Apr 23, 2011

Purple Plants Might Thrive Under Multiple Stars

Pop culture was first introduced to the notion of life under two stars in the 1977 film "Star Wars: Episode IV - A New Hope." In an introspective moment, hero Luke Skywalker watches a pair of sun-like stars set on the horizon.

His native world Tatooine is a desert planet. But two suns in the sky would be a big deal for vegetation on a tropical planet, reports Jack O'Malley-James of the University of St. Andrews in Scotland. He recently presented a study at a Royal Astronomical Society meeting in Llandudno, Wales.

Given the power of biological evolution, plant life would adapt to use energy from both suns. Or perhaps different forms of plants may evolve to use light from one specific sun, he reported.

Things could get complicated in multiple systems that have a yellow sun-like star with a red dwarf companion. Over 25 percent of sun-like stars and 50 percent of red dwarfs are found in multi-star systems. The plants would have access to a broader range of radiation than on Earth. Stellar radiation would stretch far into infrared wavelengths.

"Our simulations suggest that planets in multi-star systems may host exotic forms of the more familiar plants we see on Earth," says O'Malley-James.
Plants

In 2008, astrobiologist Nancy Kiang of Columbia University predicted that alien plants living under a red sun could evolve other photosynthetic pigments that are colored purple, or even black (O'Malley-James speculates black or gray coloring).

Unlike Earth vegetation that reflects some green light, alien vegetation might absorb across the entire visible wavelength range in order to use as much of the available light as possible. They may also be able to use infrared or ultraviolet radiation to drive photosynthesis.

Due to their interior structure, red dwarf stars can be more petulant than a solar-type star. A Hubble Space Telescope survey of 215,000 red dwarfs uncovered 100 powerful stellar flares over a seven-day period. Despite their puny mass, red dwarfs can pack a punch.

Read more at Discovery News

Apr 22, 2011

LHC Smashes 'Beam Intensity' World Record

The world's biggest atom smasher has set a new world record for beam intensity, a key measure of performance and power, the European Organization for Nuclear Research (CERN) said Friday.
On a quest to unlock some of the universe's deepest secrets, the Large Hadron Collider (LHC) in Geneva collided beams with a luminosity exceeding the mark set last year by the US Tevetron accelerator, CERN said.

In particle physics, luminosity affects the number of collisions -- the higher the luminosity, the more particles are likely to collide.

"Beam intensity is key to the success of the LHC, so this is a very important step," said CERN Director General Rolf Heuer.

"High intensity means more data, and more data means greater discovery potential," he said in a statement.

The new record measured a level of luminosity of 467,000 billion billion billion -- 467 followed by 30 zeros -- per square centimeter per second, which corresponds to several million particle collisions per second.

Enhanced power boosts the odds of identifying extremely rare sub-atomic particles, especially the elusive Higgs boson, or 'God particle'.

Earlier experiments have found most of the tiny and ephemeral matter predicted by the so-called Standard Model of particle physics -- except the Higgs boson.

Many scientists believe only the 27-kilometer (16.8-mile), 3.9-billion-euro (5.2-billion-dollar) LHC may be powerful enough to detect it.

The current run of LHC experiments is set to continue through 2012, by which time it should be possible to determine if the Higgs boson truly exists, CERN said.

"There's a lot of excitement at CERN today, and a tangible feeling that we're on the threshold of new discovery," said Serge Bertolucci, CERN's Director for Research and Scientific Computing.

Read more at Discovery News

Hundreds of Islands New to Science

Islands that suddenly appear may sound like something out of a pirate myth. But a new survey has found hundreds of islands needing modern X marks on today's maps.

The islands weren’t a result of Blackbeard’s curse; they had always been there. But like the best buried treasure spot, their locations weren't common knowledge.

“The study developed as newer and higher resolution sources of free satellite images were made accessible to the public,” geoscientist Mathew Stutz of Meredith University told Discovery News.

Stutz was one of the authors of a study published in the Journal of Coastal Research. The study added 657 islands to the world’s list of barrier islands by the researchers from Duke University and Meredith College. The grand total is now 2,149.

"Needless to say, the people who lived in these areas knew they were on islands, but the geographic/geologic classification into barrier islands was not in their realm. All in all, this was very exciting, to 'discover' new islands," geologist and co-author Orrin H. Pilkey of Duke University told Discovery News.

Barrier islands form on the coasts of landmasses and provide important protection against erosion and storm damage. They are also important habitats for wildlife. A majority of the islands, 75 percent, exist in the northern hemisphere.

Barrier islands are often long, low, narrow deposits of sand and sediment (such as the thin arc of beaches boarding the northern rim of Wrangle Island in the image at right). They also tend to erode away or build up over time due to waves, tides and ocean currents. That can make them hard to find and pin down on a map.

An earlier survey missed these 657 “new” islands. “The 2001 study relied on topographic maps and the first generation of NASA's Geocover Landsat Program,” Stutz said. “The initial Geocover was compiled from 1990-era Landsat 4/5 images, with 30-meter resolution. Small or narrow islands were still difficult to detect, a few were obscured by clouds.”

“Even today, a few regions of the world (primarily Russia) are not included in this dataset,” Stutz said.

"When the actual work was done for the first study, Google Earth was not available, at least not in its current form," Pilkey said. "We started out looking at maps and charts, which was quite an education."

Even public historical charts such as the New York Geographical Society's collection and the British Admiralty's survey of the continental shelf off the Pacific coast of Colombia missed many islands Pilkey and Stutz found using modern eyes in the sky.

“By 2004 NASA completed a Landsat 7 dataset (with 15-meter resolution) using 2000-era images and did include all the world's coasts. Prior to this program, hundreds if not thousands of satellite images would have to have been purchased individually at prohibitive cost for such a large scale survey,” Stutz said.

Read more at Discovery News

Apr 21, 2011

Neanderthals Were Overwhelmingly Right-Handed

Neanderthals and their likely ancestors were overwhelmingly right-handed, according to investigation into fossilized teeth excavated in Spanish and Croatian caves.

Writing in the British journal Laterality, an international team of researchers has concluded that right-handedness, a uniquely human trait that has right-handers outnumbering lefties nine-to-one, dominated as far back as half a million years ago.

Various researchers have attempted to determine when right-handedness first evolved by analyzing ancient tools, prehistoric art and human bones.

However, the results have not been definitive.

“We found that the best evidence comes from teeth,” David Frayer, professor of anthropology at the University of Kansas, told Discovery News.

Frayer and colleagues examined fossilized teeth from a more than 500,000-year-old chamber known as Sima de los Huesos near Burgos, Spain.

Excavated over the past quarter century, the cave has produced a trove of human remains believed to belong to ancestors of European Neanderthals.

The researchers investigated the incisor and canine teeth of 12 individuals whose estimated age ranged from 9.5 years to more than 35 years.

Quite different from the finer dietary scratches on the buccal face of premolars and molars, the wider and longer markings on the incisors and canines were probably made as humans used their front teeth like a third hand, maneuvering food and other objects clenched between them.

Produced over the lifetime of the individuals, the scratch marks were made when a stone tool was accidentally dragged across the labial face.

“Pulling with the left and cutting with the right leaves oblique scratches of a typical direction, if the stone tool accidentally hits the tooth,” Fraser said.

“Pulling with the right and cutting with the left leaves the opposite oblique marks,” he added.

Tooth Incisions angled to the right, the result of right-handed tool use, characterized all 12 individuals, suggesting that no left-handers were present in the examined sample.

The researchers also examined teeth from caves in Spain and Croatia belonging to 29 later Neanderthal populations.

It emerged that only two individuals had left-angled tooth incisions typical of left-handers, while an overwhelming 93.1 percent featured right-handedness.

"It is difficult to interpret these fossil data in any way other than that laterality was established early in European fossil record and continued through the Neandertals," the researchers wrote.

"This establishes that handedness is found in more than just recent Homo sapiens," they said.

According to Frayer, these findings can shed light in understanding the language capacity of ancient populations, as language is primarily located on the left side of the brain, which controls the right side of the body.

Read more at Discovery News

The Hubble is 21 years old

WIRED: To commemorate the upcoming 21st anniversary of the Hubble Space Telescope’s first day in space, NASA astronomers released this beautiful image of two interacting galaxies in the shape of a rose.

Together, the pair of dancing galaxies are called Arp 273. They lie in the constellation Andromeda, about 300 million light-years from Earth. Though connected by a thin bridge of stars, they’re tens of thousands of light-years from each other.

The larger galaxy, called UGC 1810, is about five times as massive as its smaller companion, UGC 1813. Astronomers think the smaller galaxy plunged straight through the larger: UGC 1810’s inner set of spiral arms is highly warped, a telltale sign of distortion by UGC 1813’s gravitational pull. Meanwhile, UGC 1813 shows an intense burst of star formation in its nucleus, possibly triggered by swan-diving through its neighbor.

WIRED

Apr 20, 2011

Fresh Evidence Adds Weight to Human Ancestor’s Identity

MINNEAPOLIS — Fossils described last year as representatives of an ancient species critical to human evolution have reentered the scientific spotlight and set off a new round of debate over the finds’ true identity.

sciencenews
Researchers described analyses of new and previously recovered remains of a South African species called Australopithecus sediba on April 16 at a meeting of the American Association of Physical Anthropologists. Evidence is accumulating, they reported, that 2-million-year-old A. sediba formed an evolutionary connection between relatively apelike members of Australopithecus and the Homo genus, which includes living people.

It’s now clear that A. sediba shares more skeletal features with early Homo specimens than any other known Australopithecus species does, said Darryl de Ruiter of Texas A&M University in College Station. “We think A. sediba is a possible candidate ancestor for the genus Homo.”

De Ruiter suspects that an isolated population of the hominid species Australopithecus africanus gradually evolved into A. sediba, resulting in a species characterized by an unusual mix of skeletal traits, some typical of Australopithecus in general and others of early Homo.

That scenario, outlined in symposium presentations by De Ruiter and Lee Berger  of the University of the Witwatersrand in Johannesburg, South Africa, remains controversial despite the new fossil discoveries.

Ian Tattersall of the American Museum of Natural History in New York City endorsed A. sediba as a distinct species, probably closely related to A. africanus. “I wouldn’t classify it as the root of the Homo genus, though,” he commented.

De Ruiter acknowledged the possibility that two partial A. sediba skeletons previously excavated from a collapsed, underground cave, as well as newly retrieved fossils from the cave, might represent a late-surviving form of Australopithecus africanus unrelated to Homo. Previous A. africanus finds date from about 3 million to 2.4 million years ago in South Africa. Fossils of A. africanus show lots of anatomical disparities from one individual to another, so that species might well encompass fossils attributed to A. sediba, remarked John Hawks of the University of Wisconsin–Madison. Much uncertainty surrounds the identity of fossil members of the human evolutionary family between 3 million and 2 million years ago, he said.

Possible Homo fossils date to around 2.3 million years ago in East Africa, suggesting that even if A. sediba truly is a new species, it evolved after Homo did.

New A. sediba fossils from the same South African cave complex, many belonging to the previously discovered partial skeletons, underscore this ancient species’ mosaic anatomy, Berger said. A largely complete female pelvis displays relatively straight, vertically aligned hips and an elongated birth canal, much like early Homo species. Other Australopithecus females possessed a relatively short, wide pelvic opening and flaring hip bones.

Read more at Wired Science

Was Last Supper a Day Earlier?

Christians have long celebrated Jesus Christ's Last Supper on Maundy Thursday but new research released Monday claims to show it took place on the Wednesday before the crucifixion.

Colin Humphreys, a scientist at the University of Cambridge, believes it is all due to a calendar mix-up -- and asserts his findings strengthen the case for finally introducing a fixed date for Easter.

Humphreys uses a combination of biblical, historical and astronomical research to try to pinpoint the precise nature and timing of Jesus's final meal with his disciples before his death.

Researchers have long been puzzled by an apparent inconsistency in the Bible.

While Matthew, Mark and Luke all say the Last Supper coincided with the start of the Jewish festival of Passover, John claims it took place before Passover.

Humphreys has concluded in a new book, "The Mystery Of The Last Supper," that Jesus -- along with Matthew, Mark and Luke -- may have been using a different calendar to John.

"Whatever you think about the Bible, the fact is that Jewish people would never mistake the Passover meal for another meal, so for the Gospels to contradict themselves in this regard is really hard to understand," Humphreys said.

"Many biblical scholars say that, for this reason, you can't trust the Gospels at all. But if we use science and the Gospels hand in hand, we can actually prove that there was no contradiction."

In Humphreys' theory, Jesus went by an old-fashioned Jewish calendar rather than the official lunar calendar which was in widespread use at the time of his death and is still in use today.

This would put the Passover meal -- and the Last Supper -- on the Wednesday, explaining how such a large number of events took place between the meal and the crucifixion.

It would follow that Jesus' arrest, interrogation and separate trials did not all take place in the space of one night but in fact occurred over a longer period.

Read more at Discovery News

Did Neanderthals Believe in an Afterlife?

Evidence for a likely 50,000-year-old Neanderthal burial ground that includes the remains of at least three individuals has been unearthed in Spain, according to a Quaternary International paper.

The deceased appear to have been intentionally buried, with each Neanderthal's arms folded such that the hands were close to the head. Remains of other Neanderthals have been found in this position, suggesting that it held meaning.

Neanderthals therefore may have conducted burials and possessed symbolic thought before modern humans had these abilities. The site, Sima de las Palomas in Murcia, Southeast Spain, may also be the first known Neanderthal burial ground of Mediterranean Europe.

"We cannot say much (about the skeletons) except that we surmise the site was regarded as somehow relevant in regard to the remains of deceased Neanderthals," lead author Michael Walker told Discovery News. "Their tools and food remains, not to mention signs of fires having been lit, which we have excavated indicate they visited the site more than once."

Walker, a professor in the Department of Zoology and Physical Anthropology at the University of Murcia, and his colleagues have been working at the site for some time. So far they have found buried articulated skeletons for a young adult female, a juvenile or child, and an adult -- possibly male -- Neanderthal.

"We cannot say whether these three individuals were related, though it is likely," he said, explaining that DNA has been denatured due to high ambient temperatures. "Surely the child was related to one of the others, though."

The three skeletons represent some of the best-preserved, and most methodically excavated remains of Neanderthals.

"Such discoveries are extraordinarily uncommon," Walker said.

The Neanderthals were found covered together with rocks burying their remains. The researchers believe it's likely that other Neanderthals intentionally placed the rocks over the bodies from a height. While it cannot be ruled out that an accident killed the three individuals, the scientists believe that wasn't the case.

"I think there is just enough evidence at Sima de las Palomas to think that three articulated skeletons are unlikely to have been the result of a single random accident to three cadavers that somehow escaped the ravages of hyenas and leopards, which were present at the site," Walker said.

Unburnt bones of two articulated panther paws were embedded in rock "in an area where the rest of the animal's skeleton was conspicuous by its absence notwithstanding its proximity to the human skeletons," the authors write.

The researchers speculate that a Neanderthal cut off the panther paws and kept them. It is also possible that the paws were added to the bodies before burial, perhaps holding some ritual significance.

The remains of six to seven other Neanderthals, including one baby and two juveniles, have also been excavated at the site. The tallest individual appears to have been an adult who stood around 5'1".

Read more at Discovery News

Apr 19, 2011

Scientists Teleport Light

Researchers from Australia and Japan have successfully teleported wave packets of light, potentially revolutionizing quantum communications and computing.

The team, led by researchers at the University of Tokyo, say this is the first-ever teleportation, or transfer, of a particular complex set of quantum information from one point to another.

They say it will make possible high-speed, high-fidelity transmission of large volumes of information, such as quantum encryption keys, via communications networks.

The research appears today in the journal Science.

Professor Elanor Huntington, of the School of Engineering and Information Technology at UNSW's Canberra campus, explains that teleportation -- the transfer of quantum information from one location to another using normal, "classical" communications -- is a fundamental quantum communication technique.

"It relies on having two things," she said.

"One is the normal fiber optic internet or even copper cables, and the other is a shared resource between the sender and the receiver, that could have been shared at any time in the past: we call that entanglement."

Huntington says the idea of quantum teleportation has been around for about ten years, but has been difficult to put into practice.

"There used to be two ways of doing teleportation and both had their limitations," she said.

"One was quite fast, but had a limited probability of succeeding. The other way of doing it was quite slow, but had a very good probability of working."

"What we've done is managed to get it both fast and good quality," she said.

They did it by teleporting the wave packets of light in a 'Schrödinger's cat' state.

In Schrödinger's famous thought experiment of the 1930s, a cat would be placed in a sealed box with a device containing atomic material. A Geiger counter was included to measure radiation if at some point an atom decayed. Should that happen, the Geiger counter would trigger the release of cyanide gas, which would kill the cat.

The idea was that it was impossible to know whether or not the cat was alive or dead without opening the box and observing it, and that until that happened, both realities existed. This became known as superposition.

Schrödinger's is said to have devised the experiment to ridicule the emerging theories of quantum physics; but since then physicists have found many examples of superposition in the quantum world.

"What was funky about Schrödinger's idea was that you could take a normal macroscopic object, which we all think we know and understand fairly well, and you could put it into a quantum superposition -- and that's kind of weird," said Huntington.

Read more at Discovery News

How to Catch a Liar: The Cognitive Clues to Deceit

Huffington Post:  The long-running TV show “NCIS,” a drama focused on the Naval Criminal Investigative Service and the hero is Special Agent Leroy Jethro Gibbs, a former Marine and disciplined detective with an uncanny ability to observe and interrogate criminal suspects. He doesn’t say much or display much emotion in the interrogation room — indeed, his cool demeanor is his trademark — yet he is a keen lie-spotter.

Psychological scientists are fascinated by real-life versions of the fictional Gibbs. Detecting lies and liars is essential to effective policing and prosecution of criminals, but it’s maddeningly difficult. Most of us can spot barely more than half of all lies and truths through listening and observation — meaning, of course, that we’re wrong almost as often as we’re right. A half-century of research has done little to polish this unimpressive track record.

But scientists are still working to improve on that, and among them is cognitive psychologist Aldert Vrij of the University of Portsmouth, in the U.K. Vrij has been using a key insight from his field to improve interrogation methods: The human mind, despite its impressive abilities, has limited capacity for how much thinking it can handle at any one time. So demanding additional, simultaneous thought — adding to cognitive “load” — compromises normal information processing. What’s more, lying is more cognitively demanding than telling the truth, so these compromised abilities should show up in detectable behavioral clues.

Full story at Huffington Post

Apr 18, 2011

Orangutans Use Simple Tools to Catch Fish

MINNEAPOLIS — Orangutans swim about as well as they fly, but research on three Indonesian islands shows that these long-limbed apes nonetheless catch and eat fish.

Orangutans living in Borneo scavenge fish that wash up along the shore and scoop catfish out of small ponds for fresh meals, anthropologist Anne Russon of York University in Toronto reported on April 14 at a meeting of the American Association of Physical Anthropologists. Over two years, Russon saw several animals on these forested islands learn on their own to jab at catfish with sticks, so that the panicked prey would flop out of ponds and into a red ape’s waiting hands.

“If orangutans can do this, then early hominids could also have practiced tool-assisted fishing,” Russon said.

Although orangutans usually fished alone, Russon observed pairs of apes catching catfish on a few occasions. In one case, an orangutan cringed and pulled away as its companion extracted a fish from a pond. Russon suspects that the onlooker was learning — or at least trying to learn — how to nab aquatic snacks.

Observations of fishing by orangutans raise the likelihood that hominids ate meat, including fish, before the emergence of the Homo genus around 2.5 million years ago (SN: 9/11/10, p. 8), said anthropologist David Braun of the University of Cape Town in South Africa. Anthropologists have traditionally held that meat-eating first assumed prominence among early Homo species and fueled brain expansion.

Fish, even more than red meat, contains fatty acids essential for human brain growth. Good archaeological evidence of fish eating goes back no further than about 2 million years ago in members of the Homo genus, which includes modern humans.

Russon and her colleagues monitored daily behavior among orangutans in Borneo from 2004 to 2006. In 2007, the researchers stocked a small pond with catfish and videotaped orangutan visits to the pond over the course of one day.

Seventeen times orangutans scavenged for fish or grabbed fish out of ponds — several times from the prestocked pond — and immediately ate their prey. Apes used sticks to jab at catfish in the prestocked pond and in other ponds, as well.

Fishing isn’t common among primates, but it does occur. Chimpanzees occasionally pluck fish out of ponds, Russon said. Some monkeys that swim well, including certain macaque and baboon species, also catch fish with their hands.

Read more at Wired Science

Uh and Um May Help Children Learn Language

The "uh" and "um" breaks in natural speech aren't as useless as you might think them to be -- at least for children learning the ins and outs of language.

A group of researchers found these breaks in speech, commonly called "disfluencies," may help youngsters pick up what's important in conversation. The team also discovered that the ability to pay attention to disfluencies develops at around 2 years of age.

For instance, if a parent says, "Come look at thee, uh, hummingbird," the disfluency "thee" and "uh" indicate something novel or important will follow.

Adults are known to pick up on these lingual cues as well.

Such communication helps listeners clarify what the speaker intends. Humans use other means to gather meaning from speech, including visual cues, pointing and eye contact to discern verbal messages, say researchers.

In the study, featured in the journal Developmental Science, parents volunteered their children to take part. In the first experiment, 16 toddlers sat on their parents' laps while researchers ran a series of objects -- both familiar and new -- on a large screen. A voice recording played back statements about the objects with and without using disfluent words.

A second experiment was conducted with 32 younger children.

During both experiments, an eye tracking machine recorded the children's visual attention toward the screen and objects.

For example, one trial presented a ball and stated, "I see the ball!" while another would repeat something along the lines of "I see thee, uh, ball!" New objects with unfamiliar names such as a "Tibble" and "Gorp" were used, too.

Since researchers presented both new and familiar objects with and without speech disfluencies, they were able to get a better idea of what was causing the increased attention in children.

Read more at Discovery News

Apr 17, 2011

Ancient Bird Sniffers on Par with Di-NOSE-saurs

The ancestors of the little feathered flying friends eating sunflower seeds from your garden inherited a strong sniffer from their ancient flightless dinosaur kin.

Birds, the modern-day descendants of the dinosaurs, were originally thought to have lost much of their sense of smell in the evolutionary race to develop the brain capacity for flight. But scientists at the University of Calgary, the Royal Tyrrell Museum and the Ohio University College of Osteopathic Medicine found that ancient birds' senses of smell actually improved at first.

"It was previously believed that birds were so busy developing vision, balance and coordination for flight that their sense of smell was scaled way back," said Darla Zelenitsky, assistant professor of paleontology at the University of Calgary and lead author of the study published in Proceedings of the Royal Society B.

"Surprisingly, our research shows that the sense of smell actually improved during dinosaur-bird evolution, like vision and balance," said Zelinsky in an Ohio University press release.

To estimate how strong the ancient birds sense of smell was in comparison to dinosaurs and modern birds, the scientists examined the skulls of 157 species of dinosaur and bird, both ancient and modern. The looked at the size of the space filled by the olfactory bulb in the skulls. The bigger the space, the better the sense of smell.

"Of course the actual brain tissue is long gone from the fossil skulls," said co-author Lawrence Witmer, professor of Paleontology at the Ohio University College of Osteopathic Medicine, "but we can use CT scanning to visualize the cavity that the brain once occupied and then generate 3D computer renderings of the olfactory bulbs and other brain parts."

The researchers found that ancient bird's even outdid their dinosaur cousins in the ability to sniff out a meal or a mate, or to catch the nasty scent of a lurking predator.

"The oldest known bird, Archaeopteryx, inherited its sense of smell from small meat-eating dinosaurs about 150 million years ago," said co-author François Therrien, curator of dinosaur palaeo-ecology at the Royal Tyrrell Museum. "Later, around 95 million years ago, the ancestor of all modern birds evolved even better olfactory capabilities."

Dinos and birds showed similarities and differences in their need for a sense of smell. The scientists noted that Archaeopteryx and pigeons had similar senses of smell.

Read more at Discovery News

Yellowstone Supervolcano's Size Exceeds Expectations

Beneath Yellowstone National Park lurks a partially molten plume rising from the Earth's mantle, fueling the park's famous geysers and hot springs, and causing the crust above to bulge and recede in response to its forces.

Now researchers report that the source beneath the surface may be even more massive than previously thought. Using a new technique, they have created an image of the plume beneath Yellowstone showing the cyclone shape stretching at a 40-degree angle to the west at a depth of 200 miles for 400 miles east to west, as far as the new technique can reach.

This study does not make any predictions about future eruptions, which the USGS Yellowstone Volcano Observatory notes are of very low probability in any given millennium, since they have been separated in the past by 800,000 and 660,000 years.

When the Yellowstone supervolcano last erupted cataclysmically 640,000 years ago, it formed the Yellowstone Caldera, a 30 by 50 mile crater. Smaller, non-explosive eruptions have happened since, the most recent about 70,000 years ago.

Previous estimates of the plume have used seismic images, which measure the reflection of seismic waves from earthquakes off of different types of materials below the surface. They reached even deeper than the new images -- to more than 400 miles down.

The new method detects differences in electrical conductivity generated by the different types of rocks and minerals below Yellowstone National Park, which provides clues to what they are made of.

Using supercomputers, the research team, led by Michael Zhdanov of the University of Utah in Salt Lake City, created images of the plume based on the electromagnetic measurements from 115 stations in Idaho, Montana and Wyoming.

"We see that there is a partially melted, conductive plume at great depths starting in the mantle, and going up," Zhdanov said.

"It's a completely different technique, completely different data," he added. "It confirms that the plume is there, but it provides another view of the plume."

The plume's high conductivity suggests it contains high levels of silicate rocks and perhaps briny water, he said. The observation that the high conductivity plume is larger and angled differently than the one found with seismic imaging suggests that the plume of molten and partially molten rock may be surrounded by additional liquid including briny water, Zhdanov said.

"I think it's an important finding to have a new technique to corroborate the way that this hotspot is rising through the mantle," said Jake Lowenstern, USGS scientist in charge of the Yellowstone Volcano Observatory.

Read more at Discovery News