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Chemical tipping point triggers eruptive transitions

During an eruption, some volcanoes vacillate unpredictably between effusive and explosive behavior. New research has identified a chemical tipping point in some magmas that may trigger the transition between such mild and violent eruptive cycles.

02 Apr 2018

No river meant no floods for ancient Indus settlements

Large Middle Eastern rivers like the Nile, Tigris, Euphrates and Tiber were critical for the development of early urban societies in Egypt, Mesopotamia and Ancient Rome. And researchers have long thought that the rise, and eventual decline, of cities in the ancient Indus Civilization, which spread across about 1 million square kilometers of what’s now northwestern India and Pakistan from roughly 4,600 to 3,900 years ago, also depended on major rivers, namely those emerging from the Himalayas. But a new study looking at river sediments from the time of the civilization and earlier suggests that wasn’t the case for every ancient Indus city; some may have benefited from being farther away from large rivers and their periodic floods.

01 Apr 2018

Oldest "Third Pole" ice core recovered

Holding massive reservoirs of ice, high-altitude glaciers, such as those in the Himalayas, are sometimes referred to as Earth’s “Third Pole.” The Guliya Ice Cap, on the Tibetan Plateau, has now produced the oldest ice ever drilled outside the Arctic or Antarctica.

29 Mar 2018

Ceres: A bright spot in the asteroid belt

Orbiting in the asteroid belt between Mars and Jupiter, Ceres is the nearest dwarf planet to Earth and the only one within the inner solar system. It has been studied closely by NASA’s Dawn spacecraft since March 2015.

28 Mar 2018

Residual strain explains later quakes

The largest earthquake in recorded history struck southern Chile on May 22, 1960. The magnitude-9.5 temblor was followed by a tsunami that, combined with the seismic shaking, killed 1,600 people and left more than 2 million homeless. New research suggests that, despite the staggering size of the event, the shaking didn’t dissipate all the strain accumulated at the time on the subduction fault between the Nazca and South American tectonic plates. The residual strain left on the fault may explain why a portion of this same section of fault ruptured again — 56 years later — on Dec. 25, 2016, in a magnitude-7.6 event.

26 Mar 2018

Measuring earthquakes using fiber-optic cables

Fiber-optic cables crisscross the world, ferrying digital data and enabling internet access and telecommunication. In a new study, published in Geophysical Research Letters, researchers tested whether fiber-optic cables can also be used to detect and measure earthquakes.

23 Mar 2018

Surveying forests from afar

Traditional surveys of forest health and diversity take hours of hiking and sampling by scientists who can only cover relatively small areas. Satellites, meanwhile, can survey large swaths of land, collecting information about forests in a fraction of the time that a ground survey might take. But the resolution and types of satellite data available don’t always allow for detailed studies. Now, a team of ecologists is staking out the middle ground by developing airborne laser scanning techniques to create high-resolution maps of tree species diversity to monitor changes in forest ecosystems.

22 Mar 2018

Globe-trotting bacteria found at both poles

The Arctic and Antarctica, separated by more than 15,000 kilometers, may be geographic opposites but they share many similarities, including their diverse arrays of bacteria and other microscopic life forms. A new study looking at the DNA of bacteria from both poles has found remarkable similarities between the two regions’ bacterial diversity, including some of the same species.

21 Mar 2018

Pesky ticks even plagued dinosaurs

Blood-sucking, disease-spreading ticks are one of the most maligned parasites in the world, and new evidence shows they’ve been doing their dirty work for a long time: Fossilized ticks dating to the mid-Cretaceous represent the first direct evidence that the ancestors of today’s pesky critters once plagued dinosaurs.

20 Mar 2018

Carbon emissions spike when continents rift

The vast majority of Earth’s carbon is stored in the planet’s interior. This buried carbon is not isolated from the surface over geologic timescales, however; some of it is released back into the atmosphere as carbon dioxide and other gases when volcanic eruptions occur above subduction zones or island arcs.

19 Mar 2018