From Mary Greeley –
LINK – http://youtu.be/xD1OMO_3a5o
[Dec. 5] The Watchers – Geophysicists challenge traditional theory underlying the origin of mid-plate volcanoes
A long-held assumption about the Earth is discussed in today’s edition of Science, as Don L. Anderson, an emeritus professor with the Seismological Laboratory of the California Institute of Technology, and Scott King, a professor of geophysics in the College of Science at Virginia Tech, look at how a layer beneath the Earth’s crust may be responsible for volcanic eruptions.
The discovery challenges conventional thought that volcanoes are caused when plates that make up the planet’s crust shift and release heat.
Instead of coming from deep within the interior of the planet, the responsibility is closer to the surface, about 80 kilometers to 200 kilometers deep — a layer above the Earth’s mantle, known as the asthenosphere.