The Geology and Geophysics Department focuses on understanding how our Earth works by investigating
the dynamics of convection in the mantle, the geologic structure and tectonics of the ocean basins, interactions of continental and oceanic geologic processes, the history of ocean circulation patterns and climate change, and the interactions between geological and biological systems.
In 2004, the G&G Department comprised 97 staff and 28 postdoctoral and Joint Program students who were involved
in 268 research projects. Bob Detrick stepped down as Chair in 2004 and was succeeded by Susan Humphris. During Bob’s term, G&G began building a coastal processes
group by hiring three assistant scientists, while simultaneously
strengthening and diversifying the geophysics,
geochemistry, and paleoceanography groups. In 2004, two new assistant scientists were appointed. Sarah Das is a glaciologist with an interest in the factors that cause surface
melting on ice sheets, and in understanding the dynamics
of ice sheets. Mark Behn, a 2002 graduate of the Joint Program, is a geophysicist who integrates field observations
with numerical modeling to understand a broad range of magmatic and tectonic processes.
G&G staff and students traveled far and wide in 2004 collecting
data and samples. Some conducted fieldwork on land, collecting
volcanic gases from Nicaragua and Sicily; studying the volcanology
of Ta’u Island, Samoa; conducting geophysical surveys across
South Africa; and investigating the geology and tectonics
of the western Sichuan basin, east of the Tibetan plateau.
Others worked near shore at the interface between land and
sea, along the east coast of the U.S. and in the Danube and
Indus river deltas. Still others led or participated in research
cruises to the East Pacific Rise, the Mid-Atlantic Ridge,
the western north Atlantic, the Gulf of Mexico, the Panama
Basin, and the Lau back-arc spreading center west of Tonga.
This year, the capabilities of the WHOI Seafloor Sampling Laboratory (right) were greatly enhanced when Liviu Giosan, Jeff Donnelly, and Rindy Ostermann received
funding for the acquisition of a core scanner. The first of its kind in the U.S., this instrument allows rapid, nondestructive, ultra-high resolution measurements of the chemical composition and density structure of sediment cores and other geologic materials. One of the major uses of this instrument will be in detecting chemical changes in sediment cores at an annual to millennial resolution that can be linked to environmental and climatic changes.
Science highlights of 2004 included significant advances in
earthquake research made by two groups. Jeff McGuire and graduate
student Margaret Boettcher, together with a colleague from
the University of Southern California, applied a mathematical
model to a database of earthquakes on the East Pacific Rise
and demonstrated that the largest earthquakes are preceded
by abundant foreshocks, thus indicating a significant amount
of predictability. This work, published in Nature,
represents an important breakthrough in earthquake predictability
studies. In addition, Jian Lin, Debbie Smith, and graduate
student Trish Gregg investigated a several year record of
earthquakes along the Siqueiros Transform Fault in the eastern
Pacific and showed that an earthquake in one area can transfer
stress and trigger an earthquake nearby. Both studies emphasized
the need for a better understanding of these oceanic faults,
and suggest that at least some earthquakes might be predictable.
—Susan Humphris (shumphris@whoi.edu)
Department Chair
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