Taxonomy term

mary caperton morton

Readying the Caribbean for the next big wave

The Caribbean is famous for clear blue waters and serene white sand beaches, and infamous for destructive hurricanes — but another type of natural disaster can also strike: tsunamis.

03 Sep 2018

Ancient DNA reveals diversity of Southeast Asia

Southeast Asia is one of the most genetically and linguistically diverse regions on Earth. New sequencing of ancient human DNA is helping scientists piece together the puzzle of how repeated influxes of hunter-gatherers and farmers to the area over the last 50,000 years created the high level of diversity seen today.

03 Sep 2018

Mercury links Big Five extinction events

Mercury concentration spikes in the geologic record have been linked to massive volcanism in the form of large igneous provinces (LIP) such as the Deccan Traps, a kilometers-thick heap of basalt layers that formed in what is now India beginning late in the Cretaceous, and the Siberian Traps, an even larger mass of lava that erupted in Siberia at the end of the Per­mian. It’s thought that vast gas emissions associated with LIP eruptions could have significantly changed climate patterns and affected conditions such as ocean acidity. 

31 Aug 2018

Sunstones useful as Viking-era GPS

The Vikings ruled the North Atlantic for hundreds of years without the benefits of magnetic compasses on the rough, often stormy waters. Legends have told of Vikings using sun compasses during clear weather and “sunstones” in cloudy conditions to navigate their weeks-long journeys between ports. A new study finds that sunstones made of calcite, cordierite or tourmaline may have indeed been accurate navigational tools.

28 Aug 2018

Gravity changes portended 2011 Tohoku earthquake

A new analysis of satellite data has revealed a distinct change in the gravity signal measured across the Japanese archipelago starting several months before the March 11, 2011, magnitude-9.1 Tohoku-Oki earthquake — one of the largest seismic events in recorded history.

27 Aug 2018

Grazing gave elephant ancestors an edge

The poor dental hygiene of some ancient elephant-like beasts has proven a boon to future scientists. In a new study, researchers used grass fragments recovered from the teeth of two extinct species of Central Asian gomphotheriids to decode the animals’ feeding habits during the middle Miocene.

24 Aug 2018

New suspect emerges in theft of Earth's surface iron

Iron is the fourth-most common element in Earth’s crust, but why there isn’t more found near the surface in continental crust has been a long-standing question among geologists. In a new study, scientists implicate an overlooked mineral culprit in the theft of iron from continental crust: garnet. But not everybody is ready to exonerate the long-implicated magnetite.

17 Aug 2018

A rocky source of nitrogen

Calculations of the planet’s nitrogen balance have always been off: plants and soils seem to sequester far more nitrogen than expected. The atmosphere has long been thought of as the only major source of nitrogen, but a new study indicates an additional source: as much as a quarter of Earth’s terrestrial nitrogen may be supplied by eroding bedrock.

07 Aug 2018

Speartips point at south-to-north Clovis dispersal

During the last ice age, long before people first entered North America, much of the Canadian and American Rockies were buried under massive ice sheets. As the ice age waned about 13,000 years ago, an ice-free corridor 1,500-kilometers long and several hundred kilometers wide opened east of the Rocky Mountains.

02 Aug 2018

Charting 500 years of Mississippi floods

The Mississippi River is notorious for flooding its muddy banks, with many critical areas actively managed by the Army Corps of Engineers to control flooding. But despite all the controls, major floods still occur. 

01 Aug 2018

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