Scientists describe 'yo-yo' Earth movement

[Turborama]

Source: UPI

Published: April 11, 2011 at 9:57 PM

CANBERRA, Australia, April 11 (UPI) -- Australian researchers, with European colleagues, have confirmed a formerly purely theoretical geologic phenomenon and have given it a name -- yo-yo subduction.

The conventional view of subduction -- in which Earth's crust is pushed down into the planet's interior in the convergence of tectonic plates -- is that it happens only once and in one direction, Daniela Rubatto at the Australian National University Research School of Earth Sciences says.

"The typical idea is that the convergence of plates creates a force that pushes rocks down from the surface of the Earth making the whole system move down like a conveyor belt," she says. "Most of the material will sink forever in the planet's mantle and only a fraction will make it back to the surface."

Rubatto and colleagues at the University of Bern and University of Torino say that's not necessarily the case, www.PhysOrg.com reported Monday.

Read more: http://www.upi.com/Science_News/2011/04/11/Scientists-describe-yo-yo-Earth-movement/UPI-46231302573463/

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More details at the links.

[WheelWalker]

1. Whoa-Yo !!

[Manifestor_of_Light]

2. I knew about the precession of the axis of the Earth, but this is wild.

Precession is what a spinning top does as it falls down. Axis describes a circle.

Dad told me about that because he worked with gyrosf in Norden Bombsights in the Air Force, during the BIG ONE, when it was called the Army Air Corps.

:patriot: --Dad, SSgt. 483rd Bombardment Group.

[aquart]

3. Norden bombsights. Wowza.

[RedCloud]

4. Adding new meaning to the phrase "down under".

[Baclava]

5. We're riding on a thin crust over a molten furnace of liquid rock.

Anything is possible. It could all crack open at any time.

[Odin2005]

6. The Mantle is solid because of high pressure.

It "flows" like solid glass flows over long time periods. It only becomes liquid magma if decompressed, it is the decompressed material that forms the magma chambers of volcanoes.

[Baclava]

7. We just want to know where it's gonna crack open - check out this new Yellowstone image

This image, based on variations in electrical conductivity of underground rock, shows the volcanic plume of partly molten rock that feeds the Yellowstone supervolcano. Yellow and red indicate higher conductivity, green and blue indicate lower conductivity. Made by University of Utah geophysicists and computer scientists, this is the first large-scale "geoelectric" image of the Yellowstone hotspot. Credit: University of Utah.

http://www.unews.utah.edu/p/?r=032411-5