The project is part of a U.S. Geological Survey effort to map coastal fault lines, a number of which are described as active, in a region that spans Humboldt Bay up to Crescent City.
The small plane being used has a magnetometer, explained USGS geophysicist Janet Watt, which measures the Earth’s magnetic field. Differences in those readings can show the shape of underground fault lines and how the fractures might move.
“Knowing those things about these faults can help us model and understand both the strong ground motions we might expect if there were an earthquake… and also how these faults might deform the sea floor and displace the water column when they go offshore,” said Watt. “Because that could generate a small tsunami.”
Watt said the data they will collect is important in helping nearby communities prepare for potential earthquakes and tsunamis. Surveys from the USGS are used to inform building codes and infrastructure. She said this is the first time the region has been mapped at this level of resolution.
The flight paths will cross eight tribal areas which has also provided a unique local partnership opportunity for the USGS. The Yurok Tribe, whose land will be mapped, has offered their plane for the effort. The tribe has an available aircraft that was previously used in a surveying project during the Klamath River dam removal.
“It’s super exciting… that we're sort of helping build capacity within the U.S. to collect more of this data because there’s not a lot of U.S. companies that do this work,” said Watt. “The local tribal members that know the area best can collect data over their own lands.”
The Yurok Tribe’s flight program Condor Aviation will work with Canadian company Xcalibur Multiphysics to operate the flights for the next few weeks.
