Taxonomy term

april 2016

Comment: How long have humans been altering Earth's climate?

The early anthropogenic hypothesis holds that greenhouse gas emissions from agriculture, as early as 7,000 years ago, kept the Holocene climate warmer than it otherwise would have been.

08 Apr 2016

Bat signals

Bats, the only true-flight mammals, first appeared during the Early Eocene after a period of acute global warming known as the Paleocene-Eocene Thermal Maximum. Despite decades of study, however, much remains unknown about bats. Recent discoveries are shedding new light on the natural history of these creatures, which today comprise one of the most diverse mammalian groups.

07 Apr 2016

An absentee note for ancient blueschist: Lack of metamorphic rock does not date onset of plate tectonics

Plate tectonics is a defining characteristic of our 4.5-billion-year-old home planet, responsible for earthquakes, mountain building, and much of the evolution of the planet’s oceans and atmosphere. But when this formative process began is a mystery. Some researchers have pointed to the lack of blueschist — a type of metamorphic rock that only forms in tectonically driven subduction zones — in rocks older than 800 million years as a clue to when subduction began. But a new study rules this option out, offering a novel explanation for the rock’s absence in ancient rocks.

05 Apr 2016

Crippling heat stress projected by midcentury in densely populated regions

Extreme heat is the world’s top weather-related killer. Exposure to extreme heat caused more than 7,800 fatalities in the U.S. from 1999 to 2009, according to a 2013 report by the U.S. Centers for Disease Control and Prevention. And a single heat wave last summer killed at least 2,300 people in India, according to NOAA.

05 Apr 2016

Downgoing plate topography stopped 2005 Sumatra rupture

In late March 2005, a magnitude-8.7 earthquake struck off the northwest coast of Sumatra, Indonesia, rupturing a portion of the Sunda Megathrust Fault and further terrorizing a region still reeling from the devastating 2004 Boxing Day earthquake and tsunami just three months prior. The March quake, however, could have been far larger than it was, according to new research. Scientists have identified a topographic barrier on the oceanic Indo-Australian Plate — which descends under the Sunda Plate in the Sumatra Subduction Zone — that may have stopped the 2005 rupture from propagating farther.

04 Apr 2016

Inside an icthyosaur's brain

While the dinosaurs were busy ruling the continents in the Mesozoic, an order of marine reptiles known as the ichthyosaurs ruled the oceans. Ichthyosaurs are well known from numerous fossils, but they are often found flattened, limiting researchers’ ability to study the skulls and braincases as they existed in life.

01 Apr 2016

Where on Earth? - April 2016

Where on Earth was this picture taken? Use these clues to guess and submit your answer via mail, email or Web by the last day of the month (April 30, 2016).

01 Apr 2016

North Sea uplift caused Jurassic cooling event

The climate of the Jurassic, long envisioned as ubiquitously warm from the equator to the poles, was actually more dynamic, sometimes cooling dramatically, according to a new study. The research joined isotopic and sedimentological data to suggest that an abrupt cooling event occurred in the midlatitudes early in the Middle Jurassic as a result of changing ocean currents associated with a feature known as the North Sea Dome.

31 Mar 2016

Sailors right about sneaky rogue waves

Sailors are notorious for telling tall tales, including legends about monstrous “rogue waves” that appear at sea without warning. Oceanographers have traditionally dismissed such stories because they thought that unusually large waves would be preceded by series of waves of increasing size.

29 Mar 2016