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.
Stanford Univ. scientists may have solved the mystery of what drives a type of earthquake that occurs deep within the Earth and accounts for one in four quakes worldwide. Known as intermediate-depth earthquakes, these temblors originate farther down inside the Earth than shallow earthquakes, which take place in the uppermost layer of the Earth's surface, called the crust.
In the first 300 days of the Mars Science Laboratory surface mission, the Curiosity rover collected soil samples in Gale Crater while the onboard Radiation Assessment Detector made detailed measurements of the radiation environment on the surface of Mars. Southwest Research Institute scientists have published the results of these studies, comparing them to typically doses received on Earth.
In a finding of relevance to the search for life in our solar system, researchers at the Georgia Institute of Technology, Univ. of Texas at Austin’s Institute for Geophysics and the Max Planck Institute for Solar System Research have shown that the subsurface ocean on Jupiter’s moon Europa may have deep currents and circulation patterns with heat and energy transfers capable of sustaining biological life.
At high pressures and low temperatures, such as those in the deep oceans, carbon dioxide occurs as a liquid that is denser than seawater. Researchers in England have identified regions beneath the oceans where the igneous rocks of the upper ocean crust could safely store very large volumes of carbon dioxide.
Scientists are interested in how the shape of Greenland’s hidden bedrock affects how ice moves, and have been employing a powerful radar technique that has been used in Antarctica to see through thousands of feet of ice. Mapping this terrain a key factor in making predictions about the future of these massive ice reservoirs and their contribution to sea level rise in a changing climate.
The presence of molecular hydrogen, in addition to carbon dioxide and water, could have created a greenhouse effect on Mars 3.8 billion years ago that pushed temperatures high enough to allow for liquid water. This is according to a team of researchers who believe this is the only way for giant canyons like Nanedi Valles could have formed.
Rain as acidic as undiluted lemon juice may have played a part in killing off plants and organisms around the world during the most severe mass extinction in Earth’s history. About 252 million years ago, the end of the Permian period brought about a worldwide collapse known as the Great Dying, during which a vast majority of species went extinct. The cause of such a massive extinction is a matter of scientific debate.
As NASA prepares to launch a new Martian probe, a scientist at Florida State Univ.’s MagLab has uncovered what may be the first recognized example of ancient Martian crust. Professor Munir Humayun’s groundbreaking discoveries are based on an analysis of a 4.4 billion-year-old Martian meteorite that was unearthed by Bedouin tribesmen in the Sahara desert.
NASA's newest Martian explorer, Maven, is on its launch pad in Florida, ready to soar. Bearing eight science instruments, the spacecraft will take 10 months to reach Mars, entering into orbit around the red planet in September 2014. Scientists hope Maven will help them learn why Mars went from being warm and wet during its first billion years, to the cold and dry place it is today.
Earth’s oldest sedimentary rocks are not only rare, but also almost always altered by hydrothermal and tectonic activity. The Pilbara district in Australia is a rare exception. A new study has revealed the well-preserved remnants of a complex ecosystem in a nearly 3.5 billion-year-old sedimentary rock sequence.
A new discovery by researchers from the Univ. of Notre Dame could change prevailing assumptions about the chemical makeup of the Earth’s mantle. The Univ. of Notre Dame team worked in cooperation with Vadim Kamenetsky of the Univ. of Tasmania, Hobart (Australia) to learn the art of conducting chemical and mineralogical analyses of melt inclusions within crystals of the mineral magnetite (Fe3O4).
A planned mission to return a sample from the Martian moon Phobos will likely be a twofer, according to a study by Brown Univ. geologists. The Russian mission launching in 2020, would return samples from Phobos that contain bits and pieces of Mars itself. The study calculates how much Martian material is on the surface of Phobos and how deep it is likely to go.
How far into the past can ice-core records go? Scientists have now identified regions in Antarctica they say could store information about Earth’s climate and greenhouse gases extending as far back as 1.5 million years, almost twice as old as the oldest ice core drilled to date.
A team of researchers has discovered a bacterium in hot springs which needs rare earth materials such as lanthanum, cerium or neodymium to grow. The bacteria need the valuable metals to produce energy as co-factor for the enzyme methanol dehydrogenase, with which the microbes produce their energy. The use of rare earths is possibly more widespread among bacteria than previously thought.
A Rice Univ.-based team of geoscientists is going to great lengths—from Earth’s core to its atmosphere—to get to the bottom of a long-standing mystery about the planet’s climate. The team will focus on how carbon moves between Earth’s external and internal systems.
Digs over the years at the La Brea Tar Pits in the heart of Los Angeles have unearthed bones of mammoths, mastodons, saber-toothed cats and dire wolves that became trapped in ponds of sticky asphalt. But it's the smaller discoveries, like plants, insects and rodents, that in recent years are shaping scientists' views of life in the region 11,000 to 50,000 years ago.
Gas and oil deposits in shale have no place to hide from an Oak Ridge National Laboratory technique that provides an inside look at pores and reveals structural information potentially vital to the nation’s energy needs. The research could clear the path to the more efficient extraction of gas and oil from shale.