Plate tectonics runs deeper than we thought

Þingvellir or Thingvellir, is a national park in southwestern Iceland, about 40 km northeast of Iceland's capital, Reykjavík. It's a site of geological significance, as the visuals may indicate.

Enlarge / Þingvellir or
Thingvellir, is a national park in southwestern Iceland, about 40
km northeast of Iceland’s capital, Reykjavík. It’s a site of
geological significance, as the visuals may indicate. (credit: Ray
Wise/Getty Images)

It’s right there in the name: “plate tectonics.”
Geology’s organizing theory hinges on plates—thin, interlocking
pieces of Earth’s rocky skin. Plates’ movements explain
earthquakes, volcanoes, mountains, the formation of mineral
resources, a
habitable climate
, and much else. They’re part of the engine
that drags carbon from the atmosphere down into Earth’s mantle,
preventing a runaway greenhouse climate like Venus. Their recycling
through the mantle helps to release heat from Earth’s liquid
metal core, making it churn and generate a magnetic field to
protect our atmosphere from erosion by the solar wind.

The name may not have changed, but today the theory is in the
midst of an upgrade to include a deeper level—both in our
understanding and in its depth in our planet. “There is a huge
transformation,” says Thorsten Becker, the Distinguished Chair in
Geophysics at The University of Texas at Austin. “Where we say:
‘plate tectonics’ now, we might mean something that’s
entirely different than the 1970s.”

Plate Tectonics emerged
in the late1960s
when geologists
realized
that plates move on Earth’s surface at
fingernail-growth speeds side-swipe each other at some places (like
California) and converge at others (like Japan). When they
converge, one plate plunges down into Earth’s mantle
under the other plate, but what happened to it deeper in the mantle
remained a mystery for most of the 20th century. Like an ancient
map labeled “here
be dragons
,” knowledge of the mantle remained skin-deep
except for its major boundaries.

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Source: FS – All – Science – News
Plate tectonics runs deeper than we thought