Magnetic anomalies and fracture pattern in the northeast Pacific Ocean

Abstract

A group of magnetic anomaly bands near the western boundary of the ‘north-south’ magnetic lineations have been traced across the major fracture zones of the northeast Pacific from the Aleutian trench to the latitude of Hawaii. The anomaly bands are parallel to each other and strike 163°. Recent studies of bathymetrie data and these magnetic anomalies revealed the existence of a new fracture, named Surveyor fracture zone, 400km north of the Mendocino fracture zone. The magnetic anomaly bands indicate a 305-km right-lateral strike-slip motion along the Surveyor fracture zone. The trend of the magnetic anomalies, the bathymetry, and the fracture pattern of the crust in the crestal area of the East Pacific rise (off the west coast of the North American continent) are significantly different from those observed in the central northeast Pacific.