Japan Raises Warning Level On Volcano Cluster One Week After Eruption Causes Fatal Avalanche

Japan has raised the warning level on a cluster of volcanos in the north of the country – just a week after an eruption at Kusatsu-Shirane caused an avalanche that killed a soldier and injured a dozen skiers at a winter resort.

Japan’s Meteorological Agency raised the alert on the Zao range from two to one, meaning tourists should stay away from its crater.

“There is a possibility of a small-scale eruption,” the agency warned in a statement after detecting a number of small earth movements and a slight bulging of the ground in one region.

It also raised the possibility of volcanic rocks being tossed as far as 1.2km should the Zao peaks erupt. They stand at 1,841 metres (6,040 feet) at their highest point.

The Zao complex of stratovolcanoes straddle the Yamagata and Miyagi Prefectures in Honsu and are thought to be the island’s most active.

Last week’s sudden Kusatsu-Shirane eruption saw rock and lava rain down on skiers in central Japan at a ski run used as a training outpost by the country’s military.

Video footage taken by the skiers showed black ash boiling up into the sky as stones crashed down, some punching holes in the metal roof of a ski lift.

Eleven people were injured while around 100 sought refuge in a mountain hut for several hours before rescuers concluded it was safe for them to re-emerge.

Zao, like Kusatsu-Shirane, is a popular resort famed for its spectacular “snow monsters,” created by water vapour being blown from a nearby lake and freezing on trees in mid-winter. Its slopes are routinely busy with skiers in winter and hikers in spring, summer and autumn.

Japan has 110 active volcanoes and carefully monitors 47 of them around the clock.

Its worst volcanic disaster in recent memory came in September 2014, when 63 people were killed on Mount Ontake.

Heavy Ash Fall From Philippine Volcano Halts Motorists

A heavy shroud of ash from erupting Mount Mayon in the Philippines halted vehicles in at least two towns due to poor visibility as the volcano blew more lava and columns of ash from its crater, officials said Tuesday.

The Philippine Institute of Volcanology and Seismology said one large lava eruption lasted more than an hour and a half late Monday. Mayon belched an ash plume that reached 1.5 kilometers (one mile) above the crater and caused significant ash fall in the towns of Camalig and Guinobatan.

Authorities urged residents to seek treatment for skin irritation and other health issues and immediately clean their roofs and cars because of the corrosive effect of the volcanic ash, Office of Civil Defense regional director Claudio Yucot said.

Mayon in northeastern Albay province has been erupting for more than two weeks, forcing more than 84,000 villagers to flee to crowded emergency shelters.

It has been belching red-hot lava fountains, huge columns of ash and molten rocks into the sky and plunging communities into darkness with falling ash. It has remained at alert level four on a scale of five, indicating a more violent eruption could be imminent.

Scientists have warned that despite repeated eruptions of lava, Mayon is still swollen with magma below the surface and could erupt explosively.

No injuries have been reported in the current eruptions, but authorities have struggled to keep people out of a danger zone 8 kilometers (5 miles) from the crater. They are worried the eruption may last months, disrupting the lives and livelihoods of people in Mayon’s shadow.

Provincial leaders told President Rodrigo Duterte, who visited Albay on Monday, that disaster funds were running low and he immediately ordered the disbursement of more funds.

The government has raised the possibility of establishing a permanent “no man’s land” around Mayon, a sensitive and complicated proposal that would affect tens and thousands of people living in the fertile farmlands nearby. One possibility is expanding a national park around the base of the volcano, where trees could grow and become a buffer against volcanic flows endangering villages and towns.

Mayon has erupted about 50 times in the last 500 years, sometimes violently. In 2013, an ash eruption killed five climbers who had ventured near the summit despite warnings.

The Philippines has about 22 active volcanoes. The explosion of Mount Pinatubo in 1991 was one of the biggest volcanic eruptions of the 20th century, killing hundreds.

Chasing Dark Matter With Oldest Stars In The Milky Way

Just how quickly is the dark matter near Earth zipping around? The speed of dark matter has far-reaching consequences for modern astrophysical research, but this fundamental property has eluded researchers for years.

In a paper published Jan. 22 in the journal Physical Review Letters, an international team of astrophysicists provided the first clue: The solution to this mystery, it turns out, lies among some of the oldest stars in the galaxy.

“Essentially, these old stars act as visible speedometers for the invisible dark matter, measuring its speed distribution near Earth,” said Mariangela Lisanti, an assistant professor of physics at Princeton University. “You can think of the oldest stars as a luminous tracer for the dark matter. The dark matter itself we’ll never see, because it’s not emitting light to any observable degree — it’s just invisible to us, which is why it’s been so hard to say anything concrete about it.”

In order to determine which stars behave like the invisible and undetectable dark matter particles, Lisanti and her colleagues turned to a computer simulation, Eris, which uses supercomputers to replicate the physics of the Milky Way galaxy, including dark matter.

“Our hypothesis was that there’s some subset of stars that, for some reason, will match the movements of the dark matter,” said Jonah Herzog-Arbeitman, an undergraduate and a co-author on the paper. His work with Lisanti and her colleagues the summer after his first year at Princeton turned into one of his junior papers and contributed to this journal article.

Herzog-Arbeitman and Lina Necib at the California Institute of Technology, another co-author on the paper, generated numerous plots from Eris data that compared various properties of dark matter to properties of different subsets of stars.

Their big breakthrough came when they compared the velocity of dark matter to that of stars with different “metallicities,” or ratios of heavy metals to lighter elements.

The curve representing dark matter matched up beautifully with the stars that have the least heavy metals: “We saw everything line up,” Lisanti said.

“It was one of those great examples of a pretty reasonable idea working pretty darn well,” Herzog-Arbeitman said.

Astronomers have known for decades that metallicity can serve as a proxy for a star’s age, since metals and other heavy elements are formed in supernovas and the mergers of neutron stars. The small galaxies that merged with the Milky Way typically have comparatively less of these heavy elements.

In retrospect, the correlation between dark matter and the oldest stars shouldn’t be surprising, said Necib. “The dark matter and these old stars have the same initial conditions: they started in the same place and they have the same properties … so at the end of the day, it makes sense that they’re both acted on only through gravity,” she said.

Why it matters

Since 2009, researchers have been trying to observe dark matter directly, by putting very dense material — often xenon — deep underground and waiting for the dark matter that flows through the planet to interact with it.

Lisanti compared these “direct detection” experiments to a game of billiards: “When a dark matter particle scatters off a nucleus in an atom, the collision is similar to two billiard balls hitting each other. If the dark matter particle is much less massive than the nucleus, then the nucleus won’t move much after the collision, which makes it really hard to notice that anything happened.”

That’s why constraining the speed of dark matter is so important, she explained. If dark matter particles are both slow and light, they might not have enough kinetic energy to move the nuclear “billiard balls” at all, even if they smack right into one.

“But if the dark matter comes in moving faster, it’s going to have more kinetic energy. That can increase the chance that in that collision, the recoil of the nucleus is going to be greater, so you’d be able to see it,” Lisanti said.

Originally, scientists had expected to see enough particle interactions — enough moving billiard balls — to be able to derive the mass and velocity of the dark matter particles. But, Lisanti said, “we haven’t seen anything yet.”

So instead of using the interactions to determine the speed, researchers like Lisanti and her colleagues are hoping to flip the script, and use the speed to explain why the direct detection experiments haven’t detected anything yet.

The failure — at least so far — of the direct detection experiments leads to two questions, Lisanti said. “How am I ever going to figure out what the speeds of these things are?” and “Have we not seen anything because there’s something different in the speed distribution than we expected?”

Having a completely independent way to work out the speed of dark matter could help shed light on that, she said. But so far, it’s only theoretical. Real-world astronomy hasn’t caught up to the wealth of data produced by the Eris simulation, so Lisanti and her colleagues don’t yet know how fast our galaxy’s oldest stars are moving.

Fortunately, that information is being assembled right now by the European Space Agency’s Gaia telescope, which has been scanning the Milky Way since July 2014. So far, information on only a small subset of stars has been released, but the full dataset will include far more data on nearly a billion stars.

“The wealth of data on the horizon from current and upcoming stellar surveys will provide a unique opportunity to understand this fundamental property of dark matter,” Lisanti said.

Grand Bend Fireball May Have Dropped Meteorites

Nothing lights up the night – or sparks the interest of researchers – quite like a meteor sighting.

At 7:23 p.m. Wednesday, a network of Western-operated cameras captured a fireball jetting across southern Ontario. Analysis of the video data suggests that fragments of the meteor likely made it to the ground between the communities of Saint Joseph and Crediton, Ontario.

The Department of Physics and Astronomy-run camera network constantly monitors the sky for meteors. Western professor Peter Brown, a leading expert in the study of meteors, confirmed the event was a meteor as 12 of the all-sky cameras from Western’s Southern Ontario Meteor Network (SOMN) recorded the fireball over western Ontario.

“This fireball was particularly significant because it ended very low in the atmosphere just to the north of Grand Bend, a good indicator material survived. In fact, it was still producing light at 24 kilometres altitude,” Brown said. “The only deeper penetrating fireball we have ever detected was the Grimsby meteorite-producing fireball of Sept. 25, 2009.”

According to Brown, other factors, which strongly favour survival of meteorites, are the very low-entry speed (only 13 km/s) and the steep entry angle (about 27 degrees from the vertical). These factors strongly suggest small meteorites made it to the ground.

“This event is very important because we have good quality video data of its passage through the atmosphere and hence know where the rock comes from in our solar system,” Brown said. “Meteorites are also of great interest to scientists like me as studying them helps us to better understand the formation and evolution of the solar system,”

Preliminary results indicate that the fireball first became visible at an altitude of 75 kilometres and travelled almost due north. The initial mass is believed to be several kilograms, leaving approximately tens to hundreds of grams of material on the ground.

Brown and the rest of the Western Meteor Physics Group are interested in speaking with anyone in the area of the potential fall, who may have heard or seen anything unusual, or who may have found possible meteorites.

Meteorites can be recognized by their dark, often scalloped, exterior. Usually they are denser than a ‘normal’ rock and will often be attracted to a magnet due to their metal content. Meteorites are not dangerous, but if recovered, it is best to place them in a clean plastic bag or wrap them in aluminum foil. They should also be handled as little as possible to help preserve their scientific value.

In Canada, meteorites belong to the owner of the land upon which they are found. If individuals plan to search, they should always obtain permission of the land-owner before venturing onto private land.

Team Sheds Light On The Mysteries Of Saturn’s Rings

A Skoltech-led team of international scientists has developed a mathematical model that makes sense of one of the great mysteries of Saturn’s rings.

The rings of Saturn are formations of dust and ice that swirl along Saturn’s equatorial plane. They were first spotted in 1610 by Galileo Galilei. At the time, he figured they were part of the planet itself. In-depth study of these unique formations only became possible in the 20th century in the era of space exploration. And many mysteries related to their formation and processes remain unanswered.

Most of the planets in the solar system have remain unchanged for millions of years, but Saturn’s rings exhibit extreme instability. This is particularly true of the F-ring, one of its outermost rings. The F-ring has been known to change over the course of days or even hours. For example, spacecraft have detected clumps of matter in the F-ring that suddenly disappear.

While it is not yet known what causes this erratic behavior, it is known that the processes of particle aggregation (fusion) and fragmentation (decay) play a role. In planetary rings, such as those of Saturn, these processes occur on a particularly large scale, necessitating a consistent balance between fragmentation and aggregation.

Scientists from universities in Russia (Skoltech, Moscow State University, the Institute of Numerical Mathematics of the Russian Academy of Sciences), the United Kingdom (the University of Leicester), and the United States (Boston University) teamed up to shed light on the mysterious F-ring using a mathematical model that had previously been used to study Saturn’s more stable elements.

Using the model, the Skoltech-led team demonstrated the possibility of ceaseless periodic oscillatory regimes for particle fusion and fragmentation within Saturn’s rings. In other words, they have identified a mechanism that could cause the formation of clots in a planetary ring such as the F-ring. Their findings satisfy the law of mass conservation, which holds that mass cannot be created or destroyed in chemical reactions.

The results of the study have been published is the scientific journal Physical Review Letters.

“We spent nearly three years working on this before presenting our results for publication. This is because it took us a great deal of time to work through our doubts and the validation stages. In the end, we found an example of a never-ending periodic oscillatory solution from the mathematical model of the aggregation and fragmentation processes of Saturn’s rings. Furthermore, we determined that these periodic regimes lead to a stable limiting cycle, which is very surprising for a model under the mass-conservation law, where stable equilibrium solutions are expected to be found. As our main results come from numerical simulations, we hope to attract interest from the mathematical community for the elaboration of rigorous analytical proofs of the presented phenomena. Anyway, we infer that those results may shed some new light on the phenomena of periodic clumps arising in the F-ring of Saturn,” said lead author and Skoltech research scientist Sergey Matvee

Researchers Study Interstellar Medium In The Galaxy NGC 3665

Using ESA’s Herschel telescope a team of Chinese researchers has performed analysis of the interstellar medium in the early-type galaxy NGC 3665. The study offers insights into physical properties of the matter between its star systems. The results were presented January 16 in a paper published on arXiv.org.

Discovered by William Herschel in 1789, NGC 3665 is a lenticular early-type galaxy located some 108 million light years away. However, contrary to typical early-type galaxies, NGC 3665 is abundant in cool gas and has a low star formation rate surface density. Studying gas, dust and other matter in this galaxy, especially in its interstellar medium, could therefore explain the galaxy’s low star formation efficiency.

A group of astronomers led by Meng-Yuan Xiao of the Nanjing University in China, has carried out an analysis of the physical properties of the interstellar medium in NGC 3665. For their research, they used far-infrared photometric and spectroscopic data obtained by ESA’s Herschel Space Observatory – an infrared telescope operating in space from 2009 to 2013. The dataset provided by Hershel was complemented by observations conducted with the Calar Alto Observatory (CAHA) in Spain.

The observational campaign allowed the researchers to physically characterize NGC 3665’s interstellar medium by obtaining its fundamental parameters, which could improve our understanding of this atypical galaxy and star formation process taking place there.

“In this paper, we focus on the photometric observations of NGC 3665 at 100, 160, 250, 350 and 500 µm, obtained with the Photodetector Array Camera and Spectrometer (PACS; – 4 – Poglitsch et al. 2010) and the Spectral and Photometric Imaging REceiver (SPIRE; Griffin et al. 2010) onboard Herschel, with five fine-structure lines of [N ii] 122 and 205 µm, [C ii] 158 µm, [O i] 63 µm, and [C i] 370 µm. We also perform optical spectroscopic observations of NGC 3665 with the CAHA 3.5m telescope,” the scientists wrote in the paper.

According to the study, the researchers found that neutral and ionized gas in NGC 3665 have extended structures and follow the carbon monoxide line gas disk distribution, adding that the fluxes are stronger at the center.

Furthermore, Xiao’s team estimates that the dust-to-stellar mass ratio of NGC 3665 is about 0.0011, which is nearly three times larger than the mean value of local lenticular galaxies. When it comes to the gas-to-dust mass ratio, this value is approximately 182, similar to that in our Milky Way galaxy.

According to the authors of the paper, these findings, together with the calculated star formation rate of around 1.7 solar masses per year, suggest that NGC 3665 has large gas reservoirs and less star formation.

Moreover, the researchers found that NGC 3665 has a weak active galactic nucleus in its central region, a very weak ultraviolet radiation field and has the lowest gas heating efficiency in photodissociation regions among different kinds of galaxies. The astronomers conclude that the new findings, compared with results provided by previous studies, indicate that suppressed star formation in NGC 3665 is most possibly caused by its compact, massive bulge through stabilizing cool gas reservoirs.

Mayon Volcano Continues To Emit Lava, Tonnes Of Poisonous Gas

Mayon Volcano continued to emit lava and poisonous gas with at least four sporadic lava fountaining episodes on Sunday.

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) said in its 8 a.m. bulletin on Monday that four lava fountaining events were recorded from 5:36 a.m. and 7:47 p.m. on Sunday.

The lava fountaining events lasted 36 to 57 minutes, which fed lava flows onthe Mi-isi and Bonga gullies, sprayed near-event lava spatter and rockfall on the summit.

“The lava fountaining events were succeeded by lava effusion in the early morning that fed new lava flow on the Bonga and Miisi Gullies,” PHIVOLCS said.

Lahar flowed from the volcano’s lava-filled Binaan Channel due to heavy rain that lasted until early Monday, the agency added.

The PHIVOLCS also recorded 41 volcanic earthquakes, six tremors that accompanied the lava fountaining events, and 16 rockfall events.

It said Mayon Volcano’s lava flow has advance to three kilometers in the Miisi Gully and 1.8 kilometers in the Bonga Gully, well within the seven-kilometer permanent danger zone.

Alert Level 4 remains in effect on the volcano, which means there is a possibility of hazardous eruption.

The volcano has also been emitting an average of 1,916 tonnes of sulfur dioxide a day.

According to the United States Geological Survey, sulfur dioxide is colorless with a pungent odor that irritages skin and penetrates the eyes, nose and throat.

It can bring health problems particularly to those with lung diseases.

The National Disaster Risk Reduction and Management Council on Sunday reported that nearly 2,000 people in Albay already have acute respiratory infection.