Variation in subaerial beach sediment volume on a small sandy beach over a monthly lunar tidal cycle

摘要: Abstract Three major patterns of sediment movement along 0.5 m deep horizontal segments beachface on a small sandy beach at Coledale, New South Wales, were determined by empirical orthogonal function (EOF) analysis 36 day record change. The fundamental response is identified the first eigenfunction mode. mode describes transfers occurring over beachface, between low-tide zone and berm crest as well beach. alongshore translocations occurred about nodal point located approximately 0.75 distance beach, from its southern end. Transfers across established comparing time series associated with eigenfunctions describing in different segments. slice-to-slice comparisons showed an increasing phase down segment to mid-tidal zone. difference was 2.5 days per segment. secondary typical supratidal occur apparent 28–30 lunar tide cycle. They unrelated short-term variations incident wave amplitude. Lower aperiodic. irregularities can be linked particular process events. However, similar changes not always related conditions they simply wave-regime fluctuations. Coledale Beach consistent reported elsewhere Clarke Eliot (1982, 1983a) that closely variation nearshore water circulation system. In particular, points EOF commonly landward inshore regions where bars most frequently developed. antinodal positions similarly rip channels are formed.