Accession Number : AD0751595

Title :   Onshore-Offshore Sand Transport on Del Monte Beach, California.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

Personal Author(s) : Williamson,John David

Report Date : SEP 1972

Pagination or Media Count : 65

Abstract : Daily sand volume transport values were calculated for a selected beach profile during a two-month period. Wave data were recorded continuously directed seaward of the profile. Tide effects were largely filtered out by use of a lunar day (24.8 hour) sampling interval. Offshore sand transport occurred in isolated events of one to two-day duration, and had a maximum value of 132.5 cubic feet/foot of beach width/lunar day. Onshore transport occurred over longer intervals of up to seven days, and had a maximum value of 47.0 cubic feet/foot/day. Onshore-offshore transport over a 24.8 hour period depends, to a first approximation, on the mean wave steepness incident upon the beach and the initial beach slope for the period. If the initial beach slope is greater (less) than the equilibrium slope associated with the existing wave conditions, or if the profile is initially at equilibrium and the wave steepness increases (decreases), sand will be moved offshore (onshore). The closer to equilibrium the beach is, the smaller the transports are. (Author)

Descriptors :   (*BEACHES, EROSION), (*SAND, TRANSPORT PROPERTIES), CALIFORNIA, OCEAN WAVES, WAVE ANALYZERS, OCEAN BOTTOM SAMPLING, TIDES, MARINE GEOLOGY

Subject Categories : Physical and Dynamic Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE