Latest Plate tectonics Stories
GEOLOGY posted ahead of print 14 Feb.–2 Mar. is a dynamic collection of papers covering modeling studies of the U.S. New Madrid Seismic Zone; landslide prediction through examination of the Slumgullion landslide, Colorado; investigation of a potential nuclear waste repository site in Finland; understanding river delta formation and long-term evolution with insights from the Mekong River, Vietnam; and an explanation of how drought drove forest decline and dune building in eastern upper...
A new twist to a 50 million-year-old tale Fifty million years ago, India slammed into Eurasia, a collision that gave rise to the tallest landforms on the planet, the Himalaya Mountains and the Tibetan Plateau. India and Eurasia continue to converge today, though at an ever-slowing pace. University of Michigan geomorphologist and geophysicist Marin Clark wanted to know when this motion will end and why. She conducted a study that led to surprising findings that could add a new wrinkle to...
Seawater circulation pumps hydrogen and boron into the oceanic plates that make up the seafloor, and some of this seawater remains trapped as the plates descend into the mantle at areas called subduction zones. By analyzing samples of submarine volcanic glass near one of these areas, scientists found unexpected changes in isotopes of hydrogen and boron from the deep mantle. They expected to see the isotope "fingerprint" of seawater. But in volcanoes from the Manus Basin they also discovered...
A mysterious cycle of booms and busts in marine biodiversity over the past 500 million years could be tied to a periodic uplifting of the world's continents, scientists report in the March issue of The Journal of Geology. The researchers discovered periodic increases in the amount of the isotope strontium-87 found in marine fossils. The timing of these increases corresponds to previously discovered low points in marine biodiversity that occur in the fossil record roughly every 60 million...
Unexpected new findings by a University of Maryland team of geochemists show that some portions of the Earth's mantle (the rocky layer between Earth's metallic core and crust) formed when the planet was much smaller than it is now, and that some of this early-formed mantle survived Earth's turbulent formation, including a collision with another planet-sized body that many scientists believe led to the creation of the Moon. "It is believed that Earth grew to its current size by collisions...
Scripps scientists propose mass melting as new force behind volcanic activity in Columbia River region Like a stream of air shooting out of an airplane's broken window to relieve cabin pressure, scientists at Scripps Institution of Oceanography at UC San Diego say lava formations in eastern Oregon are the result of an outpouring of magma forced out of a breach in a massive slab of Earth. Their new mechanism explaining how such a large volume of magma was generated is published in the Feb....
All of Earth's continents, believed to have once been joined together as a supercontinent known as Pangaea, will be reunited as a single landmass near the North Pole within the next 50 million to 200 million years, researchers from Yale University claim in a new study. According to MSNBC Science Editor Alan Boyle, the Yale researchers, including geologist Ross Mitchell, used a computer model to determine the estimated location of the new supercontinent, which they have dubbed Amasia due to...
Some climate cooling caused by past volcanic eruptions may not be evident in tree-ring reconstructions of temperature change because large enough temperature drops lead to greatly shortened or even absent growing seasons, according to climate researchers, who compared tree-ring temperature reconstructions with model simulations of past temperature changes. "We know these tree rings capture most temperature changes quite well," said Michael Mann, professor of meteorology and geosciences and...
New research suggests that eruptions at some of Earth's largest volcanoes could be predicted decades before the event actually occurs, potentially making it easier for experts to monitor danger zones and conduct pre-emptive evacuations to keep residents out of harm's way. In one study, published Thursday in the journal Nature, scientists investigate "caldera-forming volcanic eruptions," or eruptions that discharge such massive amount of magma that it can create a large depression in the...
The Alaska Volcano Observatory raised a warning level for a remote Alaskan volcano on Tuesday, indicating a possible eruption. The center elevated the alert status for Cleveland Volcano after a new lava dome was spotted in the summit crater. Officials said the dome was about 130 feet in diameter as of Monday. The volcano is a 5,675-foot peak on an uninhabited island, 940 miles southwest of Anchorage, Alaska. Authorities say sudden eruptions could occur at any time, and ash clouds...
Latest Plate tectonics Reference Libraries
The Pacific Ring of Fire, or Ring of Fire for short, is an area where a large number of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean. In a 25,000 mile horseshoe shape, it’s associated with an almost continuous series of oceanic trenches, volcanic belts, volcanic arcs and/or plate movement. The Ring of Fire contains 452 volcanoes and is home to over 75 percent of the world’s active and dormant volcanoes. It’s sometimes called the circum-Pacific belt or the...
Alfred Lothar Wegener (November 1, 1880 "“ November 2, 1930) was a German scientist, geologist, and meteorologist. He is best known for establishing the theory of the continental drift. His 1915 theory of continental drift surmised that the continents were slowly floating around the Earth. Most of his basis was strictly circumstantial evidence, and further he was not able to exhibit a mechanism for continental drift, which resulted in an unaccepted hypothesis until the 1950s. At that...
Peridotite is a dense, coarse grained ultrabasic rock, consisting mainly of the minerals olivine and pyroxene. Peridotite is also a group of mantle derived igneous rocks. They all are ultramafic or ultrabasic meaning they contain less than 45% silica and are high in iron and magnesium. Members of the peridotite family include: Dunite - predominately composed of olivine, with minor enstatite pyroxene and chromite. Harzburgite - composed of olivine, enstatite, and minor chromite....
Scoria is a term used by geologists to describe an igneous rock containing many gas bubbles, or vesicules. Scoria forms when magma rich in dissolved gases is vented. As the magma encounters lower pressures, the gasses are able to escape and form bubbles. These bubbles are trapped when the magma cools and solidifies. Volcanic cones of scoria can be left behind after eruptions, usually forming mountains with a crater at the summit. An example is Mount Wellington, Auckland in New Zealand....
Earth -- in geology and astronomy, fifth largest planet of the solar system and the only planet definitely known to support life. Gravitational forces have molded the earth, like all celestial bodies, into a spherical shape. However, the earth is not an exact sphere, being slightly flattened at the poles and bulging at the equator. The equatorial diameter is c.7,926 mi (12,760 km) and the polar diameter 7,900 mi (12,720 km); the circumference at the equator is c.24,830 mi (40,000 km)....
