Tuesday, April 21, 2009
Earth-Sized Planet Discovered in the Habitable Zone
http://www.universetoday.com/2007/04/25/earth-sized-planet-discovered-in-the-habitable-zone/
-----
http://en.wikipedia.org/wiki/Habitable_zone
22nd April, today is Earth day and the promising news is that Earth-Sized Planet has been discovered in the Habitable Zone, that means in a region of space where stellar conditions are favorable for life as it is found on Earth. There are two regions that must be favorable, one within a planetary system and the other within the galaxy. Planets and moons in these regions are the likeliest candidates to be habitable and thus capable of bearing extraterrestrial life similar to our own.
The habitable zone is not to be confused with the planetary habitability. While planetary habitability deals solely with the planetary conditions required to maintain carbon-based life, the habitable zone deals with the stellar conditions required to maintain carbon-based life, and these two factors are not meant to be juxtaposed.
Astronomers believe that life is most likely to form within the circumstellar habitable zone (CHZ) within a solar system, and the galactic habitable zone (GHZ) of the larger galaxy (though research on the latter point remains nascent). The HZ may also be referred to as the "life zone", "Comfort Zone", "Green Belt" or "Goldilocks Zone" (because it's neither too hot nor too cold, but "just right").
In our own solar system, the CHZ is thought to extend from a distance of 0.95 to 1.37 astronomical units.
-----
Gliese 581 d, the third planet of the red dwarf star Gliese 581 (approximately 20 light years distance from Earth), appears to be the best example which has been found so far of an extrasolar planet which orbits in the theoretical habitable zone of space surrounding its star.
Great big Jupiter-like planets are one thing, but the Holy Grail of extrasolar planetary discover is going to be another Earth - complete with life. We’re not there yet, but astronomers announced the next best thing yesterday: a roughly Earth-mass planet orbiting within the habitable zone of its parent star. In other words, liquid water could exist on this rocky planet.
The host star is called Gliese 581, and it’s one of the 100 closest star to us, located only 20.5 light years away in the constellation Libra. Unlike our Sun, it’s a red dwarf star, emitting much less light and energy. This brings its habitable zone in close and tight to the star. For a planet to be orbiting its parent star within this habitable zone, it’s got to have a really tight orbit.
And this is how the planet was discovered. It was made by measuring the star’s radial velocity, where the planet’s gravity tugs its parent star back and forth (aka, the Wobble Method). Astronomers can measure this velocity with tremendous precision to determine the planet’s mass and orbital period. And the tool for the job is the European Southern Observatory’s HARPS (High Accuracy Radial Velocity for Planetary Searcher) spectrograph connected to the 3.6-m telescope at La Silla, Chile.
The planet is “Earth-like”, but it wouldn’t seem much like home. It’s 50% larger than the Earth, and has about 5 times our planet’s mass. It also completes an orbit every 13 days - it’s 14 times closer to its star than the Earth is to the Sun. Since it’s in the habitable zone, there would very likely be liquid water on its surface.
Unfortunately, the radial method only tells astronomers what the planet’s mass and orbital distance are. They’re not directly observing it. So there’s no way to know if there is actually water on the surface, or even oxygen in the atmosphere that would indicate the presence of life. But future missions, like Darwin, will certainly put it in the cross hairs to get a better look for life.
The discovering team think that turning up an Earth-sized planet around a red dwarf star is now just a matter of time.
-----
http://en.wikipedia.org/wiki/Habitable_zone
22nd April, today is Earth day and the promising news is that Earth-Sized Planet has been discovered in the Habitable Zone, that means in a region of space where stellar conditions are favorable for life as it is found on Earth. There are two regions that must be favorable, one within a planetary system and the other within the galaxy. Planets and moons in these regions are the likeliest candidates to be habitable and thus capable of bearing extraterrestrial life similar to our own.
The habitable zone is not to be confused with the planetary habitability. While planetary habitability deals solely with the planetary conditions required to maintain carbon-based life, the habitable zone deals with the stellar conditions required to maintain carbon-based life, and these two factors are not meant to be juxtaposed.
Astronomers believe that life is most likely to form within the circumstellar habitable zone (CHZ) within a solar system, and the galactic habitable zone (GHZ) of the larger galaxy (though research on the latter point remains nascent). The HZ may also be referred to as the "life zone", "Comfort Zone", "Green Belt" or "Goldilocks Zone" (because it's neither too hot nor too cold, but "just right").
In our own solar system, the CHZ is thought to extend from a distance of 0.95 to 1.37 astronomical units.
-----
Gliese 581 d, the third planet of the red dwarf star Gliese 581 (approximately 20 light years distance from Earth), appears to be the best example which has been found so far of an extrasolar planet which orbits in the theoretical habitable zone of space surrounding its star.
Great big Jupiter-like planets are one thing, but the Holy Grail of extrasolar planetary discover is going to be another Earth - complete with life. We’re not there yet, but astronomers announced the next best thing yesterday: a roughly Earth-mass planet orbiting within the habitable zone of its parent star. In other words, liquid water could exist on this rocky planet.
The host star is called Gliese 581, and it’s one of the 100 closest star to us, located only 20.5 light years away in the constellation Libra. Unlike our Sun, it’s a red dwarf star, emitting much less light and energy. This brings its habitable zone in close and tight to the star. For a planet to be orbiting its parent star within this habitable zone, it’s got to have a really tight orbit.
And this is how the planet was discovered. It was made by measuring the star’s radial velocity, where the planet’s gravity tugs its parent star back and forth (aka, the Wobble Method). Astronomers can measure this velocity with tremendous precision to determine the planet’s mass and orbital period. And the tool for the job is the European Southern Observatory’s HARPS (High Accuracy Radial Velocity for Planetary Searcher) spectrograph connected to the 3.6-m telescope at La Silla, Chile.
The planet is “Earth-like”, but it wouldn’t seem much like home. It’s 50% larger than the Earth, and has about 5 times our planet’s mass. It also completes an orbit every 13 days - it’s 14 times closer to its star than the Earth is to the Sun. Since it’s in the habitable zone, there would very likely be liquid water on its surface.
Unfortunately, the radial method only tells astronomers what the planet’s mass and orbital distance are. They’re not directly observing it. So there’s no way to know if there is actually water on the surface, or even oxygen in the atmosphere that would indicate the presence of life. But future missions, like Darwin, will certainly put it in the cross hairs to get a better look for life.
The discovering team think that turning up an Earth-sized planet around a red dwarf star is now just a matter of time.
Labels: earth like, habitable zone
Sunday, March 29, 2009
Brahmapuranam - 7 islands - now 7 continents, are they same?
We all have studied that there are 7 continents in the world, i.e.
1) Africa,
2) Antarctica,
3) Asia,
4) Europe,
5) North America,
6) South America and
7) Australia.
Recently, I came across an interesting article in which it was mentioned in ancient Hindu literature Brahmapuranam that long before any transformations took place on earth, there were 7 islands, i.e.
1) Jambu,
2) Plaksha,
3) Shalmalee,
4) Kusha,
5) Krouncha,
6) Shaaka and
7) Pushkara.
Are these the same continents that we have learnt in schools?
Also, interesting to note is that all these were individual islands, which later got attached or detached due to various reasons and got transformed into present state.
1) Africa,
2) Antarctica,
3) Asia,
4) Europe,
5) North America,
6) South America and
7) Australia.
Recently, I came across an interesting article in which it was mentioned in ancient Hindu literature Brahmapuranam that long before any transformations took place on earth, there were 7 islands, i.e.
1) Jambu,
2) Plaksha,
3) Shalmalee,
4) Kusha,
5) Krouncha,
6) Shaaka and
7) Pushkara.
Are these the same continents that we have learnt in schools?
Also, interesting to note is that all these were individual islands, which later got attached or detached due to various reasons and got transformed into present state.
Labels: 7 continents, Brahmapuranam
Saturday, March 07, 2009
Turritopsis nutricula - The world’s only “immortal” creature
From Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/Turritopsis_nutricula
Turritopsis nutricula is a hydrozoan with a life cycle in which it reverts to the polyp stage after becoming sexually mature. It is the only known case of a metazoan capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage [2]. It does this through the cell development process of transdifferentiation. Theoretically, this cycle can repeat indefinitely, rendering it biologically immortal.
Description
Turritopsis nutricula has a diameter of about 5 millimetres (0.20 in). It has an equally high and bell-shaped figure. The walls are uniformly thin. The bright red, big stomach has a cruciform shape in its cross section. Young specimens have only eight tentacles along the edge, while adult specimens have 80-90 tentacles.
Distribution and range
The species is originally from the Caribbean but has spread all over the world.[3] T. nutricula are found in temperate to tropical regions in all of the world's oceans. Turritopsis is believed to be spreading across the world as ships ballast water is discharged in ports.
Life cycle
The fertilized eggs develop in the stomach and in the screen formed by the cave in the jellyfish planula. The eggs are then planted on the seabed in polyp colonies. The jellyfish hatches after two days. The jellyfish becomes sexually mature after a few weeks (the exact duration depends on the ocean temperature; at 20 °C (68 °F) it is 25 to 30 days and at 22 °C (72 °F) it is 18 to 22 days).
Immortality
Jellyfish usually die after propagating; however, the Turritopsis nutricula has developed the ability to return to a polyp state. This is done through a cell change in the external screen (exumbrella). The ability to reverse the life cycle is probably unique in the animal kingdom, and allows the jellyfish to bypass death, rendering the Turritopsis nutricula biologically immortal.
http://en.wikipedia.org/wiki/Turritopsis_nutricula
Turritopsis nutricula is a hydrozoan with a life cycle in which it reverts to the polyp stage after becoming sexually mature. It is the only known case of a metazoan capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage [2]. It does this through the cell development process of transdifferentiation. Theoretically, this cycle can repeat indefinitely, rendering it biologically immortal.
Description
Turritopsis nutricula has a diameter of about 5 millimetres (0.20 in). It has an equally high and bell-shaped figure. The walls are uniformly thin. The bright red, big stomach has a cruciform shape in its cross section. Young specimens have only eight tentacles along the edge, while adult specimens have 80-90 tentacles.
Distribution and range
The species is originally from the Caribbean but has spread all over the world.[3] T. nutricula are found in temperate to tropical regions in all of the world's oceans. Turritopsis is believed to be spreading across the world as ships ballast water is discharged in ports.
Life cycle
The fertilized eggs develop in the stomach and in the screen formed by the cave in the jellyfish planula. The eggs are then planted on the seabed in polyp colonies. The jellyfish hatches after two days. The jellyfish becomes sexually mature after a few weeks (the exact duration depends on the ocean temperature; at 20 °C (68 °F) it is 25 to 30 days and at 22 °C (72 °F) it is 18 to 22 days).
Immortality
Jellyfish usually die after propagating; however, the Turritopsis nutricula has developed the ability to return to a polyp state. This is done through a cell change in the external screen (exumbrella). The ability to reverse the life cycle is probably unique in the animal kingdom, and allows the jellyfish to bypass death, rendering the Turritopsis nutricula biologically immortal.
Labels: immortal creature, jellyfish, Turritopsis nutricula
Friday, June 29, 2007
Genome Transplant turns one species into another
http://www.newscientist.com/article/dn12157-tycoon-succeeds-in-genome-transplant.html
Tycoon succeeds in 'genome transplant'
19:00 28 June 2007
NewScientist.com news service
Peter Aldhous
Call it bacterial alchemy: using a "genome transplant", researchers have turned one species of bacterium into another. The transformation is the latest feat from US genomics pioneer Craig Venter, and marks another step towards his goal of creating a synthetic life-form.
Over the past few years, Venter and his colleagues have defined a minimal genome containing less than 400 genes needed to sustain a free-living cell.
They have done this by systematically knocking out genes in the simple bacterium Mycoplasma genitalium, a sexually-transmitted parasite that infects humans. Venter aims to chemically synthesise this genome from the nucleotide building blocks of DNA, and then put it into a bacterial cell.
Achieving that goal requires a technique to replace a Mycoplasma genome with the synthetic version – and the new work on genome "transplantation" provides proof that this should be possible.
Complex transfer
Venter's team, led by John Glass of the J. Craig Venter Institute in Rockville, Maryland, US, managed to transfer the genome of Mycoplasma mycoides to a related parasite called M. capricolum. Both species infect goats, sheep and cows.
Judging from the proteins they produced, the resulting cells seemed to have completely transformed into M. mycoides.
Mycoplasma cells are too small to manipulate mechanically, so the researchers had to devise laborious chemical and physical methods to extract the genome from one species and introduce it to the other. "It's very simple in concept, very complex in actual execution," Venter says.
The researchers took a strain of M. mycoides that is resistant to the antibiotic tetracycline, broke open the cells and carefully "digested" the proteins, leaving just the intact circular chromosomes, the DNA.
These chromosomes were then incubated with M. capricolum cells in a medium containing a polymer that encourages cell membranes to fuse. The researchers speculate that some M. capricolum cells fused together, encapsulating an M. mycoides chromosome as they did so.
Finally, the researchers treated their cultures with tetracycline, so that only M. capricolum cells containing the M. mycoides genome would survive.
Mysterious process
The transplantation worked in about 1 in every 150,000 cells, but that was enough to give healthy colonies of the transformed bacteria, which did not contain M. capricolum DNA.
Exactly how the M. mycoides genome took over the cell is unclear, but the researchers suggest that cells containing multiple genomes soon divide, with each daughter cell containing just one genome. Those containing the host M. capricolum genome would then have been quickly wiped out by the tetracycline.
Venter, who has ignited controversy by trying to patent his minimal genome, says that the team’s efforts to synthesise it from scratch are still in progress. But once the finished genome is ready, the transplant technique should allow the first "synthetic" bacterium to be created in rapid time. "It could be weeks or months," says Venter.
Journal reference: Science (DOI: 10.1126/science.1144622)
Tycoon succeeds in 'genome transplant'
19:00 28 June 2007
NewScientist.com news service
Peter Aldhous
Call it bacterial alchemy: using a "genome transplant", researchers have turned one species of bacterium into another. The transformation is the latest feat from US genomics pioneer Craig Venter, and marks another step towards his goal of creating a synthetic life-form.
Over the past few years, Venter and his colleagues have defined a minimal genome containing less than 400 genes needed to sustain a free-living cell.
They have done this by systematically knocking out genes in the simple bacterium Mycoplasma genitalium, a sexually-transmitted parasite that infects humans. Venter aims to chemically synthesise this genome from the nucleotide building blocks of DNA, and then put it into a bacterial cell.
Achieving that goal requires a technique to replace a Mycoplasma genome with the synthetic version – and the new work on genome "transplantation" provides proof that this should be possible.
Complex transfer
Venter's team, led by John Glass of the J. Craig Venter Institute in Rockville, Maryland, US, managed to transfer the genome of Mycoplasma mycoides to a related parasite called M. capricolum. Both species infect goats, sheep and cows.
Judging from the proteins they produced, the resulting cells seemed to have completely transformed into M. mycoides.
Mycoplasma cells are too small to manipulate mechanically, so the researchers had to devise laborious chemical and physical methods to extract the genome from one species and introduce it to the other. "It's very simple in concept, very complex in actual execution," Venter says.
The researchers took a strain of M. mycoides that is resistant to the antibiotic tetracycline, broke open the cells and carefully "digested" the proteins, leaving just the intact circular chromosomes, the DNA.
These chromosomes were then incubated with M. capricolum cells in a medium containing a polymer that encourages cell membranes to fuse. The researchers speculate that some M. capricolum cells fused together, encapsulating an M. mycoides chromosome as they did so.
Finally, the researchers treated their cultures with tetracycline, so that only M. capricolum cells containing the M. mycoides genome would survive.
Mysterious process
The transplantation worked in about 1 in every 150,000 cells, but that was enough to give healthy colonies of the transformed bacteria, which did not contain M. capricolum DNA.
Exactly how the M. mycoides genome took over the cell is unclear, but the researchers suggest that cells containing multiple genomes soon divide, with each daughter cell containing just one genome. Those containing the host M. capricolum genome would then have been quickly wiped out by the tetracycline.
Venter, who has ignited controversy by trying to patent his minimal genome, says that the team’s efforts to synthesise it from scratch are still in progress. But once the finished genome is ready, the transplant technique should allow the first "synthetic" bacterium to be created in rapid time. "It could be weeks or months," says Venter.
Journal reference: Science (DOI: 10.1126/science.1144622)
Labels: genome transplant
Wednesday, March 28, 2007
Tectonic plates - Eqrthquate - Tsunami
http://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake
The crust of our planet is cracked into seven large and many other smaller slabs of rock called plates, averaging about 50 miles thick. As they move (only inches per year), and depending on the direction of that movement, they collide, forming deep ocean trenches, mountains, volcanoes, and generating earthquakes.
Other userful info:
http://www.extremescience.com/PlateTectonicsmap.htm
http://www.seismo.unr.edu/ftp/pub/louie/class/100/plate-tectonics.html
http://en.wikipedia.org/wiki/Plate_tectonics
http://soundwaves.usgs.gov/2005/01/
http://iri.columbia.edu/%7elareef/tsunami/
The crust of our planet is cracked into seven large and many other smaller slabs of rock called plates, averaging about 50 miles thick. As they move (only inches per year), and depending on the direction of that movement, they collide, forming deep ocean trenches, mountains, volcanoes, and generating earthquakes.
Other userful info:
http://www.extremescience.com/PlateTectonicsmap.htm
http://www.seismo.unr.edu/ftp/pub/louie/class/100/plate-tectonics.html
http://en.wikipedia.org/wiki/Plate_tectonics
http://soundwaves.usgs.gov/2005/01/
http://iri.columbia.edu/%7elareef/tsunami/
Labels: Eqrthquate, Tectonic plates, Tsunami
Saturday, March 24, 2007
Data storage on a photon: Scientists say it's possible
http://www.computerworld.com/action/article.do?command=viewArticleBasic&articleId=9008999
January 24, 2007 (TechWorld.com) -- Scientists are claiming a breakthrough in the ability to attach an image to a photon of light and retrieve it later.
Scientists at the University of Rochester in New York used their college logo, consisting of a few hundred pixels, for the experiment and were able to attach the image to a single photon of light. The photon or pulse of light was slowed down 100 nanoseconds and compressed to 1% of its original length. The scientists claim that the technology could one day store tremendous amounts of information very densely.
Researcher John Howell, assistant professor of physics at the university, is now working on delaying dozens of pulses for as long as several milliseconds, and as many as 10,000 pulses for up to a nanosecond in a 4-in. cell of cesium gas at a warm 100 degrees Celsius.
Previous optical buffering trials have found that most information carried by the light is lost. This latest achievement is important because engineers are trying to speed up computer processing and network speeds using light. Their systems slow down when they have to convert light to electronic signals to store information, even for a short while.
"It sort of sounds impossible, but instead of storing just ones and zeros, we're storing an entire image. It's analogous to the difference between snapping a picture with a single pixel and doing it with a camera -- this is like a 6-megapixel camera," Howell said.
The device was revealed in today's online issue of the journal Physical Review Letters.
"Now I want to see if we can delay something almost permanently, even at the single photon level," Howell said. "If we can do that, we're looking at storing incredible amounts of information in just a few photons."
January 24, 2007 (TechWorld.com) -- Scientists are claiming a breakthrough in the ability to attach an image to a photon of light and retrieve it later.
Scientists at the University of Rochester in New York used their college logo, consisting of a few hundred pixels, for the experiment and were able to attach the image to a single photon of light. The photon or pulse of light was slowed down 100 nanoseconds and compressed to 1% of its original length. The scientists claim that the technology could one day store tremendous amounts of information very densely.
Researcher John Howell, assistant professor of physics at the university, is now working on delaying dozens of pulses for as long as several milliseconds, and as many as 10,000 pulses for up to a nanosecond in a 4-in. cell of cesium gas at a warm 100 degrees Celsius.
Previous optical buffering trials have found that most information carried by the light is lost. This latest achievement is important because engineers are trying to speed up computer processing and network speeds using light. Their systems slow down when they have to convert light to electronic signals to store information, even for a short while.
"It sort of sounds impossible, but instead of storing just ones and zeros, we're storing an entire image. It's analogous to the difference between snapping a picture with a single pixel and doing it with a camera -- this is like a 6-megapixel camera," Howell said.
The device was revealed in today's online issue of the journal Physical Review Letters.
"Now I want to see if we can delay something almost permanently, even at the single photon level," Howell said. "If we can do that, we're looking at storing incredible amounts of information in just a few photons."
Labels: data storage, photon
Saturday, March 10, 2007
Huge Underground Ocean Found Beneath Asia
http://news.nationalgeographic.com/news/2007/02/070227-ocean-asia_2.html
Huge Underground "Ocean" Found Beneath Asia
Richard A. Lovett
for National Geographic News
February 27, 2007
A giant blob of water the size of the Arctic Ocean has been discovered hundreds of miles beneath eastern Asia, scientists report.
Researchers found the underground "ocean" while scanning seismic waves as they passed through Earth's interior
But nobody will be exploring this sea by submarine. The water is locked in moisture-containing rocks 400 to 800 miles (700 to 1,400 kilometers) beneath the surface.
"I've gotten all sorts of emails asking if this is the water that burst out in Noah's flood," said the leader of the research team, Michael Wysession of Washington University in St. Louis.
"It isn't an ocean. [The water] is a very low percentage [of the rock], probably less than 0.1 percent."
Given the region's size, however, that's enough to add up to a vast amount of water.
Earthquakes Reveal "Ocean"
Wysession and former graduate student Jesse Lawrence discovered the damp spot by observing how seismic waves from distant earthquakes pass through Earth's mantle.
The wet zone, which runs from Indonesia to the northern tip of Russia, showed up as an area of relatively weak rock, causing the seismic waves to lose strength much more rapidly than elsewhere.
The water got there by the process of plate tectonics, in which sections of the Earth's crust shift. This process caused the ocean bottom to be pulled beneath continental plates all around the Pacific Rim.
Normally, Earth's internal heat bakes the water out of the rocks before it gets more than 60 miles (100 kilometers) deep. The water then escapes upward as volcanic gas.
But along the eastern Pacific Rim, conditions allow the rock to be drawn much deeper before the moisture is cooked out.
The find may help scientists better understand the formation of volcanic regions such as those in Iceland, Hawaii, and Yellowstone National Park.
(Read related story: "Supervolcano Raises Yellowstone, Fuels Geysers, Study Says" [March 1, 2006].)
One theory suggests that these areas are volcanic because hot spots deep within the Earth's interior melt the underlying rock like a giant blowtorch, producing large quantities of lava.
Wysession says that the presence of water may allow such hot spots to melt more rock, thereby creating more lava.
"If you add water [to the rock] you can get an increased amount of melting," he said.
"There's a consensus that not all hot spots are equal. Some are hot spots; some are wet spots."
Wysession and Lawrence report their findings in a study published by the American Geophysical Union.
A Look at Earth's Fate
The new study also reveals clues to Earth's long-term fate, says Norman Sleep, a geophysicist at Stanford University who was not involved in the project.
When the planet was young, steam came from the deep interior to the surface as volcanic gas and eventually produced today's oceans. But as Earth's interior ages and cools, it becomes easier for water to return below the surface.
"So, rather than degassing, now [Earth] may be losing water into the mantle," Sleep said.
This gradual suction of water back below the surface may be a good thing for Earth's geological stability, he notes.
Underground water acts as a kind of lubricant that allows plates in Earth's crust to keep shifting at their present rate, Sleep explains.
This helps keep the thickness and elevation of the continents relatively stable.
If things changed, he said, "we'd have Pike's Peak boat tours."
See also:World's Longest Underground River Discovered in Mexico, Divers Say
Huge Underground "Ocean" Found Beneath Asia
Richard A. Lovett
for National Geographic News
February 27, 2007
A giant blob of water the size of the Arctic Ocean has been discovered hundreds of miles beneath eastern Asia, scientists report.
Researchers found the underground "ocean" while scanning seismic waves as they passed through Earth's interior
But nobody will be exploring this sea by submarine. The water is locked in moisture-containing rocks 400 to 800 miles (700 to 1,400 kilometers) beneath the surface.
"I've gotten all sorts of emails asking if this is the water that burst out in Noah's flood," said the leader of the research team, Michael Wysession of Washington University in St. Louis.
"It isn't an ocean. [The water] is a very low percentage [of the rock], probably less than 0.1 percent."
Given the region's size, however, that's enough to add up to a vast amount of water.
Earthquakes Reveal "Ocean"
Wysession and former graduate student Jesse Lawrence discovered the damp spot by observing how seismic waves from distant earthquakes pass through Earth's mantle.
The wet zone, which runs from Indonesia to the northern tip of Russia, showed up as an area of relatively weak rock, causing the seismic waves to lose strength much more rapidly than elsewhere.
The water got there by the process of plate tectonics, in which sections of the Earth's crust shift. This process caused the ocean bottom to be pulled beneath continental plates all around the Pacific Rim.
Normally, Earth's internal heat bakes the water out of the rocks before it gets more than 60 miles (100 kilometers) deep. The water then escapes upward as volcanic gas.
But along the eastern Pacific Rim, conditions allow the rock to be drawn much deeper before the moisture is cooked out.
The find may help scientists better understand the formation of volcanic regions such as those in Iceland, Hawaii, and Yellowstone National Park.
(Read related story: "Supervolcano Raises Yellowstone, Fuels Geysers, Study Says" [March 1, 2006].)
One theory suggests that these areas are volcanic because hot spots deep within the Earth's interior melt the underlying rock like a giant blowtorch, producing large quantities of lava.
Wysession says that the presence of water may allow such hot spots to melt more rock, thereby creating more lava.
"If you add water [to the rock] you can get an increased amount of melting," he said.
"There's a consensus that not all hot spots are equal. Some are hot spots; some are wet spots."
Wysession and Lawrence report their findings in a study published by the American Geophysical Union.
A Look at Earth's Fate
The new study also reveals clues to Earth's long-term fate, says Norman Sleep, a geophysicist at Stanford University who was not involved in the project.
When the planet was young, steam came from the deep interior to the surface as volcanic gas and eventually produced today's oceans. But as Earth's interior ages and cools, it becomes easier for water to return below the surface.
"So, rather than degassing, now [Earth] may be losing water into the mantle," Sleep said.
This gradual suction of water back below the surface may be a good thing for Earth's geological stability, he notes.
Underground water acts as a kind of lubricant that allows plates in Earth's crust to keep shifting at their present rate, Sleep explains.
This helps keep the thickness and elevation of the continents relatively stable.
If things changed, he said, "we'd have Pike's Peak boat tours."
See also:World's Longest Underground River Discovered in Mexico, Divers Say
Labels: Underground Ocean
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