Measurement of Horizontal Displacement along Faults in the Ocean Floor

IN the eastern Pacific Ocean a right lateral displacement of 84 nautical miles along the Murray Fracture Zone¹ has been suggested by a total magnetic intensity survey^2,3. The Pioneer Ridge, a newly found east-west fault located between the Mendocino and the Murray Fractures along 38° 30' north latitude and known to extend between 127° and 136° west longitude, was surveyed by the R.V. Horizon of the Scripps Institution of Oceanography of the University of California for the express purpose of measuring the direction and the amount of horizontal slip. A left lateral displacement of 138 nautical miles was found.