Deep Freeze Covers Northeast, Midwest After Deadly Weekend Storm

Tens of millions of Americans are feeling the deep freeze left behind by a deadly weekend winter storm that swept through the Midwest and Northeast. More than a quarter of the country woke up to temperatures below 10 degrees Monday, reports CBS News correspondent Omar Villafranca from Killington, Vermont, where the wind chill was minus-31 degrees.

At least 3 deaths are blamed on the severe weather.

The storm also caused headaches for millions of air travelers across the U.S., with thousands of flight cancellations and delays.

Upstate New York got as much as 20 inches of snow. Parts of Ohio and Pennsylvania got up to 18 inches.

The storm buried parts of the Northeast in snow and ice. The Hudson River froze over in upstate New York.

People in Glens Falls, New York, near the Vermont border, spent Sunday digging out from more than a foot-and-a-half of snow, and plows could barely keep up with whiteout conditions on Interstate 87.

In Gray, Maine, residents raced to clear around 8 inches of snow before the Arctic temperatures froze everything. Resident Len Sherwood explained the way to do it is to “do a little bit at a time, go back in warm up, come back out later.”

Connecticut Gov. Ned Lamont said, “What we’re particularly worried about is the icy conditions and what that means to the electric grid.”

The snow, sleet and freezing rain knocked out power to more than 20,000 homes and businesses in Connecticut and New York.

A utility worker in Connecticut was killed Sunday when a tree fell on him while he was trying to restore service.

The storm was deadly from its onset. In Kansas, a snow plow driver died Saturday morning when his vehicle rolled off the road. And it created a scare in Chicago when a United Airlines jet slid off the icy runway after landing at O’Hare Airport.

“Next thing you know we were off the runway and stuck in snow…we ended up sitting on the plane for another hour,” one passenger said.

In Missouri, slick surfaces triggered a 15 car pileup crash on Interstate 55, shutting down the road for hours.

The effects of the storm reached as far south as Alabama, where at least six people were hurt in an apparent EF-2 tornado. Winds topping 135 miles an hour significantly damaged several buildings outside Montgomery.

For those who have to venture out into the bitter cold, the advice is the same whether you’re here skiing or just walking your dog: Dress in layers, stay hydrated, and take frequent breaks inside — because it can take less than 15 minutes for frostbite to set in.

Stromboli Volcano (Italy): Frequent And Strong Explosions From 6 Vents, Observation Report From Close

The activity of the volcano remains elevated – magma is still standing high inside its conduits.

When observed from close earlier today, there were 6 active vents producing intermittent strombolian explosions of small to large size (see annotated image of the crater terrace with the vents indicated as on a map):
The new cinder cone that has been built recently around the NE vent displayed mild and continuous lava spattering with intense lava glow at night, as well as strombolian explosions of small to moderate size (ejection heights racing from few tens of meters to approx. 150 m) at intervals of 10-20 minutes.

The strongest explosions, however occurred from both the easternmost vent (below the more active NE cone, far right in the picture) as well as (and more frequently) from the westernmost vent, both ejecting incandescent material to certainly more than 200 m height and bombs reaching much of the crater terrace and its surroundings. Intervals of explosions were about one every 10-15 minutes vor the western vent and more rarely from the easternmost one (once per 30-40 minutes). As has been typical for the past decades, the westernmost vent usually generated significant amounts of ashes, while all other vents had almost no ash during their explosions.

Some of the most notable eruptions, however, occurred from a vent in the NW area of the crater area: it forms a steep-sided, symmetric, conical shaped small cone and frequently erupted dense, candle-like lava fountains, as well as sometimes only mostly gas jets. Its eruptions were often accompanied by very loud detonation sounds. Occasionally, this vent also produced beautiful “smoke rings” (ring vortexes), apparently caused by pulsating gas emissions from its circular vent.

A small vent just east of the mentioned westernmost vent also erupted in similar, but weaker style (narrow jets of lava) occasionally. Last, the formerly called “central crater”, in the southern central part of the crate terrace also had infrequent, typically small to moderately-sized classic strombolian eruptions. In the past this vent (located in the lower center of the image) often displayed constant glow and spattering, but did not do so today.

All in all, explosions occurred at intervals of about 2-3 minutes from all 6 vents combined.

Waves In Saturn’s Rings Give Precise Measurement Of Planet’s Rotation Rate

Saturn’s distinctive rings were observed in unprecedented detail by NASA’s Cassini spacecraft, and scientists have now used those observations to probe the interior of the giant planet and obtain the first precise determination of its rotation rate. The length of a day on Saturn, according to their calculations, is 10 hours 33 minutes and 38 seconds.

The researchers studied wave patterns created within Saturn’s rings by the planet’s internal vibrations. In effect, the rings act as an extremely sensitive seismograph by responding to vibrations within the planet itself.

Similar to Earth’s vibrations from an earthquake, Saturn responds to perturbations by vibrating at frequencies determined by its internal structure. Heat-driven convection in the interior is the most likely source of the vibrations. These internal oscillations cause the density at any particular place within the planet to fluctuate, which makes the gravitational field outside the planet oscillate at the same frequencies.

“Particles in the rings feel this oscillation in the gravitational field. At places where this oscillation resonates with ring orbits, energy builds up and gets carried away as a wave,” explained Christopher Mankovich, a graduate student in astronomy and astrophysics at UC Santa Cruz.

Mankovich is lead author of a paper, published January 17 in the Astrophysical Journal, comparing the wave patterns in the rings with models of Saturn’s interior structure.

Most of the waves observed in Saturn’s rings are due to the gravitational effects of the moons orbiting outside the rings, said coauthor Jonathan Fortney, professor of astronomy and astrophysics at UC Santa Cruz. “But some of the features in the rings are due to the oscillations of the planet itself, and we can use those to understand the planet’s internal oscillations and internal structure,” he said.

Mankovich developed a set of models of the internal structure of Saturn, used them to predict the frequency spectrum of Saturn’s internal vibrations, and compared those predictions with the waves observed by Cassini in Saturn’s C ring. One of the main results of his analysis is the new calculation of Saturn’s rotation rate, which has been surprisingly difficult to measure.

As a gas giant planet, Saturn has no solid surface with landmarks that could be tracked as it rotates. Saturn is also unusual in having its magnetic axis nearly perfectly aligned with its rotational axis. Jupiter’s magnetic axis, like Earth’s, is not aligned with its rotational axis, which means the magnetic pole swings around as the planet rotates, enabling astronomers to measure a periodic signal in radio waves and calculate the rotation rate.

The rotation rate of 10:33:38 determined by Mankovich’s analysis is several minutes faster than previous estimates based on radiometry from the Voyager and Cassini spacecraft.

“We now have the length of Saturn’s day, when we thought we wouldn’t be able to find it,” said Cassini Project Scientist Linda Spilker. “They used the rings to peer into Saturn’s interior, and out popped this long-sought, fundamental quality of the planet. And it’s a really solid result. The rings held the answer.”

The idea that Saturn’s rings could be used to study the seismology of the planet was first suggested in 1982, long before the necessary observations were possible. Coauthor Mark Marley, now at NASA’s Ames Research Center in Silicon Valley, subsequently fleshed out the idea for his Ph.D. thesis in 1990, showed how the calculations could be done, and predicted where features in Saturn’s rings would be. He also noted that the Cassini mission, then in the planning stages, would be able to make the observations needed to test the idea.

“Two decades later, people looked at the Cassini data and found ring features at the locations of Mark’s predictions,” Fortney said.

Nepal Earthquake: Waiting For The Complete Rupture

In April 2015, Nepal — and especially the region around the capital city, Kathmandu — was struck by a powerful tremor. An earthquake with a magnitude of 7.8 destroyed entire villages, traffic routes and cultural monuments, with a death toll of some 9,000.

However, the country may still face the threat of much stronger earthquakes with a magnitude of 8 or more. This is the conclusion reached by a group of earth scientists from ETH Zurich based on a new model of the collision zone between the Indian and Eurasian Plates in the vicinity of the Himalayas.

Using this model, the team of ETH researchers working with doctoral student Luca Dal Zilio, from the group led by Professor Taras Gerya at the Institute of Geophysics, has now performed the first high-resolution simulations of earthquake cycles in a cross-section of the rupture zone.

“In the 2015 quake, there was only a partial rupture of the major Himalayan fault separating the two continental plates. The frontal, near-surface section of the rupture zone, where the Indian Plate subducts beneath the Eurasian Plate, did not slip and remains under stress,” explains Dal Zilio, lead author of the study, which was recently published in the journal Nature Communications.

Normally, a major earthquake releases almost all the stress that has built up in the vicinity of the focus as a result of displacement of the plates. “Our model shows that, although the Gorkha earthquake reduced the stress level in part of the rupture zone, tension actually increased in the frontal section close to the foot of the Himalayas. The apparent paradox is that ‘medium-sized’ earthquakes such as Gorkha can create the conditions for an even larger earthquake,” says Dal Zilio.

Tremors of the magnitude of the Gorkha earthquake release stress only in the deeper subsections of the fault system over lengths of 100 kilometres. In turn, new and even greater stress builds up in the near-surface sections of the rupture zone.

According to the simulations performed by Dal Zilio and his colleagues, two or three further Gorkha quakes would be needed to build up sufficient stress for an earthquake with a magnitude of 8.1 or more. In a quake of this kind, the rupture zone breaks over the entire depth range, extending up to the Earth’s surface and laterally — along the Himalayan arc — for hundreds of kilometres. This ultimately leads to a complete stress release in this segment of the fault system, which extends to some 2,000 kilometres in total.

Historical data shows that mega events of this kind have also occurred in the past. For example, the Assam earthquake in 1950 had a magnitude of 8.6, with the rupture zone breaking over a length of several hundred kilometres and across the entire depth range. In 1505, a giant earthquake struck with sufficient power to produce an approximately 800-kilometre rupture on the major Himalayan fault. “The new model reveals that powerful earthquakes in the Himalayas have not just one form but at least two, and that their cycles partially overlap,” says Edi Kissling, Professor of Seismology and Geodynamics. Super earthquakes might occur with a periodicity of 400 to 600 years, whereas “medium-sized” quakes such as Gorkha have a recurrence time of up to a few hundred years. As the cycles overlap, the researchers expect powerful and dangerous earthquakes to occur at irregular intervals.

However, they cannot predict when another extremely large quake will next take place. “No one can predict earthquakes, not even with the new model. However, we can improve our understanding of the seismic hazard in a specific area and take appropriate precautions,” says Kissling.

The two-dimensional and high-resolution model also includes some research findings that were published after the Gorkha earthquake. To generate the simulations, the researchers used the Euler mainframe computer at ETH Zurich. “A three-dimensional model would be more accurate and would also allow us to make statements about the western and eastern fringes of the Himalayas. However, modelling the entire 2,000 kilometres of the rupture zone would require enormous computational power,” says Dal Zilio.

From Emergence To Eruption: Comprehensive Model Captures Life Of A Solar Flare

A team of scientists has, for the first time, used a single, cohesive computer model to simulate the entire life cycle of a solar flare: from the buildup of energy thousands of kilometers below the solar surface, to the emergence of tangled magnetic field lines, to the explosive release of energy in a brilliant flash.

The accomplishment, detailed in the journal Nature Astronomy, sets the stage for future solar models to realistically simulate the Sun’s own weather as it unfolds in real time, including the appearance of roiling sunspots, which sometimes produce flares and coronal mass ejections. These eruptions can have widespread impacts on Earth, from disrupting power grids and communications networks, to damaging satellites and endangering astronauts.

Scientists at the National Center for Atmospheric Research (NCAR) and the Lockheed Martin Solar and Astrophysics Laboratory led the research. The comprehensive new simulation captures the formation of a solar flare in a more realistic way than previous efforts, and it includes the spectrum of light emissions known to be associated with flares.

“This work allows us to provide an explanation for why flares look like the way they do, not just at a single wavelength, but in visible wavelengths, in ultraviolet and extreme ultraviolet wavelengths, and in X-rays,” said Mark Cheung, a staff physicist at Lockheed Martin Solar and Astrophysics Laboratory and a visiting scholar at Stanford University. “We are explaining the many colors of solar flares.”

The research was funded largely by NASA and by the National Science Foundation (NSF), which is NCAR’s sponsor.

Bridging the scales

For the new study, the scientists had to build a solar model that could stretch across multiple regions of the Sun, capturing the complex and unique physical behavior of each one.

The resulting model begins in the upper part of the convection zone — about 10,000 kilometers below the Sun’s surface — rises through the solar surface, and pushes out 40,000 kilometers into the solar atmosphere, known as the corona. The differences in gas density, pressure, and other characteristics of the Sun represented across the model are vast.

To successfully simulate a solar flare from emergence to energy release, the scientists needed to add detailed equations to the model that could allow each region to contribute to the solar flare evolution in a realistic way. But they also had to be careful not to make the model so complicated that it would no longer be practical to run with available supercomputing resources.

“We have a model that covers a big range of physical conditions, which makes it very challenging,” said NCAR scientist Matthias Rempel. “This kind of realism requires innovative solutions.”

To address the challenges, Rempel borrowed a mathematical technique historically used by researchers studying the magnetospheres of Earth and other planets. The technique, which allowed the scientists to compress the difference in time scales between the layers without losing accuracy, enabled the research team to create a model that was both realistic and computationally efficient.

The next step was to set up a scenario on the simulated Sun. In previous research using less complex models, scientists have needed to initiate the models nearly at the moment when the flare would erupt to be able to get a flare to form at all.

In the new study, the team wanted to see if their model could generate a flare on its own. They started by setting up a scenario with conditions inspired by a particularly active sunspot observed in March 2014. The actual sunspot spawned dozens of flares during the time it was visible, including one very powerful X-class and three moderately powerful M-class flares. The scientists did not try to mimic the 2014 sunspot accurately; instead they roughly approximated the same solar ingredients that were present at the time — and that were so effective at producing flares.

Then they let the model go, watching to see if it would generate a flare on its own.

“Our model was able to capture the entire process, from the buildup of energy to emergence at the surface to rising into the corona, energizing the corona, and then getting to the point when the energy is released in a solar flare,” Rempel said.

Now that the model has shown it is capable of realistically simulating a flare’s entire life cycle, the scientists are going to test it with real-world observations of the Sun and see if it can successfully simulate what actually occurs on the solar surface.

“This was a stand-alone simulation that was inspired by observed data,” Rempel said. “The next step is to directly input observed data into the model and let it drive what’s happening. It’s an important way to validate the model, and the model can also help us better understand what it is we’re observing on the Sun.”

Scientists Find Increase In Asteroid Impacts On Ancient Earth By Studying The Moon

An international team of scientists is challenging our understanding of a part of Earth’s history by looking at the Moon, the most complete and accessible chronicle of the asteroid collisions that carved our solar system.

In a study published today in Science, the team shows the number of asteroid impacts on the Moon and Earth increased by two to three times starting around 290 million years ago.

“Our research provides evidence for a dramatic change in the rate of asteroid impacts on both Earth and the Moon that occurred around the end of the Paleozoic era,” said lead author Sara Mazrouei, who recently earned her PhD in the Department of Earth Sciences in the Faculty of Arts & Science at the University of Toronto (U of T). “The implication is that since that time we have been in a period of relatively high rate of asteroid impacts that is 2.6 times higher than it was prior to 290 million years ago.”

It had been previously assumed that most of Earth’s older craters produced by asteroid impacts have been erased by erosion and other geologic processes. But the new research shows otherwise.

“The relative rarity of large craters on Earth older than 290 million years and younger than 650 million years is not because we lost the craters, but because the impact rate during that time was lower than it is now,” said Rebecca Ghent, an associate professor in U of T’s Department of Earth Sciences and one of the paper’s co-authors. “We expect this to be of interest to anyone interested in the impact history of both Earth and the Moon, and the role that it might have played in the history of life on Earth.”

Scientists have for decades tried to understand the rate that asteroids hit Earth by using radiometric dating of the rocks around them to determine their ages. But because it was believed erosion caused some craters to disappear, it was difficult to find an accurate impact rate and determine whether it had changed over time.

A way to sidestep this problem is to examine the Moon, which is hit by asteroids in the same proportions over time as Earth. But there was no way to determine the ages of lunar craters until NASA’s Lunar Reconnaissance Orbiter (LRO) started circling the Moon a decade ago and studying its surface.

“The LRO’s instruments have allowed scientists to peer back in time at the forces that shaped the Moon,” said Noah Petro, an LRO project scientist based at NASA Goddard Space Flight Center.

Using LRO data, the team was able to assemble a list of ages of all lunar craters younger than about a billion years. They did this by using data from LRO’s Diviner instrument, a radiometer that measures the heat radiating from the Moon’s surface, to monitor the rate of degradation of young craters.

During the lunar night, rocks radiate much more heat than fine-grained soil called regolith. This allows scientists to distinguish rocks from fine particles in thermal images. Ghent had previously used this information to calculate the rate at which large rocks around the Moon’s young craters — ejected onto the surface during asteroid impact — break down into soil as a result of a constant rain of tiny meteorites over tens of millions of years. By applying this idea, the team was able to calculate ages for previously un-dated lunar craters.

When compared to a similar timeline of Earth’s craters, they found the two bodies had recorded the same history of asteroid bombardment.

“It became clear that the reason why Earth has fewer older craters on its most stable regions is because the impact rate was lower up until about 290 million years ago,” said William Bottke, an asteroid expert at the Southwest Research Institute in Boulder, Colorado and another of the paper’s coauthors. “The answer to Earth’s impact rate was staring everyone right in the face.”

The reason for the jump in the impact rate is unknown, though the researchers speculate it might be related to large collisions taking place more than 300 million years ago in the main asteroid belt between the orbits of Mars and Jupiter. Such events can create debris that can reach the inner solar system.

Ghent and her colleagues found strong supporting evidence for their findings through a collaboration with Thomas Gernon, an Earth scientist based at the University of Southampton in England who works on a terrestrial feature called kimberlite pipes. These underground pipes are long-extinct volcanoes that stretch, in a carrot shape, a couple of kilometers below the surface, and are found on some of the least eroded regions of Earth in the same places preserved impact craters are found.

“The Canadian shield hosts some of the best-preserved and best-studied of this terrain — and also some of the best-studied large impact craters,” said Mazrouei.

Gernon showed that kimberlite pipes formed since about 650 million years ago had not experienced much erosion, indicating that the large impact craters younger than this on stable terrains must also be intact.

“This is how we know those craters represent a near-complete record,” Ghent said.

While the researchers weren’t the first to propose that the rate of asteroid strikes to Earth has fluctuated over the past billion years, they are the first to show it statistically and to quantify the rate.

“The findings may also have implications for the history of life on Earth, which is punctuated by extinction events and rapid evolution of new species,” said Ghent. “Though the forces driving these events are complicated and may include other geologic causes, such as large volcanic eruptions, combined with biological factors, asteroid impacts have surely played a role in this ongoing saga.

“The question is whether the predicted change in asteroid impacts can be directly linked to events that occurred long ago on Earth.”

The findings are described in the study “Earth and Moon impact flux increased at the end of the Paleozoic,” published in Science. Support for the research was provided by the National Science and Engineering Research Council of Canada, NASA’s Solar System Exploration Research Virtual Institute, and the Natural Environment Research Council of the United Kingdom.

New Way Supermassive Black Holes Are ‘Fed’

Supermassive black holes weigh millions to billions times more than our sun and lie at the center of most galaxies. A supermassive black hole several million times the mass of the sun is situated in the heart of our very own Milky Way.

Despite how commonplace supermassive black holes are, it remains unclear how they grow to such enormous proportions. Some black holes constantly swallow gas in their surroundings, some suddenly swallow whole stars. But neither theory independently explains how supermassive black holes can “switch on” so unexpectedly and keep growing so fast for a long period.

A new Tel Aviv University-led study published today in Nature Astronomy finds that some supermassive black holes are triggered to grow, suddenly devouring a large amount of gas in their surroundings.

In February 2017, the All Sky Automated Survey for Supernovae discovered an event known as AT 2017bgt. This event was initially believed to be a “star swallowing” event, or a “tidal disruption” event, because the radiation emitted around the black hole grew more than 50 times brighter than what had been observed in 2004.

However, after extensive observations using a multitude of telescopes, a team of researchers led by Dr. Benny Trakhtenbrot and Dr. Iair Arcavi, both of TAU’s Raymond & Beverly Sackler School of Physics and Astronomy, concluded that AT 2017bgt represented a new way of “feeding” black holes.

“The sudden brightening of AT 2017bgt was reminiscent of a tidal disruption event,” says Dr. Trakhtenbrot. “But we quickly realized that this time there was something unusual. The first clue was an additional component of light, which had never been seen in tidal disruption events.”

Dr. Arcavi, who led the data collection, adds, “We followed this event for more than a year with telescopes on Earth and in space, and what we saw did not match anything we had seen before.”

The observations matched the theoretical predictions of another member of the research team, Prof. Hagai Netzer, also of Tel Aviv University.

“We had predicted back in the 1980s that a black hole swallowing gas from its surroundings could produce the elements of light seen here,” says Prof. Netzer. “This new result is the first time the process was seen in practice.”

Astronomers from the U.S., Chile, Poland and the U.K. took part in the observations and analysis effort, which used three different space telescopes, including the new NICER telescope installed on board the International Space Station.

One of the ultraviolet images obtained during the data acquisition frenzy turned out to be the millionth image taken by the Neil Gehrels Swift Observatory — an event celebrated by NASA, which operates this space mission.

The research team identified two additional recently reported events of black holes “switched on,” which share the same emission properties as AT 2017bgt. These three events form a new and tantalizing class of black hole re-activation.

“We are not yet sure about the cause of this dramatic and sudden enhancement in the black holes’ feeding rate,” concludes Dr. Trakhtenbrot. “There are many known ways to speed up the growth of giant black holes, but they typically happen during much longer timescales.”

“We hope to detect many more such events, and to follow them with several telescopes working in tandem,” says Dr. Arcavi. “This is the only way to complete our picture of black hole growth, to understand what speeds it up, and perhaps finally solve the mystery of how these giant monsters form.”