Why does the Oregon coastal region have so little seismic activity while sediment layers point to a tsunamigenic earthquake once every 200-1200 years? To study this and other complex geologic problems that active-source seismologists have not been able to study before, Woods Hole Oceanographic Institution (WHOI) purchased visualization and storage technology from Silicon Graphics in April. Scientists at WHOI will collect and interpret 3D seismic data in much the same way oil companies use the same type of SGI high performance visualization system, but instead of drilling for oil, scientists' will achieve a better understanding of processes such as tsunami genesis and earthquake recurrence that will lead to better earthquake-hazard preparedness.

WHOI, headquartered in Woods Hole, Mass., is a private, non-profit institution dedicated to research and higher education at the frontiers of ocean science. Its primary mission is to develop and effectively communicate a fundamental understanding of the processes and characteristics governing how oceans function and how they interact with Earth as a whole. For this new phase of exploration, Daniel Lizarralde, a new associate scientist at WHOI and a geophysicist specializing in active-source seismology, selected a Silicon Graphics Prism visualization system to visualize the 3D data collected to study numerous geological and biological earth processes. Lizarralde began working with the Silicon Graphics Prism system and marine seismic data in August.

"There's a whole host of science problems, unknown things out there that are happening, and we know they're happening, but we don't understand why. But we might, if we can study them with 3D seismic data," said Lizarralde. "I wanted the Silicon Graphics Prism system because it delivers a lot of computational power, which I need. The seismology community is moving in this new direction of collecting 3D cubes of data, which could range from 5 to 30 GB in size after processing, but there's no point in spending the substantial amount of money it costs to collect the data if you can't effectively visualize it. To effectively visualize the data we're collecting we needed the visualization capabilities of the Prism system to move through the data sets interactively."

Lizarralde and associates will begin their research with the area of plate tectonics known as subduction zones, where the earth fundamentally recycles itself and where the planet's biggest earthquakes occur.

"Earthquakes can be bigger or smaller, depending on how much time there's been between a release of energy," said Lizarralde. "If you have a system that's locked, even though the plates are trying to move, eventually one big release of energy will occur. What causes a subduction zone to become locked and then unlocked is, in many places, probably related to water. That's one of the areas we will focus on with our research vessels and the Silicon Graphics Prism."

Off the coast of Oregon and the Pacific Northwest, the Juan de Fuca plate is subducting beneath North America. This causes all the Cascadian volcanoes to become active, with Mount St. Helens being the most recent and most dramatic. Historical record indicates the area seems to have sourced very large earthquakes. Sediments near the shore in Oregon feature normal layers of sand, clay, sand, clay, etc. and then layers are found with typical materials carried in a tsunami. Deposits of big chunks of trees and huge boulders from inland are examples of materials that would only travel in a tsunami.

"In Oregon, you see these unusual tsunami layers that have a recurrence interval of about 1200 years," said Lizarralde. "But there's surprisingly little seismic activity along that subduction zone at present. Oregon isn't known for earthquakes, but in my mind, and in a lot of other people's minds, it's more likely that this is a place that's just locked. It's not slipping, but it is storing a lot of energy. When it goes, it could go with a very big earthquake, and that seems to be what's happened in the past. Oregon is one of the places we would like to take a look at in some detail and, using the Silicon Graphics Prism, see exactly what is controlling the seismic activity or lack of seismic activity there. Then we can get information to people who can make decisions and plan around reasonable probabilities that catastrophic things might occur in the future."

"Since their first open ocean research vessel set sail in 1931, Woods Hole Oceanographic Institution has blazed the way in oceanic, atmospheric and earth sciences research, and over the years they have collaborated on major scientific efforts with many government organizations," said Shawn Underwood, director, Visual Systems Group, SGI. "The inclusion of a Silicon Graphics Prism visualization system to support a huge technology leap in the investigation of the calamitous effects of plate tectonics will bring the world a better understanding of our oceans, which is approximately three fifths of the planet we live on, and a renewed respect for the forces of nature, which humankind struggles daily to understand."

WHOI purchased a Silicon Graphics Prism visualization system, with 16 Intel Itanium 2 processors running the Linux environment, 32 GB memory and a 1 TB SGI InfiniteStorage TP9100 storage array through James River Technical, Inc., a value-added SGI Channel partner.