Late Pleistocene Sea Surface Water Temperature Variations off Oman as Revealed by the Distribution of Long-Chain Alkenones

Late Pleistocene sea surface water temperatures (SST) offshore Oman were calculated from the U 37 ratio measured in sediment extracts from ODP holes drilled on the Oman Margin (723B, 728B) and on the Owen Ridge (721B, 731A).The data revealed a complex history of SST variations with a temperature range of 18°/19°C-27 O /28°C, which is in accord with the present-day SST range in the western Arabian Sea.We found that, notably, in the glacial periods of isotopic stages 3 and 8 the SST was lower than during the interglacials.The lowest SST values occurred during isotopic stage 3.A mechanism involving a strong influence of cold northeasterly winds during glacial periods, with the southwestern monsoon being less effective at the same time, explains cold SST during glacial periods.However, further research is necessary to approve or disapprove this mechanism, because in the present study not all glacial periods were clearly marked by low SST values.