Day-to-day variations in nearshore bar patterns on a small sandy beach through a lunar tidal cycle

Nearshore water circulation and bar patterns at Coledale, New South Wales, were surveyed daily over thirty-six consecutive days, from 3 November to 8 December 1978, to identify sequences of changes that might occur in response to spring-to-spring tide cycles of fourteen days, changing barometric and wind conditions associated with the passage of anticyclonic weather systems across the coast, and day to day variation in the nearshore wave regime. During the survey the bar patterns tended to vary from transverse bars, through a composite arrangement incorporating longshore and transverse bars, to a longshore bar pattern as the tide changed from its spring to neap tide phase. However, this sequence was too brief to unequivocally establish variations in nearshore bar pattern that might be attributed to the fourteen day, spring-to-spring tide cycle. Nevertheless, morphologic changes occurring in response to wave regime fluctuation at Coledale were broadly in accord with studies from elsewhere by Dolan et al. (1979, 1982), and Clarke and Eliot (1982, 1983) in that bars and rips were systematically distributed along the beach. At Coledale, bars tended to relocate approximately 0.4 and 0.75 of the distance along the beach from its southern end. The preferred bar spacing closely matches hypothetical standing waves trapped between the headlands of the Coledale embayment. Temporally, the nearshore morphology is highly responsive to wave regime changes such that, as primary breaker heights decrease and remain below H_max=1.0m, the bar pattern changes from longshore through mixed to transverse bar patterns within three to five days. On one occasion the bar pattern switched from a longshore to a transverse bar pattern within twenty-four hours.     

Book reviews

Derek McDougall, Harold D. Lasswell and the Study of International Relations. University Press of America, Lanham, USA, 1984, pp.370. $16.50.

John W. Burton, Global Conflict: The Domestic Sources of International Crisis. Wheatsheaf Books, UK, 1984, pp.194. $54.00.

K.J. Holsti, The Dividing Discipline: Hegemony and Diversity in International Theory. Allen and Unwin, Boston and Sydney, 1985. pp.165. $39.95.

Hedley Bull (ed.), Intervention in World Politics. Clarendon Press, Oxford, 1984, pp. viii + 198. $31.00.

Hedley Bull, Justice in International Relations. 1983–84 Hagey Lectures, University of Waterloo, 1984, pp. iii + 36. No price given. (Available from University Publications Distribution Service, Dana Porter Arts Library, University of Waterloo, Waterloo, Ontario N2L3G1, Canada.)

Benedict Anderson, Imagined Communities: Reflections on the Origin and Spread of Nationalism. Verso Editions and NLB, London, 1983, pp. 160. £15.00.

Chalmers Johnson, Revolutionary Change. Second edition. Longman, London, 1983, pp.xii + 217. $13.85.

Peter Calvert, Politics, Power and Revolution. An Introduction to Comparative Politics. Wheatsheaf Books, Brighton, 1983, pp.208. £5.95.

John Walton, Reluctant Rebels. Comparative Studies of Revolution and Underdevelopment. Columbia University Press, New York, 1984, pp.xii + 230 $US36.00 (cloth), $US10.00 (paper).

E. A. Tiryakian and R. Rogowski (eds), New Nationalisms of the Developed West. Toward Explanation. Allen and Unwin, Boston, 1985, pp.xii + 394. $69.00.

Peter H. Merkl and Ninian Smart (eds), Religion and Politics in the Modern World. New York University Press, New York, 1985, pp.276. No price given.

Richard Lowenthal, Social Change and Cultural Crisis. Columbia University Press, New York, 1984, pp.viii + 252. $US29.50.

Dietrich Fischer, Preventing War in the Nuclear Age. Rowman and Allanheld, Totowa, N.J./Croom Helm, London, 1984, pp. x + 236. $27.95.

F. Dyson, Weapons and Hope Harper and Row, New York, 1984, pp.340. $24.95.

John Langmore and David Peetz (eds), Wealth, Poverty and Survival. Australia in the World. George Allen and Unwin, Sydney, in association with the Australian Labor Party, 1983, pp. 225.