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  • Kansas Legislator Proposes Bill to Outlaw Sustainability Education
    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of ...Read more

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    Kansas Legislator Proposes Bill to Outlaw Sustainability Education

    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of sustainability. Here is a link to the one-page bill: http://www.kslegislature.org/li/b2013_14/measures/documents/hb2366_00_0000.pdf. See report on Bloomberg News.
  • Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows
    Scientists have determined the temperature near the Earth’s center to be 6000 degrees Celsius, 1000 ...Read more

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    Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows

    Scientists have determined the temperature near the Earth’s center to be 6000 degrees Celsius, 1000 degrees hotter than in a previous experiment run 20 years ago. These measurements confirm geophysical models that the temperature difference between the solid core and the mantle above, must be at least 1500 degrees to explain why the Earth has a magnetic field. For more information about this study, see the press release from the European Synchrotron Radiation Facility.
  • Ocean Volcanic Rocks Contain Samples of Recycled Crust
    Scientists have long believed that lava erupted from certain oceanic volcanoes contains materials fr...Read more

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    Ocean Volcanic Rocks Contain Samples of Recycled Crust

    Scientists have long believed that lava erupted from certain oceanic volcanoes contains materials from the early Earth’s crust. But decisive evidence for this phenomenon has proven elusive. New research from a team including Carnegie’s Erik Hauri demonstrates that oceanic volcanic rocks contain samples of recycled crust dating back to the Archean era 2.5 billion years ago. Their work is published in Nature. Oceanic crust sinks into the Earth’s mantle at so-called subduction zones, where two plates come together. Much of what happens to the crust during this journey is unknown. Model-dependent studies for how long subducted material can exist in the mantle are uncertain and evidence of very old crust returning to Earth’s surface via upwellings of magma has not been found until now. For more information about these results, see the press release from the Carnegie Institution.
This is a drawing of a process which forms mountains on Earth.
Click on image for full size

Mountain Building

Mountains are built through a general process called "deformation" of the crust of the Earth. Deformation is a fancy word which could also mean "folding". An example of this kind of folding comes from the process described below.

When two sections of the Earth's lithosphere collide, rather than being subducted, where one slab of lithosphere is forced down to deeper regions of the Earth, the slabs pile into each other, causing one or both slabs can fold up like an accordion. This process elevates the crust, folds and deforms it heavily, and produces a mountain range. Mountain building and mantle subduction usually go together.

This process is illustrated in the figure to the left. The lithospheric slab on the right is subducted, while the force of the collision gradually causes the slab on the left to fold deeply. Along the way, melting of the subducted slab leads to volcano formation.


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