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https://hdl.handle.net/11681/3379| Title: | Beaches near San Francisco, California, 1956-1957 |
| Authors: | University of California, Berkeley. Wave Research Laboratory United States. Army. Office of the Chief of Engineers Trask, Parker D. (Parker Davies), 1899-1961 |
| Keywords: | Shore protection Beaches San Francisco, California Beach profiles Beach nourishment Shore processes Beach material |
| Publisher: | United States, Beach Erosion Board Engineer Research and Development Center (U.S.) |
| Series/Report no.: | Technical memorandum (United States. Beach Erosion Board) ; no. 110. |
| Description: | Technical Memorandum Abstract: Eighteen profiles on beaches in the vicinity of San Francisco were occupied at intervals of 2 to 6 weeks from July 1956 to June 1957. Seven of these profiles were north of Golden Gate Bridge and eleven were south. The beaches vary greatly in character. Individual beaches differ from one another and the same beach differs from season to season and from place to place at any given time. The sand on the beaches tends to be relatively fine in the fall and coarse in the late winter or early spring. Individual beaches commonly build up during summer and fall and erode during the winter and spring. The front of the berm may advance or retreat as much as 100 feet throughout the year. Point Reyes Beach has the coarsest and most poorly sorted sand. It also has the highest and most variable berm. Drakes Bay on the outer side of Point Reyes Peninsula has the finest and best sorted sand. The sand on beaches south of Golden Gate becomes progressively coarser southward. Average grain sizes for Point Reyes Beach are about 600 microns; for Drakes Bay and Stinson beach, 220 microns; for the north end of Ocean Beach, 275 microns; and at Rockaway Beach 425 microns. The grain size at Point Reyes Beach is approximately twice as large in spring as in fall, and at many of the other beaches it is 50 percent greater in spring than in fall. The variability of sands found on individual beaches at any given period of occupation is greatest at Point Reyes beach and least at Drakes Bay. The drift at Point Reyes beach is predominantly from the northeast, but at times it comes from the southwest. Drift from both directions is indicated for other beaches, but the relative proportion of coming from one direction or the other is not indicated. The tendency for waves on Ocean Beach to approach the shore at an angle from the south suggests a northward drift along this beach, during part of the year at least. Ocean beach also loses considerable sand to the land by wind action. |
| Rights: | Approved for Public Release, Distribution is Unlimited |
| URI: | http://hdl.handle.net/11681/3379 |
| Appears in Collections: | Technical Memorandum |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| BEB-TM-110.pdf | 5.98 MB | Adobe PDF |  View/Open |