Hidden beneath the U.S. West's Great Basin, scientists have spied a giant blob of rocky material dripping like honey.
The Great Basin consists of small mountain ranges separated by valleys and includes most of Nevada, the western half of Utah and portions of other nearby states.
While studying the area, John West of Arizona State University (ASU) and his colleagues found evidence of a large cylindrical blob of cold material far below the surface of central Nevada.
Comparison of the results with CAT scans of the inside of Earth taken by ASU's Jeff Roth suggested they had found a so-called lithospheric drip. (Earth's lithosphere comprises the crust or outer layer of Earth and the uppermost mantle.)
Here's how it works: "The Earth's mantle, which lies below the thin outer crust we live on, consists of rock which deforms plastically on very long time scales due to the heat and pressure at depth," West said. "In any material which can flow (including the mantle), a heavy object will tend to sink through lighter material."
And this is what the scientists think is happening with the lithospheric drip. A region of heavier material trapped in the lithosphere gets warmed up and begins to sink into the lighter, less dense mantle beneath, pulling a long tail of material after it.
"Honey dripping off of a spoon is a visual aid to what we think the drip looks like," West told LiveScience. "Dripping honey tends to lead with a large blob of honey, with a long tail of material following the initial blob."
Wednesday, May 27, 2009
Researchers Discover Giant Blob Beneath Nevada
Naturally, he's the first thing I thought of when I saw the words giant blob.