Coastal erosion is a problem of increasing concern that affects 60% of 

 the world's sandy coastline. This erosion has been attributed to increased 

 storminess, tectonic subsidence, eustatic sea- level rise, decreased shoreward 

 sediment movement from the shelf, permanent longshore leakage of sediment from 

 beach compartments, shifts in global pressure belts resulting in changes in 

 the directional component of wave climates, and human interference. No one 

 explanation has worldwide applicability because all factors vary regionally in 

 importance. Evaluation of factors is complicated by a lack of accurate 

 continuous, long-term erosional data. Historical map evidence spanning 100- 

 1000 year has been used in a few isolated areas; however, temporal resolution 

 has not been sufficient to evaluate the effect of climate variable. Air 

 photographic evidence is restricted to the past 40 year and often suffers from 

 insufficient ground control for accurate mapping over time. Ground surveying 

 of beaches was rarely conducted before 1960 and is often discontinuous in time 

 and space. The author resolved the problems of temporal and spatial continu- 

 ity by studying change for the whole of Stanwell Park beach, N.S.W., 

 Australia, for the period 1895-1980. By using the average high- tide wave run- 

 up position measured accurately to + 2.5 m from oblique and vertical 

 photographs, changes could be linked to regional sea- level variation and a 

 globally significant climatic variable, the Southern Oscillation (SO). 

 (Author) . 



040 BURKE, C. D. 1987. "The Effects of Late Quaternary Climatic Changes and 

 Glacioisostatic Rebound on Lake Level Fluctuations and Benthos of Lake 

 Michigan," Palaios . Vol 2, pp 514-522. 



Past lake stages of Lake Michigan are the result of water level still- 

 stands and fluctuations initiated by the withdrawal of the Wisconsin glacial 

 ice sheet (approximately 10,000-5,000 years before present). Dominance 

 diversity, evenness, and community profiles were used to determine the effects 

 of these fluctuations on ostracode populations and to reconstruct the paleo- 

 envlronment of glacial Lake Michigan. 



Results indicate that ostracode community diversity was low, and 

 evenness was high during this period. Few species of ostracodes could 

 tolerate the cold temperatures and oligotrophic conditions of the prehistoric 

 lake system. This assemblage consists of Candona subtriangulata and C. 

 crogmaniana. 



Community profiles changed with fluctuations in water level. One 

 significant change in diversity indices is recorded between the oldest lake 

 stage (Alonquin) and the stratigraphically overlying, shallowest stage 

 (Chippewa) . Increase in diversity was probably a result of increasing 

 nutrient availability and salinity, two by-products of erosional processes and 

 evaporation initiated when the lake level declined and the climate warmed. 

 These changes in diversity and abundance may imply an increase in primary 

 productivity. 



As much as 32% of lake-bottom sediments were exposed during the Chippewa 

 water level minimum. This exposure of land and the resulting decrease in lake 

 surface may have affected local and regional climate. 



Glacioisostatic rebound of channel openings caused the lake level to 

 rise to an extreme high (Nipissing stage). With increasing water levels, 

 ostracode profiles changed and suggest that the hypolimnion decreased in 



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