Is not there Big Bang ? A quantum equation show that the universe has no beginning

The universe could have existed forever, according to a new model that applies quantum correction terms to complement the theory of general relativity of Einstein. The model can also explain dark matter and dark energy.

The widely accepted age of the universe, according to estimates of general relativity, is 13,800 million years. At first, everything was dealt a single infinitely dense point or, in other words, the singularity. After that point began to expand to trigger the Big Bang, considered the origin of the universe, has  Science Direct .

Although the Big Bang singularity arises directly and inevitably mathematics of general relativity, some scientists consider the problematic issue because mathematics can only explain what happened after and not before the singularity .

However, Ahmed Ali Farag, Benha University, Egypt, and Saurya Das University of Lethbridge, Canada, say the Big Bang singularity can be resolved by its new model in which the universe has no beginning nor end .

The researchers used Raychaudhuri equation and the Friedmann equations, which describe the expansion and evolution of the universe (including the Big Bang) in the context of general relativity. The model of Ali and Das contains elements of both quantum theory, of general relativity .

In physical terms, the model describes the universe as full of "quantum fluid" . Scientists propose that this fluid could be composed of gravitons, hypothetical massless particles that mediate the force of gravity.

To understand the origin of the universe, they analyzed the behavior of the fluid over time. Surprisingly, they found that this does not converge towards the singularity, but, on the contrary, the universe seems to have always existed . Although it was smaller in the past, says Das.

Source: RT

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Study reveals how oxygen is like kryptonite to titanium

UC Berkeley scientists have found the mechanism by which titanium, prized for its high strength-to-weight ratio and natural resistance to corrosion, becomes brittle with just a few extra atoms of oxygen.

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Shown is a cross section of grade 3 titanium (containing 0.3 percent oxygen) that has been put under stress and deformed. The defects in the crystal are evident. Oxygen impurities forced the defects to spread onto different planes of the material. (Image by Qian Yu)

The discovery, described in the Feb. 6 issue of the journal Science, has the potential to open the door to more practical, cost-effective uses of titanium in a broader range of applications. The popular silver-gray metal can already be found in high-end bicycles, laptops and human implants, among other products. But high-grade titanium with low levels of oxygen is hard to come by, and the expense of purifying the metal has prevented its wider use in applications for the construction, automotive and aerospace industries.

“If you could process titanium in a way that retained its optimal properties but at a cost comparable to aluminum, you would find uses in cars, trucks, aircraft and ships,” said study senior author Andrew Minor, an associate professor of materials science and engineering and faculty scientist at Lawrence Berkeley National Laboratory. “The high corrosion resistance and excellent specific properties of titanium are very attractive, and reducing the costs to the level of aluminum would make using the material a no-brainer.”

Minor led a research team from the department of materials science and engineering that focused on solving the long-standing mystery in metallurgy of how oxygen causes such a profound change in the characteristics of metals.

“Oxygen is like poison to titanium,” said Minor. “With more oxygen, the material gets harder and more susceptible to cracks, qualities that are not desirable for structural materials.”

A good structural material will have the right balance of ductility — the ability to bend in response to stress — and strength. Minor noted that glass is strong and hard, but not ductile, which is why that material is not used to build vehicles or bridges.

The light blue lines in this schematic illustrate a moving defect, or dislocation, in titanium. The interaction between the dislocation and an oxygen impurity (red atom) leads to the creation of additional dislocations, shown as dark blue lines. (Image by Liang Qi)

Minor added that while many metals have the potential to become brittle with oxygen, titanium is particularly sensitive to even tiny bits of the element. Grade 3 titanium is only 0.3 percent oxygen, yet it is one-third as tough as grade 1 titanium, which is 0.1 percent oxygen. Understanding how oxygen hardens titanium offers a target for research into control of the process, the study authors said.

The researchers subjected various grades of titanium samples to nanocompression tests and examined the resulting impact using advanced transmission electron microscopy techniques and quantum mechanical predictions of defect structures. They found that the interactions between oxygen and the crystalline defects, known as dislocations, that are characteristic of titanium were key to how the material hardened.

The researchers found that oxygen atoms acted like bumps in the road for the corkscrew-shaped dislocations found in titanium. “The mechanical shuffling that occurs as dislocations pop up and over those atomic bumps creates a domino effect of more dislocations,” said study co-author Daryl Chrzan, a professor of materials science and engineering who led the theoretical effort in the project. With increased oxygen, the titanium becomes more difficult to bend and therefore more susceptible to cracking, the researchers found.

A similar effect is seen by bending a paper clip until it breaks. The more the metal bends, the greater the number of dislocations. Dislocations interfere with the motion of other defects, making the paper clip more difficult to bend. Eventually, the number of dislocations is so high that the paper clip can no longer bend, and instead it breaks.

“Now that we know what it is about the oxygen found in inexpensive titanium that causes the material to harden, we can work on figuring out a way to process it to move oxygen atoms to a place where they don’t cause problems,” said study co-author Mark Asta, a professor of materials science and engineering.

Minor noted that this is already done in the semiconductor industry since oxygen and other impurities are also damaging to silicon-based microprocessors.

Other co-authors of the study included researchers from the Berkeley Lab, Japan’s Nuclear Science and Engineering Directorate and Rolls Royce.

The Office of Naval Research helped support this work. Experiments were performed at the National Center for Electron Microscopy in the Molecular Foundry at Berkeley Lab, which is supported by the U.S. Department of Energy.

Source: UC Berekely

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Tail discovered on long-known asteroids

The faint tail can be seen in active asteroid 62412. Image courtesy of Scott Sheppard

Washington, D.C.--A two-person team of Carnegie's Scott Sheppard and Chadwick Trujillo of the Gemini Observatory has discovered a new active asteroid, called 62412, in the Solar System's main asteroid belt between Mars and Jupiter. It is the first comet-like object seen in the Hygiea family of asteroids. Sheppard will present his team's findings at the American Astronomical Society's Division of Planetary Sciences meeting and participate today in a press conference organized by the society.

Active asteroids are a newly recognized phenomenon. 62412 is only the 13th known active asteroid in the main asteroid belt. Sheppard and Trujillo estimate that there are likely about 100 of them in the main asteroid belt, based on their discovery.

Active asteroids have stable orbits between Mars and Jupiter like other asteroids. However, unlike other asteroids, they sometimes have the appearance of comets, when dust or gas is ejected from their surfaces to create a sporadic tail effect. Sheppard and Trujillo discovered an unexpected tail on 62412, an object which had been known as a typical asteroid for over a decade. Their findings reclassify it as an active asteroid. The reasons for this loss of material and subsequent tail in active asteroids are unknown, although there are several theories such as recent impacts or sublimation from solid to gas of exposed ices.

"Until about ten years ago, it was pretty obvious what a comet was and what a comet wasn't, but that is all changing as we realize that not all of these objects show activity all of the time," Sheppard said.

In the past, asteroids were thought to be mostly unchanging objects, but an improved ability to observe them has allowed scientists to discover tails and comas, which are the thin envelope of an atmosphere that surrounds a comet's nucleus.

"We're actually looking anew through our deep survey at a population of objects that other people cannot easily observe, because we're going much deeper," Sheppard said, explaining why they were able to see that 62412 was active when it had been considered a typical main belt asteroid for 15 years.;

Discoveries such as this one can help researchers determine the processes that cause some asteroids to become active. Sheppard will discuss his and Trujillo's theories about the genesis of 62412's activity. They found that 62412 has a very fast rotation that likely shifts material around its surface, some of which may be emitted to form the comet-like appearance. The tail may be created directly from ejected material off the fast rotating nucleus, or from ice within the asteroid subliming into water vapor after being freshly exposed on the surface. They also find a density for 62412 typical of primitive asteroids and not consistent with the much lower-density comets. Further monitoring of this unusual object will help confirm the activity's source.

Sheppard and Trujillo have a paper about this work in press at The Astronomical Journal.


Source: NASA

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Oldest stone tool ever found in Turkey discovered

Stone tool approximately 1.2 million years old. Credit: Image courtesy of University of Royal Holloway London

Scientists have discovered the oldest recorded stone tool ever to be found in Turkey, revealing that humans passed through the gateway from Asia to Europe much earlier than previously thought, approximately 1.2 million years ago.

According to research published in the journal Quaternary Science Reviews, the chance find of a humanly-worked quartzite flake, in ancient deposits of the river Gediz, in western Turkey, provides a major new insight into when and how early humans dispersed out of Africa and Asia.

Researchers from Royal Holloway, University of London, together with an international team from the UK, Turkey and the Netherlands, used high-precision equipment to date the deposits of the ancient river meander, giving the first accurate timeframe for when humans occupied the area.

Professor Danielle Schreve, from the Department of Geography at Royal Holloway, said: "This discovery is critical for establishing the timing and route of early human dispersal into Europe. Our research suggests that the flake is the earliest securely-dated artefact from Turkey ever recorded and was dropped on the floodplain by an early hominin well over a million years ago."

The researchers used high-precision radioisotopic dating and palaeomagnetic measurements from lava flows, which both pre-date and post-date the meander, to establish that early humans were present in the area between approximately 1.24 million and 1.17 million years ago. Previously, the oldest hominin fossils in western Turkey were recovered in 2007 at Koçabas, but the dating of these and other stone tool finds were uncertain.

"The flake was an incredibly exciting find," Professor Schreve said. "I had been studying the sediments in the meander bend and my eye was drawn to a pinkish stone on the surface. When I turned it over for a better look, the features of a humanly-struck artefact were immediately apparent.

"By working together with geologists and dating specialists, we have been able to put a secure chronology to this find and shed new light on the behaviour of our most distant ancestors."

Source: University of Royal Holloway London

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New species of beetle discovered in the world's deepest cave

This is a drawing of Duvalius abyssimus. Credit: Sinc - José Antonio Peñas

The unusual habitat of the Krubera cave in the Western Caucasus remains a mystery. Researchers from two Spanish universities have discovered a new species of beetle in the depths of this cave.

Cave beetles are one of the most iconic species found in subterranean habitats. They were historically the first living organisms described by science that are adapted to the conditions of hypogean or subterranean life.

Now, a Portuguese scientist and a Spaniard have discovered a new species of beetle in the deepest cave known to man; a cave 2,140 metres deep. It is the Krubera cave, situated in the Arabika massif in the Western Caucasus.

Ana Sofía Reboleira, researcher from the Universities of Aveiro and La Laguna, and Vicente M. Ortuño, from the University of Alcalá, have published their discovery in the scientific journal 'Zootaxa'.

"The new species of cave beetle is called Duvalius abyssimus. We only have two specimens, a male and a female. Although they were captured in the world's deepest cave, they were not found at the deepest point," Ortuño, who has dedicated the last 10 years to studying subterranean fauna, said.

The Duvalius genus is a successful colonizer of Earth's depths. The majority of species have a hypogean lifestyle and live in caves or the superficial underground compartment.

"The new species' characteristics indicate that it is moderately adapted to life underground. Proof of this is that they still have eyes, which are absent in the highly specialised cave species," added the expert.

The Arabika massif region in Abkhazia, where this cave is found, is biogeographically a very interesting area. Altitudes fluctuate between 1,900 and 2,500 metres and the cave is composed of lower and upper Jurassic-Cretaceous limestone.

Its large area has provided endless subterranean refuges for fauna. In fact, various genera of endemic cave beetles live in the Western Caucasus. "Its location is strategic, since there are fauna of European, Asian and also endemic origin in the zone," the scientist underlined.

The entrance to the cave is 2,240 metres above sea level and 15 kilometres from the Black Sea. Below numerous vertically-cutting sections, it reaches a depth of 1,400 metres. From this level, it splits into branches and in order to reach the greatest known depth, it is necessary to pass various flooded underground chambers using diving techniques.

"The discovery of the new beetle provides important data on species that co-exist in these almost unknown ecosystems, even more so when they are found in a geographical area that is very difficult to access, such is the case with this cave," Ortuño concluded.

Source:  FECYT - Spanish Foundation for Science and Technology

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'Non-echolocating' fruit bats actually do echolocate, with wing clicks

In a discovery that overturns conventional wisdom about bats, researchers reporting in the Cell Press journal Current Biology on Dec. 4 have found that Old World fruit bats -- long classified as "non-echolocating" -- actually do use a rudimentary form of echolocation. Perhaps most surprisingly, the clicks they emit to produce the echoes that guide them through the darkness aren't vocalizations at all. They are instead produced by the bats' wings, although scientists don't yet know exactly how the bats do it.

In a discovery that overturns conventional wisdom about bats, researchers reporting in the Cell Press journal Current Biology on December 4 have found that Old World fruit bats--long classified as "non-echolocating"--actually do use a rudimentary form of echolocation. Perhaps most surprisingly, the clicks they emit to produce the echoes that guide them through the darkness aren't vocalizations at all. They are instead produced by the bats' wings, although scientists don't yet know exactly how the bats do it.

"I was surprised by the fact that all of the fruit bats we recorded clicked and by the fact that clicks are produced by the wings," says Yossi Yovel of Tel Aviv University in Israel. "Arjan and I still find that hard to believe."

Yovel and postdoctoral fellow Arjan Boonman got their first hint about the fruit bats from a friendly man on a bus in Indonesia who told them about a species of bat that clicked with its wings. As further confirmation, Boonman found a single old paper about a fruit bat with wings that clicked, but it wasn't clear whether those clicks were good for anything.

Rather than look for that one earlier-described species in particular, Yovel suggested something else: "Why not check other fruit bats?"

They selected a total of 19 wild individuals representing three species of fruit bat and different parts of the evolutionary family tree to find that all of them did produce audible clicks with their wings.

"We did all we could to prove it wrong, including sealing the bats' mouths and anesthetizing their tongues, but nothing stopped them from clicking, except for when we interfered with their wing flaps," Yovel says.

Further study showed that two of the three species increased their clicking rate by a factor of three to five or even more when placed in a dark tunnel, implying that the clicks are a natural behavior for the bats.

Tests of the animals' ability to find their way in the dark showed that the fruit bats do have echolocation abilities, although they are poorer than those of other echolocating species. The fruit bats constantly crashed into thick cables, but they could readily learn to discriminate between larger objects: an acoustically reflective black board versus a similar-looking sheet of cloth. Even with large objects, however, the fruit bats didn't exactly come in for a smooth landing, suggesting that their ability is rather rudimentary in comparison to that of bats that rely on clicks produced from their larynxes.

The findings are interesting in light of earlier suggestions that echolocation may have evolved initially for bats to identify and avoid crashing into large objects such as cave walls, Boonman and Yovel say. The new discovery in fruit bats offers insight into how this sophisticated ability in other bats may have evolved over time, although it is unlikely that the laryngeal clicks of those other bats evolved directly from fruit bats' wing clicks. In fact, Yovel says, it's possible that echolocation in bats has independently evolved many times.

"When we study extant species of echolocating bats, we see a developed sensory system that has been adapted and improved over millions of years of evolution," Yovel says. "The rudimentary echolocation of the fruit bat is one example of how the first types of echolocation may have evolved."

Source: Cell Press

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The New insight may help predict volcanic eruption behavior

Using friction experiments University of Liverpool scientists have shown that frictional melting plays a role in determining how a volcano will erupt. Credit: Dr. Jackie Kendrick

A new discovery in the study of how lava dome volcanoes erupt may help in the development of methods to predict how a volcanic eruption will behave, say scientists at the University of Liverpool.

Volcanologists at the University have discovered that a process called frictional melting plays a role in determining how a volcano will erupt, by dictating how fast magma can ascend to the surface, and how much resistance it faces en-route.

The process occurs in lava dome volcanoes when magma and rocks melt as they rub against each other due to intense heat. This creates a stop start movement in the magma as it makes its way towards Earth's surface. The magma sticks to the rock and stops moving until enough pressure builds up, prompting it to shift forward again (a process called stick-slip).

Volcanologist, Dr Jackie Kendrick, who lead the research said: "Seismologists have long known that frictional melting takes place when large tectonic earthquakes occur. It is also thought that the stick-slip process that frictional melting generates is concurrent to 'seismic drumbeats' which are the regular, rhythmic small earthquakes which have been recently found to accompany large volcanic eruptions.
"Using friction experiments we have shown that the extent of frictional melting depends on the composition of the rock and magma, which determines how fast or slow the magma travels to the surface during the eruption."

Analysis of lava collected from Mount St. Helens, USA and the Soufrière Hills volcano in Montserrat by volcanology researchers from the University's School of Environmental Sciences revealed remnants of pseudotachylyte, a cooled frictional melt. Evidence showed that the process took place in the conduit, the channel which lava passes through on its way to erupt.

Dr Kendrick, from the University's School of Environmental Sciences, added: "The closer we get to understanding the way magma behaves, the closer we will get to the ultimate goal: predicting volcanic activity when unrest begins. Whilst we can reasonably predict when a volcanic eruption is about to happen, this new knowledge will help us to predict how the eruption will behave.

"With a rapidly growing population inhabiting the flanks of active volcanoes, understanding the behaviour of lava domes becomes an increasing challenge for volcanologists."

Source: University of Liverpool

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More than 40 percent of minors in Lorca suffer post-traumatic stress a year after earthquake

A mask, painted by a U.S. Marine who attended art therapy to relieve posttraumatic stress disorder symptoms

Spanish researchers have analysed the impact of the Lorca catastrophe by the percentage of minors suffering post-traumatic stress. Results reveal that 55% of young people displayed this disorder a month on from the earthquake and 40% were still suffering a year later.

On 11 May 2011, Lorca suffered an earthquake measuring 5.1, preceded by another of 4.5, which killed nine people and caused significant material damage.

Two experts from the University of Murcia compared the prevalence of post-traumatic stress disorder (PTSD) on the population of minors in the region in its acute phase (one month after the quake) and as a chronic condition (one year later).

"The analysis indicates that 55% of the minors suffered from post-traumatic stress one month after the earthquake, while after one year this had decreased to 40%," as Concepción López Soler, researcher from the University of Murcia and co-author of the study with Juan José López García, explained.
The results, published in the journal Gaceta Sanitaria, reveal that 75% of the minors presented re-experiencing symptoms (recurrent thoughts, nightmares and physiological manifestations) after one month and 60% after one year.

In addition, a month later, 42% suffered from avoidance of anything related to the tragedy (memory disturbances, emotional blockage) and 24% after one year. 51% also displayed hyperarousal (sleeping difficulties, irritability and concentration problems) after a month and 38% a year later.

The authors argue that post-traumatic reactions generally tend to disappear over time. "After the earthquake new mental health resources were implemented to assist people with severe post-traumatic stress," stresses López Soler.

Primary school pupils in their 3rd and 6th year in educational centres from the municipal area were asked for their voluntary participation in this study. One month after the earthquake the level of PTSD was assessed in 495 minors and in 374 after one year.

"It is important to highlight that the younger age groups and girls are more sensitive to developing these symptoms, which coincides with the results of other studies," the Murcian researcher points out. "Young girls in particular are a special risk group."

Among the younger students, 54% of girls showed symptoms of post-traumatic stress compared to 39% of boys.

The evaluation was carried out using the Diagnostic and Statistical Manual of Mental Disorders criteria (DSM-IV-TR), using the Child PTSD Symptom Scale (CPSS) questionnaire which was developed to evaluate the post-traumatic stress in minors after an earthquake in Northridge (Los Angeles, USA) in 1994.

Stress after trauma
"Natural disasters create a sense of loss of personal safety and endangered survival among the population," adds López Soler. Earthquakes are one of the disasters which cause the greatest psychological disturbances in the population and PTSD is the reaction most associated with adverse conditions.

"With previous earthquakes, the affected population has been quite variable," she states. Three years after the Turkey earthquake in 1999, the prevalence of PTSD was 59%; 18 months after the earthquake in Kashmir (between India and Pakistan), it was 64.8% and ten months after the disaster in L'Aquila (Italy) in 2009, it was greater than 60%.

In comparison with other studies, the prevalence of PTSD is somewhat lower, which according to the authors can be understood to be due both to the lesser intensity of the earthquake and its consequences, and swift normalisation of the environment.

About Posttraumatic stress disorder >>

Source: Plataforma SINC

Summary: Spanish researchers have analyzed the impact of the Lorca catastrophe by the percentage of minors suffering post-traumatic stress. Results reveal that 55% of young people displayed this disorder a month on from the earthquake and 40% were still suffering a year later. On 11 May 2011, Lorca suffered an earthquake measuring 5.1, preceded by another of 4.5, which killed nine people and caused significant material damage.

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The Building 'belt' offers cheap, quick repair of earthquake damage

A damaged building joint repaired with post tensioned metal straps and tested on a shaking table to the equivalent level of a magnitude 7 earthquake. Credit: University of Sheffield

Four years after the January 2010 earthquake, 145,000 people still remain homeless in Haiti. A cheap and simple technology to repair earthquake damaged buildings -- developed at the University of Sheffield -- could help to reduce these delays by quickly making buildings safe and habitable.

Recent tests showed that a damaged building repaired using the technique could withstand a major earthquake -- similar in scale and proximity to the buildings that collapsed during the Haiti earthquake.
The technology involves wrapping metal straps around each floor of the building, which are then tensioned either by hand or using compressed air tools. It is designed for use on reinforced concrete frame buildings -- a common construction technique around the world, including countries like Haiti. Unlike other repair methods, it does not require expensive materials or a high level of technical knowledge, making it ideal for use in the developing world.

Lead researcher, Professor Kypros Pilakoutas, explains: "The strapping works very much like a weight-lifter's belt, by keeping everything tightly compressed to reduce tension on the concrete columns of the structure.

Concrete works well under compression, but not when pulled under tension and this is why it has to be reinforced for use in construction. When the reinforcement is faulty or damaged, it can be very expensive to repair.

"Our method not only makes the building stable again very quickly, but it increases the building's ability to deform without breaking, making it more able to withstand further earthquake movement."
The team tested the technique on a full scale, two-storey building, built according to an old European standard which has inadequate reinforcing to withstand earthquakes. This construction is typical of many buildings in the developing world, as well as many Mediterranean buildings built before the 1980s.

The building was constructed on a specially designed 'shaking table' which can simulate ground movement caused by earthquakes. During the first test, the building was very near collapse following a small earthquake similar in scale to a magnitude 4 on the Richter scale having about 10000 times less energy than the Haiti earthquake.

The building was then repaired using the post-tensioned metal straps and retested. The researchers were unable to make the building fail during a major earthquake similar in scale to the magnitude 7 Haiti earthquake at the epicentre and stopped the test at that point.

Professor Pilakoutas hopes the new technology will not only speed up the response to major earthquakes, but could also prevent the damage happening in the first place. The cost of the materials for a typical small building column is about £20 and it would take a crew of two people around 2 hours to complete the strengthening. For a typical small dwelling having 6 columns, the seismic rehabilitation would cost around £200 and could be completed in a few days, rather than cost several thousand pounds and take months with other traditional rehabilitation techniques such as jacketing with steel plates or concrete.

"Ideally, governments shouldn't wait until a disaster happens, but should be identifying buildings at risk and taking steps to make them strong enough to withstand any future earthquakes," he says. "Because this method causes minimal disruption and is cheap to apply, it's ideal for bringing existing buildings up to standard -- both in the developing world and in earthquake risk areas in Europe as well."


Source: University of Sheffield

Summary: Four years after the January 2010 earthquake, 145,000 people still remain homeless in Haiti. A cheap and simple technology to repair earthquake damaged buildings could help to reduce these delays by quickly making buildings safe and habitable.

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Scientists have reproduced the conditions inside the magma chamber of a supervolcano to understand what it takes to trigger its explosion.

This artist’s impression depicts the magma chamber of a supervolcano with partially molten magma at the top. The pressure from the buoyancy is sufficient to initiate cracks in the Earth’s crust in which the magma can penetrate. Credit: ESRF/Nigel Hawtin

Scientists have reproduced the conditions inside the magma chamber of a supervolcano to understand what it takes to trigger its explosion. These rare events represent the biggest natural catastrophes on Earth except for the impact of giant meteorites. Using synchrotron X-rays, the scientists established that supervolcano eruptions may occur spontaneously, driven only by magma pressure without the need for an external trigger. The results are published in Nature Geosciences.

The team was led by Wim Malfait and Carmen Sanchez-Valle of ETH Zurich (Switzerland) and comprised scientists from the Paul Scherrer Institute in Villigen (Switzerland), Okayama University (Japan), the Laboratory of Geology of CNRS, Université Lyon 1 and ENS Lyon (France) and the European Synchrotron (ESRF) in Grenoble (France).

A well-known supervolcano eruption occurred 600,000 years ago in Wyoming in the United States, creating a huge crater called a caldera, in the centre of what today is Yellowstone National Park. When the volcano exploded, it ejected more than 1000 km3 of ash and lava into the atmosphere, 100 times more than Mt Pinatubo in the Philippines did in 1992. Big volcanic eruptions have a major impact on the global climate. The Mt Pinatubo eruption decreased the global temperature by 0.4 degrees Celsius for a few months. The predictions for a super volcano are a fall in temperatures by 10 degrees Celsius for 10 years.

According to a 2005 report by the Geological Society of London, "Even science fiction cannot produce a credible mechanism for averting a super-eruption. We can, however, work to better understand the mechanisms involved in super-eruptions, with the goal of being able to predict them ahead of time and provide a warning for society. Preparedness is the key to mitigation of the disastrous effects of a super-eruption."

The mechanisms that trigger supervolcano eruptions have remained elusive to date. The main reason is that the processes inside a supervolcano are different from those in conventional volcanoes like Mt. Pinatubo which are better understood. A supervolcano possesses a much larger magma chamber and it is always located in an area where the heat flow from the interior of Earth to the surface is very high. As a consequence, the magma chamber is very large and hot but also plastic: its shape changes as a function of the pressure when it gradually fills with hot magma. This plasticity allows the pressure to dissipate more efficiently than in a normal volcano whose magma chamber is more rigid. Supervolcanoes therefore do not erupt very often.

So what changes in the lead up to an eruption? Wim Malfait explains: "The driving force is an additional pressure which is caused by the different densities of solid rock and liquid magma. It is comparable to a football filled with air under water, which is forced upwards by the denser water around it." Whether this additional pressure alone could eventually become sufficiently high to crack Earth's crust, leading to a violent eruption, or whether an external energy source like an Earthquake is required has only now been answered.

Whilst it is virtually impossible to drill a hole into the magma chamber of a supervolcano given the depth at which these chambers are buried, one can simulate these extreme conditions in the laboratory. "The synchrotron X-rays at the ESRF can then be used to probe the state -- liquid or solid -- and the change in density when magma crystallises into rock" says Mohamed Mezouar, scientist at the ESRF and member of the team. Jean-Philippe Perrillat from the Laboratory of Geology of CNRS, Université Lyon 1 and ENS Lyon adds: "Temperatures of up to 1700 degrees and pressures of up to 36,000 atmospheres can be reached inside the so-called Paris-Edinburgh press, where speck-sized rock samples are placed between the tips of two tungsten carbide anvils and then heated with a resistive furnace. This special set-up was used to accurately determine the density of the liquid magma over a wide range of pressures and temperatures."

Magma often includes water, which as vapour adds additional pressure. The scientists also determined magma densities as a function of water content.

The results of their measurements showed that the pressure resulting from the differences in density between solid and liquid magma rock is sufficient in itself to crack more than ten kilometres of Earth's crust above the magma chamber. Carmen Sanchez-Valle concludes: "Our research has shown that the pressure is actually large enough for Earth's crust to break. The magma penetrating into the cracks will eventually reach Earth's surface, even in the absence of water or carbon dioxide bubbles in the magma. As it rises to the surface, the magma will expand violently, which is the well known origin of a volcanic explosion."


Source: CNRS

Summary: Scientists have reproduced the conditions inside the magma chamber of a supervolcano to understand what it takes to trigger its explosion. These rare events represent the biggest natural catastrophes on Earth except for the impact of giant meteorites. Using synchrotron X-rays, the scientists established that supervolcano eruptions may occur spontaneously, driven only by magma pressure without the need for an external trigger.

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