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Acid oceans followed Chicxulub impact

Within days after the massive Chicxulub impact that ended the Cretaceous Period 65.5 million years ago, a deluge of acid rain may have turned Earth’s ocean surfaces into suddenly inhospitable homes for a multitude of microorganisms, ultimately pushing them to extinction, according to a new study.
 

21 Aug 2014

Africa's impact is one that even the dinosaurs would have seen coming

The crater left by the infamous Chicxulub asteroid responsible for finishing off the dinosaurs about 65 million years ago, was more than 19 kilometers deep and 177 kilometers in diameter. Those dimensions correspond to a huge energy release estimated at 100 teratons of TNT, but that’s puny compared to an impact that struck South Africa’s Barberton Greenstone Belt about 3.26 billion years ago. Now, researchers have estimated just how big that massive asteroid was and the catastrophic effect it might have had on Earth and its budding plate tectonic system.

14 Aug 2014

Unprecedented low water-vapor levels detected on exoplanets

In a recent study, a team of astronomers found that the atmospheres of Jupiter-sized planets located outside of the solar system are much drier than predicted. The discovery has raised questions about the commonly held understanding of the processes involved in planet formation.

13 Aug 2014

La Brea climate adaptation as different as cats and dogs

The La Brea tar pits are famous for being a predator trap. For every herbivore, a dozen or more carnivores are pulled from the prolific Pleistocene fossil site in downtown Los Angeles. Two new studies focusing on the two most common species found at the tar pits — dire wolves and saber-toothed cats — are characterizing how the tar pits’ two top predators coped with the warming climate toward the end of the last ice age, and the results are surprisingly dissimilar: While the wolves got smaller, the cats got bigger.

12 Aug 2014

Are slow-slip earthquakes under Tokyo stressing faults?

More than 13 million people live in Tokyo, a city that has been devastated by earthquakes in the past and is likely to be rocked again. Since the massive magnitude-9 Tohoku earthquake and tsunami in March 2011, recurrence intervals for nondamaging slow-slip quakes beneath Japan's capital have shortened. And that has left seismologists to wonder if this aseismic creep could be signaling a countdown to Tokyo's next "big one."

07 Aug 2014

Oso landslide report yields some answers

Early on March 22, 2014, the most damaging landslide in U.S. history devastated the community of Oso, Washington. Forty-three people perished, most inside their homes, when a saturated hillside nearby gave way and a massive mudflow swept over their neighborhood. On July 22, a search crew recovered the last of the 43 bodies, exactly four months after the landslide, and coincidentally on the same day, a team of scientists and engineers released an exhaustive report detailing the event and its implications.

01 Aug 2014

A real rift in the midcontinent

In the heart of the U.S. Midwest, basalt cliffs and lava flows point to a massive break in the continental crust that occurred a little more than a billion years ago, a feature known as the Midcontinent Rift. Splitting the strong, thick North American craton — the stable interior of the continent — would have required dramatic geologic events. Geologists have long suspected two leading scenarios: a plume of hot mantle rock that sat beneath the several-hundred-kilometer-thick lithosphere, something like the one that sits below Yellowstone today; or mantle material upwelling beneath a zone where the Grenville Orogeny had pulled the rigid continental crust apart as a new supercontinent formed.

30 Jul 2014

Augustine Volcano's earthquakes and explosive eruption caused by a clogged conduit

New research shows that the explosive eruption in 2006 of Alaska’s Augustine Volcano, and the series of earthquakes that preceded it, were caused by a clogged conduit. The findings may help geologists monitor future eruptions at Augustine and elsewhere. 

29 Jul 2014

Moving cars could help gauge rainfall

Accurate and timely rainfall measurements are crucial for the design of drainage systems, dams and other modern infrastructure. But rain gauges are often spread too sparsely to provide the necessary coverage in densely populated regions. In parts of Germany, for example, gauges equipped to make hourly readings are especially scarce — just one per 1,800 square kilometers. To help fill in the gaps, researchers at the Leibniz University of Hannover are developing an idea they call “RainCars” — using moving cars to measure rainfall.

23 Jul 2014

Rings not just for planets anymore

Saturn is famously circled by halo-like rings of dust and debris, as are Jupiter, Uranus and Neptune. Now, a 250-kilometer-wide rock named Chariklo is breaking up the planetary monopoly and showing that other extraterrestrial bodies can host rings as well.

23 Jul 2014

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