Following Deadly January Eruption, Alert Level For Nearby Mount Shirane Raised To Level 2

The Meteorological Agency said Sunday it has raised the volcanic alert level for Mount Shirane near Gunma and Nagano prefectures from Level 1 to Level 2 to ban entry to areas near the crater.

Since Saturday evening, volcanic earthquakes at the Yugama crater have been on the rise, accompanied by slight crustal movement signaling higher eruption risk, the agency said.

Large ash deposits might also emerge within 1 km of the crater, it warned.
Mount Shirane is part a cluster of volcanoes in the two prefectures that is collectively called Mount Kusatsu-Shirane.

After the announcement, the Gunma Prefectural Government closed an 8.5-km stretch of Route 292, a scenic national road connecting the two prefectures.
The so-called Shiga-Kusatsu road is used by many people traveling to the nearby Kusatsu hot springs resort. Local tourism officials are concerned its closure could discourage tourists from visiting the popular resort, particularly during Golden Week, the string of public holidays lasting from the end of April to early May.

“It’s regrettable right ahead of Golden Week . . . but we need to keep monitoring the situation for a certain period of time,” Kusatsu Mayor Nobutada Kuroiwa said.

In January, Mount Motoshirane, another volcano in the Kusatsu-Shirane chain to the south of Mount Shirane, erupted, killing one person and injuring 11 others.

The Level 2 warning for Mount Motoshirane remains unchanged, the agency said.

Tornadoes, Strong Winds Injure Four In Southern Alabama

Four people were injured Sunday when a Southern storm system sent a tornado ripping through an RV park in coastal Alabama, authorities said.

The National Weather Service said two tornadoes were tracked through Baldwin County on Sunday. One of them, in Foley, about 20 miles southeast of Mobile, caused widespread damage, Fire Chief Joseph Darby told NBC affiliate WPMI of Mobile.

Darby said that five RVs were overturned and that four people were injured at Anchors Aweigh RV Resort. The extent of their injuries couldn’t immediately be determined.

“I could see the rain suddenly turning horizontal and the wind really picked up and our camper started to shake and then I told my husband — I grabbed my dog and told my husband — let’s get down because something is going on,” Peggy Stanton of Michigan, who was visiting Foley with her husband, told WPMI.

The tornado was part of a severe weather system that threatens to douse the Southeast with heavy rain through the early part of the week, the National Weather Service said. Rainfall totals of 3 to 6 inches are expected in the southern Appalachians, where flood watches have been issued through Tuesday morning.

Locally heavy rainfall could cause flash flooding to a larger section the Southeast and the mid-Atlantic through Tuesday night, it said.

Severe winds, including at least one possible tornado, were also reported in northern Florida late Saturday and Sunday. The Okaloosa County Sheriff’s said numerous trees were down, especially in Fort Walton Beach, where city officials said City Hall was damaged by a fallen tree.

Clear As Mud: Desiccation Cracks Help Reveal The Shape Of Water On Mars

As Curiosity rover marches across Mars, the red planet’s watery past comes into clearer focus.

In early 2017 scientists announced the discovery of possible desiccation cracks in Gale Crater, which was filled by lakes 3.5 billion years ago. Now, a new study has confirmed that these features are indeed desiccation cracks, and reveals fresh details about Mars’ ancient climate.

“We are now confident that these are mudcracks,” explains lead author Nathaniel Stein, a geologist at the California Institute of Technology in Pasadena. Since desiccation mudcracks form only where wet sediment is exposed to air, their position closer to the center of the ancient lake bed rather than the edge also suggests that lake levels rose and fell dramatically over time.

“The mudcracks show that the lakes in Gale Crater had gone through the same type of cycles that we see on Earth,” says Stein. The study was published in Geology online ahead of print on 16 April 2018.

The researchers focused on a coffee table-sized slab of rock nicknamed “Old Soaker.” Old Soaker is crisscrossed with polygons identical in appearance to desiccation features on Earth. The team took a close physical and chemical look at those polygons using Curiosity’s Mastcam, Mars Hand Lens Imager, ChemCam Laser Induced Breakdown Spectrometer (LIBS), and Alpha-Particle X-Ray Spectrometer (APXS).

That close look proved that the polygons — confined to a single layer of rock and with sediment filling the cracks between them — formed from exposure to air, rather than other mechanisms such as thermal or hydraulic fracturing. And although scientists have known almost since the moment Curiosity landed in 2012 that Gale Crater once contained lakes, explains Stein, “the mudcracks are exciting because they add context to our understanding of this ancient lacustrine system.”

“We are capturing a moment in time,” he adds. “This research is just a chapter in a story that Curiosity has been building since the beginning of its mission.”

Scientists Decipher The Magma Bodies Under Yellowstone

Using supercomputer modeling, University of Oregon scientists have unveiled a new explanation for the geology underlying recent seismic imaging of magma bodies below Yellowstone National Park.

Yellowstone, a supervolcano famous for explosive eruptions, large calderas and extensive lava flows, has for years attracted the attention of scientists trying to understand the location and size of magma chambers below it. The last caldera forming eruption occurred 630,000 years ago; the last large volume of lava surfaced 70,000 years ago.

Crust below the park is heated and softened by continuous infusions of magma that rise from an anomaly called a mantle plume, similar to the source of the magma at Hawaii’s Kilauea volcano. Huge amounts of water that fuel the dramatic geysers and hot springs at Yellowstone cool the crust and prevent it from becoming too hot.

With computer modeling, a team led by UO doctoral student Dylan P. Colón has shed light on what’s going on below. At depths of 5-10 kilometers (3-6 miles) opposing forces counter each other, forming a transition zone where cold and rigid rocks of the upper crust give way to hot, ductile and even partially molten rock below, the team reports in a paper in Geophysical Research Letters.

This transition traps rising magmas and causes them to accumulate and solidify in a large horizontal body called a sill, which can be up to 15 kilometers (9 miles) thick, according to the team’s computer modeling.

“The results of the modeling matches observations done by sending seismic waves through the area,” said co-author Ilya Bindeman, a professor in the UO’s Department of Earth Sciences. “This work appears to validate initial assumptions and gives us more information about Yellowstone’s magma locations.”

This mid-crustal sill is comprised of mostly solidified gabbro, a rock formed from cooled magma. Above and below lay separate magma bodies. The upper one contains the sticky and gas-rich rhyolitic magma that occasionally erupts in explosions that dwarf the 1980 eruption of Mount St. Helens in Washington state.

Similar structures may exist under super volcanoes around the world, Colón said. The geometry of the sill also may explain differing chemical signatures in eruptive materials, he said.

Colón’s project to model what’s below the nation’s first national park, which was sculpted 2 million years ago by volcanic activity, began soon after a 2014 paper in Geophysical Research Letters by a University of Utah-led team revealed evidence from seismic waves of a large magma body in the upper crust.

Scientists had suspected, however, that huge amounts of carbon dioxide and helium escaping from the ground indicated that more magma is located farther down. That mystery was solved in May 2015, when a second University of Utah-led study, published in the journal Science, identified by way of seismic waves a second, larger body of magma at depths of 20 to 45 kilometers (12-27 miles).

However, Colón said, the seismic-imaging studies could not identify the composition, state and amount of magma in these magma bodies, or how and why they formed there.

To understand the two structures, UO researchers wrote new codes for supercomputer modeling to understand where magma is likely to accumulate in the crust. The work was done in collaboration with researchers at the Swiss Federal Institute of Technology, also known as ETH Zurich.

The researchers repeatedly got results indicating a large layer of cooled magma with a high melting point forms at the mid-crustal sill, separating two magma bodies with magma at a lower melting point, much of which is derived from melting of the crust.

“We think that this structure is what causes the rhyolite-basalt volcanism throughout the Yellowstone hotspot, including supervolcanic eruptions,” Bindeman said. “This is the nursery, a geological and petrological match with eruptive products. Our modeling helps to identify the geologic structure of where the rhyolitic material is located.”

The new research, for now, does not help to predict the timing of future eruptions. Instead, it provides a never-before-seen look that helps explain the structure of the magmatic plumbing system that fuels these eruptions, Colón said. It shows where the eruptible magma originates and accumulates, which could help with prediction efforts further down the line.

“This research also helps to explain some of the chemical signatures that are seen in eruptive materials,” Colón said. “We can also use it to explore how hot the mantle plume is by comparing models of different plumes to the actual situation at Yellowstone that we understand from the geologic record.”

Colón is now exploring what influences the chemical composition of magmas that erupt at volcanoes like Yellowstone.

Studying the interaction of rising magmas with the crustal transition zone, and how this influences the properties of the magma bodies that form both above and below it, the scientists wrote, should boost scientific understanding of how mantle plumes influence the evolution and structure of continental crust.

Black Hole And Stellar Winds Form Giant Butterfly, Shut Down Star Formation In Galaxy

Researchers at the University of Colorado Boulder have completed an unprecedented “dissection” of twin galaxies in the final stages of merging.

The new study, led by CU Boulder research associate Francisco Müller-Sánchez, explores a galaxy called NGC 6240. While most galaxies in the universe hold only one supermassive black hole at their center, NGC 6240 contains two — and they’re circling each other in the last steps before crashing together.

The research reveals how gases ejected by those spiraling black holes, in combination with gases ejected by stars in the galaxy, may have begun to power down NGC 6240’s production of new stars. Müller-Sánchez’s team also shows how these “winds” have helped to create the galaxy’s most tell-tale feature: a massive cloud of gas in the shape of a butterfly.

“We dissected the butterfly,” said Müller-Sánchez of CU Boulder’s Department of Astrophysical and Planetary Sciences (APS). “This is the first galaxy in which we can see both the wind from the two supermassive black holes and the outflow of low ionization gas from star formation at the same time.”

The team zeroed in on NGC 6240, in part, because galaxies with two supermassive black holes at their centers are relatively rare. Some experts also suspect that those twin hearts have given rise to the galaxy’s unusual appearance. Unlike the Milky Way, which forms a relatively tidy disk, bubbles and jets of gas shoot off from NGC 6240, extending more than 30,000 light years into space and resembling a butterfly in flight.

“Galaxies with a single supermassive black hole never show such a phenomenal structure,” Müller-Sánchez said.

In research that will be published April 18 in Nature, the team discovered that two different forces have given rise to the nebula. The butterfly’s northwest corner, for example, is the product of stellar winds, or gases that stars emit through various processes. The northeast corner, on the other hand, is dominated by a single cone of gas that was ejected by the pair of black holes — the result of those black holes gobbling up large amounts of galactic dust and gas during their merger.

Those two winds combined evict about 100 times the mass of Earth’s sun in gases from the galaxy every year. That’s a “very large number, comparable to the rate at which the galaxy is creating stars in the nuclear region,” Müller-Sánchez said.

Such an outflow can have big implications for the galaxy itself. He explained that when two galaxies merge, they begin a feverish burst of new star formation. Black hole and stellar winds, however, can slow down that process by clearing away the gases that make up fresh stars — much like how a gust of wind can blow away the pile of leaves you just raked.

“NGC 6240 is in a unique phase of its evolution,” said Julie Comerford, an assistant professor in APS at CU Boulder and a co-author of the new study. “It is forming stars intensely now, so it needs the extra strong kick of two winds to slow down that star formation and evolve into a less active galaxy.”

Meteorite Diamonds Tell Of A Lost Planet

Using transmission electron microscopy, EPFL scientists have examined a slice from a meteorite that contains large diamonds formed at high pressure. The study shows that the parent body from which the meteorite came was a planetary embryo of a size between Mercury to Mars. The discovery is published in Nature Communications.

On October 7, 2008, an asteroid entered Earth’s atmosphere and exploded 37 km above the Nubian Desert in Sudan. The asteroid, now known as “2008 TC3,” was just over four meters in diameter. When it exploded in the atmosphere, it scattered multiple fragments across the desert. Only fifty fragments, ranging in size from 1-10 cm, were collected, for a total mass of 4.5 kg. Over time, the fragments were gathered and catalogued for study into a collection named Almahata Sitta (Arabic for “Station Six,” after a nearby train station between Wadi Halfa and Khartoum).

The Almahata Sitta meteorites are mostly ureilites, a rare type of stony meteorite that often contains clusters of nano-sized diamonds. Current thinking is that these tiny diamonds can form in three ways: enormous pressure shockwaves from high-energy collisions between the meteorite “parent body” and other space objects; deposition by chemical vapor; or, finally, the “normal” static pressure inside the parent body, like most diamonds on Earth.

The unanswered question, so far, has been the planetary origin of 2008 TC3 ureilites. Now, scientists at Philippe Gillet’s lab at EPFL, with colleagues in France and Germany, have studied large diamonds (100-microns in diameter) in some of the Almahata Sitta meteorites and discovered that the asteroid came from a planetary “embryo” whose size is between Mercury to Mars.

The researchers studied the diamond samples using a combination of advanced transmission electron microscopy techniques at EPFL’s Interdisciplinary Centre for Electron Microscopy. The analysis of the data showed that the diamonds had chromite, phosphate, and iron-nickel sulfides embedded in them — what scientists refer to as “inclusions.” These have been known for a long time to exist inside Earth’s diamonds, but are now described for the first time in an extraterrestrial body.

The particular composition and morphology of these materials can only be explained if the pressure under which the diamonds were formed was higher than 20 GPa (giga-Pascals, the unit of pressure). This level of internal pressure can only be explained if the planetary parent body was a Mercury- to Mars-sized planetary “embryo,” depending on the layer in which the diamonds were formed.

Many planetary formation models have predicted that these planetary embryos existed in the first million years of our solar system, and the study offers compelling evidence for their existence. Many planetary embryos were Mars-sized bodies, such as the one that collided with Earth to give rise to the Moon. Other of these went on to form larger planets, or collided with the Sun or were ejected from the solar system altogether. The authors write “This study provides convincing evidence that the ureilite parent body was one such large ‘lost’ planet before it was destroyed by collisions some 4.5 billion years ago.”

Warning As Japan Volcano Erupts For First Time In 250 Years

A volcano in southern Japan has erupted for the first time in 250 years, spewing steam and ash hundreds of metres into the air, as authorities warned locals not to approach the mountain.

“There is a possibility that (Mount Io) will become more active,” an official from the Japan Meteorological Agency (JMA) said, confirming the eruption.

In a televised press conference, the official warned residents in the area to stay away from the mountain, part of the Mount Kirishima group of volcanoes, as major ash deposits spread from the crater.

It was the first eruption of the mountain since 1768, the JMA said.

The agency warned that large flying rocks could fall over a 3km radius.

The eruption threw smoke and ash 400m into the air.

Footage captured by the JMA and local media showed thick white and grey smoke rising from several areas of the mountain.

There were no immediate reports of injuries, Chief Cabinet Secretary Yoshihide Suga said, adding that the Japanese government was “taking all possible measures” to prevent damage and casualties.

The eruption occurred a few kilometres away from Shinmoedake, which featured in the 1967 James Bond film “You Only Live Twice” and erupted in March.

Japan, with scores of active volcanoes, sits on the so-called Pacific “Ring of Fire” where a large proportion of the world’s earthquakes and volcanic eruptions are recorded.

In January, a Japanese soldier was killed and several other people injured after an eruption near a popular ski resort in northwest of Tokyo.

On 27 September 2014, Japan suffered its deadliest eruption in almost 90 years when Mount Ontake, in central Nagano prefecture, burst unexpectedly to life.

An estimated 63 people were killed in the shock eruption which occurred as the peak was packed with hikers out to see the region’s spectacular autumn colours.