Krakatau Volcano (Indonesia):Continuous Intense Explosions Heard 42 Km Away, Off Scale Seismicity

Our Indonesian volcano expedition leader Andi has sent us the below video of the current seismicity of Anak Krakatau: “Krakatau is going crazy …100 times explosion a day … very loud could be heard untill Carita 42 km away.

The explosive activity of the volcano continues and seems to be increasing with strombolian to vulcanian-style explosions from the summit crater.

Ash plumes can be seen on satellite imagery now, but so far have been low and do not affect air traffic significantly.

We will be visiting the island and camp 3 nights during our next Volcano Special tour from 10-15 August.

Hawaii Kilauea Volcano Update: School, Park Destroyed By Lava, Collapse Events Continue

The Kilauea volcano in Hawaii continues to cause disruptions in daily life for the people on the island. Near-daily collapse events that feel like earthquakes are rocking the island where some people have lost homes since the volcano started erupting in early May.

Lava is continuously flowing from Fissure 8 and a channel, or river, of lava has formed that leads from the fissure to the ocean. That ocean entry point filled an entire bay with lava. A map from the United States Geological Survey shows where the coastline was before it was covered with lava.

That map, which is up to date as of Thursday, also shows that while there were two entry points where the lava was entering the ocean earlier this week, there is now only one.

The channel of lava that formed from Fissure 8 was experiencing some blockages and consequent overflows earlier this week, which have since stopped. On Thursday afternoon, the caldera of the volcano, or the area above the magma pit that’s been feeding the fissures, experienced a collapse event. These events have been fairly common at Kilauea, but each one causes what feels like an earthquake on the island.

Thursday’s collapse event caused an increase in activity from Fissure 8, but the lava didn’t significantly overflow the edges of the channel due to the collapse, according to the USGS. Typically after each collapse, the seismic activity around the summit decreases for a few hours before ramping back up until the next collapse event. Hawaii Civil Defense recommends that residents “check their utility connections of electricity, water and gas after earthquakes.”

One of the most recent island locations to be overrun with lava was Ahalanui Beach Park and the Kua O Ka La Public Charter School along Highway 137, the Hawaii Tribune-Herald reported.

In addition to the danger hot flowing lava presents, there are also gases being released into the air from the lava and the summit of the volcano, as well as where the lava is meeting the ocean.

The ocean-entry point created a lava haze, or laze, plume that is made up of steam and hydrochloric acid and which can cause lung damage to anyone who gets too close. The reaction of the cold water meeting the hot lava can also produce explosive episodes that are potentially dangerous.

The volcano itself was releasing sulfur dioxide and volcanic ash and glass, which can cause irritation to the eyes, skin and lungs.

Could Gravitational Waves Reveal How Fast Our Universe Is Expanding?

Since it first exploded into existence 13.8 billion years ago, the universe has been expanding, dragging along with it hundreds of billions of galaxies and stars, much like raisins in a rapidly rising dough.

Astronomers have pointed telescopes to certain stars and other cosmic sources to measure their distance from Earth and how fast they are moving away from us — two parameters that are essential to estimating the Hubble constant, a unit of measurement that describes the rate at which the universe is expanding.

But to date, the most precise efforts have landed on very different values of the Hubble constant, offering no definitive resolution to exactly how fast the universe is growing. This information, scientists believe, could shed light on the universe’s origins, as well as its fate, and whether the cosmos will expand indefinitely or ultimately collapse.

Now scientists from MIT and Harvard University have proposed a more accurate and independent way to measure the Hubble constant, using gravitational waves emitted by a relatively rare system: a black hole-neutron star binary, a hugely energetic pairing of a spiraling black hole and a neutron star. As these objects circle in toward each other, they should produce space-shaking gravitational waves and a flash of light when they ultimately collide.

In a paper to be published July 12th in Physical Review Letters, the researchers report that the flash of light would give scientists an estimate of the system’s velocity, or how fast it is moving away from the Earth. The emitted gravitational waves, if detected on Earth, should provide an independent and precise measurement of the system’s distance. Even though black hole-neutron star binaries are incredibly rare, the researchers calculate that detecting even a few should yield the most accurate value yet for the Hubble constant and the rate of the expanding universe.

“Black hole-neutron star binaries are very complicated systems, which we know very little about,” says Salvatore Vitale, assistant professor of physics at MIT and lead author of the paper. “If we detect one, the prize is that they can potentially give a dramatic contribution to our understanding of the universe.”

Vitale’s co-author is Hsin-Yu Chen of Harvard.

Competing constants

Two independent measurements of the Hubble constant were made recently, one using NASA’s Hubble Space Telescope and another using the European Space Agency’s Planck satellite. The Hubble Space Telescope’s measurement is based on observations of a type of star known as a Cepheid variable, as well as on observations of supernovae. Both of these objects are considered “standard candles,” for their predictable pattern of brightness, which scientists can use to estimate the star’s distance and velocity.

The other type of estimate is based on observations of the fluctuations in the cosmic microwave background — the electromagnetic radiation that was left over in the immediate aftermath of the Big Bang, when the universe was still in its infancy. While the observations by both probes are extremely precise, their estimates of the Hubble constant disagree significantly.

“That’s where LIGO comes into the game,” Vitale says.

LIGO, or the Laser Interferometry Gravitational-Wave Observatory, detects gravitational waves — ripples in the Jell-O of space-time, produced by cataclysmic astrophysical phenomena.

“Gravitational waves provide a very direct and easy way of measuring the distances of their sources,” Vitale says. “What we detect with LIGO is a direct imprint of the distance to the source, without any extra analysis.”

In 2017, scientists got their first chance at estimating the Hubble constant from a gravitational-wave source, when LIGO and its Italian counterpart Virgo detected a pair of colliding neutron stars for the first time. The collision released a huge amount of gravitational waves, which researchers measured to determine the distance of the system from Earth. The merger also released a flash of light, which astronomers focused on with ground and space telescopes to determine the system’s velocity.

With both measurements, scientists calculated a new value for the Hubble constant. However, the estimate came with a relatively large uncertainty of 14 percent, much more uncertain than the values calculated using the Hubble Space Telescope and the Planck satellite.

Vitale says much of the uncertainty stems from the fact that it can be challenging to interpret a neutron star binary’s distance from Earth using the gravitational waves that this particular system gives off.

“We measure distance by looking at how ‘loud’ the gravitational wave is, meaning how clear it is in our data,” Vitale says. “If it’s very clear, you can see how loud it is, and that gives the distance. But that’s only partially true for neutron star binaries.”

That’s because these systems, which create a whirling disc of energy as two neutron stars spiral in toward each other, emit gravitational waves in an uneven fashion. The majority of gravitational waves shoot straight out from the center of the disc, while a much smaller fraction escapes out the edges. If scientists detect a “loud” gravitational wave signal, it could indicate one of two scenarios: the detected waves stemmed from the edge of a system that is very close to Earth, or the waves emanated from the center of a much further system.

“With neutron star binaries, it’s very hard to distinguish between these two situations,” Vitale says.

A new wave

In 2014, before LIGO made the first detection of gravitational waves, Vitale and his colleagues observed that a binary system composed of a black hole and a neutron star could give a more accurate distance measurement, compared with neutron star binaries. The team was investigating how accurately one could measure a black hole’s spin, given that the objects are known to spin on their axes, similarly to Earth but much more quickly.

The researchers simulated a variety of systems with black holes, including black hole-neutron star binaries and neutron star binaries. As a byproduct of this effort, the team noticed that they were able to more accurately determine the distance of black hole-neutron star binaries, compared to neutron star binaries. Vitale says this is due to the spin of the black hole around the neutron star, which can help scientists better pinpoint from where in the system the gravitational waves are emanating.

“Because of this better distance measurement, I thought that black hole-neutron star binaries could be a competitive probe for measuring the Hubble constant,” Vitale says. “Since then, a lot has happened with LIGO and the discovery of gravitational waves, and all this was put on the back burner.”

Vitale recently circled back to his original observation, and in this new paper, he set out to answer a theoretical question:

“Is the fact that every black hole-neutron star binary will give me a better distance going to compensate for the fact that potentially, there are far fewer of them in the universe than neutron star binaries?” Vitale says.

To answer this question, the team ran simulations to predict the occurrence of both types of binary systems in the universe, as well as the accuracy of their distance measurements. From their calculations, they concluded that, even if neutron binary systems outnumbered black hole-neutron star systems by 50-1, the latter would yield a Hubble constant similar in accuracy to the former.

More optimistically, if black hole-neutron star binaries were slightly more common, but still rarer than neutron star binaries, the former would produce a Hubble constant that is four times as accurate.

“So far, people have focused on binary neutron stars as a way of measuring the Hubble constant with gravitational waves,” Vitale says. “We’ve shown there is another type of gravitational wave source which so far has not been exploited as much: black holes and neutron stars spiraling together,” Vitale says. “LIGO will start taking data again in January 2019, and it will be much more sensitive, meaning we’ll be able to see objects farther away. So LIGO should see at least one black hole-neutron star binary, and as many as 25, which will help resolve the existing tension in the measurement of the Hubble constant, hopefully in the next few years.”

This research was supported, in part, by the National Science Foundation and the LIGO Laboratory.

Chris Downgraded To Tropical Storm, Still Moving Away From NC Coast

Chris has been downgraded from a hurricane to a tropical storm, the National Weather Service said Thursday.

The storm became a hurricane Tuesday as it moved further away from the coast of the Carolinas.

Even though Chris is on the move, it is still causing high rip currents at the Outer Banks.

No coastal watches or warnings are in effect.

As of 6 a.m. Thursday, the storm was 245 miles off the coast of Novia Scotia.

Massive Mars Dust Storm Won’t Stop NASA’s Next Lander

The global dust storm currently raging on Mars shouldn’t disrupt the touchdown of NASA’s InSight lander this fall, agency officials said.

The planet-encircling storm is expected to subside by the time InSight arrives in November. But it won’t be a disaster for the new lander if the storm still swirls or if another one takes its place, officials said.

Rob Grover, leader of Insight’s Entry, Descent and Landing (EDL) team at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, told Space.com. [NASA’s InSight Mars Lander: Here’s 10 Surprising Facts]

Even if the storm subsides as expected, a dusty haze will likely still hang in the Martian atmosphere when InSight arrives, said Richard Zurek, chief scientist of the Mars Program Office at JPL. That haze could affect how InSight’s science instruments function, because it will prevent some sunlight from reaching the solar-powered lander. But touchdown should be fine, Zurek added.

Not a shock

Martian dust storms can pop up suddenly and last for weeks or even months. The current tempest contains several smaller, active dust storms and appears to have been triggered by a single local storm first observed at the end of May.

Previous NASA Mars missions have dealt with such storms or observed them up close.

When NASA’s Mariner 9 spacecraft reached Mars in November 1971, for example, it caught sight of a global dust storm that had been raging for several weeks. This was the second major storm of the year, researchers knew, because they had observed the first from Earth before the spacecraft’s Red Planet arrival. The Mariner 9 storm was huge and dramatic; it covered the entire Martian surface in dust, except the peaks of the tallest volcanoes.

Another major dust storm, comparable in size to the current one, raged across Mars when NASA’s Viking mission arrived in 1976. That, too, was the second global storm that year.

Landing in a storm

If the storm lasts for its maximum estimated duration, it should falL off just before InSight arrives, NASA officials have said. But it will likely leave traces in the Red Planet’s air regardless.

From an EDL standpoint, the biggest impact of the storm will be the way air is distributed in the Martian atmosphere, Grover said. During storms, dust heats the upper atmosphere, while the shaded lower atmosphere gets cooler. From the beginning of the InSight project, atmospheric modelers have provided a range of conditions that the lander might fly through during its critical EDL sequence, including dust storms, Grover said.

InSight will deploy a big parachute to slow down in the Martian atmosphere, then wrap up its descent by firing retro-rockets when close to the ground. A dusty atmosphere might require the parachute to be deployed as much as 0.9 miles (1.5 kilometers) lower than it would be in clear skies, Grover said. That would shave about 20 seconds off the 6.5-minute entry-to-landing timeline, he added.

When the parachute deploys, the suddenly slowed spacecraft will jerk backward, feeling what Grover called a “snatch force.” The goal is to keep that force under 15,000 lbs. (6,800 kilograms), he said. The amount of force is related to atmospheric density, which changes during or after a dust storm.

“We can tune how we’re actually going to fly on landing day,” Grover said. Minor changes could be sent to the spacecraft as soon as 2 hours before the landing, allowing the team to make adjustments based on the weather closer to the planet.

InSight also boasts an extra 0.2 inches (0.5 centimeters) of thermal protection on its heat shield, because a dust-thickened atmosphere generates more heat than clear skies do.

Like previous NASA Mars missions, InSight — which launched in early May — will use radar to assist with its landing. Ten minutes before it enters the atmosphere, the spacecraft will link with Earth to update its position and velocity based on radar observations. As it plunges into the (likely dusty) Martian atmosphere, InSight will rely on an inertial measurement unit (IMU), which uses an accelerometer and gyros to figure out the craft’s position as it flies through the atmosphere. The radar will then provide critical updates on the spacecraft’s altitude so that the lander knows where it is in relation to the ground.

“We can’t land successfully without the radar,” Grover said. This radar is capable of seeing through dust, allowing the mission to land safely even in a storm, he stressed.

Things will be different, by the way, for NASA’s Mars 2020 rover mission, which will rely on Terrain-Relative Navigation. Mars 2020 will use a camera to create a map of the landing site, comparing the landmarks in the images to those found on the craft’s onboard map. This new technology will allow the spacecraft to shift its direction to avoid landing on dangerous objects. Grover said that a dust storm would impede the device, making a safe landing a challenge. But, unlike InSight, Mars 2020 won’t arrive during dust-storm season.

On the ground
InSight — which is short forU —robot in depthThe stationary lander will help researchers map out the Red Planet’s interior by precisely measuring heat flow and analyzing tiny “marsquakes.”

Dust could affect InSight’s scientific work, because the lander relies on solar panels to power its instruments.

A new dust storm could affect “the deployment of instruments from this solar-powered platform,” Zurek said. The dust could also cover the panels after the instruments have been deployed.

“That’s the main worry, that the dust storm is going to cover your solar panels,” said Matt Siegler, a research scientist at the Planetary Science Institute in Arizona who works on InSight’s heat-probe instrument.

The problem is similar to the one NASA’s solar-powered Opportunity rover currently faces. The nearly 15-year old Opportunity has hunkered down during the global storm, likely entering a “low-power fault mode,” in which all subsystems other than the mission clock turn off. The mission clock is programmed to wake the computer to check its power levels.

The massive dust storm has blotted out the sun, keeping Opportunity from charging its batteries. The batteries don’t just run the instruments; they also keep the rover warm during the cold Martian nights. Without such heat, big problems can arise.

“Some soldered joint will get too cold and split, and then your computer dies,” Siegler said.

The dust storm itself could help keep Opportunity warm, because dust can trap heat close to the planet’s surface. Indeed, calculations by the Opportunity team suggest that temperatures won’t get cold enoughin the immediate future to freeze that rover out, NASA officials said last month.

When InSight lands, it should have enough power to keep its instruments warm for some time, Zurek said. Once the storm passes and the skies clear somewhat, the spacecraft will be able to begin its mission exploring the Martian interior.

In the meantime, scientists will keep their eyes on the enormous weather event.

“The current storm is still developing, and atmospheric scientists here at JPL are continuing to observe it,” Grover said.

Scientists Discover Earth’s Youngest Banded Iron Formation In Western China

The banded iron formation, located in western China, has been conclusively dated as Cambrian in age. Approximately 527 million years old, this formation is young by comparison to the majority of discoveries to date. The deposition of banded iron formations, which began approximately 3.8 billion years ago, had long been thought to terminate before the beginning of the Cambrian Period at 540 million years ago.

“This is critical, as it is the first observation of a Precambrian-like banded iron formation that is Early Cambrian in age. This offers the most conclusive evidence for the presence of widespread iron-rich conditions at a time, confirming what has recently been suggested from geochemical proxies,” said Kurt Konhauser, professor in the Department of Earth and Atmospheric Sciences and co-author. Konhauser supervised the research that was led by Zhiquan Li, a PhD candidate from Beijing while on exchange at UAlberta.

The Early Cambrian is known for the rise of animals, so the level of oxygen in seawater should have been closer to near modern levels. “This is important as the availability of oxygen has long been thought to be a handbrake on the evolution of complex life, and one that should have been alleviated by the Early Cambrian,” says Leslie Robbins, a PhD candidate in Konhauser’s lab and a co-author on the paper.

The researchers compared the geological characteristics and geochemistry to ancient and modern samples to find an analogue for their deposition. The team relied on the use of rare earth element patterns to demonstrate that the deposit formed in, or near, a chemocline in a stratified iron-rich basin.

“Future studies will aim to quantify the full extent of these Cambrian banded iron formations in China and whether similar deposits can be found elsewhere,” says Kurt Konhauser.

Dominican Republic: Tropical Storm Beryl Leaves Thousands Displaced, Without Water, Power

The capital of Santo Domingo was left without electricity from the first major storm of the 2018 Atlantic hurricane season.

Heavy rains from Tropical Storm Beryl have left at least 8,000 people displaced, and 19 villages without communication in the Dominican Republic, the Emergency Operations Center said.

Thousands are left without drinking water, as the storm has knocked 75 aqueducts out of service.

The capital of Santo Domingo was left without electricity from the first major storm of the 2018 Atlantic hurricane season.

The Center still has 22 provinces on alert for flooding and landslides.

In San Cristobal province, 700 homes were flooded and two schools collapsed.

A member of National Congress, Ito Bisono, tweeted pictures of a recently opened hospital flooded.

“A country with a supposedly growing economy cannot have hospitals where it rains more inside than outside,” Bisono tweeted.

Tropical Storm Beryl was earlier a category 1 hurricane, but was then downgraded to a tropical storm. In spite of having lost its earlier heavy wind power, strong rains pose an equally dangerous threat.