Oct 1, 2010 13:04 GMT  ·  By
This mulitbeam sonar image shows the San Andreas Fault cutting through the head of Noyo Canyon, offshore approximately 12 miles northwest of Fort Bragg, California
   This mulitbeam sonar image shows the San Andreas Fault cutting through the head of Noyo Canyon, offshore approximately 12 miles northwest of Fort Bragg, California

Investigators with the US National Oceanic and Atmospheric Administration (NOAA) will for the first time ever lead a study that will seek to map the unexplored offshore Northern San Andreas Fault line.

The investigation will cover an area spanning from San Francisco all the way to the area off the coast of Mendocino, California, where the plate ends. An innovative suite of instruments will be used for the job.

Scientists plan to use an advanced NOAA research vessel and new technology in order to conduct this advanced research, which is scheduled to conclude this Sunday.

Experts with the research team came from the NOAA National Marine Fisheries Service, the Oregon State University, the California Seafloor Mapping Program, the US Geological Survey (USGS) and Woods Hole Oceanographic Institution (WHOI).

Funds for the investigation were provided by the NOAA Office of Ocean Exploration and Research.

“By relating this 3D model with ongoing studies of the ancient record of seismic activity in this volatile area, scientists may better understand past earthquakes – in part because fault exposure on land is poor, and the sedimentary record of the northern California offshore fault indicates a rich history of past earthquakes,” explains Chris Goldfinger.

He is the co-principal investigator of the research effort, and he holds an appointment as a marine geologist and geophysicist at the Oregon State University.

“The model will also benefit geodetic studies of the buildup of energy to help better understand the potential for earthquakes,” he goes on to say.

Erosion, vegetation and urbanization in many places make the onshore portion of the San Andreas Fault very difficult to analyze for clues of past events, but the offshore portion is a lot more open to study.

“This is a tectonically and chemically active area,” explains NOAA Northwest Fisheries Science Center research fisheries biologist Waldo Wakefield, who is also a co-principal investigator of the work.

“I am looking for abrupt topographic features as well as vents or seeps that support chemosynthetic life – life that extracts its energy needs from dissolved gases in the water,” he goes on to say.

“I’m also looking at sonar maps of the water column and images of the seafloor for communities of life,” the expert adds.

The new study is conducted from aboard the Research Vessel Pacific Storm, which is being operated by Oregon State University Marine Mammal Institute.

The autonomous underwater vehicle (AUV) Lucille is also being used for deep diving and monitoring of the seafloor.