Skip to main content
U.S. flag

An official website of the United States government

Magnetic map of San Pablo Bay

Detailed Description

This map illustrates the magnetic strengths around the San Pablo Bay and the Hayward Fault which runs through the bay. The warmer colors (pink, red, orange) indicate a high magnetic field strength. The cooler colors (blue, green, yellow) show low magnetic field strength. Plus signs mark locations of the Hayward fault seen in seismic-reflection profiles. Based on the colors illustrated on the map, it appears that there are stronger magnetic field strengths (magnetic anomaly) directly over, and immediately adjacent to the Hayward Fault (from 101.7 down to approximately -52.0 nT) and roughly within 2 km of the center of the fault. As the distance increases away from the fault, the magnetic strengths decrease further down to -116.1 nT


Public Domain.