Late Holocene hydrographic settings of the northern Red Sea

Abstract

Temporal variability of the paleo-oceanographic setting of the northern Red Sea during the last 6 Ky was deduced from high-resolution faunal results and stable isotope records of planktonic foraminifera in three short cores sediment obtained by the German R/V Meteor vessel. In general, the investigated time interval is fundamentally comparable to the present day composition and distribution of planktonic foraminifera. However, interrupted short enhanced arid phase spanning the last 4–2 Ky appears to have existed in the northern Red Sea, and resulted in elevation of salinity and somehow productivity, as hypersaline, dense surface water favored vertical mixing of the water column resulting in an increase in productivity. This paleoclimatic reconstruction is revealed from the distinct gradient in the composition and distribution of planktonic foraminifera, as well as the significant distribution trend of Globigerinoides ruber versus Globigerinoides sacculifer correlated with the stable isotope records. Starting from the last 2 Ky to the present time, less strength arid conditions relative to the previous period prevailed, reflected from a gradual decrease in surface water salinity and productivity assuming that the present water conditions and consequently current climatic conditions began to develop from that time with minor fluctuations reaching the recent conditions.

Keywords

• Northern Red Sea
• Paleo-oceanography
• Surface water salinity
• Late quaternary hydrographic conditions
• Planktonic foraminifera