L. M. Dorman, A. W. Sauter and others, Observations and causes of seismic
background noise in the nearshore region. Unpublished
The spectral density of ocean waves (swell) measured by an array of Ocean-Bottom
Seismometers at a depth of 30 meters offshore of Southern California, more
specifically off Marine Corps Base Camp Pendleton. At the center
of the plane defined by the red and green vectors, the horizontal slowness
is zero (infinite velocity) and the maximum values are 200 seconds per
kilometer. Up (opposite the blue axis) is increasing period, with
the greatest value being 16 seconds. The strongest component is in
the ENE direction with a subsidiary peak in a more northerly direction.