An analysis of gravity and topography data from Saturn's largest moon, Titan, has revealed unexpected features of the moon's outer ice shell. The best explanation for the findings, say scientists, is that Titan's ice shell is rigid and that relatively small topographic features on the surface are associated with large roots extending into the underlying ocean.
During the Cold War, U.S. and international monitoring agencies could spot nuclear tests and focused on measuring their sizes. Today, they’re looking around the globe to pinpoint much smaller explosives tests. Sandia National Laboratories and Los Alamos National Laboratory have partnered to develop a 3-D model of the Earth’s mantle and crust called SALSA3D, with the purpose to assist in locating explosions.
Using indicator molecules, a team of researchers working in Eurasia has for the first time assessed contributions of old carbon from permafrost soils to riverine carbon headed. They were also able to demonstrate that permafrost soils where the frozen areas are interspersed with gaps release more old carbon than those where the permafrost is uninterrupted.
Reservoirs of silica-rich magma can persist in Earth’s upper crust for hundreds of thousands of years without triggering an eruption, according to new modeling research. That means an area known to have experienced a massive volcanic eruption in the past, such as Yellowstone National Park, could have a large pool of magma festering beneath it and still not be close to going off as it did 600,000 years ago.
With a series of quick blasts and a cloud of dust a 13-story building on the Cal State-East Bay campus crashed to the ground Saturday morning as scientists monitored the impact on the nearby Hayward Fault. U.S. Geological Survey scientists had placed more than 600 seismographs in concentric circles within a mile of the building to pick up the vibrations and verify whether their predictions were correct.
Analysis of ice samples taken by the West Antarctic Ice Sheet (WAIS) Divide drilling project reveals that warming in Antarctica began about 22,000 years ago, a few thousand years earlier than suggested by previous records. This timing shows that West Antarctica did not "wait for a cue" from the Northern Hemisphere to start warming, as scientists had previously supposed.
Researchers at the Carnegie Institution and the Univ. of Illinois have for the first time been able to experimentally simulate the pressure conditions in the Earth’s mantle to measure thermal conductivity. A new technique using the mantle material magnesium oxide allowed the team to discover that heat transfer is actually lower than what has been claimed by other predictions and amounts to about 60% used by civilization today.
High pressures and temperatures cause materials to exhibit unusual properties, some of which can be special. Understanding such new properties is important for developing new materials for desired industrial uses and also for understanding the interior of Earth, where everything is hot and squeezed.
Brown Univ. planetary geologists have an explanation for the formation of more than 600 “double-layer ejecta” (DLE) craters on Mars. The Martian surface was covered with a thick sheet of ice at impact. Ejected material would later slide down steep crater sides and across the ice, forming a second layer.
Climate change alters the way in which species interact with one another—a reality that applies not just to today or to the future, but also to the past, according to a recent study which analyzed information about past episodes of rapid climate change from Earth's history. The researchers hope to use this finding to help predict future changes to our planet's ecosystems.
Sugars are important sources of energy for all organisms. Virginia Tech researchers have discovered that certain types of sugars, known as polysaccharides, may also control the timing and placement of minerals that animals use to produce hard structures such as shells and exoskeletons of mollusks, lobsters, and shrimp.
It's well known that the dinosaurs were wiped out 66 million years ago when a meteor hit what is now southern Mexico; but evidence is accumulating that the biggest extinction of all, 252.3 million years ago, at the end of the Permian period, was also triggered by an impact that changed the climate.
Researchers have demonstrated the reliability and efficiency of "real-time hybrid simulation" for testing a type of powerful damping system that might be installed in buildings and bridges to reduce structural damage and injuries during earthquakes. The magnetorheological-fluid dampers are shock-absorbing devices containing a liquid that becomes far more viscous when a magnetic field is applied.
The George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES), based at Purdue Univ., includes 14 laboratories for earthquake engineering and tsunami research, tied together to provide information technology for the network. A new study has found that online tools, access to experimental data and other services provided through this "cyberinfrastructure" are helping to accelerate progress in earthquake science.
Researchers at Brown Univ. have shown that some Martian valleys appear to have been caused by runoff from orographic precipitation—moisture carried part of the way up a mountain and deposited on the slopes. The new findings are the most detailed evidence yet of an orographic effect on ancient Mars.
In events that could exacerbate sea level rise over the coming decades, stretches of ice on the coasts of Antarctica and Greenland are at risk of rapidly cracking apart and falling into the ocean, according to new iceberg calving simulations from the Univ. of Michigan.
A landmark federal study on hydraulic fracturing, or fracking, shows no evidence that chemicals from the natural gas drilling process moved up to contaminate drinking water aquifers at a western Pennsylvania drilling site. After a year of monitoring, the researchers found that the chemical-laced fluids used to free gas trapped deep below the surface stayed thousands of feet below the shallower areas that supply drinking water
If the Earth arose from the collision of asteroids, as is widely thought, its composition should resemble that of meteoroids, which break off of asteroids. But the Earth’s mantle is missing an amount of lead found in meteorites whose composition has been analyzed following impact with the Earth. New research points to large reservoirs of material deep in the mantle that may help solve the mystery and explain Earth’s origins.
At the end of the last Ice Age, as the world began to warm, a brief pulse of biological productivity in the Pacific Ocean gave rise to large numbers of phytoplankton, foraminifera and other creatures. Researchers have hypothesized that iron sparked this surge of ocean life, but a new study determines instead that “perfect storm” of nutrients and light spurred the bloom.
It is not unusual for swarms of small earthquakes to precede a volcanic eruption. They can create a signal called harmonic tremor, which resembles that generated by musical instruments but at a much lower frequency. A new analysis of an eruption sequence at Alaska’s Redoubt Volcano in March 2009 shows that the harmonic tremor glided to substantially higher frequencies and then stopped abruptly just before erupting.
The powerful earthquake that rocked Japan in 2011 set off tremors around a West Texas oil field, according to new research that suggests oil and gas drilling operations may make fault zones sensitive to shock waves from distant big quakes. Large quakes have been known to trigger minor jolts thousands of miles from the epicenter, but less is known about the influence of remote quakes on faults that have been weakened by man-made activity.
New research in Australia shows that existing copper resources can sustain increasing worldwide demand for at least a century, meaning social and environmental concerns could be the most important restrictions on future copper production. The finding runs contrary to other predictions estimating that supplies of this important metal would run out in around 30 years.
A Univ. of Michigan researcher worked with Univ. of Utah colleagues to develop a new weapon to fight poachers who kill elephants, hippos, rhinos and other wildlife. By measuring radioactive carbon-14 deposited in tusks and teeth following open-air nuclear bomb tests, the method reveals the year an animal died, and thus whether the ivory was taken illegally.
Earth’s atmosphere did not always contain oxygen, and one of science's greatest mysteries is how and when oxygenic photosynthesis—the process responsible for producing oxygen on Earth through the splitting of water molecules—first began. A team has now found evidence of a precursor photosystem involving manganese that predates cyanobacteria, the first group of organisms to release oxygen into the environment via photosynthesis.
Using data gathered by NASA’s Lunar Reconnaissance Orbiter mission, scientists believe they have solved a mystery from one of the solar system’s coldest regions—a permanently shadowed crater on the moon. They have explained how energetic particles penetrating lunar soil can create molecular hydrogen from water ice. The finding provides insight into how radiation can change the chemistry of water ice throughout the solar system.