This striking image represents the chemical composition of Martian sand recently collected by the Curiosity rover. Analysis of it reveals that Martian dirt is similar to volcanic soil from Hawaii, containing crystalline feldspar, pyroxene and olivine. To create this image, the rover’s Chemistry and Mineralogy (CheMin) instrument bombarded sand samples with X-rays, which bounce off in different patterns depending on the sample composition, allowing scientists to figure out which chemicals are present and in what quantities.
Image via NASA
The excavation at Spitalfields
The churchyard at St. Mary’s in Spitalfields, London, was the final resting place for more than 10,000 people in medieval times. But among the run-of-the-mill gravesites, archaeologists with the Museum of London Archaeology have found, were 175 mass graves, containing the closely packed bodies of thousands of men, women, and children. What happened to these people? The answer, it turns out, could be decidedly unusual.
The team’s first thought was the obvious: the Black Death, which ravaged England starting in 1347. But once the bodies in the mass graves were carbon dated, it was clear that they had died a hundred years before the first plague-carrying flea came to Britain: around 1250. “As soon as we got the radiocarbon dates back, we knew that couldn’t possibly be the case. There had to be some other event,” says Natasha Powers, the head of osteology at the Museum of London Archaeology.
Mount St. Helens eruption in 1980
Step aside, crystal balls—another kind of crystal could help scientists forecast eruptions. The structure of microscopic crystals in lava oozing out of volcanoes give clues into when and how a volcano will erupt, according to a study on Mount St. Helens just published in Science.
For six years after Mount St. Helens infamously blew its top in 1980, the volcano in Washington continued to spew and sputter, erupting periodically. Each eruption brought more magma to the surface, and crystals embedded in the magma are snapshots of what happened inside the volcano just before each eruption. They contain concentric circles of elements like iron and magnesium, just like tree rings. Volcanologists examined over 300 of these crystals from Mount St. Helens, each no more than 1/10 of a millimeter in size.
Pulling together decades of data from the Voyager, Galileo, Cassini, and New Horizon probes, as well as the Hubble Space Telescope, scientists at the US Geological Survey have put together a complete geological map of Io, the beautiful, mysterious Jovian moon. Io is the most volcanically active object in the solar system, and its surface reflects that: unlike everything else around, it has no craters, a sign that its surface is constantly being remade. That’s thanks to volcanoes that shoot out more than 100 times more lava per year than Earth’s.
The map is a lovely thing, and you can play around with it yourself here.
The Laki fissure’s eruption in Iceland was behind tens of thousands of deaths in the 1780s.
What’s the News: Iceland’s busy volcanoes have caused their share of air traffic snafus in Europe lately, but they have the potential to be deadly, not just inconvenient. A new model examining how air quality would change should the volcanoes erupt as spectacularly as they occasionally have in the past suggests that increased particulates in the air could kill more than 140,000 people in Europe in the year following the eruption.
What’s the News: Jupiter’s moon Io is more volcanically active than any other object in our solar system, releasing 30 times more heat than Earth through volcanism. It’s thought that Jupiter’s gravity pulls so hard on the moon and causes so much friction that the resulting thermal energy melts a huge amount of underground rock, feeding Io’s 400 active volcanoes.
For years, astronomers have debated whether Io’s spewing lava comes from isolated pockets of magma or a layer that spans the entire moon. Astronomers have now peered into Io’s interior for the first time, discovering that it has a global sea of magma roughly 30 miles thick. “It turns out Io was continually giving off a ‘sounding signal’ in Jupiter’s … magnetic field that matched what would be expected from molten or partially molten rocks deep beneath the surface,” lead researcher Krishan Khurana told Wired. Read More
The Permian extinction event was the biggest shake-up of life that Earth has ever seen: in the “Great Dying” that took place 250 million years ago, more than 90 percent of marine species were killed and about 70 percent of land animals vanished. The cause of this catastrophe has been debated for years, but new research suggests that volcanic eruptions triggered massive coal fires that pumped pollution into the air, eventually poisoning the planet.
The study, published in Nature Geoscience, is based on new findings from arctic rocks that date back to the Permian period, when all of the planet’s land masses formed a supercontinent called Pangaea. When the researchers analyzed the rocks, they found signs of a coal-based apocalypse.
Besides the usual miniscule clumps of organic matter, they also found tiny bubble-filled particles called cenospheres. These frothy little blobs form only when molten coal spews into the atmosphere, the researchers say…. [The cenospheres] must have been created when massive amounts of molten rock—more than 1 trillion metric tons—erupted through overlying coal deposits in Siberia to form lava deposits known as the Siberian Traps. [ScienceNOW]
Saturn’s moon Titan has lakes on its surface and a thick atmosphere, but there’s one more way this cold, distant world is like the Earth: It appears to have volcanoes—though they’re a little chillier than Eyjafjallajökull.
Scientists have long suspected and presented some evidence that Titan could have these features, and this week at the American Geophysical Union meet-up, researchers presented a finding from the Cassini spacecraft that they say is the best evidence yet of a Titanic volcano.
“We finally have some proof that Titan is an active world,” said geophysicist Randolph Kirk of the U.S. Geological Survey, who presented the findings. [NPR]
Japan’s new spacecraft has reached Venus; that much we know. But today Akatsuki left its creators hanging when it lost contact with home for longer than expected, and Japan’s space agency JAXA is now trying to make sure the $300 million mission reached the orbit they intended for it above the second planet from the sun.
When Akatsuki arrived at Venus and swung around the backside, it was expected to lose contact with Earth for a little over 20 minutes. Instead, it couldn’t reach JAXA for an hour and a half, sending the space scientists scrambling to make sure nothing went awry.
Communications with the probe were eventually resumed, but it’s currently unclear whether Akatsuki successfully entered orbit around Venus. “It is not known which path the probe is following at the moment,” JAXA official Munetaka Ueno told the AFP news agency. “We are making maximum effort to readjust the probe.” [National Geographic]
In those volcanoes that kids (or their parents) build for elementary school science fairs, the style is generally simple: There’s one chamber in which the baking soda rests, ready to meet the vinegar and erupt. Most real volcanoes are a little like this, in that they have a single magma chamber that fuels their eruptions.
But not Eyjafjallajökull.
The Icelandic volcano that stirred in March and grounded European air travel has a peculiar kind of plumbing, scientists report today in Nature. Freysteinn Sigmundsson and colleagues combined 20 years’ worth of GPS, satellite, and seismic observations of the volcano see note how it changed over the years—and especially what was happening in the lead-up to this year’s eruption.