Boston Blog

Earth science on the big screen

Geoscientists take virtual field trips at Harvard lab

Jennifer Weeks

The Visualization Lab at Harvard’s Department of Earth and Planetary Sciences looks rather modest with the lights on. It’s a small room with three large overhead projectors and several long tables that seat about a dozen researchers and face a 23-by-8-foot curved screen. It looks like a high-end home theater. But when I sat down in the front row during a recent visit and put on a pair of heavy 3-D goggles, things got more interesting.

A graduate student dimmed the lights, and I saw a large image of southern California hovering in front of me, spattered with colored dots. Each dot represented an earthquake, color-coded by date. A second image showed the region’s active faults as colored ribbons standing on edge to show their depth, location, and interconnections.

“The depth of a fault affects the size of a quake, so it’s important to map how far it extends downward,” says John Shaw, head of the department’s Structural Geology and Earth Resources Group, which opened the lab last year. Seeing the faults’ interconnections is also important. Southern California sits on top of a network of interlacing faults, and a quake on one fault may rupture another and trigger more quakes.

This 3-D imaging technology gives researchers a system-level perspective on earthquake risks in the region and helps them to identify the most vulnerable areas. Shaw is working with the Southern California Earthquake Center, a collaborative network of more than 50 institutions nationwide, to develop 3-D models of active quake faults for use by emergency planners in southern California.

The lab’s digital projectors create stereo views by transmitting two rapidly alternating views of the same image taken from slightly different angles. Researchers wear heavy plastic goggles with liquid crystal shutters that alternately block information from reaching the left and right eyes in time with the onscreen images, so that each eye sees a view that corresponds to its perspective. The small difference in the two views causes viewers to perceive images in 3-D.

Immersive visualization lets geoscientists analyze and integrate large amounts of different types of complex data—remote-sensing images, acoustic imaging of subsurface faults and geologic formations, and simulations of large-scale phenomena like ocean and atmospheric circulation patterns. “The Harvard Visualization Lab is quickly becoming a critical cyber facility for earthquake system science,” says Tom Jordan, director of the Southern California Earthquake Center and a professor at the University of Southern California.

The lab lets researchers sit together and see the same image. “You can’t see that kind of detail on a PC, especially in a group,” says Nneka Williams, a recent graduate of Harvard’s earth sciences department and now a research geologist in Cambridge with Schlumberger, a global company that serves the oil and gas industry. “The Viz Lab takes collaboration and brainstorming to a new level. And also, it’s fun.”

Similar facilities exist at a few other institutions in the U.S. and U.K. but are more commonly used in the energy industry for oil and gas exploration. Indeed, Harvard researchers collaborate with Exxon Mobil, Chevron, BP, and other energy companies on basic research questions such as how fault structures grow and how rocks shifting along fault lines can help create hydrocarbon deposits. Energy companies also helped fund the building of the lab.

The technology has other potential applications such as mapping archaeological sites and climate modeling. The Department of Earth and Planetary Sciences recently developed a series of labs and software tools for an undergraduate geology course that adapts some of the lab’s functions for PCs. Plans are in the works to expand these tools next year for courses in global seismology, environmental studies, and planetary sciences.

Jennifer Weeks is a freelance writer based in Watertown, Massachusetts.

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