Snapshots of tsunami from 1906 Great Earthquake

Results of modeling indicate that the tsunami from the 1906 San Francisco earthquake was caused primarily by downdropping of the seafloor north of Lake Merced, between overlapping segments of the San Andreas fault. Three observations are apparent from hydrodynamic modeling of this tsunami:

1. the tsunami propagated from the source region to the Golden Gate as a trapped wave (i.e., a particular class of waves that propagate parallel to the shoreline);
2. trapped waves generated by this earthquake were reflected and scattered, resulting in the 40-45 min. period oscillations apparent on the tide gauge record; and
3. relatively little wave energy is transmitted through the Golden Gate to San Francisco Bay.

These snapshots of the tsunami are derived from the discontinuous fault model (black lines are current vectors located at every model grid point spaced 250 m apart).