In order to understand Earth's earliest history -- its formation from solar system material into the present-day layering of metal core and mantle, and crust -- scientists look to meteorites. New research focuses on one particularly old type of meteorite called diogenites. These samples were examined using an array of techniques, including precise analysis of certain elements for important clues to some of the solar system's earliest chemical processing.
The powerful magnitude-8.6 earthquake that shook Sumatra on April 11, 2012, was the largest strike-slip quake ever recorded. Now, as researchers report on their findings from the first high-resolution observations of the underwater temblor, they point out that the earthquake was also unusually complex -- rupturing along multiple faults that lie at nearly right angles to one another, as though racing through a maze.
Scientists have recreated the conditions at Earth's core-mantle boundary 2,900 km beneath the surface. Using X-rays at the European Synchrotron Radiation Facility, they probed tiny rock samples at extreme temperature and pressure showing for the first time that partially molten rock under these conditions is buoyant and should segregate towards the surface. This observation is strong evidence for the theory that volcanic hotspots like the Hawaiian Islands originate from mantle plumes generated at the core-mantle boundary.
A new analysis of the common accretion-disk model explaining how planets form in a debris disk around our Sun uncovered a possible reason for Earth's comparative dryness. The study found that our planet formed from rocky debris in a dry, hotter region, inside of the so-called "snow line." The snow line in our solar system currently lies in the middle of the asteroid belt, a reservoir of rubble between Mars and Jupiter; beyond this point, the Sun's light is too weak to melt the icy debris left over from the protoplanetary disk. Previous accretion-disk models suggested that the snow line was much closer to the Sun 4.5 billion years ago, when Earth formed.
Over the July 14-15, 2012 weekend and through the early morning of July 16, Earth experienced what's called a geomagnetic storm, which happens when the magnetic bubble around Earth, the magnetosphere, quickly changes shape and size in response to incoming energy from the sun. In this case that energy came from a coronal mass ejection (CME) associated with a July 12 X-class flare.
Scientists have long believed that comets and, or a type of very primitive meteorite were the sources of early Earth's volatile elements. Understanding where these volatiles came from is crucial for determining the origins of both water and life. New research focuses on ice that was distributed throughout much of the early Solar System. The team's findings contradict prevailing theories and suggest that meteorites are the most-likely sources of the Earth's water.
A volcanic eruption around 579 million years ago buried a 'nursery' of the earliest-known animals under a Pompeii-like deluge of ash, preserving them as fossils in rocks in Newfoundland, new research suggests.
Scientists have discovered that aerosols from relatively small volcanic eruptions can be boosted into the high atmosphere by weather systems such as monsoons, where they can affect global temperatures. The massive eruption of Mount Pinatubo in the Philippines in 1991 temporarily dropped temperatures by half a degree Celsius world-wide.
The earth is shaken daily by strong earthquakes recorded by a number of seismic stations worldwide. Tectonic tremor, however, is a new type of seismic signal that seismologist started studying only within the last few years. Tremor is less hazardous than earthquakes and occurs at greater depth. The link between tremor and earthquakes may provide clues about the more destructive earthquakes that occur at shallower depths. Geophysicists have collected seismic data of tectonic tremor in California. These data are now being evaluated in order to better understand this new seismic phenomenon.
A favorite theme of science fiction is "the portal" -- an extraordinary opening in space or time that connects travelers to distant realms. A good portal is a shortcut, a guide, a door into the unknown. If only they actually existed. It turns out that they do, sort of, and a researcher has figured out how to find them.
The world has gotten smaller and more accessible since applications like Google Earth became mainstream, says an expert. However, there is still a long way to go, and there are important steps to take to get there.
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