EFFECT OF LONG PERIOD WAVES ON HYDROGRAPHIC SURVEYS

Orville T. Magoon, William O. Sarlin

Abstract


In conjunction with routine hydrographic surveys at Santa Cruz Harbor, California, bottom elevation discrepancies were observed which were not associated with positional errors It was suspected that these errors were associated with long period wave activity, common at this particular location on the Pacific Coast The existing practice for obtaining hydrographic soundings is by use of floating craft using either echo sounding techniques or a "lead line " Both of the above techniques utilize the instantaneous water surface at the survey boat as a datum reference Normally the water surface elevation is determined by use of a water level recorder Based on the analysis of 50 repetitions of a well monumented cross section in Santa Cruz Harbor, it was concluded that long period waves affect the results of hydrographic surveys by slowly varying the datum plane In the case of Santa Cruz Harbor, the maximum error due to this effect would be about +15 feet.

Keywords


hydrographic survey; long period waves

Full Text: PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.