Creating A Stopwatch For Volcanic Eruptions


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We’ve long known that beneath the scenic landscapes of Yellowstone National Park sleeps a supervolcano with a giant chamber of hot, partly molten rock below it.

Though it hasn’t risen from slumber in nearly 70,000 years, many wonder when Yellowstone volcano will awaken and erupt…

We’ve long known that beneath the scenic landscapes of Yellowstone National Park sleeps a supervolcano with a giant chamber of hot, partly molten rock below it.

yellowstone

Though it hasn’t risen from slumber in nearly 70,000 years, many wonder when Yellowstone volcano will awaken and erupt again. According to new research at Arizona State University, there may be a way to predict when that happens.

While geological processes don’t follow a schedule, petrologist Christy Till, a professor in ASU’s School of Earth and Space Exploration, has produced one way to estimate when Yellowstone might erupt again.

“We find that the last time Yellowstone erupted after sitting dormant for a long time, the eruption was triggered within 10 months of new magma moving into the base of the volcano, while other times it erupted closer to the 10 year mark,” says Till.

The new study, published Wednesday in the journal Geology, is based on examinations of the volcano’s distant past combined with advanced microanalytical techniques. Till and her colleagues were the first to use NanoSIMS ion probe measurements to document very sharp chemical concentration gradients in magma crystals, which allow a calculation of the timescale between reheating and eruption for the magma.

This does not mean that Yellowstone will erupt in 10 months, or even 10 years. The countdown clock starts ticking when there is evidence of magma moving into the crust. If that happens, there will be some notice as Yellowstone is monitored by numerous instruments that can detect precursors to eruptions such as earthquake swarms caused by magma moving beneath the surface.

And if history is a good predictor of the future, the next eruption won’t be cataclysmic.

Geologic evidence suggests that Yellowstone has produced three enormous eruptions within the past 2.1 million years, but these are not the only type of eruptions that can occur. Volcanologists say there have been more than 23 smaller eruptions at Yellowstone since the last major eruption approximately 640,000 years ago. The most recent small eruption occurred approximately 70,000 years ago.

If a magma doesn’t erupt, it will sit in the crust and slowly cool, forming crystals. The magma will sit in that state – mostly crystals with a tiny amount of liquid magma – for a very long time. Over thousands of years, the last little bit of this magma will crystallize unless it becomes reheated and reignites another eruption.

For Till and her colleagues, the question was, “How quickly can you reheat a cooled magma chamber and get it to erupt?”

Till collected samples from lava flows and analyzed the crystals in them with the NanoSIMS. The crystals from the magma chamber grow zones like tree rings, which allow a reconstruction of their history and changes in their environment through time.

“Our results suggest an eruption at the beginning of Yellowstone’s most recent volcanic cycle was triggered within 10 months after reheating of a mostly crystallized magma reservoir following a 220,000-year period of volcanic quiescence,” says Till. “A similarly energetic reheating of Yellowstone’s current sub-surface magma bodies could end approximately 70,000 years of volcanic repose and lead to a future eruption over similar timescales.”

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The Cosmic Start Of Lightning


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Even though lightning is a common phenomenon, the exact mechanism triggering a lightning discharge remains elusive. Scientists at the Dutch national research institute for mathematics CWI, the University of Groningen and the University of Brussels now published a realistic model involving large…

Even though lightning is a common phenomenon, the exact mechanism triggering a lightning discharge remains elusive. Scientists at the Dutch national research institute for mathematics CWI, the University of Groningen and the University of Brussels now published a realistic model involving large ice particles and cosmic rays.

thestartofli

The big picture of lightning is clear: charge separation occurs inside a thundercloud and is eventually short-circuited by a conductive tube of ionized air. However, the electric field inside these clouds is usually an order of magnitude too low to create the conductive tube. This is why lightning inception is first out of the ‘top ten questions in lightning research’, according to a recent review.

Lightning researchers at CWI (Amsterdam), the University of Groningen (KVI-CART), and the University of Brussels now claim to have cracked this question. Large ice particles or hydrometeors form the first ingredient of their model. These grow out of hailstones moving up and down in the turbulent air inside thunderclouds. When they grow in an elongated shape, this will focus the electric field inside the cloud on their tips. The increased electric field is high enough to accelerate free electrons and start an ionization cascade, necessary to create a conductive tube.

Simulations showed that ice particles of 6 cm length and a narrow, elongated shape would increase the electric field enough to cause discharge inception. Estimates from the literature suggest such hydrometeors occur inside thunderclouds in a density of roughly 0.1 m-3.

Normally there are too few free electrons present in the surrounding air to cause a discharge. However, these could be provided by high energy cosmic rays, which can generate large showers of free electrons. Computer simulations showed that in an electric field of 3 meters high and 0.2 km2, one air shower per minute of free electrons capable of discharge inception would occur.

In short, free electrons from air showers caused by cosmic particles entering the atmosphere are accelerated in the electric field at the tip of a hydrometeor, and form self-propagating tubes of ionized air. These conductive tubes can short-circuit the built-up charge difference inside a thundercloud, between clouds or between a cloud and the earth’s surface. The results, presented in a Physical Review Letters paper, show that this mechanism for discharge inception is realistic.

The proposed model would predict that lightning inception at higher altitudes (e.g. 12 km) is less likely, as the hydrometeors would have to be longer to reach the required electric field density, while electron density in air showers caused by cosmic particles is lower at this altitude.

If these results are confirmed, a big question will have been solved. However, professor of particle physics Olaf Scholten, says there are still plenty of questions remaining. “Our institute is using data from large radio telescopes, like the Dutch Low Frequency Array LOFAR, to study lightning and increase our understanding of this phenomenon.” Future projects include studying the charge separation in clouds and the location of the discharge inside a cloud.

The study was partly funded by the project ‘Creeping Sparks’ from Technology Foundation STW and ‘Cosmic Lightning’ from the Foundation for Fundamental Research on Matter (FOM).

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Human Brain May Contain A Map For Social Navigation


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The brain region that helps people tell whether an object is near or far may also guide how emotionally close they feel to others and how they rank them socially, according to a study conducted at the Icahn School of Medicine at Mount Sinai and published today in the journal Neuron. The findings…

The brain region that helps people tell whether an object is near or far may also guide how emotionally close they feel to others and how they rank them socially, according to a study conducted at the Icahn School of Medicine at Mount Sinai and published today in the journal Neuron. The findings promise to yield new insights into the social deficits that accompany psychiatric disorders like schizophrenia and depression.

brain

The study focused on evidence for the existence of a “social map” in the hippocampus, the part of the brain that remembers locations in physical space and the order in which events occur. While previous studies had suggested that the hippocampus records a 3-dimensional representation of our surroundings when a key set of nerve cells fires, how the hippocampus contributes to social behavior had not been previously described.

“By quantifying the response patterns of people making decisions based on social interactions, we found that the hippocampus tracks relationships, intimacy and hierarchy within a kind of ‘social map’,” says Rita Tavares, PhD, postdoctoral fellow in the Schiller Laboratory of Affective Neuroscience at the Icahn School of Medicine at Mount Sinai. “Our data suggests a common mechanism for how the brain codes for physical space, time and for social relationships.”

Previous social psychology studies and theory had identified two main factors that define social relationships: power (competence, dominance, hierarchy) and affiliation (intimacy, trustworthiness, love). In the new study, Mount Sinai researchers gauged participants’ sense of affiliation and power using a social space model: in a role-playing game, healthy subjects were tasked with finding a new home and job through power and affiliation interactions with virtual cartoon characters.

To quantify social interactions, study investigators used power and affiliation as the x and y axes of a two-dimensional graph where they recorded the social coordinates of each interaction. Each time the participant interacted with a character during the game, that character’s coordinates moved along a trajectory of greater or lesser intimacy or power. The researchers designed a mathematical analysis where they asked whether the brain activity being measured in the functional neuroimaging (fMRI) scanner tracked those changing social coordinates. The research team found a correlation between hippocampal activity and movement through the abstract social “space.”

“We found that participants who reported better social skills showed better hippocampal tracking of the movement of the game characters through that social space,” says Daniela Schiller, PhD, Assistant Professor of Psychiatry and Neuroscience and Lab Director of the Schiller Laboratory for Affective Neuroscience at the Icahn School of Medicine at Mount Sinai. “Our results suggest that the hippocampus is crucial for social cognition and imply that beyond framing physical locations, the hippocampus computes a more general, inclusive, abstract and multidimensional social map.”

Navigating through social space may be relevant to many disorders that impair social cognition, such as sociopathy, borderline personality disorder, schizophrenia, depression and autism. Many of these disorders are known to involve hippocampal dysfunction. The current study results predict that an impaired geometric representation of social space in the hippocampus may accompany social dysfunction across psychiatric populations. Further exploration of these hypotheses could lead to improved diagnostic and therapeutic options for several psychiatric populations.

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Sinkholes Offer Glimpse into Comet’s Heart


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Strange pits and divots observed on the surface of Comet 67P/Churyumov-Gerasimenko may be sinkholes, not unlike those that appear on Earth, a new analysis suggests.

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Images of the comet taken by the European Space Agency’s Rosetta probe show the object’s surface is spotted with…

Strange pits and divots observed on the surface of Comet 67P/Churyumov-Gerasimenko may be sinkholes, not unlike those that appear on Earth, a new analysis suggests.

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Images of the comet taken by the European Space Agency’s Rosetta probe show the object’s surface is spotted with flat-bottomed pits that are emitting jets of gas. New research reveals how the steep divots could be created by melting ice under the comet’s surface, which creates empty spaces that can suddenly cave in.

Since August 2014, Rosetta has been orbiting Comet 67P (as it’s known for short) and photographing its every facet. But the inner workings of the comet, and its unusual pits and jets, have gone unexplained — until now. [Living on a Comet: ‘Dirty Snowball’ Facts Explained (Infographic)]

The new research suggests that when subsurface ice melts and the empty spaces suddenly cave in, new parts of the comet become exposed to the sun’s glare and heat up. This additional heat can generate gases inside the comet that escape as jets. The researchers say that understanding the sinkholes’ formation might help determine the comet’s’ makeup and age.

“Now, for the first time, we have a clear link between jets and between these pits that we have observed on the surface,” Jean-Baptiste Vincent, a planetary scientist at the Max Planck Institute for Solar System Research in Germany, told Space.com “And it’s also telling us a lot of things about the evolution of the comet and about the inner structure.”

Vincent is first author on the new research, which was published online today (July 1) in the journal Nature.

Photos of the comet revealed two types of pits: There are shallower pits, with more gradual, sloping sides. And there are pits with deep, nearly vertical walls, which create empty cylinders in the ground. Jets of material fly out of these steep pits’ sides, and researchers originally thought this was evidence that explosions were creating the pits. But now the scientists say that cannot be the case.

“The small jets that you see, it could take them forever to carve the pits that we observe now,” Vincent said.

The new analysis of data from Rosetta suggests instead that the pits form when the roof of an empty space in the comet collapses, similar to sinkholes that form on Earth and Mars. Vincent said that the voids could come from ice within the comet’s core turning to gas and escaping after exposure to heat. Then, the newly exposed walls of the pits begin to react in the sunlight by releasing material in jets, slowly collapsing and flattening them over time.

If found on other comets, the pits could offer insight into the makeup of those objects’ cores, as well as serving as a sign of age or exposure to the sun: the longer a comet was exposed to sunlight, the more worn away the pits would be.

“We think it’s a common process. It’s happening on all comets — maybe on slightly different timescales, but we think it’s happening everywhere,” Vincent said.

“We’re able to make a discovery like this now because Rosetta is a rendezvous mission, and everything before has been flybys,” Paul Weissman, a researcher at NASA’s Jet Propulsion Laboratory in Pasadena, California, who wrote a commentary about the new paper in the same issue of Nature, told Space.com.

“We’re literally orbiting the comet at walking speed, typically a meter a second or less,” Weissman added.”And so this gives us the opportunity to stay there, see changes occurring, see what happens to the comet as it losses mass, as different areas come into sunlight and get active.”

As of June 23, the Rosetta mission has been extended until September 2016, so the spacecraft will be able to continue investigating Comet 67P after the space rock reaches its closest point to the sun next month and moves away again. Rosetta will keep gathering more detailed images and measurements. In the meantime, researchers will continue to scrutinize the existing data for details about the comet’s formation and composition.

“And there’s still going to be surprises to come, I think,” Weissman said.

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Tiny Glider Could Cruise Through Martian Skies


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A tiny aircraft could be plying Mars’ skies less than a decade from now.
NASA researchers are developing a glider, called Preliminary Research Aerodynamic Design to Land on Mars (Prandtl-m), for possible inclusion on a Mars rover mission in the 2022-2024 time frame.

Prandtl-m would weigh…

A tiny aircraft could be plying Mars’ skies less than a decade from now.

NASA researchers are developing a glider, called Preliminary Research Aerodynamic Design to Land on Mars (Prandtl-m), for possible inclusion on a Mars rover mission in the 2022-2024 time frame.

mars-glider-prandtl-m

Prandtl-m would weigh a maximum of 2.6 lbs. (1.2 kilograms) here on Earth (1 lb., or 0.45 kg, in Mars’ reduced-gravity environment) and feature a wingspan of just 24 inches (61 centimeters), project team members said. The craft would fold up to fit inside a 3U cubesat — a spacecraft about the size of a loaf of bread — that would tag along with the rover.

“The aircraft would be part of the ballast that would be ejected from the aeroshell that takes the Mars rover to the planet,” Prandtl-m program manager Al Bowers, the chief scientist at NASA’s Armstrong Flight Research Center in Edwards, California, said in a statement.

“It would be able to deploy and fly in the Martian atmosphere and glide down and land,” Bowers added. “The Prandtl-m could overfly some of the proposed landing sites for a future astronaut mission and send back to Earth very detailed high-resolution photographic map images that could tell scientists about the suitability of those landing sites.”

The glider would have a flight time of 10 minutes in the Martian sky, and could cover about 20 miles (32 kilometers), Bowers said.

Bowers and his team plan to test a Prandtl-m prototype (which will be designed and built with the help of community college students this summer) during a high-altitude balloon flight later this year, either from Tucson, Arizona, or Tillamook, Oregon.

The balloon will drop the aircraft at an altitude of about 100,000 feet (30,480 meters), where the thin air provides a good analog of the Martian atmosphere.

“We could have one of two small science payloads on the Prandtl-m on that first balloon flight,” Bowers said. “It might be the mapping camera, or one might be a small, high-altitude radiometer to measure radiation at very high altitudes of Earth’s atmosphere. Eventually the aircraft may carry both of them at the same time.”

A second balloon flight to about the same altitude is planned for 2016. In that test, Prandtl-m will be folded inside a cubesat container; after the drop, the glider will deploy from the container, unfold and fly away, Bowers said.

NASA’s Flight Opportunities Program has agreed to fund both of these balloon-aided tests. If everything goes well, Prandtl-m may then find its way onto a sounding rocket that goes into suborbital space.

“That mission could be to 450,000 feet [137,160 m] and the release from a cubesat at apogee. The aircraft would fall back into the Earth’s atmosphere, and as it approaches the 110,000-to-115,000-feet [33,530 to 35,050 m] altitude range, the glider would deploy just as though it was over the surface of Mars,” Bowers said.

“If the Prandtl-m completes a 450,000-foot drop, then I think the project stands a very good chance of being able to go to NASA Headquarters and say we would like permission to ride to Mars with one of the rovers,” he added.

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Cyclone Raquel Forms As Earliest Big Storm Recorded Off Australia’s North-East


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Tropical Cyclone Raquel has formed in the south-west Pacific near the Solomon Islands, triggering the earliest cyclone warning on record issued for the Queensland zone.

“Certainly it’s a unique scenario,” Jess Carey, a spokesman from the bureau’s Queensland office, said….

Tropical Cyclone Raquel has formed in the south-west Pacific near the Solomon Islands, triggering the earliest cyclone warning on record issued for the Queensland zone.

raquel

“Certainly it’s a unique scenario,” Jess Carey, a spokesman from the bureau’s Queensland office, said. “Since we’ve been tracking cyclones with satellite-based technology, we haven’t seen one in July.”

The storm became a category 1 cyclone early on Wednesday morning and had a central pressure of 999 hPa about 410 km north of the Solomon Islands’ capital of Honiara as of just before 5am, AEST, the Bureau of Meteorology said. It is forecast to strengthen to a category 2 system on Thursday.

“The cyclone is moving southwest at about 16 km per hour and should gradually intensify over the next 24 hours as it approaches the Solomon Islands,” the bureau said in a statement. “The system will remain very far offshore and does not pose a threat to the Queensland coast.”

The official cyclone season runs from November 1-April 30. Any cyclone after May or before October is considered unusual.

The Queensland region has recorded a June event – Cyclone Ida, back in late May and early June of 1972 – and there was also a July cyclone off the west coast of Australia in 1996.

Mr Casey said the storm was carrying winds of about 130km/h, and since it comes in the second half of the year, will become the earliest recorded in any season for the zone.

While the storm is forecast to remain far from the Queensland coast, it is “certainly not good news for the Solomon Islands”, Mr Casey said.

“We’ve also heard some reports of pretty strong winds in Papua New Guinea,” he said. “It’s affecting quite a wide area.”

Also of note is that a typhoon – as such storms are described in the north-west Pacific basin – is also taking shape to the north of Cyclone Raquel.

“There’s almost an identical system forming on the other side of the equator,” Mr Casey said. “It’s sort of a pigeon pair of cyclones – so it’s an interesting scenario we’ve got at the moment.”

El Nino watch

One consequence of the cyclones in the western Pacific is that they may contribute to strengthening the El Nino now taking hold in the central and eastern equatorial Pacific.

“It’s plausible, it could happen,” Mr Casey said.

“You’ve got quite a significant El Nino brewing at the moment for us,” he said. “What effect does a cyclone have on how the El Nino plays out for the rest of the year, probably we’ll be able to answer that in December or January.”

Cyclone Raquel is likely to trigger westward wind bursts that would reinforce the reversal of the easterly trade winds, shifting more heat to the west as is typical during El Nino events.

The previous mid-year event off north-eastern Australia – 1972’s Cyclone Ida – came prior to a powerful El Nino event forming later that year.

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Weather Alerts Across Western Europe As Heatwave Sets In


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European countries including France, Spain, Italy and Britain have issued weather alerts and the United Nations has urged countries to create better warning systems as a heatwave sweeping western Europe was expected to push temperatures to a nine-year high on Wednesday.

The heatwave, enveloping…

European countries including France, Spain, Italy and Britain have issued weather alerts and the United Nations has urged countries to create better warning systems as a heatwave sweeping western Europe was expected to push temperatures to a nine-year high on Wednesday.

heat

The heatwave, enveloping Britain, Spain, France, Belgium, the Netherlands, Switzerland and northern Italy, is expected to last several days and has already seen temperatures rise as high as 40C.

In the west of France, in Brittany and the Pays de la Loire, there was a massive power cut which saw between 600,000 and a million homes left without electricity between Tuesday night and the early hours of Wednesday morning after high temperatures affected power equipment. State authorities said it was “exceptional” for the weather to have such repercussions on power supply to homes. The heatwave sparked a further power cut in the western town of Vannes early on Wednesday morning, leaving up to 120,000 homes without electricity at 7am.

In France, where temperatures in some areas have reached 40C, train transport continued to be disrupted and delayed on several lines, including between Paris and Toulouse, as metal tracks and cabling were affected. Within Paris, the RER C trains which link the capital to the suburbs were experiencing delays as trains were slowed and maintenance work was carried out to avoid tracks buckling in the heat.

France’s weather office put 40 regions on orange alert, warning of an “enduring heatwave of significant intensity requiring particular vigilance”.

France, which has activated its national heatwave emergency plan, is particularly sensitive to the risks after thousands of its elderly people in isolated areas died in a European-wide heatwave in 2003 that led to nearly 20,000 deaths. In 2003, Europe was caught off-guard by the severity of the heatwave, and authorities are currently working to ensure the most vulnerable – such as elderly people, young children and those who are ill – are monitored.

Temperatures in Paris are expected to hit 39C on Wednesday afternoon, after south-west France saw temperatures of 42C and Córdoba in southern Spain recorded nearly 44C.

In Paris, which has seen a spike in air pollution during the heatwave, the city hall took measures to limit drivers’ journeys, making residential parking free, imposing speed limits and encouraging use of public transport.

Spanish authorities said the past week brought record June temperatures, with Madrid recording its highest temperature in 95 years as thermometers came close to 40 C (104 F).

Portugal, which is bracing for a challenging forest fire season after an exceptionally dry winter and spring, had the hottest, driest June for 12 years.

The Civil Protection Service said more than 9,700 firefighters, 2,000 vehicles and 45 aircraft would be on permanent standby this season.

From Italy to the Netherlands, governments warned of the risks to older people, young children and those with serious illnesses.

The UN has urged countries to create alert systems to counter the health risks of heatwaves as they become more frequent, intense and dangerous due to climate change.

For the first time, the UN’s World Health Organisation (WHO) and its World Meteorological Organisation (WMO) have joined forces to create guidelines for experts and authorities for how to lower the health risks of heatwaves such as the ones currently scorching Asia and Europe.

“Heatwaves have emerged as an important hydrometeorological hazard and will remain so, given projected changes in the frequency of extreme heat events associated with human-induced climate change,” the UN text warned.

The main recommendation was to create heatwave warning systems that highlight the health hazards and inform people what they should do to protect themselves.

While such systems exist in countries such as France, Diarmid Campbell-Lendrum of the WHO voiced concern about places such as Pakistan, where more than 1,200 people have died amid soaring temperatures in the south of the country.

That crisis came a month after neighbouring India suffered a deadly heatwave that killed more than 2,000 people.

“It is common to have weather forecasts tell people what the temperature is going to be, but in many countries they have not looked at what that means to health,” he told the news agency Agence France-Presse.

WHO and WMO are calling on countries, even those not traditionally hit by extreme temperatures, to put in place heatwave preparedness systems, allowing them to quickly alert the population to dangers and put hospitals on standby for an influx of patients suffering from heat-related ailments.

“Climate change is not only likely to bring about changes in the frequency and duration of heatwaves in ‘core’ heatwave regions but also an alteration of the geographical distribution of heatwave disasters,” WMO and WHO warned in their guidelines, based on several previous scientific studies.

This meant heatwaves might occur in places where they had not happened previously, they said.

They also warned that urbanisation had exacerbated the problem, since cities tend to be hotter than elsewhere, putting vulnerable populations such as the elderly and chronically ill more at risk.

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