Tropical Storm Mindulle To Threaten Tokyo Early This Week

Tropical season is in full swing in the West Pacific, as evidenced by the three tropical storms currently spinning in the basin.

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“The biggest threat to the Japanese mainland will be the storm farthest away currently, as Tropical Storm Mindulle will approach southeast Honshu early this week,” AccuWeather Meteorologist Eric Leister said.

Mindulle will maintain its strength as a tropical storm as it moves through warm ocean waters and battles upper-level winds.

Eastern Honshu will begin to feel impacts from Mindulle on Monday morning, local time. Conditions will worsen as the storm makes landfall southwest of Tokyo Monday night into Tuesday.

The main threats from Mindulle will be flooding rainfall, with widespread amounts of 100 to 150 mm (3 to 6 inches) expected from Tokyo to Sendai and up to Sapporo. Locally higher amounts are possible from the heavier rain bands.

Residents should be on alert for the potential for mudslides and take precautions when driving in areas that may be flooded.

The strongest wind gusts will be along coastal regions.

There are two other tropical systems in the vicinity of Japan.

Tropical Storm Kompasu will continue on a northward track through Monday.

“Kompasu made landfall Sunday night local time in southern Hokkaido. The storm will bring locally heavy rainfall and gusty winds to northern Honshu and eastern Hokkaido into Monday,” AccuWeather Meteorologist Eric Leister said.

This first round of flooding from Kompasu will set the stage for an enhanced flood risk from Mindulle when it moves through late Monday into Tuesday.

The final storm, Tropical Storm Lionrock, is located several hundred kilometers southwest of Tokyo and is expected to drift slowly to the west-southwest before stalling near the Ryukyu Islands.

Tropical Storm Lionrock could intensify into a typhoon next week and bring flooding rain and damaging winds to the Ryukyu Islands.

Guatemalan Volcano Erupts Spewing Ash Plumes 20,000 Feet High

GUATEMALA CITY – The Santiaguito volcano has erupted multiple times in recent days, sending ash plumes thousands of feet high, the National Coordination of Disaster Reduction of Guatemala said.


“Santiaguito volcano this morning recorded an eruption with a moderate explosion that generated” an ash plume about 10,000 feet high, the disaster agency, also known as CONRED, said in a statement Wednesday.

CONRED has warned nearby residents of falling ash.

On Tuesday, CONRED reported an “explosive activity” that caused a “strong explosion” in the Santiaguito volcano.

On Sunday, the Santiaguito volcano – also known as the Santa Maria volcano – had a moderate explosion that generated an ash plume nearly 20,000 feet high.

Mexico’s Popocatépetl Volcano Erupts 4 Times In Under 24 Hours

MEXICO CITY – Mexico’s National Center for Disaster Prevention said the Popocatépetl volcano has erupted multiple times, spewing ash and burning rocks into the air.


The disaster prevention center, or CENAPRED, Monday afternoon said Popocatépetl erupted four times in the previous 24 hours, had 73 volcanic plumes and had two volcano tectonic earthquakes — measuring in magnitudes 1.2 and 1.6, respectively.

Popocatépetl is about 43 miles southeast of Mexico City.

CENAPRED in March raised the environmental alert level to the second degree out of three, meaning nearby residents should be prepared to evacuate.

“The CENAPRED urges you not to approach the volcano, especially the crater, due to the danger of falling ballistic fragments,” CENAPRED said in a statement.

Earth’s Mantle Appears To Have A Driving Role In Plate Tectonics

Deep down below us is a tug of war moving at less than the speed of growing fingernails. Keeping your balance is not a concern, but how the movement happens has been debated among geologists.


New findings from under the Pacific Northwest Coast by University of Oregon and University of Washington scientists now suggest a solution to a mystery that surfaced when the theory of plate tectonics arose: Do the plates move the mantle, or does the mantle move the plates.

The separation of tectonic plates, the researchers proposed in a paper online ahead of print in the journal Nature Geoscience, is not simply dictating the flow of the gooey, lubricating molten material of the mantle. The mantle, they argue, is actually fighting back, flowing in a manner that drives a reorientation of the direction of the plates.

The new idea is based on seismic imaging of the Endeavor segment of the Juan de Fuca Plate in the Pacific Ocean off Washington and on data from previous research on similar ridges in the mid-Pacific and mid-Atlantic oceans.

“Comparing seismic measurements of the present mantle flow direction to the recent movements of tectonic plates, we find that the mantle is flowing in a direction that is ahead of recent changes in plate motion,” said UO doctoral student Brandon P. VanderBeek, the paper’s lead author. “This contradicts the traditional view that plates move the mantle.”

While the new conclusion is based on a fraction of such sites under the world’s oceans, a consistent pattern was present, VanderBeek said. At the three sites, the mantle’s flow is rotated clockwise or counterclockwise rather than in the directions of the separating plates. The mantle’s flow, the researchers concluded, may be responsible for past and possibly current changes in plate motion.

The research—funded through National Science Foundation grants to the two institutions – also explored how the supply of magma varies under mid-ocean ridge volcanoes. The researchers conducted a seismic experiment to see how seismic waves moved through the shallow mantle below the Endeavor segment.

They found that the middle of the volcanic segment, where the seafloor is shallowest and the inferred volcanic activity greatest, the underlying mantle magma reservoir is relatively small. The ends, however, are much deeper with larger volumes of mantle magma pooling below them because there are no easy routes for it to travel through the material above it.

Traditional thinking had said there would be less magma under the deep ends of such segments, known as discontinuities.

“We found the opposite,” VanderBeek said. “The biggest volumes of magma that we believe we have found are located beneath the deepest portions of the ridges, at the segment ends. Under the shallow centers, there is much less melt, about half as much, at this particular ridge that we investigated.

“Our idea is that the ultimate control on where you have magma beneath these mountain ranges is where you can and cannot take it out,” he said. “At the ends, we think, the plate rips apart much more diffusely, so you are not creating pathways for magma to move, build mountains and allow for an eruption.”

How Comets Are Born

Detailed analysis of data collected by Rosetta show that comets are the ancient leftovers of early Solar System formation, and not younger fragments resulting from subsequent collisions between other, larger bodies.


Understanding how and when objects like Comet 67P/Churyumov-Gerasimenko took shape is of utmost importance in determining how exactly they can be used to interpret the formation and early evolution of our Solar System.

A new study addressing this question led by Björn Davidsson of the Jet Propulsion Laboratory, California Institute of Technology in Pasadena (USA), has been published in Astronomy & Astrophysics.

If comets are primordial, then they could help reveal the properties of the solar nebula from which the Sun, planets and small bodies condensed 4.6 billion years ago, and the processes that transformed our planetary system into the architecture we see today.

The alternative hypothesis is that they are younger fragments resulting from collisions between older ‘parent’ bodies such as icy trans-Neptunian objects (TNOs). They would then provide insight into the interior of such larger bodies, the collisions that disrupted them, and the process of building new bodies from the remains of older ones.

“Either way, comets have been witness to important Solar System evolution events, and this is why we have made these detailed measurements with Rosetta – along with observations of other comets – to find out which scenario is more likely,” says Matt Taylor, ESA’s Rosetta project scientist.

During its two-year sojourn at Comet 67P/Churyumov-Gerasimenko, Rosetta has revealed a picture of the comet as a low-density, high-porosity, double-lobed body with extensive layering, suggesting that the lobes accumulated material over time before they merged.

The unusually high porosity of the interior of the nucleus provides the first indication that this growth cannot have been via violent collisions, as these would have compacted the fragile material. Structures and features on different size scales observed by Rosetta’s cameras provide further information on how this growth may have taken place.


Earlier work showed that the head and body were originally separate objects, but the collision that merged them must have been at low speed in order not to destroy both of them. The fact that both parts have similar layering also tells us that they must have undergone similar evolutionary histories and that survival rates against catastrophic collision must have been high for a significant period of time.

Merging events may also have happened on smaller scales. For example, three spherical ‘caps’ have been identified in the Bastet region on the small comet lobe, and suggestions are that they are remnants of smaller cometesimals that are still partially preserved today.

At even smaller scales of just a few metres across, there are the so-called ‘goosebumps’ and ‘clod’ features, rough textures observed in numerous pits and exposed cliff walls in various locations on the comet.

While it is possible that this morphology might arise from fracturing alone, it is actually thought to represent an intrinsic ‘lumpiness’ of the comet’s constituents. That is, these ‘goosebumps’ could be showing the typical size of the smallest cometesimals that accumulated and merged to build up the comet, made visible again today through erosion due to sunlight.

According to theory, the speeds at which cometesimals collide and merge change during the growth process, with a peak when the lumps have sizes of a few metres. For this reason, metre-sized structures are expected to be the most compact and resilient, and it is particularly interesting that the comet material appears lumpy on that particular size scale.

Further lines of evidence include spectral analysis of the comet’s composition showing that the surface has experienced little or no in situ alteration by liquid water, and analysis of the gases ejected from sublimating ices buried deeper within the surface, which finds the comet to be rich in supervolatiles such as carbon monoxide, oxygen, nitrogen and argon.

These observations imply that comets formed in extremely cold conditions and did not experience significant thermal processing during most of their lifetimes. Instead, to explain the low temperatures, survival of certain ices and retention of supervolatiles, they must have accumulated slowly over a significant time period.

“While larger TNOs in the outer reaches of the Solar System appear to have been heated by short-lived radioactive substances, comets don’t seem to show similar signs of thermal processing. We had to resolve this paradox by taking a detailed look at the time line of our current Solar System models, and consider new ideas,” says Björn.


Björn and colleagues propose that the larger members of the TNO population formed rapidly within the first one million years of the solar nebula, aided by turbulent gas streams that rapidly accelerated their growth to sizes of up to 400 km.

Around three million years into the Solar System’s history, gas had disappeared from the solar nebula, only leaving solid material behind. Then, over a much longer period of around 400 million years, the already massive TNOs slowly accreted further material and underwent compaction into layers, their ices melting and refreezing, for example. Some TNOs even grew into Pluto or Triton-sized objects.

Comets took a different path. After the rapid initial growth phase of the TNOs, leftover grains and ‘pebbles’ of icy material in the cold, outer parts of the solar nebula started to come together at low velocity, yielding comets roughly 5 km in size by the time gas has disappeared from the solar nebula. The low speeds at which the material accumulated led to objects with fragile nuclei with high porosity and low density.

This slow growth also allowed comets to preserve some of the oldest, volatile-rich material from the solar nebula, since they were able to release the energy generated by radioactive decay inside them without heating up too much.

The larger TNOs played a further role in the evolution of comets. By ‘stirring’ the cometary orbits, additional material was accreted at somewhat higher speed over the next 25 million years, forming the outer layers of comets. The stirring also made it possible for the few kilometre-sized objects in size to bump gently into each other, leading to the bi-lobed nature of some observed comets.

“Comets do not appear to display the characteristics expected for collisional rubble piles, which result from the smash-up of large objects like TNOs. Rather, we think they grew gently in the shadow of the TNOs, surviving essentially undamaged for 4.6 billion years,” concludes Björn.

“Our new model explains what we see in Rosetta’s detailed observations of its comet, and what had been hinted at by previous comet flyby missions.”
“Comets really are the treasure-troves of the Solar System,” adds Matt.

“They give us unparalleled insight into the processes that were important in the planetary construction yard at these early times and how they relate to the Solar System architecture that we see today.”

Loneliest Young Star Seen By Spitzer And WISE

Alone on the cosmic road, far from any known celestial object, a young, independent star is going through a tremendous growth spurt.


The unusual object, called CX330, was first detected as a source of X-ray light in 2009 by NASA’s Chandra X-Ray Observatory while it was surveying the bulge in the central region of the Milky Way. Further observations indicated that this object was emitting optical light as well. With only these clues, scientists had no idea what this object was.

But when Chris Britt, postdoctoral researcher at Texas Tech University in Lubbock, and colleagues were examining infrared images of the same area taken with NASA’s Wide-field Infrared Survey Explorer (WISE), they realized this object has a lot of warm dust around it, which must have been heated by an outburst.

Comparing WISE data from 2010 with Spitzer Space Telescope data from 2007, researchers determined that CX330 is likely a young star that had been outbursting for several years. In fact, in that three-year period its brightness had increased by a few hundred times.

Astronomers looked at data about the object from a variety of other observatories, including the ground-based SOAR, Magellan, and Gemini telescopes. They also used the large telescope surveys VVV and the OGLE-IV to measure the intensity of light emitted from CX330. By combining all of these different perspectives on the object, a clearer picture emerged.

“We tried various interpretations for it, and the only one that makes sense is that this rapidly growing young star is forming in the middle of nowhere,” said Britt, lead author of a study on CX330 recently published in the Monthly Notices of the Royal Astronomical Society.

The lone star’s behavior has similarities to FU Orionis, a young outbursting star that had an initial three-month outburst in 1936-7. But CX330 is more compact, hotter and likely more massive than the FU Orionis-like objects known. The more isolated star launches faster “jets,” or outflows of material that slam into the gas and dust around it.

“The disk has probably heated to the point where the gas in the disk has become ionized, leading to a rapid increase in how fast the material falls onto the star,” said Thomas Maccarone, study co-author and associate professor at Texas Tech.

Most puzzling to astronomers, FU Orionis and the rare objects like it—there are only about 10 of them—are located in star-forming regions. Young stars usually form and feed from their surrounding gas and dust-rich regions in star-forming clouds. By contrast, the region of star formation closest to CX330 is over a thousand light-years away.

“CX330 is both more intense and more isolated than any of these young outbursting objects that we’ve ever seen,” said Joel Green, study co-author and researcher at the Space Telescope Science Institute in Baltimore. “This could be the tip of the iceberg—these objects may be everywhere.”

In fact, it is possible that all stars go through this dramatic stage of development in their youth, but that the outbursts are too short in cosmological time for humans to observe many of them.

How did CX330 become so isolated? One idea is that it may have been born in a star-forming region, but was ejected into its present lonely pocket of the galaxy. But this is unlikely, astronomers say. Because CX330 is in a youthful phase of its development—likely less than 1 million years old—and is still eating its surrounding disk, it must have formed near its present location in the sky.

“If it had migrated from a star-forming region, it couldn’t get there in its lifetime without stripping its disk away entirely,” Britt said.

CX330 may also help scientists study the way stars form under different circumstances. One scenario is that stars form through turbulence. In this “hierarchical” model, a critical density of gas in a cloud causes the cloud to gravitationally collapse into a star. A different model, called “competitive accretion,” suggests that stars begin as low-mass cores that fight over the mass of material left in the cloud. CX330 more naturally fits into the first scenario, as the turbulent circumstances would theoretically allow for a lone star to form.

It is still possible that other intermediate- to low-mass stars are in the immediate vicinity of CX330, but have not been detected yet.

When CX330 was last viewed in August 2015, it was still outbursting. Astronomers plan to continue studying the object, including with future telescopes that could view it in other wavelengths of light.

Outbursts from a young star change the chemistry of the star’s disk, from which planets may eventually form. If the phenomenon is common, that means that planets, including our own, may carry the chemical signatures of an ancient disk of gas and dust scarred by stellar outbursts.

But as CX330 is continuing to devour its disk with increasing voracity, astronomers do not expect that planets are forming in its system.

“If it’s truly a massive star, its lifetime is short and violent, and I wouldn’t recommend being a planet around it,” Green said. “You could experience some pretty intense heat for a few centuries.”

The Role Of Magnetic Fields In Star Formation

The star forming molecular clump W43-MM1 is very massive and dense, containing about 2100 solar masses of material in a region only one-third of a light year across (for comparison, the nearest star to the Sun is a bit over four light years away).


Previous observations of this clump found evidence for infalling motions (signaling that material is still accumulating onto a new star) and weak magnetic fields. These fields are detected by looking for polarized light, which is produced when radiation scatters off of elongated dust grains aligned by magnetic fields. The Submillimeter Array recently probed this source with high spatial resolutions and found evidence for even stronger magnetic fields in places. One of the outstanding issues in star formation is the extent to which magnetic fields inhibit the collapse of material onto stars, and this source seems to offer a particularly useful example.

CfA astronomers Josep Girart and TK Sridharan and their colleagues have used the ALMA submillimeter facility to obtain images with spatial scales as small as 0.03 light years. Their detailed polarization maps show that the magnetic field is well ordered all across the clump, which itself is actually fifteen smaller fragments, one of which (at 312 solar masses) appears to be the most massive fragment known.

The scientists analyze the magnetic field strengths and show that, even in the least massive fragment the field is not strong enough to inhibit gravitational collapse. In fact, they find indications that gravity, as it pulls material inward, drags the magnetic field lines along. They are, however, unable to rule out possible further fragmentation. The research is the most precise study of magnetic fields in star forming massive clumps yet undertaken, and provides a new reference point for theoretical models.