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Keyword: continentaldrift

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  • The Earth Is Eating Its Own Oceans

    11/15/2018 1:49:49 PM PST · by ETL · 39 replies ^ | Nov 14, 2018 | Stephanie Pappas, Live Science Contributor
    As Earth's tectonic plates dive beneath one another, they drag three times as much water into the planet's interior as previously thought. Those are the results of a new paper published today (Nov. 14) in the journal Nature. Using the natural seismic rumblings of the earthquake-prone subduction zone at the Marianas trench, where the Pacific plate is sliding beneath the Philippine plate, researchers were able to estimate how much water gets incorporated into the rocks that dive deep below the surface. The find has major ramifications for understanding Earth's deep water cycle, wrote  marine geology and geophysics researcher Donna Shillington...
  • Here's What'll Happen When Plate Tectonics Grinds to a Halt

    10/29/2018 2:21:32 PM PDT · by ETL · 55 replies
    National Geographic ^ | August 29, 2018 | Robin George Andrews
    A new study says we may only have another 1.45 billion years to enjoy the dynamic action of Earth’s geologic engine There’s no geological artist quite like Earth’s plate tectonics. Thanks to this ongoing operation, we have mountains and oceans, terrifying earthquakes, incandescent volcanic eruptions, and new land being born every single second. But nothing lasts forever. Eventually, the mantle will cool to such an extent that this planetwide conveyor belt will grind to a halt. At that point, you can say farewell to the carbon cycle, as well as the constant reshaping and reshuffling of landmasses that have been...
  • The 'Dino-Brexit': Ancient animals sparked Europe's first migration crisis [T-Rex-it]

    07/06/2018 1:28:11 PM PDT · by SunkenCiv · 12 replies
    Express UK ^ | Mon, Apr 25, 2016 | Sean Martin
    In the early Cretaceous period, between 125 and 120 million years ago, researchers discovered that dinosaurs began moving away from Europe. A team of scientists from the University of Leeds created a computer model of the fossil record of dinosaurs to figure out their migration pattern up until their extinction 65 million years ago. They found that there was a mass exodus of dinosaurs between 125 and 120m years ago while no new species were moving in. Lead author of the study published in the Journal of Biogeography, Dr Alex Dunhill, of Leeds University, said: "This is a curious result...
  • Large meteorite impacts drove plate-tectonic processes on the early Earth

    10/12/2017 1:03:40 PM PDT · by JimSEA · 15 replies ^ | 9/26/17 | C. O’Neill
    An international study led by researchers at Macquarie University has uncovered the ways in which giant meteorite impacts may have helped to kick-start our planet's global tectonic processes and magnetic field. The study, being published in the premier journal Nature Geoscience, explores the effect of meteorite bombardment, in geodynamic simulations of the early Earth. Our results indicate that giant meteorite impacts in the past could have triggered events where the solid outer section of the Earth sinks into the deeper mantle at ocean trenches – a process known as subduction. This would have effectively recycled large portions of the Earth's...
  • Long-lost chunk of Canada found in Australia

    01/29/2018 11:48:40 AM PST · by simpson96 · 35 replies
    CBC News ^ | 1/29/2018 | Emily Chung
    A piece of Canada that broke off about 1.7 billion years ago has been found in Australia. Geologists analyzed chemical signatures for very ancient sedimentary rocks in Georgetown, Queensland, that offer clues about where those rocks were when they formed. At that time, the continents were drifting together to form a supercontinent called Nuna or Columbia. The data suggests that the Georgetown rocks broke off from Canada and collided with northern Australia around 1.6 billion years ago. It remained there even after Nuna broke apart 300 million years later. The researchers found a geological signature that "cannot be linked with...
  • 1.7-Billion-Year-Old Chunk of North America Found Sticking to Australia

    01/22/2018 10:10:38 PM PST · by BenLurkin · 38 replies
    Geologists matching rocks from opposite sides of the globe have found that part of Australia was once attached to North America 1.7 billion years ago. Researchers from Curtin University in Australia examinedrocks from the Georgetown region of northern Queensland. The rocks — sandstone sedimentary rocks that formed in a shallow sea — had signatures that were unknownin Australia but strongly resembled rocks that can be seen in present-day Canada. The researchers, who described their findings online Jan. 17 in the journal Geology, concluded that the Georgetown area broke away from North America 1.7 billion years ago. Then, 100 million years...
  • How the spectacular Hawaiian-Emperor seamount chain became so bendy

    05/12/2016 5:23:38 PM PDT · by JimSEA · 4 replies
    Science Daily ^ | 5/11/2016 | University of Sydney
    The physical mechanism causing the unique, sharp bend in the Hawaiian-Emperor seamount chain has been uncovered in a collaboration between the University of Sydney and the California Institute of Technology (Caltech). Led by a PhD candidate at the University of Sydney's School of Geosciences, researchers used the Southern Hemisphere's most highly integrated supercomputer to reveal flow patterns deep in the Earth's mantle -- just above the core -- over the past 100 million years. The flow patterns explain how the enigmatic bend in the Hawaiian-Emperor seamount chain arose. True to the old adage -- as above, so below -- the...
  • The south is SINKING: Giant chunks of the Earth's mantle are falling off and causing quakes across

    05/04/2016 7:43:25 PM PDT · by Fractal Trader · 60 replies
    Daily Mail ^ | 4 MAy 2014 | MARK PRIGG
    The southeastern United States has been hit by a series of strange unexplained quakes - most recently, the 2011 magnitude-5.8 earthquake near Mineral, Virginia that shook the nation's capital. Researchers have been baffled, believing the areas should be relatively quiet in terms of seismic activity, as it is located in the interior of the North American Plate, far away from plate boundaries where earthquakes usually occur. Now, they believe the quakes could be caused by pieces of the Earth's mantle breaking off and sinking into the planet.
  • Ancient tectonic activity was trigger for ice ages

    04/19/2016 2:48:05 PM PDT · by JimSEA · 19 replies
    Science Daily ^ | 4/19/2016 | Oliver Jagoutz, Francis A. Macdonald, Leigh Royden
    For hundreds of millions of years, Earth's climate has remained on a fairly even keel, with some dramatic exceptions: Around 80 million years ago, the planet's temperature plummeted, along with carbon dioxide levels in the atmosphere. The Earth eventually recovered, only to swing back into the present-day ice age 50 million years ago. Now geologists at MIT have identified the likely cause of both ice ages, as well as a natural mechanism for carbon sequestration. Just prior to both periods, massive tectonic collisions took place near the Earth's equator -- a tropical zone where rocks undergo heavy weathering due to...
  • India is Sinking into Earth's Mantle

    01/31/2010 6:41:28 PM PST · by SunkenCiv · 31 replies · 961+ views
    Discovery News ^ | Saturday, January 30, 2010 | Michael Reilly (derived from Nature Geoscience)
    Fun fact for you: scientists don't really know how the Himalayas formed. I mean yeah, they realize that the India tectonic plate is slamming into the Eurasia plate and has been for about 50 million years, but the mystery is why the mountain range is still growing. Usually when two continents collide it's like a car wreck -- there may be a bunch of mangled crust in the middle (mountains), but both vehicles stop moving. Turns out, India appears to be sinking into the mantle. A new study based on computer models of the two plates shows that the formation...
  • The Case Against Pangea

    04/22/2012 3:53:17 PM PDT · by Windflier · 84 replies ^ | Unknown | Neal Adams
    First… it’s important to understand that this is the most profound disagreement in all of science in a century and a half… and, even so, it is the tip of the iceberg, the ramifications of this disagreement will change everything we know in science, top to bottom. To begin with basic stuff. All science knows… The earth has two crusts. One…the mostly basalt lower crust or the oceanic crust which is 2 – 4 miles deeper down than the higher upper continental crust. This lower crust, essentially covers the Earth. It … this crust is being made daily at rift...
  • Digital magnetic map goes global

    11/03/2007 9:14:23 AM PDT · by BGHater · 13 replies · 2,572+ views
    BBC ^ | 03 Nov 2007 | Liz Seward
    The first global map of magnetic peculiarities - or anomalies - on Earth has been assembled by an international team of researchers. Magnetic anomalies are caused by differences in the magnetisation of the rocks in the Earth's crust. Many years of negotiation were required to obtain confidential data from governments and institutes. Scientists hope to use the map to learn more about the geological composition of our planet. The World Digital Magnetic Anomaly Map (WDMAM) is available through the Commission for the Geological Map of the World. The magnetic signature of the Earth's crust has been measured for many decades...
  • Meet 'Amasia,' the Next Supercontinent

    02/09/2012 9:45:24 AM PST · by LibWhacker · 29 replies · 1+ views
    Science ^ | 2/8/12 | Sid Perkins
    No boats required. In the distant future, most if not all of today's continents (brown fragments, depicted with current-day outlines) will assemble into a single landmass called Amasia (shown approximately 100 million years from now). Over the next few hundred million years, the Arctic Ocean and the Caribbean Sea will disappear, and Asia will crash into the Americas forming a supercontinent that will stretch across much of the Northern Hemisphere. That's the conclusion of a new analysis of the movements of these giant landmasses. Unlike in today's world, where a variety of tectonic plates move across Earth's surface carrying the...
  • 'Snowball Earth' theory melted

    01/11/2011 7:05:08 PM PST · by SunkenCiv · 47 replies
    BBC ^ | Wednesday, March 6, 2002
    Geoscientists in Scotland say they have evidence to disprove the controversial "Snowball Earth" theory - the idea that the planet was completely encased in ice just over 600 million years ago.We are claiming that in reality there was not a totally frozen snowball Earth and that even during the coldest conditions large regions remained ice-free -- Dr Dan CondonThe team, from the University of St Andrews, has published its findings in the scientific journal Geology, after studying rocks in the west of Scotland, Ireland, Namibia and California. Drs Dan Condon, Tony Prave and Doug Benn say they have found evidence...
  • The shifting face of a 200-million-year-old mystery

    10/14/2011 6:33:24 AM PDT · by decimon · 26 replies
    BBC ^ | October 13, 2011 | Jason Palmer
    Five times in the last half a billion years, tremendous, global-scale extinctions have wiped out a significant fraction of life on Earth - and each of them presents a grand puzzle. The most recent and the most familiar is the extinction that wiped out the dinosaurs - between the Cretaceous and Tertiary periods, about 65 million years ago. But before that, 205 million years ago, was the "End-Triassic Event" - it set the stage for the Jurassic Period, which saw the rise to prominence of the dinosaurs. Just what happened that killed off half the species on the planet, though,...
  • Ancient Earth Remnant Is Inside Earth, Study Says

    06/28/2014 6:53:52 PM PDT · by 2ndDivisionVet · 64 replies
    The Guardian Liberty Voice ^ | June 28, 2014 | Gregory Baskin
    A team from Harvard University presented a study this month that remnants from an ancient Earth exists, right now, inside contemporary Earth. The group believes that their comparisons of isotopic ratios of noble gases from materials deep inside Earth with those near the surface provide testimony that the deep-down material is actually from the Earth that existed before its massive collision with another planet. That immense impact – the largest in geologic history – is what many believe led to creation of the Moon. The currently favored theory about how the Moon originated says that it was formed 4.5 billion...
  • Snapshot Of Past Climate Reveals No Ice In Antarctica Millions Of Years Ago

    03/06/2009 1:04:30 PM PST · by SunkenCiv · 37 replies · 1,583+ views
    ScienceDaily ^ | July 29, 2008 | Natural Environment Research Council and Cardiff University
    A snapshot of New Zealand's climate 40 million years ago reveals a greenhouse Earth, with warmer seas and little or no ice in Antarctica, according to research recently published in the journal Geology. The study suggests that Antarctica at that time was yet to develop extensive ice sheets. Back then, New Zealand was about 1100 km further south, at the same latitude as the southern tip of South America -- so was closer to Antarctica -- but the researchers found that the water temperature was 23-25°C at the sea surface and 11-13°C at the bottom. "This is too warm to...
  • Australia sucks up ocean's waters, sea levels study shows

    08/22/2013 2:08:01 PM PDT · by naturalman1975 · 57 replies ^ | 22nd August 2013
    THE world's sea levels fell in 2011 and it's all Australia's doing. New US research shows Australia's dry soil and mountainous coastline soaked up heavy rainfall in 2010 and 2011 and stopped it from flowing back into the ocean. That effectively halted a longterm trend of rising sea levels which have been caused by higher temperatures and melting ice sheets. "No other continent has this combination of atmospheric set-up and topography," scientist John Fasullo, who worked on the study, said in a statement. "Only in Australia could the atmosphere carry such heavy tropical rains to such a large area, only...
  • Relic of ancient asteroid found ..punched 160km-wide (100 miles) hole in the Earth's surface

    05/10/2006 10:42:29 PM PDT · by Ernest_at_the_Beach · 38 replies · 1,266+ views
    BBC ^ | Wednesday, 10 May 2006, 17:10 GMT 18:10 UK | Rebecca Morelle BBC News science reporter
    A large fragment of an asteroid that punched 160km-wide (100 miles) hole in the Earth's surface has been found. The beachball-sized fossil meteorite was dug out of the 145-million-year-old Morokweng crater in South Africa. It is a unique discovery because large objects are widely believed to completely melt or vaporise as they collide with the planet. Writing in the journal Nature, an international team says the find will further knowledge on asteroid impacts. The Morokweng crater is one of the largest on Earth, and was formed at the boundary of the Jurassic and Cretaceous periods. Created by an asteroid...
  • Palm trees 'grew on Antarctica' (in the early Eocene period, about 53 million years ago.)

    08/02/2012 1:05:45 PM PDT · by NormsRevenge · 24 replies
    BBC News ^ | 8/2/12 | Jason Palmer
    Scientists drilling deep into the edge of modern Antarctica have pulled up proof that palm trees once grew there. Analyses of pollen and spores and the remains of tiny creatures have given a climatic picture of the early Eocene period, about 53 million years ago. The study in Nature suggests Antarctic winter temperatures exceeded 10C, while summers may have reached 25C. Better knowledge of past "greenhouse" conditions will enhance guesses about the effects of increasing CO2 today. The early Eocene - often referred to as the Eocene greenhouse - has been a subject of increasing interest in recent years as...