Client: San Diego Association of Governments (SANDAG)
Completion Date: 1999
Contract Value: $ 500,000

In 1999, the San Diego Association of Governments (SANDAG) contracted Sea Surveyor to conduct precision hydrographic, geophysical, and vibracoring investigation of 10 offshore borrow sites in San Diego County. The objective of the offshore sand investigation is to: 1) map the horizontal and vertical extent of suitable beach sand within the 10 proposed borrow sites, and 2) compute the volume of suitable beach replenishment material contained within each site.

Sea Surveyor conducted Geophysical Surveys at the proposed borrow sites and then collected 125 sediment core samples using an ALPINE vibracore. The geophysical surveys used differential GPS navigation to map each site with a side-scan sonar, marine magnetometer, 2 types of subbottom profilers, and a survey-grade depthfinder. After interpreting the geophysical data, 125 sediment core samples of nominal 20’ length were collected, logged, photographed, subsampled and archived. The subsamples from the vibracores were analyzed for grain-size, lithology, and chemical constituents.