Earth Sciences

Tilt is a 100,000-year planetary pacemaker

Scientists have long debated what causes glacial/interglacial cycles, which have occurred most recently at intervals of about 100,000 years. A new study reported in the March 24 issue of Nature finds that these glacial cycles are paced by variations in the tilt of Earth’s axis, and that glaciations end when Earth’s tilt is large.

With more than 30 explanations proposed for these glacial cycles, researchers at the Woods Hole Oc

A small autonomous underwater vehicle, or AUV, named Spray was launched yesterday about 12 miles southeast of Bermuda. The two-meter-(6-foot)-long orange glider with a four-foot wingspan will slowly make its way northwest, crossing the Gulf Stream and reaching the continental shelf on the other side before turning around and heading back to Bermuda, where it will be recovered in July.

The voyage will be the vehicle’s second trip across the Gulf Stream.Spray made history last

Predicting when large earthquakes might occur may be a step closer to reality, thanks to a new study of undersea earthquakes in the eastern Pacific Ocean. The study, reported in today’s Nature, is the first to suggest that small seismic shocks or foreshocks preceding a major earthquake can be used in some cases to predict the main tremors.

Scientists from the Woods Hole Oceanographic Institution (WHOI) and the University of Southern California (USC) report that some types of larg

NASA continues to explore the impact of black carbon or soot on the Earth’s climate. NASA uses satellite data and computer models that recreate the climate. New findings show soot may be contributing to changes happening near the North Pole, such as accelerating melting of sea ice and snow and changing atmospheric temperatures.

Dorothy Koch of Columbia University, New York, and NASA’s Goddard Institute for Space Studies (GISS), New York, and James Hansen of NASA GISS are c

Research published in Nature shows theoretical feasibility of quake forecasting

Earthquakes along a set of fault lines in the Pacific Ocean emit small “foreshocks” that can be used to forecast the main tremor, according to research in the March 24 issue of Nature. It is the first demonstration that some types of large imminent earthquakes may be systematically predictable on time scales of hours or less. Statistically reliable forecasting of imminent quakes has been an elusive goal f

Rising sea levels 20,000 years ago, as the last ice age was beginning to wane, often are attributed in part to melting in West Antarctica.

But in a new study led by University of Washington researchers, an ice core of 1,000 meters was used as a sort of dipstick to show that a key section of the West Antarctic Ice Sheet probably never contained as much ice as scientists originally thought it did. That means it couldn’t have contributed as much to the higher sea level. In an area c