Submarine searching for seismic clues in lake
July 24, 2013
Lake Tahoe doesn't have a lot in common with the Antarctic, at least on the surface. But a research crew from Northern Illinois University has found enough similarities with the depths to test their polar submarine in the lake.
"It a hugely complex undertaking just to get out on the ice," said Liz Taylor, president of Deep Ocean Exploration and Research Marine, which built the remotely operated vehicle. "Picking a place like Lake Tahoe, which has cold water and some depth, to test the sub really mitigates the risk."
While here, the 28-foot cylindrical submarine will collect data about the West Shore fault and historic seismic activity in Lake Tahoe. The team from NIU is collaborating with the California Seismic Safety Commission and the California Department of Conservation, as well as DOER Marine.
"We are proud to be a part of this because this is a valuable research project that could save lives," said Anna Caballero, secretary of the California State and Consumer Services Agency, which oversees the Seismic Safety Commission.
The data the submarine will collect here is expected to help researchers understand the earthquake and tsunami hazard at Lake Tahoe. The goal is to make residents and visitors safer in the event of a quake, said Mark Nechodom, director of the California Department of Conservation.
"We all hope that when the big one comes, we helped reduced the risk," Nechodom said.
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While on the bottom, down to depths of 1,200 feet, the submarine will survey the fault line that runs beneath the lake for some 31 miles, from south of Emerald Bay to the North Shore, and underground to a point east of Tahoe City.
The machine will photograph areas of the fault and gather data on sediment, which can provide insight into past seismic activity. Though the fault has been imaged using Light Detection and Radar technology, few photographs, if any, have ever been taken of the underwater area.
"We've never been able to see the delicate detail," said Gordon Seitz, an earthquake and seismic expert with the California Geologic Survey. "It will give us the first views of the lake bottom and we might get a very detailed picture of what's happened in the past."
After the sub's many functions and sensors are tested and funding is secured, the project will head to Antarctica, where researchers will follow an ambitious plan to place the sub beneath the Ross Ice Shelf — a chunk of floating ice the size of France. Just to get to the site of the launch, the team will have to traverse over the ice for 21 days. Then, a nearly half-mile-deep hole will be drilled and the long cylindrical vehicle will be lowered to the bottom.
"(The sub) gives us an opportunity to go places where no one has ever gone and collect data no one has ever seen before," Taylor said.
The submarine can travel up to 3,000 meters deep. Once through the hole, the sub transforms its orientation, allowing the sensors and cameras access to the surroundings. Though complex, DOER Marine — the same company that helped James Cameron develop the submarine that touched down in the deepest trench in the world — has a lot of background knowledge of the technology.
"Basically, we took a lot of the common components and tailored them to this custom configuration," Taylor said.
In Antarctica, the 2,000-pound submarine will study changes in the ice sheet due to global warming and the microbial life that lives under the ice. Northern Illinois University has been performing research in Antarctica since the 1970s. Ross Powell, an NIU geologist, has been working on this project for 8 years.
"It's been a long, hard road going through development," Powell said. "My main drive is to make sure this instrument is fully equipped to go to the Antarctic."