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Volcanism spiked global temps during past hothouse

Roughly 56 million years ago, global temperatures rose 5 degrees Celsius within a few thousand years in an event called the Paleocene-Eocene Thermal Maximum (PETM). Scientists have often attributed the relatively rapid warming of the PETM — frequently used as an analogue for understanding modern warming trends — to large-scale biogenic methane emissions from seafloor reservoirs. But in a new study, researchers tracking carbon and boron isotopes preserved in the shells of tiny marine creatures called foraminifera, or forams, question the conventional wisdom, instead pointing to a volcanic source for the carbon emitted during the PETM.

25 Dec 2017

Earthquakes shaped ancient Greek culture

In ancient Greece, earthquakes frequently shook the ground and devastated cities and temples. But time after time, people built — and rebuilt — prominent structures near dangerous faults. How much the ancient Greeks knew about earthquakes and fault behavior is unclear. But in a new study in Proceedings of the Geologists’ Association, researchers suggest that the relationship between sacred sanctuaries and faults is more than coincidental, and that earthquakes may have had a previously underappreciated cultural significance to the ancient civilization.

22 Dec 2017

New Zealand quake triggers two large slow-slip events

On Nov. 14, 2016, a magnitude-7.8 earthquake struck near Kaikoura on New Zealand’s South Island, setting off a cascade of fault ruptures in the region. Within hours, seismic waves from the quake triggered a two-week-long slow-slip event on a section of the Hikurangi Subduction Zone between 250 and 600 kilometers north of the initial epicenter, as well as ongoing slow slip on the Hikurangi beneath New Zealand’s capital, Wellington, according to a new study in Nature Geoscience. Thanks to New Zealand’s advanced seismic and tectonic monitoring networks, the event is one of the best-documented examples of an earthquake triggering slow slip on distant faults.

21 Dec 2017

19th-century discovery now reveals modern human arrival in Sumatra

Modern humans began journeying out of Africa by at least 75,000 years ago, eventually expanding across the planet. Evidence of these early human travels, including fossils and artifacts, is typically spotty and difficult to find. But one such discovery more than a century ago has shed new light on the appearance of humans in Southeast Asia.

19 Dec 2017

Climate change linked to specific weather events for the first time

Three extreme weather events that occurred in 2016 would not have been possible in Earth’s pre-industrial climate, according to the sixth annual report on the attribution of extreme weather events issued Dec. 13 by NOAA and the American Meteorological Society (AMS). This marks the first time that researchers have concluded that a specific weather event would not have been possible without the influence of humans.

14 Dec 2017

Both urban flooding and rural drying to intensify

In a comprehensive global analysis, including data from more than 43,000 rainfall stations and 5,300 river monitoring stations in 160 countries, researchers report that global rainfall is increasing, likely due to warming air temperatures that allow more moisture into the atmosphere, causing more intense rainfall. Rural areas tend to absorb excess water during storms, preventing widespread flooding in rural zones, but between storms, rising temperatures also mean more evaporation from exposed soils, creating drier conditions over the long term, the team noted in Scientific Reports. Meanwhile, in urban environments, more intense rainfall often overwhelms stormwater catchments in places with less exposed soil, leading to a higher incidence of flooding.

11 Dec 2017

Red Planet Roundup: December 2017

With two rovers patrolling the surface of Mars, six spacecraft orbiting above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.

08 Dec 2017

Transitional Chilesaurus fills gap between major dinosaur groups

In 2015, a new dinosaur was discovered in southern Chile, but its odd set of characteristics left paleontologists scratching their heads: Was it a carnivore or an herbivore? A closer look at the bones of the dinosaur, named Chile­saurus, is helping scientists determine how it fit into the Late Jurassic landscape.

06 Dec 2017

What drives hot spots of sea-level rise?

As sea levels creep up around the world, scientists have observed hot spots where regional rates of sea-level rise greatly outpace the global average. But what drives the formation of these hot spots, and how long they last, have been mysteries. In a new study, scientists tracking sea levels along the Florida coast suggest that the combined effects of two naturally occurring climate processes, the El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO), control sea-level hot spot formation along the U.S. East Coast.

01 Dec 2017

Dino deaths cleared the way for frogs

Frogs make up almost 90 percent of amphibians, and with 6,775 described species, frogs are considered one of the most diverse groups of vertebrates on the planet. In a new study in Proceedings of the National Academy of Sciences, researchers indicate that frogs’ rapid diversification stems back to the Cretaceous-Paleogene (K-Pg, formerly the K-T) boundary, about 66 million years ago, when nonavian dinosaurs and many other animals went extinct.

30 Nov 2017

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