Strong Earthquake Strikes Indonesia, Killing At Least 20 People

 

A 6.5-magnitude earthquake struck the remote Maluku Islands in eastern Indonesia on Thursday morning, killing at least 20 people.

Indonesian officials said the quake, which was detected at 8:46 a.m. local time, did not present the threat of a tsunami. But it was classified as a “strong” earthquake in Ambon, a city of more than 300,000 people and the capital of Maluku Province. The United States Geological Survey said the epicenter was about 23 miles northeast of Ambon.

At least 20 people were killed in the quake, the authorities said, including a man who was killed when a building partially collapsed at an Islamic university in Ambon, according to Reuters. More than 100 people were reported injured in the quake, and the authorities said about 2,000 had been displaced from their homes.

It was not immediately known how many people were injured or how extensive the damage was across the islands, but the nation’s disaster management agency posted several photos and videos on Twitter showing cracked roads and damaged buildings. The nation’s meteorology, climate and geophysics agency reported at least 69 aftershocks, including one of magnitude 5.6.

Deadly earthquakes are common for Indonesia and its roughly 260 million people. In 2004, a tsunami generated by an earthquake largely destroyed the city of Banda Aceh, killing about 225,000 people in more than a dozen countries.

In 2018 alone, six quakes had at least a 6.0 magnitude. More than 4,300 people were killed in an earthquake and subsequent tsunami in Sulawesi in September 2018, and the previous month, a magnitude 7.0 earthquake killed more than 550 people when it struck the island of Lombok, near Bali.

 

For 400 years people have tracked sunspots, the dark patches that appear for weeks at a time on the Sun’s surface. They have observed but been unable to explain why the number of spots peaks every 11 years.

A University of Washington study published this month in the journal Physics of Plasmas proposes a model of plasma motion that would explain the 11-year sunspot cycle and several other previously mysterious properties of the Sun.

“Our model is completely different from a normal picture of the Sun,” said first author Thomas Jarboe, a UW professor of aeronautics and astronautics. “I really think we’re the first people that are telling you the nature and source of solar magnetic phenomena — how the Sun works.”

The authors created a model based on their previous work with fusion energy research. The model shows that a thin layer beneath the Sun’s surface is key to many of the features we see from Earth, like sunspots, magnetic reversals and solar flow, and is backed up by comparisons with observations of the Sun.

“The observational data are key to confirming our picture of how the Sun functions,” Jarboe said.

In the new model, a thin layer of magnetic flux and plasma, or free-floating electrons, moves at different speeds on different parts of the Sun. The difference in speed between the flows creates twists of magnetism, known as magnetic helicity, that are similar to what happens in some fusion reactor concepts.

“Every 11 years, the Sun grows this layer until it’s too big to be stable, and then it sloughs off,” Jarboe said. Its departure exposes the lower layer of plasma moving in the opposite direction with a flipped magnetic field.

When the circuits in both hemispheres are moving at the same speed, more sunspots appear. When the circuits are different speeds, there is less sunspot activity. That mismatch, Jarboe says, may have happened during the decades of little sunspot activity known as the “Maunder Minimum.”

“If the two hemispheres rotate at different speeds, then the sunspots near the equator won’t match up, and the whole thing will die,” Jarboe said.

“Scientists had thought that a sunspot was generated down at 30 percent of the depth of the Sun, and then came up in a twisted rope of plasma that pops out,” Jarboe said. Instead, his model shows that the sunspots are in the “supergranules” that form within the thin, subsurface layer of plasma that the study calculates to be roughly 100 to 300 miles (150 to 450 kilometers) thick, or a fraction of the sun’s 430,000-mile radius.

“The sunspot is an amazing thing. There’s nothing there, and then all of a sudden, you see it in a flash,” Jarboe said.

The group’s previous research has focused on fusion power reactors, which use very high temperatures similar to those inside the Sun to separate hydrogen nuclei from their electrons. In both the sun and in fusion reactors the nuclei of two hydrogen atoms fuse together, releasing huge amounts of energy.

The type of reactor Jarboe has focused on, a spheromak, contains the electron plasma within a sphere that causes it to self-organize into certain patterns. When Jarboe began to consider the Sun, he saw similarities, and created a model for what might be happening in the celestial body.

“For 100 years people have been researching this,” Jarboe said. “Many of the features we’re seeing are below the resolution of the models, so we can only find them in calculations.”

Other properties explained by the theory, he said, include flow inside the Sun, the twisting action that leads to sunspots and the total magnetic structure of the sun. The paper is likely to provoke intense discussion, Jarboe said.

“My hope is that scientists will look at their data in a new light, and the researchers who worked their whole lives to gather that data will have a new tool to understand what it all means,” he said.

The research was funded by the U.S. Department of Energy. Co-authors are UW graduate students Thomas Benedett, Christopher Everson, Christopher Hansen, Derek Sutherland, James Penna, UW postdoctoral researchers Aaron Hossack and John Benjamin O’Bryan, UW affiliate faculty member Brian Nelson, and Kyle Morgan, a former UW graduate student now at CTFusion in Seattle.

Category 4 Hurricane Lorenzo is the Most Intense Hurricane So Far East in the Atlantic Ocean on Record

 

Hurricane Lorenzo became the most intense hurricane so far east in the Atlantic Ocean on record Thursday night, and poses a danger to the Azores next week.

Lorenzo rapidly intensified into a Category 4 hurricane Thursday, with maximum winds estimated at 145 mph.

According to Dr. Phil Klotzbach, a tropical scientist at Colorado State University, Lorenzo became the most intense hurricane east of 45 degrees West longitude in the historical record.

Lorenzo is even a bigger outlier when considering only those Category 4 hurricanes from Sept. 26 through the end of the season, as pointed out by Richard Dixon, a meteorologist at CatInsight and Michael Lowry, an atmospheric scientist at FEMA.

Even in the heart of hurricane season, tropical waves moving off the coast of western Africa usually take some time to mushroom into intense hurricanes.

This is often due to intrusions of dry air, known as Saharan air layers, moving off Africa’s Sahara Desert. Fledgling tropical disturbances need warm, moist air to intensify, so battling these intrusions can prevent intensification or even spell doom in the eastern Atlantic Ocean.

In Lorenzo’s case, that wasn’t a big problem.

A lack of shearing winds, typically warm ocean water and moist air allowed Lorenzo to rapidly intensify so far east.

Lorenzo strengthened from a tropical storm on Tuesday into a hurricane on Wednesday, before reaching Category 4 hurricane strength by late Thursday morning.

Azores Threat
The storm is no immediate threat to land, but it is forecast to pass near the Azores Tuesday night or early Wednesday as a weaker, but still formidable hurricane.

The National Hurricane Center mentioned Lorenzo’s wind field is large, increasing the chances it may impact the group of Portuguese islands about 900 miles west of Portugal.

NHC forecaster Eric Blake tweeted Thursday its size resembled that of a super typhoon in the western Pacific Ocean than an eastern Atlantic hurricane.

According to NOAA’s historical database, only seven Category 2 or stronger hurricanes have tracked within 200 nautical miles of the Azores, in records dating to the mid-19th century.

Ophelia passed south the Azores as a Category 3 hurricane in mid-October 2017, but produced tropical storm-force winds, downing a few trees and triggering some minor flooding, according to the NHC’s final report.

A September 1926 Category 2 hurricane with estimated winds of 105 mph tracked over the island of São Miguel.

As meteorologist Yaakov Cantor mentioned Thursday, there have been a number of strange eastern Atlantic hurricanes and tropical storms in recent years, including Leslie almost making it to Portugal as a hurricane in 2018 and a bizarre January strike from Hurricane Alex in the Azores.

Hidden World Of Undersea Volcanoes And Lava Flows Discovered Off Italian Coast

 

Hidden beneath the waves of the Tyrrhenian Sea near southwestern Italy lies a newfound volcanic mosaic dotted with geothermal chimneys and flat-topped seamounts.

This complex is new to both science and the planet, geologically speaking; it’s only about 780,000 years old. Scientists aren’t particularly surprised to find volcanism in the region, which is home to active volcanoes like Mount Vesuvius and Mount Etna. But the new complex is unusual because it was created by a rare kind of fault, said study leader Fabrizio Pepe, a geophysicist at the University of Palermo, in Italy.

“This is a very complex area,” Pepe told Live Science.

Restless region

The western Mediterranean is seismically restless because of the collision of three tectonic plates: the African, the Eurasian and the Anatolian. Making matters more complex is a small chunk of crust called the Adriatic-Ionian microplate, which broke off of the African Plate more than 65 million years ago and is now being pushed under the larger Eurasian Plate in a process called subduction. Mount Vesuvius is one of the volcanoes created by subduction.

Previously, scientists discovered a series of undersea volcanic arcs created by this tectonic unrest, starting near the Sardinian coast, with increasingly younger arcs southward and eastward. These arcs were like an arrow pointing ever farther eastward, prompting Pepe and his colleagues to search for an even younger arc about 9 miles (15 kilometers) off the coast of Calabria, called the “toe” of the “boot” of Italy.

There, based on seafloor mapping, seismic data and magnetic anomalies, the researchers found a 772-square-mile (2,000 square km) region of lava flows, volcanic mountains and hydrothermal chimneys; vents in the seafloor allow hot minerals to spew out and form chimney-like structures. They dubbed the new area the Diamante‐Enotrio‐Ovidio Volcanic‐Intrusive Complex, after three flat-topped seamounts (underwater mountains formed by extinct volcanoes) that dominate the seafloor.

STEP by step
Those fractures are what allowed magma to rise to the surface at the Diamonte-Enotrio-Ovidio complex, creating an undersea landscape of lava flows and mountainous volcanoes. These volcanic seamounts are now plateaus because they protruded from the ocean when the sea level was lower, and they eroded into their present, flat-topped shape, Pepe said.

The volcanic complex is inactive, but there are small intrusions of lava in some parts of the seafloor there, the researchers reported July 6 in the journal Tectonics. However, the area could become active in the future, Pepe said, and active volcanism is ongoing on the eastern side of the Tyrrhenian Sea. The researchers are working to build a volcanic risk map of the complex to better understand if it could endanger human life or property. They are also investigating the possibility of tapping the complex to produce geothermal energy.

Strong Earthquake Strikes Indonesia, Killing At Least 20 People

 

At least 20 people have been killed in a magnitude 6.5 earthquake on one of Indonesia’s least populated islands.

Graphic shows large earthquake logo over broken earth and Richter scale reading

The quake hit at 6:46 a.m. local time Thursday about 20.5 miles northeast of Ambon in Indonesia’s Maluku province, the U.S. Geological Survey said.

Indonesia’s disaster mitigation agency said dozens of homes, a number of buildings and other public facilities were damaged, including a major bridge in Ambon, Reuters reported.

A teacher was killed when parts of a building at an Islamic university collapsed, according to The Associated Press.

“He was just getting out of a car and entering a door and the collapsing rubble fell onto him,” Benny Bugis, a cameraman who works for Reuters, said. He also said two people were injured.

Agus Wibowo, a spokesman for the disaster mitigation agency, said at least 19 others were killed and about 100 were injured. He said more than 2,000 people took refuge in various shelters.

Rahmat Triyono, head of the earthquake and tsunami division at Indonesia’s Meteorology, Climatology and Geophysical Agency, told the AFP news agency the earthquake did not have the potential to cause a tsunami. Still people along the coast fled to higher ground.

“The tremor was so strong, causing us to pour into the streets,” said Musa, an Ambon resident who uses a single name.

Maluku is one of Indonesia’s least populous provinces with a population of about 1.7 million people.

The earthquake Thursday came two days ahead of the first anniversary of a magnitude 7.5 earthquake in Palu on Sulawesi island that killed more than 4,000 people.

Indonesia sits on the seismically active Pacific Ring of Fire and often experiences deadly earthquakes and tsunamis.

In 2004, a powerful Indian Ocean quake and tsunami killed 230,000 people in a dozen countries, most of them in Indonesia.

Most Massive Neutron Star Ever Detected, Almost Too Massive To Exist

 

Neutron stars — the compressed remains of massive stars gone supernova — are the densest “normal” objects in the known universe. (Black holes are technically denser, but far from normal.) Just a single sugar-cube worth of neutron-star material would weigh 100 million tons here on Earth, or about the same as the entire human population. Though astronomers and physicists have studied and marveled at these objects for decades, many mysteries remain about the nature of their interiors: Do crushed neutrons become “superfluid” and flow freely? Do they breakdown into a soup of subatomic quarks or other exotic particles? What is the tipping point when gravity wins out over matter and forms a black hole?

A team of astronomers using the National Science Foundation’s (NSF) Green Bank Telescope (GBT) has brought us closer to finding the answers.

The researchers, members of the NANOGrav Physics Frontiers Center, discovered that a rapidly rotating millisecond pulsar, called J0740+6620, is the most massive neutron star ever measured, packing 2.17 times the mass of our Sun into a sphere only 30 kilometers across. This measurement approaches the limits of how massive and compact a single object can become without crushing itself down into a black hole. Recent work involving gravitational waves observed from colliding neutron stars by LIGO suggests that 2.17 solar masses might be very near that limit.

“Neutron stars are as mysterious as they are fascinating,” said Thankful Cromartie, a graduate student at the University of Virginia and Grote Reber pre-doctoral fellow at the National Radio Astronomy Observatory in Charlottesville, Virginia. “These city-sized objects are essentially ginormous atomic nuclei. They are so massive that their interiors take on weird properties. Finding the maximum mass that physics and nature will allow can teach us a great deal about this otherwise inaccessible realm in astrophysics.”

Pulsars get their name because of the twin beams of radio waves they emit from their magnetic poles. These beams sweep across space in a lighthouse-like fashion. Some rotate hundreds of times each second. Since pulsars spin with such phenomenal speed and regularity, astronomers can use them as the cosmic equivalent of atomic clocks. Such precise timekeeping helps astronomers study the nature of spacetime, measure the masses of stellar objects, and improve their understanding of general relativity.

In the case of this binary system, which is nearly edge-on in relation to Earth, this cosmic precision provided a pathway for astronomers to calculate the mass of the two stars.

As the ticking pulsar passes behind its white dwarf companion, there is a subtle (on the order of 10 millionths of a second) delay in the arrival time of the signals. This phenomenon is known as “Shapiro Delay.” In essence, gravity from the white dwarf star slightly warps the space surrounding it, in accordance with Einstein’s general theory of relativity. This warping means the pulses from the rotating neutron star have to travel just a little bit farther as they wend their way around the distortions of spacetime caused by the white dwarf.

Astronomers can use the amount of that delay to calculate the mass of the white dwarf. Once the mass of one of the co-orbiting bodies is known, it is a relatively straightforward process to accurately determine the mass of the other.

Cromartie is the principal author on a paper accepted for publication in Nature Astronomy. The GBT observations were research related to her doctoral thesis, which proposed observing this system at two special points in their mutual orbits to accurately calculate the mass of the neutron star.

“The orientation of this binary star system created a fantastic cosmic laboratory,” said Scott Ransom, an astronomer at NRAO and coauthor on the paper. “Neutron stars have this tipping point where their interior densities get so extreme that the force of gravity overwhelms even the ability of neutrons to resist further collapse. Each “most massive” neutron star we find brings us closer to identifying that tipping point and helping us to understand the physics of matter at these mindboggling densities.”

These observation were also part of a larger observing campaign known as NANOGrav, short for the North American Nanohertz Observatory for Gravitational Waves, which is a Physics Frontiers Center funded by the NSF.

Water Detected On An Exoplanet Located In Its Star’s Habitable Zone

 

 

Ever since the discovery of the first exoplanet in the 1990s, astronomers have made steady progress towards finding and probing planets located in the habitable zone of their stars, where conditions can lead to the formation of liquid water and the proliferation of life.

Results from the Kepler satellite mission, which discovered nearly 2/3 of all known exoplanets to date, indicate that 5 to 20% of Earths and super-Earths are located in the habitable zone of their stars. However, despite this abundance, probing the conditions and atmospheric properties on any of these habitable zone planets is extremely difficult and has remained elusive… until now.

A new study by Professor Björn Benneke of the Institute for Research on Exoplanets at the Université de Montréal, his doctoral student Caroline Piaulet and several of their collaborators reports the detection of water vapour and perhaps even liquid water clouds in the atmosphere of the planet K2-18b. This exoplanet is about nine times more massive than our Earth and is found in the habitable zone of the star it orbits. This M-type star is smaller and cooler than our Sun, but due to K2-18b’s close proximity to its star, the planet receives almost the same total amount of energy from its star as our Earth receives from the Sun.

The similarities between the exoplanet K2-18b and the Earth suggest to astronomers that the exoplanet may potentially have a water cycle possibly allowing water to condense into clouds and liquid water rain to fall. This detection was made possible by combining eight transit observations — the moment when an exoplanet passes in front of its star — taken by the Hubble Space Telescope.

The Université de Montréal is no stranger to the K2-18 system located 111 light years away. The existence of K2-18b was first confirmed by Prof. Benneke and his team in a 2016 paper using data from the Spitzer Space Telescope. The mass and radius of the planet were then determined by former Université de Montréal and University of Toronto PhD student Ryan Cloutier. These promising initial results encouraged the iREx team to collect follow-up observations of the intriguing world.”

Scientists currently believe that the thick gaseous envelope of K2-18b likely prevents life as we know it from existing on the planet’s surface. However, the study shows that even these planets of relatively low mass which are therefore more difficult to study can be explored using astronomical instruments developed in recent years. By studying these planets which are in the habitable zone of their star and have the right conditions for liquid water, astronomers are one step closer to directly detecting signs of life beyond our Solar System.

“This represents the biggest step yet taken towards our ultimate goal of finding life on other planets, of proving that we are not alone. Thanks to our observations and our climate model of this planet, we have shown that its water vapour can condense into liquid water. This is a first,” says Björn Benneke.