Volcanic Lightning Forms Glass Balls

by Becky Oskin, Senior Writer | March 13, 2015 02:12pm ET
http://www.livescience.com/50137-volcanic-lightning-glass-balls.html?cmpid=559238

Inside towering clouds of volcanic ash, stunning lightning storms can create tiny crystal balls, a new study reports.

Researchers recently discovered smooth glass spheres in ash from explosive volcanic eruptions. Kimberly Genareau, a volcanologist at the University of Alabama, first spotted the orbs while scanning ash from Alaska’s 2009 Mount Redoubt eruption with a powerful microscope. She also found them in ash from Iceland’s 2010 Eyjafjallajökull eruption.

-Forged in a Flash_ Volcanic Lightning Forms Glass Balls

Both volcanoes blasted out billowing ash clouds that triggered spectacular displays of volcanic lightning. Inside these murky clouds, ash particles rub together, generating static electricity that discharges as lightning. [Big Blasts: History’s 10 Most Destructive Volcanoes]
https://www.youtube.com/user/NaturalezaSalvajeHD
Genareau and her colleagues said they think the lightning displays forged the glass balls from particles of volcanic glass. Their findings were published Feb. 27 in the journal Geology.

Volcanoes spit out jagged glass shards during eruptions, along with sharp scraps of rocks and minerals. But lightning within the ash cloudcan heat the air to 54,000 degrees Fahrenheit (30,000 degrees Celsius) for a few millionths of a second, melting the glass particles. These molten droplets then form into balls as they fall through the air, Genareau said.

Electrifying Images of Volcano Lightning

Researchers previously knew that volcanic eruptions could produce glass, but the new findings show how that glass can be made into spheres.

“You don’t need volcanic lightning to make glass [in ash], just to get that unusual shape,” Genareau told Live Science.

The round spherules from Mount Redoubt and Eyjafjallajökull are only 50 microns across (1/25,000th of an inch), hundreds of times smaller than the spherules that can be ejected during meteorite impacts. Fountaining lava caught by the wind can also form such glass spherules, called Pele’s tears.

-pele’s tears – Google Search

Some of the glass spherules examined in the study were as smooth as crystal balls, but others were hazed by cracks and pits that may have formed when water expanded into steam as the glass melted.

The research team is planning further studies into how and why the spherules formed. For instance, the scientists verified that a violent shock can produce glass spheres in ash when they found a version of the tiny balls in ash left over from experiments by researchers at the University of Canterbury in New Zealand. In the experiments, the Canterbury researchers, who are also co-authors on the new findings, zapped artificial ash to investigate how volcanic ash disrupts high-voltage insulators. Their tests were similar to lightning discharges inside an ash cloud, Genareau said.

Electrifying Images of Volcano Lightning

Now, after studying samples from several eruptions, the researchers suspect that it is the size of the ash particles that determines whether the glass spheres appear after volcanic lightning strikes, Genareau said. All the spherules found so far are about 50 microns or smaller in size, she said. Larger ash fragments were partially melted, but didn’t completely transform into spherical shapes.

Forged in a Flash_ Volcanic Lightning Forms Glass Balls

Genareau said she hopes that the new discovery will spark a search for similar spheres in older ash deposits, which could provide new clues about where and when volcanic lightning strikes.

“Not much is known about how often volcanic lightning occurs, and this provides physical evidence that may be preserved in the geologic record,” she said.

Electrifying Images of Volcano Lightning

Follow Becky Oskin @beckyoskin. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.
http://www.livescience.com/50137-volcanic-lightning-glass-balls.html?cmpid=559238

How Dark Matter Could Cause Mass Extinctions

http://www.theepochtimes.com/n3/1261896-how-dark-matter-could-cause-mass-extinctions/?utm_source=Epoch10&utm_medium=email&utm_campaign=8

The Milky Way and Andromeda Galaxy, visible in the upper right. (Andyspictures/Flickr via Wikimedia Commons

The Earth’s infrequent but predictable path around and through our galaxy’s disc may have a direct and significant effect on geological and biological phenomena on Earth, according to new research.

 

 

In a new paper in Monthly Notices of the Royal Astronomical Society, New York University biology professor Michael Rampino concludes that movement through dark matter may perturb the orbits of comets and lead to additional heating in the Earth’s core, both of which could be connected with mass extinction events.

The galactic disc is the region of the Milky Way Galaxy where our solar system resides. It is crowded with stars and clouds of gas and dust, and also a concentration of elusive dark matter—small subatomic particles that can be detected only by their gravitational effects.

Previous studies have shown that Earth rotates around the disc-shaped galaxy once every 250 million years. But the Earth’s path around the galaxy is wavy, with the sun and planets weaving through the crowded disc approximately every 30 million years.

 

Dark Matter Inside the Earth

Analyzing the pattern of the Earth’s passes through the galactic disc, Rampino notes that these disc passages seem to correlate with times of comet impacts and mass extinctions of life. The famous comet strike 66 million ago that led to the extinction of the dinosaurs is just one example.

What causes this correlation between Earth’s passes through the galactic disc, and the impacts and extinctions that seem to follow?

While traveling through the disc, the dark matter concentrated there disturbs the pathways of comets typically orbiting far from the Earth in the outer solar system, Rampino observes. This means that comets that would normally travel at great distances from the Earth instead take unusual paths, causing some of them to collide with the planet.

But even more remarkably, with each dip through the disc, the dark matter can apparently accumulate within the Earth’s core. Eventually, the dark matter particles annihilate each other, producing considerable heat.

MORE:

• Decoding the Gravitational Evolution of Dark Matter Halos
• Dark Matter and the Milky Way: More Little Than Large

The heat created by the annihilation of dark matter in Earth’s core could trigger events such as volcanic eruptions, mountain building, magnetic field reversals, and changes in sea level, which also show peaks every 30 million years.

Rampino therefore suggests that astrophysical phenomena derived from the Earth’s winding path through the galactic disc, and the consequent accumulation of dark matter in the planet’s interior, can result in dramatic changes in Earth’s geological and biological activity.

His model of dark matter interactions with the Earth as it cycles through the galaxy could have a broad impact on our understanding of the geological and biological development of Earth, as well as other planets within the galaxy.

“We are fortunate enough to live on a planet that is ideal for the development of complex life,” Rampino says. “But the history of the Earth is punctuated by large scale extinction events, some of which we struggle to explain.

“It may be that dark matter—the nature of which is still unclear but which makes up around a quarter of the universe—holds the answer. As well as being important on the largest scales, dark matter may have a direct influence on life on Earth.”

In the future, he suggests, geologists might incorporate these astrophysical findings in order to better understand events that are now thought to result purely from causes inherent to the Earth. This model, Rampino adds, likewise provides new knowledge of the possible distribution and behavior of dark matter within the galaxy.

Source: NYU. Originally published on Futurity.org