February 4, 2008
John Tarduno explores traveling
‘hotspots’
jonathan.sherwood@rochester.edu
Most people think of a trip to the Hawaiian Islands as
a vacation, but for John Tarduno, professor of earth and environmental
sciences, the trip was all work.
International team studies super-heated magma in the Hawaiian Islands.
In the January issue of Scientific American, Tarduno
writes of his voyages to the Hawaiian Islands and the nearby Emperor
seamounts to solve a mystery of the islands’ creation. Conventional
theories say the chain of islands formed as the Pacific tectonic plate
moved across a fixed “hotspot”—a point where super-heated
magma from deep in the Earth rises close to the crust and generates
intensified volcanic activity. Most theories assume these hotspots are
fixed in place, but some geophysicists felt this picture was
incomplete.
Tarduno and an international team spent months aboard
an ocean drilling ship, retrieving and testing samples of rock from the
Emperor-Hawaiian seamount chain miles beneath the sea’s surface.
Their magnetic studies of the samples suggested these rocks formed much
farther north than the hotspot currently beneath Hawaii. Tarduno’s
findings mean the hotspot, once thought to be an unmoving
multi-million-year fixture beneath the Earth’s crust, actually sways
about as currents of magma flow around it.
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