Holocene relative sea-level changes and coastal evolution along the coastlines of Kamaran Island and As-Salif Peninsula, Yemen, southern Red Sea

Abstract

Geomorphic features (fossil terraces, notches and sea cliffs) from the southern Red Sea coasts provide valuable indicators of past sea-level change that enable the quantification of both the timing and magnitude of the mid-Holocene sea-level highstand. We demonstrate the utility of wave-cut notches in the southern Red Sea, and present U-series dated sea-level indicators from two locations on the As-Salif Peninsula that suggest a mid-Holocene highstand of ∼0.5–1 m above present mean sea level (apmsl) at about 5–5.4 ka BP. In addition, the similarity of the elevations of the different sea-level indicators at the two locations in As-Salif Peninsula and Kamran Island suggest relative tectonic stability, with limited influence of salt diapirism. Comparison of our data to other estimates of the Red Sea mid-Holocene highstand, and glacio-isostatic predictions suggest that water loading (and deformational response) is the primary factor in the spatial and temporal variability the mid-Holocene highstand, with some possible localized tectonic and neotectonic overprinting.