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.
A cave discovered near the source of Indonesia's massive earthquake-spawned tsunami contains the footprints of past gigantic waves dating up to 7,500 years ago, a rare natural record that suggests the next disaster could be centuries away, or perhaps only decades. The findings provide the longest and most detailed timeline for tsunamis that have occurred off the far western tip of Sumatra island, where deadly 100-ft waves struck in 2004.
Nearly 25% of earthquakes occur more than 50 km below the Earth’s surface in a region called the lithosphere. But limited data and knowledge have prevented researchers from finding the cause of these intermediate and deep earthquakes. A team has recently found immense heating at high pressures at these depths, helping explain the “runaway” process propagates an earthquake in the lithosphere.
An international research team has produced a high-quality genome sequence of a Neanderthal woman from a toe bone found in 2010 by Russian archaeologists. The genome will allow detailed insights into the relationships and population history of the Neanderthals and other extinct hominin groups.
In 2007 and 2008, two research papers reported in the journal Nature that a suite of zircons from the Jack Hills included diamonds, requiring a radical revision of early Earth history. The papers posited that the diamonds formed, somehow, before the oldest zircons, or more than 4.3 billion years ago. A research team now claims the oldest “diamonds” on the Earth are simply fragments of polishing compound.
To support research efforts in Antarctica, a Penn State Univ. geoscience professor has developed a new type of seismometer, which measures the way seismic waves move through the ice. The “geoPebbles” act as laptops without screens. Equipped with WiFi, they don’t have to be plugged in and charge wirelessly, letting scientists collect data without exposure to the cold.
Researchers are developing a new kind of geothermal power plant that will lock away unwanted carbon dioxide underground and use it as a tool to boost electric power generation by at least 10 times compared to existing geothermal energy approaches. The technology to implement this design already exists in different industries, so the researchers are optimistic that their new approach could expand the use of geothermal energy in the U.S.
An atmospheric peculiarity the Earth shares with Jupiter, Saturn, Uranus and Neptune is likely common to billions of planets, Univ. of Washington astronomers have found, and knowing that may help in the search for potentially habitable worlds. The paper uses basic physics to show why this happens, and suggests that tropopauses are probably common to billions of thick-atmosphere planets and moons throughout the galaxy.