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News

Mediterranean tsunami record may be overreported

Tsunamis are one of the most destructive natural hazards on Earth, sometimes even upstaging the major earthquakes that send the waves surging across entire ocean basins. Knowing when, where and how severely tsunamis have struck coastlines in the past is valuable for countries trying to prepare for the impacts of future tsunamis. But distinguishing tsunami deposits in geologic paleorecords from deposits left by more common storm waves is notoriously difficult. Researchers recently highlighted this challenge by taking a hard look at tsunami- and storm-wave records around the Mediterranean Sea over the last 4,500 years. The findings may serve as a cautionary tale for scientists interpreting tsunami records elsewhere in the world.

18 Jan 2018

Mediterranean drawdown may have caused burst of volcanism

Between 5 million and 6 million years ago, during an event known as the Messinian Salinity Crisis (MSC), large amounts of seawater evaporated from the Mediterranean Sea leaving massive salt deposits in the basin. How much the sea surface dropped during the MSC is debated, but in a new study in Nature Geoscience, researchers suggest that a large, kilometer-scale drawdown of the Mediterranean Sea may explain not just the thick salt deposits but also a pulse of magmatic activity around the region that occurred at the same time as the MSC.

17 Jan 2018

Small warm ponds: Ideal incubators for first life?

The first embers of life are thought to have emerged on Earth between 4.5 billion and 3.7 billion years ago, but how and where the initial sparks arose remains a mystery. Two leading theories suggest that the first self-replicating molecules — a necessity for life — may have gotten a start either in deep-ocean hydrothermal vents or in small warm ponds on land. In a new study, researchers suggest that the wet-dry cycles occurring in small, seasonal ponds would have made a better natural incubator.

17 Jan 2018

Ice (Re)Cap: January 2018

From Antarctica to the Arctic; from polar caps, permafrost and glaciers to ocean-rafted sea ice; and from burly bears to cold-loving microbes, fascinating science is found in every nook and crevasse of Earth’s cryosphere, and new findings are announced often. Here are a few of the latest updates.

 
15 Jan 2018

It's an asteroid, no wait, a comet, no wait…

NASA’s Hubble Space Telescope has spied a unique object in the debris-filled asteroid belt between Mars and Jupiter: a pair of asteroids — orbiting tightly around each other — that also show comet-like characteristics, including a bright halo of ice and dust known as a coma and a long tail of dust. The odd object, called 2006 VW139/288P, is the first known binary asteroid that is also classified as a main-belt comet.

12 Jan 2018

Predators may have spurred evolution of ancient brittle stars

Threats to species can encourage evolution, leading to animals with harder shells or other defensive adaptations. In a recent study in the Journal of Systematic Palaeontology, researchers found that while some ancient brittle stars — relatives of starfish with long, whip-like arms — evolved in the face of threats, some adapted a different approach: they moved.

10 Jan 2018

Western wildfires affect water quality

Wildfires have burned increasing acreage in recent decades, a trend that’s expected to continue with global climate change. In the U.S. West, the frequency of fires has implications for water availability — both water used to fight wildfires and municipal water supplies, which can be contaminated by loosened debris from eroding, fire-burned slopes.

09 Jan 2018

Nothing is clear about who left marks on ancient bones

An ongoing debate regarding the origin of scrape marks on ancient animal bones has taken a new turn. The marks were first thought to have been made by early hominid butchers, then by trampling, and now it’s looking like crocodiles might have been responsible, according to a recent study in Proceedings of the National Academy of Sciences (PNAS).

05 Jan 2018

Impact signature in rock produced by lightning strikes

When a meteorite smashes into Earth’s rocky surface, the immense temperatures and pressures created can melt rock into glass and leave signatures of the impact behind. Impacts produce tell-tale planar features in quartz grains called shock lamellae — picture a scrambled television signal, with repeating horizontal lines chopping and distorting the image into layers — that scientists have thought were produced only by meteorites.

05 Jan 2018

In feats of tectonic strength, grain size matters

Plate tectonics involves some of the most powerful forces on Earth, but the lithosphere, of which the plates are made, is not infinitely strong: Weaknesses in the lithosphere allow it to break apart and form plate boundaries. Determining the strength of tectonic plates based on field observations has proved tricky, however, due to the sheer scale of plates, while experiments and calculations in the lab on olivine — the main mineral that makes up the lithosphere — have depicted plates as misleadingly strong. In a new lab-based study, researchers have taken a novel approach to testing olivine’s strength, and the results fit existing models of plate tectonics better than previous efforts.

04 Jan 2018

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