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 Post subject: Antarctica Observatory: Searching for the Hottest Mystery in Science
PostPosted: Thu Apr 16, 2009 12:34 am 
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Dark_energy_cluster_2“We’re looking at a tug-of-war with dark energy and gravity trying to expand or collapse the universe.”



John Carlstrom, South Pole astronomer and University of
Chicago astrophysicist.

Sptpole_2
A big telescope, as high as a seven-story building, with a main
mirror measuring 32 1/2 feet across is being built at the
Amundsen-Scott Station in the Antarcticanbsp; looming over a barren plain
of ice that gets colder than anywhere else on the planet.



The instrument at the far end of the world is being built scientists
can search for clues that might identify the most powerful, plentiful
but elusive substance in the universe -- dark energy.



The telescope will help scientists to reveal new details regarding a mysterious phenomenon called dark energy, which makes the expansion of the universe accelerate. Albert Einstein"s famous quot;cosmological constant,quot; which is one possibility for the dark energy, also will come under the telescope"s scrutiny. The quot;gravityquot; of dark energy is repulsive. It pushes the universe apart and overwhelms ordinary gravity, the attractive force exerted by all matter in the universe. Dark energy is invisible, but astronomers will be able to see its influence on clusters of galaxies that formed within the last few billion years.

quot;With the South Pole Telescope we can look at when galaxy clusters formed and how they formed. That is critically dependent on the nature of the dark energy, this elusive component of the universe,quot; said Carlstrom, who heads the project. quot;We"ve only known about dark energy for a few years. No one really knows what it is.quot;

quot;One of our main goals is to figure out what the dark energy is,quot; said center Director Bruce Winstein, the University"s Samuel K. Allison Distinguished Service Professor in Physics. quot;Is it a cosmological constant or is it dynamical? The South Pole Telescope holds the promise to give us a lot of new, valuable information on this.quot;

Understanding dark energy is one of the key scientific questions called out in the Astronomical Decadal Survey. In the survey, astronomers identified a South Pole telescope as one of their highest-priority projects for the next 10 years. quot;It"s a way of taking the next step in understanding this crazy new cosmology that we find ourselves in,quot; said astronomer Tony Stark of the Harvard-Smithsonian Center for Astrophysics.

First described just nine years ago, dark energy is a mysterious
force so powerful that it will decide the fate of the universe. Having
already overruled the laws of gravity, it is pushing galaxies away from
one another, causing the universe to expand at an ever faster rate.



Though dark energy is believed to account for 70 percent of the
universe"s mass, it is invisible and virtually undetectable. Nobody
knows what it is, where it is or how it behaves.



Solving the
mystery of dark energy is would explain the history and future of the
universe and generate new understanding of physical laws that, applied
to human invention, almost certainly will change the way we live --
just as breakthroughs in quantum mechanics brought us the computer chip.



Swinging its massive mirror skyward, the South Pole Telescope (SPT) for
the last few months has begun to search the southern polar heavens for
shreds of evidence of the elusive stuff. Controlled remotely from the
University of Chicago, the $19.2 million telescope has quickly
succeeded in its first mission: finding unknown galaxy clusters, clues
to the emergence of dark energy.



The cold, dry atmosphere above the South Pole will allow the SPT to more easily detect the cosmic microwave background radiation (CMB), the afterglow of the big bang, with minimal interference from water vapor. On the electromagnetic spectrum, the CMB falls somewhere between heat radiation and radio waves.

The CMB is largely uniform, but it contains tiny ripples of varying density and temperature. These ripples reflect the seeds that, through gravitational attraction, grew into the galaxies and galaxy clusters visible to astronomers in the sky today. The SPT’s first key science project will be to study small variations in the CMB to determine if dark energy began to affect the formation of galaxy clusters by fighting against gravity over the last few billion years.

Galaxy clusters (image at top) are groups of galaxies, the largest celestial bodies that gravity can hold together. Our galaxy, the Milky Way, is in one of these clusters, which actually change with time.

The CMB allows astronomers to take snapshots of the infant universe, when it was only 400,000 years old. No stars or galaxies had yet formed. If dark energy changed the way the universe expanded, it would have left its “fingerprints” in the way that it forced galaxies apart over the deep history of time. Different causes would produce a different pattern in the formation of galaxy clusters as reflected in the distortion of the CMB.

According to one idea, dark energy could be Einstein’s cosmological constant: a steady force of nature operating at all times and in all places. Einstein introduced the cosmological constant into his theory of general relativity to accommodate a stationary universe, the dominant idea of the day. If Einstein’s idea is correct, scientists will find that dark energy was much less influential in the universe five billion years ago than it is today.

“Clusters weren’t around in the early universe. They took a long time to evolve,” Carlstrom said.

Another version of the dark energy theory, called quintessence, suggests a force that varies in time and space. Some scientists even suggest that there is no dark energy at all, and that gravity merely breaks down on vast intergalactic scales.



Scientists expect the telescope to detect thousands, or even tens of thousands, of galaxy clusters within a few years.



The giant telescopes components had to be custom-built by scientists and craftsmen in
several different parts of the world, then shipped to Antarctica in
pieces for final assembly. The largest sections of the telescope were
carefully designed so each could fit into ski-equipped military
transport planes. It took 25 flights to ferry 260 tons of telescope
components.



quot;We have to get these pieces into place to within 1/2000th of an
inch of accuracy,quot; said Jeff McMahon, 29, a postdoctoral physics
student. quot;If you move, you risk screwing it up, so you stand motionless
at 20 degrees below zero.quot;



Posted by Casey Kazan.



Related Galaxy posts:



Google “Sky”—New Virtual Telescope Using NASA Hubble Images Plans to Turn Millions into Stargazers
Map of the Missing Cosmos
1st 3-D Map of the Universe"s Dark Matter
Cosmic Collisionnbsp; Sheds Light on Mystery of Dark Matter
New, Revised Hitchhiker"s Guide to the Galaxy



Source:



http://www-news.uchicago.edu/releases/07/070226.southpole.shtml








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 Post subject: Does the Milky Way Influence Earth"s Biodiversity? Research Says "Yes"
PostPosted: Thu Apr 16, 2009 12:38 am 
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Butterfly3 Horoscope enthusiasts will be happy to hear that a grand cosmic force does indeed seem to be responsible for controlling the direction of all life on Earth. However, this grand cosmic cycle has more to do with extinction than finding a tall, handsome stranger.



Research has revealed that the rise and fall of species on Earth seems
to be driven by the undulating motions of our solar system as it
travels through the Milky Way. Some scientists believe that this cosmic
force may offer the answer to some of the biggest questions in our
Earth’s biological history—especially where evolution has fallen short.

Researchers at the University of California, Berkeley found that marine
fossil records show that biodiversity increases and decreases based on
a 62-million-year cycle. At least two of the Earth"s great mass
extinctions-the Permian extinction 250 million years ago and the
Ordovician extinction about 450 million years ago-correspond with peaks
of this cycle, which can"t be explained by evolutionary theory.




Early last year, a team of researchers at the University of Kansas
came up with an out-of-this-world explanation for the phenomenon. Their
idea hinges upon the fact that stars move through space and sometimes
rush headlong through galaxies, or approach closely enough to cause a
brief cosmic tryst.




Our own star moves toward and away from the Milky Way"s center, and
also up and down through the galactic plane. One complete up-and-down
cycle takes 64 million years- suspiciously close to the Earth"s
biodiversity cycle.




Once the researchers independently confirmed the biodiversity cycle,
they then proposed a novel mechanism whereby which the Sun"s galactic
travels is causing it.




It’s no secret that the Milky Way is being gravitationally pulled
toward a massive cluster of galaxies, called the Virgo Cluster, which
is located about 50 million light years away. Adrian Melott and his
colleague Mikhail Medvedev, speculate that as the Milky Way rushes
towards the Virgo Cluster, it generates a so-called bow shock in front
of it that is similar to the shock wave created by a supersonic jet.




"Our solar system has a shock wave around it, and it produces a good
quantity of the cosmic rays that hit the Earth. Why shouldn"t the
galaxy have a shock wave, too?" Melott asks.




The galactic bow shock is only present on the north side of the Milky
Way"s galactic plane, because that is the side facing the Virgo Cluster
as it moves through space, and it would cause superheated gas and
cosmic rays to stream behind it, the researchers say. Normally, our
galaxy"s magnetic field shields our solar system from this "galactic
wind." But every 64 million years, the solar system"s cyclical travels
take it above the galactic plane.




"When we emerge out of the disk, we have less protection, so we become exposed to many more cosmic rays," Melott has said.




The boost in cosmic-ray exposure may have a direct effect on Earth"s
organisms, according to paleontologist Bruce Lieberman. The radiation
would lead to higher rates of genetic mutations in organisms or
interfere with their ability to repair DNA damage. In this way, the
process could lead to new species while killing off others.




Cosmic rays are also associated with increased cloud cover, which could
cool the planet by blocking out more of the Sun"s rays. They also
interact with molecules in the atmosphere to create nitrogen oxide, a
gas that eats away at our planet"s ozone layer, which protects us from
the Sun"s harmful ultraviolet rays.




Richard Muller, one of the UC Berkeley physicists who co-discovered the
cycle, said Melott and his colleagues have come up with a plausible
galactic explanation for the biodiversity cycle.




If future studies confirm the galaxy-biodiversity link, it would force
scientists to broaden their ideas about what can influence life on
Earth. "Maybe it"s not just the climate and the tectonic events on
Earth," Lieberman said. "Maybe we have to start thinking more about the
extraterrestrial environment as well."




Posted by Rebecca Sato.



Related Galaxy posts:







GAIA -Mapping the Family Tree of the Milky Way
The "Hubble Effect" -A Galaxy Insight
The 6th Mass Extinction
"The Great Extinction" & the Rise of Modern Species
Coming of Age in the Holocene







Link 1

Link 2




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 Post subject: Nat"l Geographic Explorer: Why Arctic Is Critical to Earth"s Health
PostPosted: Thu Apr 23, 2009 10:38 pm 
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 Post subject: "Solar Cycle 24" -Are the Sun"s Cycles a Factor in Global Warming?
PostPosted: Tue Jun 02, 2009 8:37 pm 
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Eit_mdi_20000429

Over the span of 11 years images from the Solar and Heliospheric Observatory (SOHO) spacecraft have shown the Sun’s activity varying in intensity as magnetic field lines that are wound and tangled inside the Sun periodically break through to the surface. 



Solar Cycle 24 began in early 2008 (image left), but has shown minimal
activity through early 2009 (image right). The small changes in solar
irradiance that occur during the solar cycle exert a small influence on
Earth’s climate, with periods of intense magnetic activity producing
slightly higher temperatures, and solar minimum periods such as that
seen in 2008 and early 2009 likely to have the opposite effect.



Skeptics have been saying that global temperature rises might be due to changes in the sun, pretty much the ultimate "it wasn"t us, a big boy did it," with a giant fusion reactor as the elusive culprit.   Researchers have shown that this isn"t the case and unlike the original claim, their work involves advanced computer models, a distinct lack of the word "might", and has been published in Science.

Carnegie Mellon University"s Peter Adams along with Jeff Pierce from Dalhousie University in Halifax, Canada, have developed a model to test the controversial hypothesis that says changes solar activity are causing global warming.

The hypothesis they tested was that increased solar activity reduces cloudiness by variations in cosmic rays. So, when clouds decrease, more sunlight is let in, causing the earth to warm. Some climate change skeptics have tried to use this hypothesis to suggest that greenhouse gases may not be the global warming culprits that most scientists agree they are. They found that changes in the concentration of particles that affect clouds are 100 times too small to affect the climate.

Professors Peter Adams and Jeff Pierce did a bunch of things that those throwing around the solar excuse didn"t:

a)  They did detailed work analyzing the actual effects of such activity
b)  They actually understood what such effects would really even be
c)  They rigorously applied scientific procedures to this research, constructed computer models, and would have reported the results either away
d)  They spent many, many years earning PhDs in scientific research and the title of "Professor."

We have to say, d) is our favorite.

The simulations show that the effects of cosmic rays from the sun are barely 1% of what they"d have to be to explain what we"ve seen.  The scientists are even one step ahead of the "maybe-sorta" game, admitting their simulations can"t account for everything that exists, because nothing could ever do that (including their opponents" arguments), but pointing out that nothing omitted or missed could skew the results enough to appreciably alter the results.


Posted by Luke McKinney with Casey Kazan.

Changes in the Sun are not causing Global Warming, Study Says http://www.sciencedaily.com/releases/2009/05/090511122425.htm


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 Post subject: Antarctic Search for a 2,000-Year-Old Supernova
PostPosted: Mon Jul 20, 2009 10:06 am 
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6a00d8341bf7f753ef0115720f9008970b-500wi

Japanese scientists journeyed to Antarctica
to recover evidence of alterations to Earth"s atmosphere caused in
medieval times by supernovae recorded by scholars - including obscure
Irish monasteries where monks later interpreted them signs of the
Antichrist . No, this isn"t the plot of the next Dan Brown novel (or a
Dan Brow fanfiction written by an X-Files addict): this is real science.












Supernovae release terrific amounts of energy, as in "If one happened
too close, the planet would be sterilized" truly terror-inducing
terrific.  Some of this energy is fired off as gamma rays, which can
travel thousands of light-years and still pack enough of a punch after
to alter the atmosphere - which is exactly what happened in 1006 and
again in 1054, when gamma rays blasted the upper atmosphere and created
spikes in NO3 levels.  There was also quite a lot of visible light,
creating a star visible even during the day which was noted by various
Chinese, Egyptian and even monastic records.




To access past records of the atmosphere, a team of Japanese scientists
carefully extracted 122 meters of ice core from Antarctica.  Even
better, to locate events on such a stretch of frozen time you use known
volcanic atmosphere-altering events as reference points - in other
words, these guys use exploding mountains as a ruler. 




The team found NO3 spikes at times corresponding to 1006 and 1054, as
well as a mysterious unknown third event - and we remind you that this
is not a movie, even though that sounds so much like a second act
reveal leading to a lost city or something, we can practically see
Nicolas Cage"s shocked expression.




Unlike any movie adventurer of the unknown, who has a tendency to
steal/detonate every single relic they find, the Japanese team have
also made things easier for anyone who follows them.  The unprecedented
detail of their observations reveals a standard 11-year cycle in
ice-core records, corresponding to the sunspot cycle. This will help
future ice-core observers track the time of events.




These people look at timescales so huge that the pulsing of the sun itself is just the ticking of a clock. 



Posted by Luke McKinney.



Links:




http://arxivblog.com/?p=1239




https://www.cs.tcd.ie/Dan.McCarthy/#Astro_obs_Vistas







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 Post subject: Discovery of Ancient Antarctica Mountain Range May Alter Global Climate-Change Predictions
PostPosted: Fri Aug 14, 2009 6:37 am 
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The-Antarctica-Challenge

An international team of experts have mapped a huge, incredibly old
location, mentioned in the notes of a Russian explorer from half a
century ago, buried under hundreds of meters of ice.  In an amazing
break with tradition this process did not result in the unleashing of
ancient horrors, a self-destruct sequence, alien invasion or anyone
shooting at Indiana Jones.  They"ve examined the entire Gamburtsev
mountain range, 700 meters tall and buried under a kilometer of
Antarctica.








The team used an array of tools including seismic wave reflection,
radar, and precise gravitational measurements to map the frozen
features - there are a lot more differences between ice and rock than
"one works in drinks", and they used them all.  If "Sub-Antarctic
Mountain Range" isn"t good enough for you, the valleys between the
peaks come complete with rivers and lakes - yes, lakes.  Under the
ice.  At the South Pole.



081021gamburtsev02_2
The mountains are a massive mystery - they seem to be half a billion
years old, but on a tectonic scale you can"t just say "that"s a long
time ago so who cares."  There are no other indications of such titanic
tectonics in the area at the time, and the range has none of the signs
of volcanic formation.  Which is a pity, as volcanoes erupting into
thousands of tons of solid ice is probably the only way this incredible
landscape could sound any more awesome.



The researchers predicted a flat plateau, but instead found a range
similar in height and shape to the Alps - with massive peaks as high as
Mount Blanc and deep valleys.

Water, turned to liquid due to the
pressure of East Antarctic Ice Sheet above, could be seen in rivers and
lakes nestled in valleys. One lake, Vostok, a possible living
biological lab of ancient lifeforms, was an incredible 300 kilometers.

Scientists
hope the findings will aid predictions about the effects of climate
change on ice sheets and challenge long-held views that the ice sheet
formed over millions of years.The new research suggests they formed in
a fraction of the time and the area could have been ice free at some
points in history.

This means any rapid fluctuation in global
temperature could have a much faster effect on the formation of ice
sheets than previously thought



Posted by Luke McKinney



Related Galaxy posts:



Secrets of Antarctica"s 15-Million Year-Old Lake -A Galaxy Classic
World"s Oldest Living Microbes May Cast Light on Aging amp; Life on Mars
Will Jupiter"s Moon -Europa- Provide the 1st Proof of Extraterrestrial Life? -A Galaxy Insight
Ancient Antarctic Microbes Revived in Lab

Antarctica -Mapping The White Continent



Links:



Lake Vostok Slide Show



http://www.unspecial.org/UNS633/UNS_633_T13.htm



A PDF on the Vostok drilling
Wiki to Vostok -
Wiki on the Antarctic Treaty





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 Post subject: Antarctica Islands Rival Galapagos in Biodiversity
PostPosted: Sat Sep 19, 2009 4:26 am 
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6a00d8341bf7f753ef011570768207970b-800wi
A team from British Antarctic Survey and University of Hamburg combed
the land, sea and shores of the South Orkney Islands last year near
the tip of the Antarctic Peninsula using scuba divers and trawled nets
to capture creatures as deep as 1,500 meters.












Animals recorded were then checked with a century of literature and
modern databases and the team concluded that there are over 1200 known
marine and land species, including sea urchins, free-swimming worms,
crustaceans and mollusks, mites and birds. Five were previously unknown
to science.






“This is the first time anybody has done an inventory like this
in the polar regions," said Lead author Dr David Barnes from British
Antarctic Survey. "It’s part of the Census of Marine Life (COML) – an
international effort to assess and explain the diversity and
distribution of marine life in the world’s oceans. If we are to
understand how these animals will respond to future change, a starting
point like this is really important.”



Gallery_ten_antarc_470x300
“We never knew there were so many different species on and around
these islands," said Stefanie Kaiser from University of Hamburg. "This
abundance of life was completely unexpected for a location in the polar
regions, previously perceived to be poor in biodiversity.”



The research team, consisting of 23 scientists from five research
institutes, spent seven weeks on the BAS Royal Research Ship James
Clark Ross in 2006.



Posted by Jason McManus.






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 Post subject: Was Antarctica Once "112 Degrees F in the Shade"? New Findings Show Warming Cycle 15 Million Years Ago
PostPosted: Wed Oct 07, 2009 12:21 am 
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3_Puffins_alt3 An international team of scientists now have proof of a sudden, remarkably warm period in Antarctica that occurred about 15.7 million years ago and lasted for a few thousand years.

Last year, as Sophie Warny, LSU assistant professor of geology and geophysics was studying samples sent to her from the latest Antarctic Geologic Drilling Program, or ANDRILL one sample stood out as a complete anomaly.

“First I thought it was a mistake, that it was a sample from another location, not Antarctica, because of the unusual abundance in microscopic fossil cysts of marine algae called dinoflagellates. But it turned out not to be a mistake, it was just an amazingly rich layer,” said Warny. “I immediately contacted my U.S. colleague, Rosemary Askin, our New Zealand colleagues, Michael Hannah and Ian Raine, and our German colleague, Barbara Mohr, to let them know about this unique sample as each of our countries had received a third of the ANDRILL samples.”

The two scientists in charge of the drilling, David Harwood of University of Nebraska – Lincoln, and Fabio Florindo of Italy, were equally excited about the discovery,” said Warny. “They had noticed that this thin layer had a unique consistency that had been characterized by their team as a diatomite, which is a layer extremely rich in fossils of another algae called diatoms.”

All research parties involved met at the Antarctic Research Facility at Florida State University in Tallahassee. Together, they sampled the zone of interest in great detail and processed the new samples in various labs. One month later, the unusual abundance in microfossils was confirmed.

Among the 1,107 meters of sediments recovered and analyzed for microfossil content, a two-meter thick layer in the core displayed extremely rich fossil content. This is unusual because the Antarctic ice sheet was formed about 35 million years ago, and the frigid temperatures there impede the presence of woody plants and blooms of dinoflagellate algae.

Nielsen “We all analyzed the new samples and saw a 2,000 fold increase in two species of fossil dinoflagellate cysts, a five-fold increase in freshwater algae and up to an 80-fold increase in terrestrial pollen,” said Warny. “Together, these shifts in the microfossil assemblages represent a relatively short period of time during which Antarctica became abruptly much warmer.”

These palynomorphs, a term used to described dust-size organic material such as pollen, spores and cysts of dinoflagellates and other algae, provide hard evidence that Antarctica underwent a brief but rapid period of warming about 15 million years before present.

“This event will lead to a better understanding of global connections and climate forcing, in other words, it will provide a better understanding of how external factors imposed fluctuations in Earth’s climate system,” said Harwood. “The Mid-Miocene Climate Optimum has long been recognized in global proxy records outside of the Antarctic region. Direct information from a setting proximal to the dynamic Antarctic ice sheets responsible for driving many of these changes is vital to the correct calibration and interpretation of these proxy records.”

These startling results will offer new insight into Antarctica’s climatic past – insights that could potentially help climate scientists better understand the current climate change scenario.

“In the case of these results, the microfossils provide us with quantitative data of what the environment was actually like in Antarctica at the time, showing how this continent reacted when climatic conditions were warmer than they are today,” said Warny.

According to the researchers, these fossils show that land temperatures reached a January average of 10 degrees Celsius – the equivalent of approximately 50 degrees Fahrenheit – and that estimated sea surface temperatures ranged between zero and 11.5 degrees Celsius. The presence of freshwater algae in the sediments suggests to researchers that an increase in meltwater and perhaps also in rainfall produced ponds and lakes adjacent to the Ross Sea during this warm period, which would obviously have resulted in some reduction in sea ice.

These findings most likely reflect a poleward shift of the jet stream in the Southern Hemisphere, which would have pushed warmer water toward the pole and allowed a few dinoflagellate species to flourish under such ice-free conditions. Researchers believe that shrub-like woody plants might also have been able to proliferate during an abrupt and brief warmer time interval.

“An understanding of this event, in the context of timing and magnitude of the change, has important implications for how the climate system operates and what the potential future response in a warmer global climate might be,” said Harwood. “A clear understanding of what has happened in the past, and the integration of these data into ice sheet and climate models, are important steps in advancing the ability of these computer models to reproduce past conditions, and with improved models be able to better predict future climate responses.”

“The SMS Project Science Team is currently looking at the stratigraphic sequence and timing of climate events evident throughout the ANDRILL AND-2A drillcore (image above), including those that enclose this event,” said Florindo. “A broader understanding of ice sheet behavior under warmer-than-present conditions will emerge.”

Jason McManus -adapted from materials provided by LSU.

Source: http://www.lsu.edu/highlights/2009/10/antarctic.shtml





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 Post subject: Were Antarctica and North America Once One Continent A Singl
PostPosted: Wed Oct 07, 2009 11:20 pm 
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2362572700_26d3c0679cThecontinual shifting of continents has led to the theories that, as inthe cases of Pangaea and Rodinia, many, if not all of our continentswere at one time or another connected. One particular theory -the SWEAT theory ( standing for southwestern United Statesand East Antarctica)- theorizes that the southwestern UnitedStates was at one time connected to East Antarctica.

John Goodge, an NSF-funded researcher with the Department of GeologicalSciences at the University of Minnesota-Duluth, and his team published a paper that details findings that they believe addconsiderable weight to SWEAT.

Goodge and his team were conducting a search for rocks that mightprovide links to the composition of the underlying continental crust ofAntarctica. "We were picking up boulders in the moraines that lookedinteresting," Goodge said. "It was basically just a hodge-podge ofmaterial."

One of the rocks that they picked up turned out to be, later, a veryspecific form of granite with, as Goodge describes it, "a particulartype of coarse-grained texture." Chemical and isotopic tests conductedby the team in laboratories in the US revealed the boulder to have achemistry "very similar to a unique belt of igneous rocks in NorthAmerica" that stretches from what is now California eastward throughNew Mexico to Kansas, Illinois and eventually through New Brunswick andNewfoundland in Canada.

This particular belt of rocks is known to once have been part of Laurentia, a component of what was once Rodinia.

"There is a long, linear belt of these igneous rocks that stretchesacross Laurentia. But "bang" it stops, right there at the (western)margin where we knew that something rifted away" from what is now theWest Coast of the United States," Goodge said."It just ends right wherethat ancient rift margin is, and these rocks are basically not found inany other part of the world."

Goodge notes that there is no real alternative explanation for how therock got to where it was, other than a once continental meet withsouthwestern United States. The rock had been, as Goodge describes it,bull-dozed over from that interior region of Antarctica, thanks toice streams which slowly pushed rubble underneath them as they moved.

"This is first-rate work and a fascinating example of scientists atwork putting together the pieces of a much larger puzzle," said ScottBorg, director of the division of Antarctic sciences in NSF"s Office ofPolar Programs. "Not only do the authors pull together a diverse arrayof data to address a long-standing question about the evolution of theEarth"s crust during a critical time for biological evolution, but theresearch shows how the ideas surrounding the SWEAT hypothesis havedeveloped over time."

Posted by Josh Hill.


http://www.eurekalert.org/pub_releases/2008-07/nsf-asb071708.php


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 Post subject: NASA Prepares Massive Aerial Survey of Antarctica to Fill Sa
PostPosted: Tue Oct 13, 2009 8:35 am 
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Operation Ice Bridge will be the most extensive aerial survey ever of Antarctica

This Thursday, NASA will kick off the largest aerial survey ever undertaken of Earth"s polar regions. The effort will help fill a multi-year gap between the satellite missions that usually track changes in ice, and should also help scientists understand how the changing ice sheets might contribute to sea level rise around the world.

The huge endeavor, named Operation Ice Bridge, will be done from NASA"s DC-8 airborne laboratory. The aircraft carries laser mapping and gravity instruments as well as radar to peer down into the ice sheets. About 50 scientists and support staff are slated to take part in the 17 flights over Antarctica during the next six years, starting from a base at Punta Arenas, Chile.

ICESat-I has used a laser altimeter to take time-series measurements of changes in sea ice thickness at the polar climates. But the end of the mission sometime this year would have left NASA without such valuable data until the launch of ICESat-II in 2014 or 2015.

Other targets for the aerial survey besides Antarctica include Greenland, Alaskan glaciers, and Arctic sea ice.

[via Agence France-Presse]



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