Month: October 2017

Sloshing Of Earth’s Core May Spike Major Earthquakes

The world doesn’t stop spinning. But every so often, it slows down. For decades, scientists have charted tiny fluctuations in the length of Earth’s day: Gain a millisecond here, lose a millisecond there. Last week at the annual meeting of the Geological Society of America here, two geophysicists argued that these minute changes could be enough to influence the timing of major earthquakes—and potentially help forecast them.

During the past 100 years, Earth’s slowdowns have correlated surprisingly well with periods with a global increase in magnitude-7 and larger earthquakes, according to Roger Bilham of the University of Colorado (CU) in Boulder and Rebecca Bendick at the University of Montana in Missoula. Usefully, the spike, which adds two to five more quakes than typical, happens well after the slow-down begins. “The Earth offers us a 5-years heads up on future earthquakes, which is remarkable,” says Bilham, who presented the work.

Most seismologists agree that earthquake prediction is a minefield. And so far, Bilham and Bendick have only fuzzy, hard-to-test ideas about what might cause the pattern they found. But the finding is too provocative to ignore, other researchers say. “The correlation they’ve found is remarkable, and deserves investigation,” says Peter Molnar, a geologist also at CU.

The research started as a search for synchrony in earthquake timing. Individual oscillators, be they fireflies, heart muscles, or metronomes, can end up vibrating in synchrony as a result of some kind of cross-talk—or some common influence. To Bendick, it didn’t seem a far jump to consider the faults that cause earthquakes, with their cyclical buildup of strain and violent discharge, as “really noisy, really crummy oscillators,” she says. She and Bilham dove into the data, using the only complete earthquake catalog for the past 100 years: magnitude-7 and larger earthquakes.

In work published in August in Geophysical Research Letters they reported two patterns: First, major quakes appeared to cluster in time—although not in space. And second, the number of large earthquakes seemed to peak at 32-year intervals. The earthquakes could be somehow talking to each other, or an external force could be nudging the earth into rupture.

Exploring such global forces, the researchers eventually discovered the match with the length of day. Although weather patterns such as El Nino can drive day length to vary back and forth by a millisecond over a year or more, a periodic, decades-long fluctuation of several milliseconds—in particular, its point of peak slow down about every three decades or so—lined up with the quake trend perfectly. “Of course that seems sort of crazy,” Bendick says. But maybe it isn’t. When day length changes over decades, Earth’s magnetic field also develops a temporary ripple. Researchers think slight changes in the flow of the molten iron of the outer core may be responsible for both effects. Just what happens is uncertain—perhaps a bit of the molten outer core sticks to the mantle above. That might change the flow of the liquid metal, altering the magnetic field, and transfer enough momentum between the mantle and the core to affect day length.

Seismologists aren’t used to thinking about the planet’s core, buried 2900 kilometers beneath the crust where quakes happen. But they should, Bilham said during his talk here. The core is “quite close to us. It’s closer than New York from here,” he said.

At the equator, Earth spins 460 meters per second. Given this high velocity, it’s not absurd to think that a slight mismatch in speed between the solid crust and mantle and the liquid core could translate into a force somehow nudging quakes into synchrony, Molnar says. Of course, he adds, “It might be nonsense.” But the evidence for some kind of link is compelling, says geophysicist Michael Manga of the University of California, Berkeley. “I’ve worked on earthquakes triggered by seasonal variation, melting snow. His correlation is much better than what I’m used to seeing.”

One way or another, says James Dolan, a geologist at the University of Southern California in Los Angeles, “we’re going to know in 5 years.” That’s because Earth’s rotation began a periodic slow-down 4-plus years ago. Beginning next year, Earth should expect five more major earthquakes a year than average—between 17 to 20 quakes, compared with the anomalously low four so far this year. If the pattern holds, it will put a new spin on earthquake forecasting.

Typhoon Saola Downgraded But Expected To Drench Pacific Coastal Areas As It Nears Hokkaido

Typhoon Saola was churning along the Pacific coast of Honshu toward Hokkaido Monday morning, with the Meteorological Agency warning the storm was bound to release more heavy rain to northern regions.

But the season’s 22nd typhoon was weakened into a low-pressure system off Japan’s northeastern coastline early Monday morning after passing south of the Kanto region, the agency said.

The typhoon was moving off the Sanriku coast of Iwate Prefecture as of 12:50 a.m. and had an atmospheric pressure reading of 980 hectopascals. It was heading northeast at a speed of 100 kph, the weather agency said.

The agency warned of strong winds, river flooding caused by heavy rain, and mudslides.

On Sunday, the typhoon brought heavy rain to many regions. The cities of Miyazaki and Nichinan, in Miyazaki Prefecture, saw a record amount of rainfall in 24 hours, with more than 400 mm by Sunday morning.

In Miyazaki and Oita prefectures, two women, one aged 79 yand the other 86, fell down and broke their legs.

The agency said the Tokai region would get up to 180 mm of rain over a 24-hour period ending at noon on Monday, 150 mm in the Hokuriku and Kanto-Koshin regions, and 100 mm in the Tohoku region.

The typhoon disturbed transportation networks, forcing operators to cancel some services.

According to an NHK report, a total of 86 flights, mostly in Kyushu and Okinawa, were canceled Sunday.

Kyushu Railway Co. halted some operations on sections of the Nippo and Nichinan lines, while East Japan Railway Co. suspended the Sunrise Izumo limited express sleeper service and other services.

The typhoon also disrupted various events, including the 37th Oita International Wheelchair Marathon in Oita Prefecture. The race was due to start Sunday morning but was canceled, its organizers said.

Saola follows in the wake of Typhoon Lan, which battered much of the country with heavy rain and strong winds just a week ago. Lan killed seven people and injured nearly 100 others, causing floods, mudslides and traffic disruptions.

When Lan hit, it also disrupted ballot counting for the Oct. 22 House of Representatives election.

A number of municipalities had issued evacuation advisories to residents and regional election boards had to forgo vote-counting until the ballots could be delivered. On Oct. 23, Lan made landfall in Shizuoka Prefecture and ran over Tokyo, triggering floods, mudslides and traffic disruptions.

Earthquake Risk Elevated With Detection Of Spontaneous Tectonic Tremor In Anza Gap

Scientists at the University of California, Riverside have detected spontaneous tectonic tremor—a signature of slow earthquakes deep below the earth’s surface—in the Anza Gap region of the San Jacinto Fault. Tectonic tremors are believed to increase the likelihood of a moderate to large, damaging earthquake occurring close to the earth’s surface by altering the stress along the fault.

Abhijit Ghosh, an assistant professor of earth sciences in UCR’s College of Natural and Agricultural Sciences, and Alexandra Hutchinson, an earth sciences graduate student, published the research in the Bulletin of the Seismologic Society of America.

The paper is titled “Ambient Tectonic Tremor in the San Jacinto Fault, Near the Anza Gap, Detected by Multiple Mini Seismic Arrays.”

The San Jacinto Fault zone, which is part of the San Andreas Fault system, runs underneath densely populated areas of Inland Southern California, including San Bernardino, Redlands, and Moreno Valley. It is the most active fault in Southern California and sits five miles from the UCR campus. While it is technically not a plate boundary, the San Jacinto Fault accommodates some of the movement that occurs as the North American Plate and the Pacific Plate grind together at the San Andreas Fault.

Over the past 200 years, the 20-km region known as the Anza Gap is the only stretch along the 200-km fault line that has not experienced an earthquake of magnitude 5.5 or greater.

“While other regions of the San Jacinto fault give rise to small and moderate earthquakes on a regular basis, the Anza Gap is surprisingly quiet, which raises questions about how it is releasing the stress it accumulates,” Ghosh said. “For that reason, many experts suspect that this area is ripe to produce a damaging earthquake.”

Using data from 2011 and a new, highly sensitive detection method developed by Ghosh called “multibeam backprojection,” the researchers uncovered the first evidence of a spontaneous tectonic tremor in the Anza Gap. Relatively little is known about tectonic tremors, which were first identified in Japan in 2001. Researchers now know they are associated with a phenomenon called “slow slip,” a slow and transient movement of plates deep below the earth’s surface that can last from several minutes to several years and may occur daily, annually, or anywhere between, depending on the fault.

“While relatively little is known about tectonic tremors, in part because they have historically been difficult to detect, we know that these tremors are being caused by slow slip deep in the fault, and that when the deep part of the fault slips it adds stress to the shallow part. This may ultimately help to cause a damaging earthquake,” Ghosh said.

Ghosh said seismologists should further study tremor activity in the area to learn how the deep roots of fault zones impact activity closer to the earth’s surface and affect earthquake hazard.

“Tectonic tremors and slow slip will change the way we view faults. For example, our research on the Anza gap shows that the fault is spontaneously slipping at a greater depth than we previously thought, with slow earthquakes occurring between 13 and 24 km deep.”

“Since there is a connection between deep slow slip and damaging earthquakes closer to the surface, it may be possible that tectonic tremors will enable us to forecast major earthquakes in the future. Much more research is needed before that can happen, though.”

Small Asteroid Or Comet ‘Visits’ From Beyond The Solar System

A small, recently discovered asteroid — or perhaps a comet — appears to have originated from outside the solar system, coming from somewhere else in our galaxy. If so, it would be the first “interstellar object” to be observed and confirmed by astronomers.

This unusual object — for now designated A/2017 U1 — is less than a quarter-mile (400 meters) in diameter and is moving remarkably fast. Astronomers are urgently working to point telescopes around the world and in space at this notable object. Once these data are obtained and analyzed, astronomers may know more about the origin and possibly composition of the object.

A/2017 U1 was discovered Oct. 19 by the University of Hawaii’s Pan-STARRS 1 telescope on Haleakala, Hawaii, during the course of its nightly search for near-Earth objects for NASA. Rob Weryk, a postdoctoral researcher at the University of Hawaii Institute for Astronomy (IfA), was first to identify the moving object and submit it to the Minor Planet Center. Weryk subsequently searched the Pan-STARRS image archive and found it also was in images taken the previous night, but was not initially identified by the moving object processing.

Weryk immediately realized this was an unusual object. “Its motion could not be explained using either a normal solar system asteroid or comet orbit,” he said. Weryk contacted IfA graduate Marco Micheli, who had the same realization using his own follow-up images taken at the European Space Agency’s telescope on Tenerife in the Canary Islands. But with the combined data, everything made sense. Said Weryk, “This object came from outside our solar system.”

“This is the most extreme orbit I have ever seen,” said Davide Farnocchia, a scientist at NASA’s Center for Near-Earth Object Studies (CNEOS) at the agency’s Jet Propulsion Laboratory in Pasadena, California. “It is going extremely fast and on such a trajectory that we can say with confidence that this object is on its way out of the solar system and not coming back.”

The CNEOS team plotted the object’s current trajectory and even looked into its future. A/2017 U1 came from the direction of the constellation Lyra, cruising through interstellar space at a brisk clip of 15.8 miles (25.5 kilometers) per second.

The object approached our solar system from almost directly “above” the ecliptic, the approximate plane in space where the planets and most asteroids orbit the Sun, so it did not have any close encounters with the eight major planets during its plunge toward the Sun. On Sept. 2, the small body crossed under the ecliptic plane just inside of Mercury’s orbit and then made its closest approach to the Sun on Sept. 9. Pulled by the Sun’s gravity, the object made a hairpin turn under our solar system, passing under Earth’s orbit on Oct. 14 at a distance of about 15 million miles (24 million kilometers) — about 60 times the distance to the Moon. It has now shot back up above the plane of the planets and, travelling at 27 miles per second (44 kilometers per second) with respect to the Sun, the object is speeding toward the constellation Pegasus.

“We have long suspected that these objects should exist, because during the process of planet formation a lot of material should be ejected from planetary systems. What’s most surprising is that we’ve never seen interstellar objects pass through before,” said Karen Meech, an astronomer at the IfA specializing in small bodies and their connection to solar system formation.

The small body has been assigned the temporary designation A/2017 U1 by the Minor Planet Center (MPC) in Cambridge, Massachusetts, where all observations on small bodies in our solar system — and now those just passing through — are collected. Said MPC Director Matt Holman, “This kind of discovery demonstrates the great scientific value of continual wide-field surveys of the sky, coupled with intensive follow-up observations, to find things we wouldn’t otherwise know are there.”

Since this is the first object of its type ever discovered, rules for naming this type of object will need to be established by the International Astronomical Union.

“We have been waiting for this day for decades,” said CNEOS Manager Paul Chodas. “It’s long been theorized that such objects exist — asteroids or comets moving around between the stars and occasionally passing through our solar system — but this is the first such detection. So far, everything indicates this is likely an interstellar object, but more data would help to confirm it.”

The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) is a wide-field survey observatory operated by the University of Hawaii Institute for Astronomy. The Minor Planet Center is hosted by the Harvard-Smithsonian Center for Astrophysics and is a sub-node of NASA’s Planetary Data System Small Bodies Node at the University of Maryland (http://www.minorplanetcenter.net/ ). JPL hosts the Center for Near-Earth Object Studies (CNEOS). All are projects of NASA’s Near-Earth Object Observations Program, and elements of the agency’s Planetary Defense Coordination Office within NASA’s Science Mission Directorate.

Hurricane Philippe Path Update: Latest Track Model Shows Tropical Storm Smashing Florida

Tropical storm Philippe is moving across Florida and towards New York with major rain and winds battering parts of the United States.

Tropical storm Philippe, with winds of up to 40mph, is heading northwestward across southern Florida in the United States, according to US weather team StormTracker 13.

Philippe is set to cause three to five inches of rain across south Florida over the weekend.

Heavy rain and gusty winds are predicted to hit parts of Cuba and Florida on Sunday.

Meteorologist Erik Taylor of StormTracker 13, said the storm would “hamper” clean-up operations in Florida Keys after Hurricane Irma hit last month.

The National Hurricane Center has issued an alert for mainland USA including the Keys and New York as Philippe heads north across the country.

NOAA latest update shows tropical storm Philippe moving “erratically near Key West.”

A tropical storm warning is in effect for Cuban provinces of Isla de la Juventud, La Habana, Ciudad de la Habana, Matanzas, Cienfuegos, and Villa Clara and Northwestern Bahamas.

Tropical storm Philippe is currently travelling at 12mph. The NOAA have confirmed at 2am EDT that a rapid motion toward the northeast is expected through Monday.

On the forecast track, the centre of Philippe will move across the Florida Keys or the southern tip of the Florida peninsula this morning, and across the northwestern Bahamas later today.

Tropical-storm-force winds extend outward up to 105 miles (165 km) mainly to the east and southeast of the centre.

Yesterday tracking maps showed the storm moving over Cuba on course to hit Florida.

Powerful Storm Rolls Into Northeast on 5th Anniversary of Hurricane Sandy

A powerful storm was forecast to slam the Northeast overnight into Monday, threatening to bring heavy rains, flooding and damaging winds to the region on the fifth anniversary of the devastating Hurricane Sandy.

Heavy rain covered the region late Sunday, and the storm was expected to bring as much as 5 inches of rain to some areas through Monday, the National Weather Service said.

Heavy rains and potentially damaging winds could continue over parts of New England and Upstate New York into Monday.

“We have high wind warnings and high wind advisories that are up throughout the Northeast,” said Heather Tesch, a meteorologist for The Weather Channel. “Expect a lot of delays at the major airports.”

The National Weather Service issued a flood warning for much of southeastern New York, including Manhattan, on Sunday night. A flash flood watch was in effect through late Sunday night for all of Connecticut, Massachusetts and Rhode Island.

“Widespread rainfall totals of 3 to 5 inches are expected, but locally higher amounts, perhaps 6 inches or more, are possible,” the NWS said.

And the storm was expected to bring “hurricane force wind gusts” to coastal waters from eastern Massachusetts to southern Maine early Monday, according to the National Weather Service. A hurricane-force wind warning means winds of 64 knots or greater are imminent or already happening, according to the NWS.

“All vessels should remain in port … or take shelter as soon as possible …. until winds and waves subside,” the weather service said.

Experts are recommending recreational boaters to keep their boats at the seaport and avoid sailing in the waters while the storm watch is in effect. The National Weather Service also advised people to prepare for strong winds and take shelter.

Power outages and tree damage were possible across the Northeast as well, likely along the coast, according to the Weather Channel. Winds were expected to trigger delays at major airports in the region.

The storm comes five years after Sandy made landfall in New Jersey, beginning its devastation to the area. Sandy led to the death of 182 individuals and more than $71 billion in damage in the United States. The hurricane knocked out power in millions of homes, the Associated Press reported.

John Rowe, senior meteorologist at the Weather Channel, expects the storm to merge with Tropical Storm Philippe on the East Coast. “The whole system is going to intensify [Sunday night] and it’ll bring heavy rains from Eastern Pennsylvania and heavy rain and wind,” he said. Philippe is forming around the Bahamas and veering away from Florida, according to the Weather Channel.

Rowe said he expects the storm to peak Sunday night and “lift away” on Monday

Martian Landscapes Formed From Sand ‘Levitating’ On A Little Boiling Water

Scientists from The Open University (OU) have discovered a process that could explain the long-debated mystery of how land features on Mars are formed in the absence of significant amounts of water.

Experiments carried out in the OU Mars Simulation Chamber — specialised equipment, which is able to simulate the atmospheric conditions on Mars — reveal that Mars’ thin atmosphere (about 7 mbar — compared to 1,000 mbar on Earth) combined with periods of relatively warm surface temperatures causes water flowing on the surface to violently boil. This process can then move large amounts of sand and other sediment, which effectively ‘levitates’ on the boiling water.

This means that, in comparison to Planet Earth, relatively small amounts of liquid water moving across Mars’ surface could form the large dune flows, gullies and other features, which characterise the Red Planet.

Dr Jan Raack, Marie Skłodowska-Curie Research Fellow at The Open University, is lead author of the research; he said:

“Whilst planetary scientists already know that the surface of Mars has ‘mass-wasting’ features — such as dune flows, gullies, and recurring slope lineae — which occur as a result of sediment transportation down a slope, the debate about what is forming them continues.

“Our research has discovered that this levitation effect caused by boiling water under low pressure enables the rapid transport of sand and sediment across the surface. This is a new geological phenomenon, which doesn’t happen on Earth, and could be vital to understanding similar processes on other planetary surfaces.”

Dr Raack conducted these experiments in the Hypervelocity Impact (HVI) Laboratory based at the OU. He added:

“The sources of this liquid water will require more observational studies; however, the research shows that the effects of relatively small amounts of water on Mars in forming features on the surface may have been widely underestimated.

“We need to carry out more research into how water levitates on Mars, and missions such as the ESA ExoMars 2020 Rover will provide vital insight to help us better understand our closest neighbour.”

The research is funded by the Europlanet 2020 Research Infrastructure through the European Union’s Horizon 2020 Research and Innovation Programme [Grant Agreement No. 654208], and co-authored by academics from the STFC Rutherford Appleton Laboratory, Universität Bern, and Université de Nantes. The initial research concept was developed by Susan J. Conway of Université de Nantes.