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  • richardmitnick 1:28 pm on December 6, 2017 Permalink | Reply
    Tags: , , , Huge Bubble of Hot Rock May Be Rising Under New England, natgeo.com,   

    From natgeo.com: “Huge Bubble of Hot Rock May Be Rising Under New England” 

    National Geographic

    National Geographics

    December 5, 2017
    Erin Blakemore

    1
    Colorful forests fill the landscape in the Berkshires of western Massachusetts. Photograph by Berthold Steinhilber, laif, Redux

    At first glance, New England doesn’t seem like a hotbed of geologic activity. The region doesn’t have any rumbling volcanoes. Earthquakes are almost unheard of. And its mountains are mere hills compared to ranges like the Rockies or the Sierra Nevada in the western U.S.

    But don’t underestimate what’s going on beneath the surface: It turns out this idyllic pocket of the northeastern U.S. may sit atop a rising mass of warm rock—a smaller, slower version of the magma pockets under well-known volcanic zones.

    The findings, recently published in the journal Geology, suggest that New England may not be so immune to abrupt geological change.

    A team of researchers at Rutgers University and Yale University made this surprising discovery using an advanced array of seismic sensors, which show what lies in the otherwise hidden rock below our feet.

    “Ten years ago, this would not have been possible,” says study coauthor Vadim Levin, a professor at Rutgers University-New Brunswick’s department of Earth and planetary sciences.

    “Now, all of a sudden, we have a much better eye to see inside the Earth.”

    Rising Rock

    Inside our planet, heat from the volatile core makes its way up through the mantle—the hot, high-pressure zone that lies below the planet’s crust. That heat causes the crust’s tectonic plates to slip and slide around. Where those plates collide or divide is where we most often see mountains, earthquakes, and volcanoes.

    The tectonic plates of the world were mapped in 1996, USGS.

    Since we can’t see that deep into the planet, geologists use seismic vibrations caused by earthquakes to visualize the features within rock. Sensing how fast seismic ripples move, for instance, provides details about the structure and temperature of Earth’s mantle.

    In this case, Levin’s team studied data from EarthScope, a National Science Foundation program that deploys hundreds of geophysical instruments across the United States. The project’s Transportable Array, a temporary network of seismic sensors, made its way around the country starting in 2007. The array picked up readings from small earthquakes and observed the motions of seismic waves in various regions.

    The team piggybacked off previous research showing a relatively hot spot beneath New England’s upper mantle. Using data from EarthScope, they then observed a localized plume of warm rock beneath central Vermont, western New Hampshire, and western Massachusetts—and found geologic evidence that it’s on the move.

    Less dense areas are where the rock is hotter, and seismic waves move more slowly. That’s what the team saw under New England. They also observed wave patterns that suggest deformations in the rock itself.

    Normal plate motion leaves the geologic equivalent of skid marks in its wake, which seismic sensors can detect. In this region, however, the skid marks were gone—erased by the upward movement of warmer rock.

    Shifting Perspectives

    New England residents don’t need to panic. The upwelling is likely tens of millions of years old, which would make it a relatively recent development in geological terms, and it’s moving very slowly. For now, it certainly hasn’t gotten close enough to the surface to shape New England’s geography or create a volcano.

    “Maybe it didn’t have time yet, or maybe it is too small and will never make it,” says Levin. “Come back in 50 million years, and we’ll see what happens.”

    Instead, the discovery is a sign that it may be time to rethink the region’s geology.

    The big takeaway from this paper is that Earth’s structure is even more intricate and dynamic than anyone realized, says Meghan S. Miller, a structural seismologist and associate professor at the Australian National University’s Research School of Earth Sciences who was not involved in the project.

    “I think that kind of sounds simple and obvious in retrospect, but the Transportable Array data has allowed us to visualize how complex Earth’s structure really is,” she says.

    The find also helps put the planet in perspective, says Levin. New England has traditionally been considered a place of little geologic change, but EarthScope data suggests that the subsurface reality is anything but stagnant.

    “People think of mountains and lakes and geology as forever—there’s a general sense that Earth is a permanent thing,” says Levin. “Well, it’s not.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The National Geographic Society has been inspiring people to care about the planet since 1888. It is one of the largest nonprofit scientific and educational institutions in the world. Its interests include geography, archaeology and natural science, and the promotion of environmental and historical conservation.

     
  • richardmitnick 3:56 pm on May 15, 2017 Permalink | Reply
    Tags: , natgeo.com, SASSEPHOTO, See the Awesome March of the Milky Way Across the Night Sky,   

    From natgeo.com: “See the Awesome March of the Milky Way Across the Night Sky” 

    National Geographic

    National Geographics

    15 May 2017
    Nadia Drake

    A photographer captures rare views of the galaxy as it spirals over southern Australia.

    1
    High overhead, the Milky Way galaxy twists itself into a whirling pinwheel, its glittering stars and dense, dark clouds weaving spirals on the sky.

    At least, that’s the view photographer Christian Sasse revealed when he shared this image of the nighttime sky over southern Australia. Seen from Earth’s vantage point in one arm of the Milky Way, our galaxy appears to dive through the cosmos, its curling spine anchored to the sky by the southern celestial pole — one of the points around which the stars and all their minions appear to wander as Earth spins on its axis.

    2
    Time: 10 minutes
    PHOTOGRAPH BY SASSEPHOTO

    3
    Time: 120 minutes
    PHOTOGRAPH BY SASSEPHOTO

    Sasse made the image he shared on Twitter from a series of 30-second-long exposures, each taken 50 minutes apart, over 10 hours on April 28. He stacked those photographs using Startrails software and then edited the final composite image using Photoshop.

    “The southern sky is fascinating in so many ways,” says Sasse, who set up his gear near one of the telescopes at Siding Spring Observatory in New South Wales.

    5
    Siding Spring, near Coonabarabran, New South Wales, Australia

    AAO 1.2m UK Schmidt Telescope at Siding Spring Observatory, near Coonabarabran, New South Wales, Australia

    ANU Skymapper telescope, a fully automated 1.35 m (4.4 ft) wide-angle optical telescope, at Siding Spring Observatory , near Coonabarabran, New South Wales, Australia

    Siding Spring Observatory, near Coonabarabran, New South Wales, Australia

    “I remember hearing the dome roaring deeply all night whenever the telescope moved from object to object.”

    Based in Vancouver, Sasse had travelled to Australia to visit a friend. He rented a small camper van, decked out its interior with the gadgets he’d need to capture both wildlife and the glorious southern sky, and headed out to a spot where “the skies are pristine and you can be all on your own at night … often accompanied by curious kangaroos.”

    Indeed, some of the most notable treasures in the immediate cosmic neighborhood are visible primarily in the south: Alpha Centauri, the nearest star system to our own, the bright star grouping known as the Southern Cross, a dark blotch called the Coalsack Nebula, small satellite galaxies known as the Large and Small Magellanic Clouds, and the glowing backbone of the Milky Way.

    “In the Northern hemisphere, I tend to look South, and in the Southern hemisphere — well, I also look South,” says Sasse, who captured those curiosities in the great looping footprint he constructed.

    Photographers often use a similar technique to create images depicting stars tracing circles around the celestial poles. Sasse initially did the same thing, stitching together roughly 1,250 images from the same night. But when he smeared the stars into circles, Sasse saw that our home galaxy had vanished, taking with it some of the most striking textures in the sky.

    So he experimented with layering images taken at different intervals (see gallery), and was astounded by the result.

    “What appeared were circular patterns with intrinsic beauty. Each feature of the Milky Way has its own distinct pattern, and details became finer the closer one moved to the pole,” Sasse says. “The Milky Way is creating this incredible pattern all the time, and the way we freeze it is the way we like it.”

    I’ve been looking at the heavens all my life, and that great, milky spiral is unlike anything I’ve ever seen before — it reminds me of a galactic mandala, a demonstration of celestial geometry, an accidental fractal, a rippling kaleidoscope of stars.

    “I have a fascination with light patterns in nature — iridescence of birds and fish, feather structure of eagles, anything that changes with small angles such as diffraction and reflection,” says Sasse, who has a doctorate in optics.

    To me, it evokes a sense of awe and appreciation for the intricate patterns hiding in the skies, and a restless yearning to throw myself onto grass still warmed by the southern sun, snuggle in for a few hours, and stare into the twinkling tapestry that twirls overhead.

    PHOTOGRAPHY BY SASSEPHOTO

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The National Geographic Society has been inspiring people to care about the planet since 1888. It is one of the largest nonprofit scientific and educational institutions in the world. Its interests include geography, archaeology and natural science, and the promotion of environmental and historical conservation.

     
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