Scientists at NIST have determined that polonium-209, the longest-lived isotope of this radioactive heavy element, has a half-life about 25% longer than the previously determined value, which had been in use for decades. The new NIST measurements could affect geophysical studies such as the dating of sediment samples from ocean and lake floors.
Picture the fearsome creatures of "Jurassic Park" crossed with the shark from "Jaws." Then super-size to the biggest predator ever to roam Earth. Now add a crocodile snout as big as a person and feet like a duck's. The result gives you some idea of a bizarre dinosaur scientists unveiled Thursday. This patchwork of critters, a 50-foot predator, is the only known dinosaur to live much of its life in the water.
A new study published in The Journal of Geology provides support for the theory that a cosmic impact event over North America some 13,000 years ago caused a major period of climate change known as the Younger Dryas stadial, or “Big Freeze.” The key to the mystery of the Big Freeze lies in nanodiamonds scattered across Europe, North America, and portions of South America.
When a segment of a major fault line goes quiet, it can mean one of two things: The “seismic gap” may simply be inactive, or the segment may be a source of potential earthquakes, quietly building tension over decades until an inevitable seismic release. Researchers from Massachusetts Institute of Technology and Turkey have found evidence for both types of behavior on different segments of the North Anatolian Fault.
A high-tech survey reveals that there is more to Stonehenge than meets the eye, finding previously unknown monuments. Researchers have produced digital maps of what's beneath the World Heritage Site, using ground-penetrating radar, high-resolution magnetometers and other techniques to peer deep into the soil. And they have found some surprises.
In the typical textbook picture, volcanoes, such as those that are forming the Hawaiian islands, erupt when magma gushes out as narrow jets from deep inside Earth. But that picture is wrong, according to a new study from researchers at Caltech and the Univ. of Miami. New seismology data are now confirming that such narrow jets don't actually exist.
For years scientists have theorized about how large rocks, some weighing hundreds of pounds, zigzag across Racetrack Playa in Death Valley National Park, leaving long trails etched in the earth. Now two researchers at the Scripps Institution of Oceanography at the Univ. of California, San Diego, have photographed these "sailing rocks" being blown by light winds across the former lake bed.
An international group of scientists posit that a comet collision with Earth played a major role in the extinction of most of North America’s megafauna close to 13,000 years ago. In a new study, they have focused on the character and distribution of nanodiamonds, which are produced during such an extraterrestrial collision. The researchers found an abundance of these tiny diamonds distributed over 50 million km2 in the Northern Hemisphere.
According to a new study, in the unlikely event of a volcanic super-eruption at Yellowstone National Park, the northern Rocky Mountains would be blanketed in meters of ash, and millimeters would be deposited as far away as New York City, Los Angeles and Miami. An improved computer model finds that the hypothetical, large eruption would create a distinctive kind of ash cloud known as an umbrella, which expands evenly in all directions.
Astronomers using the Green Bank Telescope have discovered that filaments of star-forming gas near the Orion Nebula may be brimming with pebble-size particles: planetary building blocks 100 to 1,000 times larger than the dust grains typically found around protostars. If confirmed, these dense ribbons of rocky material may well represent a new, mid-size class of interstellar particles that could help jump-start planet formation.
Research published last week in Science suggested that the makeup of the Earth's lower mantle, which makes up the largest part of the Earth by volume, is significantly different than previously thought. According to scientists, the work performed at Argonne National Laboratory’s Advanced Photon Source will have a significant impact on our understanding of the lower mantle.
The tectonic plate that dominates the Pacific “Ring of Fire” is not as rigid as many scientists assume, according to researchers at Rice Univ. and the Univ. of Nevada. The researchers have determined that cooling of the lithosphere makes some sections of the Pacific plate contract horizontally at faster rates than others and cause the plate to deform.
The moon appears to be a tranquil place, but modeling done by Univ. of New Hampshire and NASA scientists suggests that, over the eons, periodic storms of solar energetic particles may have significantly altered the properties of the soil in the moon’s coldest craters through the process of sparking—a finding that could change our understanding of the evolution of planetary surfaces in the solar system.
As climate change alters habitats for birds and bees and everything in between, so too does the way humans decide to use land. Researchers have, for the first time, found a way to determine the potential combined impacts of both climate and land-use change on plants, animals and ecosystems across the country.
Since 2006, when NASA’s Stardust spacecraft delivered its aerogel and aluminum foil dust collectors back to Earth, a team of scientists has combed through them. They now report finding seven dust motes that probably came from outside our solar system, perhaps created in a supernova explosion and altered by eons of exposure to the extremes of space. They would be the first confirmed samples of contemporary interstellar dust.
From research stations drifting on ice floes to high-tech aircraft radar, scientists have been tracking the depth of snow that accumulates on Arctic sea ice for almost a century. Now that people are more concerned than ever about what is happening at the poles, research led by the Univ. of Washington and NASA confirms that snow has thinned significantly in the Arctic, particularly on sea ice in western waters near Alaska.
The Jurassic and Cretaceous periods were the golden age of dinosaurs, during which the prehistoric giants roamed the Earth for nearly 135 million years. Paleontologists have unearthed numerous fossils from these periods, suggesting that dinosaurs were abundant throughout the world. But where and when dinosaurs first came into existence has been difficult to ascertain.
Turning what seemed like a science fiction tale into reality, an unmanned probe swung alongside a comet on Wednesday after a 4-billion mile chase through outer space over the course of a decade. Europe's Rosetta probe will orbit and study the giant lump of dust and ice as it hurtles toward the sun and, if all goes according to plan, drop a lander onto the comet in the coming months.
Aerosols, tiny particles in the atmosphere, play a significant role in Earth's climate, scattering and absorbing incoming sunlight and affecting the formation and properties of clouds. Currently, the effect that these aerosols have on clouds represents the largest uncertainty among all influences on climate change.
Scientists are searching through a massive collection of 20-million-year-old amber found in the Dominican Republic more than 50 years ago, and the effort is yielding fresh insights into ancient tropical insects and the world they inhabited. When the collection is fully curated, a task that will take many years, it will be the largest unbiased Dominican amber collection in the world, the researchers report.
As the climate warms and sea ice retreats, the North is changing. An ice-covered expanse now has a season of increasingly open water that is predicted to extend across the whole Arctic Ocean before the middle of this century. Storms thus have the potential to create Arctic swell. A Univ. of Washington researcher made the first study of waves in the middle of the Arctic Ocean, and detected house-sized waves during a September 2012 storm.
Reactions among minerals and organic compounds in hydrothermal environments are critical components of the Earth’s deep carbon cycle. They provide energy for the deep biosphere, and may have implications for the origins of life. However, very little is known about how minerals influence organic reactions. A team of researchers has demonstrated how a common mineral acts as a catalyst for specific hydrothermal organic reactions.
The U.S. Geological Survey plans this summer and next to map the outer limits of the continental shelf, and also study underwater landslides that would help predict where and when tsunamis might occur. But environmentalists say it could cause the same type of marine life damage they fought unsuccessfully to prevent this month off the coast of New Jersey.
Russian scientists say they believe a 66-yard wide crater discovered recently in far northern Siberia could be the result of changing temperatures in the region. Andrei Plekhanov, a senior researcher at the Scientific Research Center of the Arctic who visited the crater this week, the crater was mostly likely the result of a "build-up of excessive pressure" underground due to rising temperatures.
A 25-year-long study published in Geology provides the first quantitative measurement of in situ calcium-magnesium silicate mineral dissolution by ants, termites, tree roots, and bare ground. This study reveals that ants are one of the most powerful biological agents of mineral decay yet observed. This discovery might offer a line of research on how to "geoengineer" accelerated carbon dioxide consumption by Ca-Mg silicates.