Seeking to better understand the composition of the lowermost part of Earth’s mantle, located nearly 2,900 km (1,800 miles) below the surface, a team of Arizona State Univ. researchers has developed new simulations that depict the dynamics of deep Earth. A paper published in Nature Geoscience reports the team’s findings, which could be used to explain the complex geochemistry of lava from hotspots such as Hawaii.
An international research team has documented evidence suggesting that part of the reason that the Earth has become neither sweltering like Venus nor frigid like Mars lies with a built-in atmospheric carbon dioxide regulator. Basically, ”fresh” rock exposed by uplift also emits carbon through a chemical weathering process, which replenishes the atmospheric carbon dioxide.
The frustrated attempts of a Univ. of California, Los Angeles graduate student to quantify the amount of water draining from Greenland's melting ice sheet led him to devise a new way to measure river flows from outer space, he and his professor report in a new study. The new approach relies exclusively on the measurements of a river's width over time, which can be obtained from freely available satellite imagery.
Will one-atom-thick layers of molybdenum disulfide, a compound that occurs naturally in rocks, prove to be better than graphene for electronic applications? Recent research into phenomena occurring in the crystal network of this material show signs that might prove to be the case. But physicists in Poland have shown that the nature of the phenomena occurring in layered materials are still ill-understood.
The Earth’s magnetic field, or magnetosphere, stretches from the planet’s core out into space, where it meets the solar wind, a stream of charged particles emitted by the sun. For the most part, the magnetosphere acts as a shield to protect the Earth from this high-energy solar activity. But when this field comes into contact with the sun’s magnetic field, powerful electrical currents from the sun can stream into Earth’s atmosphere.
Researchers from ETH Zurich and the Univ. of Tubingen in Europehave recently described a process that suppresses the formation of methane in soils that are rich in humic substances. The soils act as a battery, releasing to and accepting electrons from soil bacteria depending on the presence of oxygen. The study shows that electron transfer to and from humic substances is an important process with global implications for methane release.
Volcanic eruptions in the early part of the 21st century have cooled the planet, according to a study led by Lawrence Livermore National Laboratory. This cooling partly offset the warming produced by greenhouse gases. Despite continuing increases in atmospheric levels of greenhouse gases, and in the total heat content of the ocean, global-mean temperatures at the surface of the planet have shown relatively little warming since 1998.
For centuries, geologists have recognized that the rocks that line riverbeds tend to be smaller and rounder further downstream. But these experts have not agreed on the reason these patterns exist. Does abrasion reduce the size of rocks significantly, or is it that smaller rocks are simply more easily transported downstream? A new study has arrived at a resolution to this puzzle.
Using images from NASA’s Voyager Mission in the 1970s and the orbital Galileo Mission of 1995, researchers have created the first global geological map of Jupiter’s largest moon, Ganymede. With its varied terrain and possible underground ocean, Ganymede is considered a prime target in the search for habitable environments in the solar system.
The largest mass extinction in the history of animal life occurred some 252 million years ago, wiping out more than 96% of marine species and 70% of life on land. Multiple theories have aimed to explain the cause of what’s now known as the end-Permian extinction. But pinpointing the cause of the extinction requires better measurements of how long the extinction period lasted.
Martian experts have known since 2011 that mysterious, possibly water-related streaks appear and disappear on the planet’s surface. These features were given the descriptive name of recurring slope lineae (RSL) because of their shape, annual reappearance and occurrence generally on steep slopes such as crater walls. A team has been looking closer at this phenomenon to try to understand the nature of these features: water-related or not?
Instrumentation company FEI has acquired Lithicon AS of Trondheim, Norway, and Canberra, Australia. Lithicon provides digital rock technology services and pore-scale micro computed tomography (µCT, or microCT) equipment to oil and gas companies worldwide. In conjunction with the acquisition, FEI has obtained the helical scan microCT product and associated software from the Australia National Univ.
The release of volatile organic compounds from Earth’s forests and smoke from wildfires 3 million years ago had a far greater impact on global warming than ancient atmospheric levels of carbon dioxide, a new Yale Univ. study finds. The research provides evidence that dynamic atmospheric chemistry played an important role in past warm climates, underscoring the complexity of climate change and the relevance of natural components.
The latest observations of Jakobshavn Glacier show that Greenland’s largest glacier is moving ice from land into the ocean at a speed that appears to be the fastest ever recorded. Researchers from the Univ. of Washington and the German Space Agency measured the speed of the glacier in 2012 and 2013.
In the Earth Surface Dynamics Lab at the California Institute of Technology the behavior of rivers is modeled through the use of artificial rivers—flumes—through which water can be pumped at varying rates over a variety of carefully graded sediments while drag force and acceleration are measured. The largest flume is a 12-m tilting version that can model many river conditions.
Sandia National Laboratories is developing computer models that show how radioactive waste interacts with soil and sediments, shedding light on waste disposal and how to keep contamination away from drinking water. Researchers have studied the geochemistry of contaminants such as radioactive materials and toxic heavy metals, including lead, arsenic and cadmium. But laboratory testing of soils is difficult.
Scientists at the Univ. of Liverpool have shown that deep sea fault zones could transport much larger amounts of water from the Earth’s oceans to the upper mantle than previously thought. They have estimated that over the age of the Earth, the Japan subduction zone alone could transport the equivalent of up to three and a half times the water of all the Earth’s oceans to its mantle.
In 2009, a borehole drilled at Krafla, northeast Iceland, as part of the Icelandic Deep Drilling Project (IDDP), unexpectedly penetrated into magma at only 2100 m depth, with a temperature of 900-1000 C. The borehole, called IDDP-1, essentially created the world’s first magma-enhanced geothermal system, and is now blowing superheated 450 C steam directly from a molten magma.
Recreating the story of humanity’s past by studying ancient bones can hit a snag when they deteriorate, but scientists are now reporting an advance inspired by seashells that can better preserve valuable remains. Their findings, which appear in Langmuir, could have wide-ranging implications for both archeology and paleontology.
After a 10-year journey and a long, deep sleep the Rosetta space probe will be awoken on Jan. 20, 2014. The vehicle then starts the last leg of its journey which will lead it to the 67P/Churyumov-Gerasimenko comet. Then, mission leaders will attempt a space exploration first: setting the Philae lander down on the comet’s surface in November.
Scientists studying the atmosphere above Barrow, Alaska, have discovered unprecedented levels of molecular chlorine in the air, a new study reports. Molecular chlorine, from sea salt released by melting sea ice, reacts with sunlight to produce chlorine atoms. These chlorine atoms are highly reactive and can oxidize many constituents of the atmosphere including methane and elemental mercury.
Seismologists say Seahawks fans shook the ground under Seattle's CenturyLink Field during Saturday's defeat of the New Orleans Saints, causing another fan-generated earthquake even stronger than Marshawn Lynch's famous "beast quake" touchdown run three years ago. That quake registered a magnitude 1 or 2.
By effectively “exploding” instead of erupting, supervolcanos release tremendous energy. Because none are currently “live”, how supervolcanos become active has remained a mystery. Geologists have now demonstrated that the pressure generated through the difference in density between magma and the surrounding rock alone can be sufficient to cause one of these geological giants to erupt.
According to a new study, the Atlas Mountains in Morocco defy the standard model for mountain structure in which high topography must have deep roots for support. In a new model, researchers show that the mountains are floating on a layer of hot molten rock that flows beneath the region’s lithosphere, perhaps all the way from the volcanic Canary Islands.
New model calculations indicate that the extreme density of the base of the thickened primary crust caused it to subside vertically, or “drip”, into Earth's mantle during the Archean eon, which began about 4 billion years ago. In contrast, the movements of today's tectonic plates involve largely lateral movements with oceanic lithosphere recycled in subduction zones.