Source of mid-plate volcanoes may be much closer than scientists thought

vtech-logoA 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 as the asthenosphere.

“For nearly 40 years there has been a debate over a theory that volcanic island chains, such as Hawaii, have been formed by the interaction between plates at the surface and plumes of hot material that rise from the core-mantle boundary nearly 1,800 miles below the Earth’s surface,” King said. “Our paper shows that a hot layer beneath the plates may explain the origin of mid-plate volcanoes without resorting to deep conduits from halfway to the center of the Earth.”

Traditionally, the asthenosphere has been viewed as a passive structure that separates the moving tectonic plates from the mantle.

As tectonic plates move several inches every year, the boundaries between the plates spawn most of the planet’s volcanoes and earthquakes.

“As the Earth cools, the tectonic plates sink and displace warmer material deep within the interior of the Earth,” explained King. “This material rises as two broad, passive updrafts that seismologists have long recognized in their imaging of the interior of the Earth.”

The work of Anderson and King, however, shows that the hot, weak region beneath the plates acts as a lubricating layer, preventing the plates from dragging the material below along with them as they move.

The researchers show this lubricating layer is also the hottest part of the mantle, so there is no need for heat to be carried up to explain mid-plate volcanoes.

“We’re taking the position that plate tectonics and mid-plate volcanoes are the natural results of processes in the plates and the layer beneath them,” King said.

The College of Science at Virginia Tech gives students a comprehensive foundation in the scientific method. Outstanding faculty members teach courses and conduct research in biological sciences, chemistry, economics, geosciences, mathematics, physics, psychology, and statistics. The college offers programs in cutting-edge areas including, among others, those in energy and the environment, developmental science across the lifespan, infectious diseases, computational science, nanoscience, and neuroscience. The College of Science is dedicated to fostering a research-intensive environment that promotes scientific inquiry and outreach.

Books from AFP

2018-19 UVA Basketball Preview: Just $1.99 on Amazon!

UVA Basketball finished the 2017-18 season ranked at the top of the national polls. Augusta Free Press editor Chris Graham offers his insight and analysis on the 2018-19 'Hoos, breaking down the roster, the legacy of coach Tony Bennett, and how the loss to UMBC could fuel a run through March Madness next spring.

The Worst Wrestling Pay-Per-View Ever: Just $3.49 on Amazon!

Chris Graham offers a glimpse behind the curtain of the pro wrestling business in his new book, The Worst Wrestling Pay-Per-View Ever, the inside story of the 2011 Night of Legends, a live pay-per-view event featuring stars including WWE Hall of Famers Kevin Nash, "Hacksaw" Jim Duggan and The Rock 'n Roll Express that was met with almost universally negative reviews.

Mad About U: History of University Hall available on Amazon for just $5.99!

Mad About U: Four Decades of at University Hall is a comprehensive book covering the players, coaches and memories of University Hall at the University of Virginia. Join us as we look back at the memories from more than 40 years in U Hall.


News From Around the Web


Shop Google



Comment