and time here. The visual scale ranges from the microscopic to the mighty: midges and mites to blue whales and icebergs as big as countries (the largest recorded was the size of Belgium). Days go on and on and on in surreal 24 hour austral summer light, and a ubiquitous silence, interrupted only by the occasional avalanche or calving ice sheet, consecrates the place. It's an immersion that will force you to place yourself in the context of the earth's geological history. And for humans, the prognosis isn't good.

Human impact

Human civilisations have been around for a paltry 12,000 years — barely a few seconds on the geological clock. In that short amount of time, we've managed to create quite a ruckus, etching our dominance over Nature with our villages, towns, cities, megacities. The rapid increase of human populations has left us battling with other species for limited resources, and the unmitigated burning of fossil fuels has now created a blanket of carbon dioxide around the world, which is slowly but surely increasing the average global temperature.

Climate change is one of the most hotly contested environmental debates of our time. Will the West Antarctic ice sheet melt entirely? Will the Gulf Stream ocean current be disrupted? Will it be the end of the world as we know it? Maybe. Maybe not. Either way, Antarctica is a crucial element in this debate — not just because it's the only place in the world, which has never sustained a human population and therefore remains relatively "pristine" in this respect; but more importantly, because it holds in its ice-cores half-million-year-old carbon records trapped in its layers of ice. If we want to study and examine the Earth's past, present and future, Antarctica is the place to go.

Students on Ice, the programme I was working with on the Shokaskiy, aims to do exactly this by taking high school students to the ends of the world and providing them with inspiring educational opportunities which will help them foster a new understanding and respect for our planet. It's been in operation for six years now, headed by Canadian Geoff Green, who got tired of carting celebrities and retired, rich, curiosity-seekers who could only "give" back in a limited way. With Students on Ice, he offers the future generation of policy-makers a life-changing experience at an age when they're ready to absorb, learn, and most importantly, act.


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The reason the programme has been so successful is because it's impossible to go anywhere near the South Pole and not be affected by it. It's easy to be blasé about polar icecaps melting while sitting in the comfort zone of our respective latitude and longitudes, but when you can visibly see glaciers retreating and ice shelves collapsing, you begin to realise that the threat of global warming is very real.

Antarctica, because of her simple ecosystem and lack of biodiversity, is the perfect place to study how little changes in the environment can have big repercussions. Take the microscopic phytoplankton — those grasses of the sea that nourish and sustain the entire Southern Ocean's food chain. These single-celled plants use the sun's energy to assimilate carbon and synthesise organic compounds in that wondrous and most important of processes called photosynthesis. Scientists warn that a further depletion in the ozone layer will affect the activities of phytoplankton, which in turn will affect the lives of all the marine animals and birds of the region, and the global carbon cycle. In the parable of the phytoplankton, there is a great metaphor for existence: take care of the small things and the big things will fall into place.

Walk on the ocean

My Antarctic experience was full of such epiphanies, but the best occurred just short of the Antarctic Circle at 65.55 degrees south. The Shokalskiy had managed to wedge herself into a thick white stretch of ice between the peninsula and Tadpole Island which was preventing us from going any further. The Captain decided we were going to turn around and head back north, but before we did, we were all instructed to climb down the gangplank and walk on the ocean. So there we were, all 52 of us, kitted out in Gore-Tex and glares, walking on a stark whiteness that seemed to spread out forever. Underneath our feet was a metre-thick ice pack, and underneath that, 180 metres of living, breathing, salt water. In the periphery Crabeater seals were stretching and sunning themselves on ice floes much like stray dogs will do under the shade of a banyan tree. It was nothing short of a revelation: everything does indeed connect.

Nine time zones, six checkpoints, three bodies of water and many ecospheres later, I was still wondering about the beauty of balance in play in our planet. How would it be if Antarctica were to become the warm place that it once used to be? Will we be around to see it, or would we have gone the way of the dinosaurs, mammoths and woolly rhinos? Who's to say? But after spending two weeks with a bunch of teenagers who still have the idealism to save the world, all I can say is that a lot can happen in a million years, but what a difference a day makes!

For more information on Students on ice visit www.studentsonice.com


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Nimii
post Mar 21 2006, 03:19 PM
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OF TIME MACHINES AND ICEBERGS



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To some people, Antarctica is a giant, freezing time machine. That's because the continent's ice sheets hold deeply buried air bubbles that can tell researchers a lot about what Earth's atmosphere was like thousands and even millions of years ago. As NATURE's ANTARCTICA: THE END OF THE EARTH shows, scientists can retrieve these gaseous time capsules by drilling out deep ice cores. What these icy time travelers have discovered has generated intense interest -- and controversy. In particular, their studies have shown that the amount of carbon dioxide in Earth's atmosphere has risen rapidly in the industrial era. That's a concern because many researchers believe carbon dioxide acts as a global warming gas, trapping heat near the planet's surface and causing long-term changes in climate. While the change of weather could be good news for some people, it could be disastrous for others. If warmer temperatures were to melt Antarctica's ice caps, for instance, researchers estimate that the global sea level would rise an average of 230 feet, flooding most coastal cities and drowning places like New York, London, and Hong Kong.

Some scientists say it's too early to see such signs of global warming. But others say there is evidence -- and it can be found in the enormous icebergs that are breaking free from Antarctica every year.

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In August, 1992, for instance, a monster iceberg 20 times bigger than Manhattan sheared off from an Antarctic glacier jutting into the Bellingshausen Sea. In 1999, it drifted into shipping lanes off Argentina, prompting a worldwide warning to ships to stay clear of the 41-mile-long, 13-mile-wide slab, which rises 180 feet out of the sea and reaches a depth of 900 feet. Maritime officials fear the mother berg may eventually give birth to hundreds of calves, each of which could pose a substantial threat to cargo and passenger vessels. "We're watching it very closely," says one U.S. official, who notes that everything from satellites to rowboats is being used to track the floe.

Many researchers believe more giant bergs are on their way as Antarctica's massive ice sheets melt back due to warmer temperatures, but that could take a very long time. Scientists recently estimated that it could take 7,000 years for the giant West Antarctic ice sheet to eventually disappear. And other researchers note that while some ice sheets are shrinking, others appear to be growing -- for reasons nobody yet understands.

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Nimii
post Mar 21 2006, 03:23 PM
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LOOKING FOR LIFE



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The fact that life -- from simple viruses to elegant seabirds -- has learned to survive in inhospitable Antarctica has made the continent a magnet for scientists interested in discovering life in another hostile environment: outer space. In the last decade of the 20th century, researchers flocked to Antarctica to study its hardy life forms, looking for clues to the kinds of organisms that might thrive on the barren moons of our solar system -- or somewhere else in the universe.

At Russia's Vostok Antarctic scientific station, for instance, scientists are eager to get a look at an ancient lake that sits under more than 10,000 feet of ice. Because Lake Vostok, as the huge buried lake is known, has been isolated for hundreds of thousands of years, scientists believe it may contain strange organisms adapted to its cold, black waters -- just the kind of animal that might live on Europa, one of Jupiter's frozen moons. IPB Image

Researchers have already drilled down to within a few hundred feet of the lake's surface. But they won't go any farther until they figure out a way to send down a probe capable of penetrating the lake without contaminating it. Carrying out such a robotic mission will be difficult and expensive, costing $20 million or more. And some people doubt it can be done at all, and are opposing international efforts to collect samples from the lake. "Vostok's value to science is too important to be compromised for the sake of finding a method of exploring other planets," says a spokesman for the Antarctic and Southern Ocean Coalition, an advocacy group.

That debate won't be settled soon. And neither will another extraterrestrial argument that has its origin in Antarctica. Scientists have long known that Antarctica's ice sheets are an excellent place to find unspoiled meteorites, which fall to Earth and are then sealed in the ice. One truly remarkable falling star is known as meteorite ALH84001. The stone was a piece of the planet Mars, blasted from the red planet in some ancient celestial collision. And in 1996, a team of three NASA scientists announced that this potato-sized rock appeared to contain something truly astounding: microscopic fossils of bacteria that had at one time flourished on Mars. This discovery meant the unthinkable: that Mars had once supported life.

The claim made headlines -- and drew a crowd of skeptics. After several years of further studies, few scientists still believe the Mars rocks contain evidence of life. The original study, many researchers say, found only mineral grains that look like bacteria. "You would have a hard time finding even a small number of people who are enthused by the idea of life being recorded in this meteorite," paleontologist Andrew Knoll of Harvard University told the magazine SCIENCE in 1998. Still, many researchers hope that Antarctica will one day help solve that age-old question: Are we alone in the universe, or is Earth just one life-holding globe among many?
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Nimii
post Oct 4 2006, 05:47 PM
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Arctic region Eruption - some 100 years back and its effect now.. Found this interesting read in my mailbox from NASA.

Novarupta

Oct. 3 , 2006: In June 1912, Novarupta—one of a chain of volcanoes on the Alaska Peninsula—erupted in what turned out to be the largest blast of the twentieth century. It was so powerful that it drained magma from under another volcano, Mount Katmai, six miles east, causing the summit of Katmai to collapse to form a caldera half a mile deep. Novarupta also expelled three cubic miles of magma and ash into the air, which fell to cover an area of 3,000 square miles more than a foot deep.

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Despite the fact that the eruption was comparable to that of the far more famous eruption of Krakatau in Indonesia in 1883 and so near the continental United States, it was hardly known at the time because the area was so remote from English-speaking people.


Right: An aerial view of the Novarupta Dome in Alaska. USGS photo by Gene Iwatsubo, July 29, 1987. [More]

Almost a hundred years later, researchers are paying attention. Novarupta is near the Arctic Circle and its impact on climate appears to be quite different from that of "ordinary" tropical volcanoes, according to recent research by climatologists using a NASA computer model.

When a volcano anywhere erupts, it does more than spew clouds of ash, which can shadow a region from sunlight and cool it for a few days. It also blows sulfur dioxide—a gas irritating to the lungs and smelling like rotten eggs. If the eruption is strongly vertical, it shoots that sulfur dioxide high into the stratosphere more than 10 miles above Earth.


Up in the stratosphere, sulfur dioxide reacts with water vapor to form sulfate aerosols. Because these aerosols float above the altitude of rain, they don't get washed out. They linger, reflecting sunlight and cooling Earth's surface. This can create a kind of nuclear winter (a.k.a. "volcanic winter") for a year or more after an eruption. In April 1815, for instance, the Tambora volcano in Indonesia erupted. The following year, 1816, was called "the year without a summer," with snow falling across the United States in July. Even the smaller June 1991 eruption of Pinatubo in the Philippines cooled the average temperature of the northern hemisphere summer of 1992 to well below average.

But both those volcanoes as well as Krakatau were in the tropics.

Novarupta is just south of the Arctic Circle.

Using a NASA computer model at the the Goddard Institute for Space Studies (GISS), Prof. Alan Robock of Rutgers University and colleagues found that Novarupta's effects on the world's climate would have been different. (Their research was funded by the National Science Foundation.)

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Robock explains: "The stratosphere's average circulation is from the equator to the poles, so aerosols from tropical volcanoes tend to spread across all latitudes both north and south of the Equator." Aerosols would quickly circulate to all parts of the globe.


But the NASA GISS climate model showed that aerosols from an arctic eruption such as Novarupta tend to stay north of 30ºN—that is, no further south than the continental United States or Europe. Indeed, they would mix with the rest of Earth's atmosphere only very slowly.

Right: The inner workings of "volcanic winter." [More] [Larger image]

This bottling up of Novarupta's aerosols in the north would make itself felt, strangely enough, in India. According to the computer model, the Novarupta blast would have weakened India's summer monsoon, producing "an abnormally warm and dry summer over northern India," says Robock.

Why India? Cooling of the northern hemisphere by Novarupta would set in motion a chain of events involving land and sea surface temperatures, the flow of air over the Himalayan mountains and, finally, clouds and rain over India. It's devilishly complex, which is why supercomputers are needed to do the calculations.

To check the results, Robock and colleagues are examining weather and river flow data from Asia, India, and Africa in 1913, the year after Novarupta. They are also investigating the consequences of other high-latitude eruptions in the last few centuries.

Do Indians need to keep an eye on Arctic volcanoes? The GISS computer says so.
courtesy: NASA.
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