Alert

Due to a lapse in appropriations, the NRC has ceased normal operations. However, excepted and exempted activities necessary to maintain critical health and safety functions—as well as essential progress on designated critical activities, including those specified in Executive Order 14300—will continue, consistent with the OMB-Approved NRC Lapse Plan.

Tim Johnson

Dr. Tim Johnson is the principle computational geophysicist at the Pacific Northwest National Laboratory. He is internationally recognized for his contributions toward characterizing and monitoring subsurface properties and processes using autonomous geophysical measurements, with an emphasis on electrical methods.

Page Last Reviewed/Updated Thursday, May 22, 2025