September 2001

From University of Rhode Island

URI geological oceanographer receives $143,000 grant to study the dynamics of the Earth’s mantle

University of Rhode Island Graduate School of Oceanography (GSO) geophysicist Chris Kincaid has received $143,000 from the National Science Foundation (NSF) to study flow patterns in the Earth’s mantle in subduction zones. The proposal Kincaid wrote to acquire the grant was the top-ranked out of 45 proposals submitted to the NSF margins program.

Subduction occurs along convergent plate boundaries, where one of the colliding lithospheric plates descends into the mantle. More than half of the Earth's present 25,000 miles of subduction zones are associated with continental margins where a large and rapidly increasing percentage of the Earth's population resides.

Subduction-induced hazards along active continental margins include those associated with volcanic processes such as lava flows, pyroclastic flows and ash fallout and tectonic processes, such as faulting, tsunamis and earthquakes. All of the great earthquakes in recorded history (with a magnitude greater than 9) have occurred at subduction zones.

Kincaid will study how large-scale motions of subducting plates modulate flow in the mantle, which in turn influence patterns in mantle temperature and magma generation. As part of this project, Kincaid will work with world-renowned geophysicist, Dr. Ross Griffiths, of the Australia National University.

The two will design and fabricate a laboratory apparatus for developing scaled, three-dimensional models of subduction. Initially, the experiments will take place at Australia National University (ANU) where Kincaid will work with Griffiths in ANU's state-of-the-art geophysical fluid dynamics laboratory. The apparatus will return to GSO's own fluid dynamics laboratory, where it will be used in future research projects and as a teaching tool in both undergraduate and graduate oceanography classes.

Previous studies have primarily used numerical models to look at subduction, but only in a two-dimensional sense. This study will help scientists to understand 3-D aspects of subduction which, in turn, will enhance models for chemical evolution of volcanic arcs, like the Aleutians and the Marianas, and seismicity within subduction zones.

“There is a long history of using scaled models to study fluid flow processes in both engineering and scientific applications,” said Kincaid. “They provide great scientific data, but also an intuitive glimpse into the processes being studied. This apparatus will allow scientists and non-scientists to sit and watch subduction unfold before them. It is great for me to be able to work with Ross on this project. He is truly one of the world's best at unscrambling how things flow above and below our planet’s surface. Along with Bobby Orr, he has been an idol of mine for many years.”

Kincaid received his B.S. in earth science from Wesleyan University, and his M.A. and Ph.D. in geophysical fluid dynamics from Johns Hopkins University. He came to GSO as an assistant professor in 1991 and was promoted to associate professor in 1997. He is a resident of Saunderstown.

This article comes from Science Blog. Copyright © 2004

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