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The AAPG/Datapages Combined Publications Database

CSPG Special Publications

Abstract


Shelf Sands and Sandstones — Memoir 11, 1986
Pages 345-345
Symposium Abstracts: Tide-Dominated Shelves

Tidal Currents in Continental Shelf Seas, Ancient and Modern: Abstract

M. J. Howarth1

Abstract

Tides and storms dominate the dynamics of most continental shelf seas. Whereas tides are ever present, storms are intermittent events, generating surface waves and wind-driven/storm-surge currents. The tides are generated in the oceans by forcing at well defined frequencies determined by the Moon’s orbit around the Earth and the Earth’s orbit around the Sun — predominantly daily and twice-daily, with longer period modulations. The response of a continental shelf sea to the tide propagating into it from the ocean is mainly determined by the shelf’s width and depth, largest amplification at the coast occurring for frac14.gif (857 bytes) wavelength (organ pipe) type of resonance. Tidal energy is dissipated in shelf seas by bottom friction and hence the current Previous HitspeedNext Hit decreases near the sea bed and the sea bed experiences a stress that can sometimes move sand. Since sand transport is generally thought to depend nonlinearly on the current Previous HitspeedTop, the total current is important, particularly higher tidal harmonics. The principles governing the present distribution of tidal currents in continental shelf seas can be applied to ancient continental shelf seas, based on estimates of the ocean and shelf configurations and the Moon’s distance from the Earth.


 

Acknowledgments and Associated Footnotes

1 Institute of Oceanographic Sciences, Birkenhead L43 7RA, U.K.

Copyright © 2008 by the Canadian Society of Petroleum Geologists