Feedbacks between sea-floor spreading,trade winds and precipitation in the Southern Red Sea

Abstract

Feedbacks between climatic and geological processes are highly controversialand testing them is a key challenge in Earth sciences. The Great Escarpment ofthe Arabian Red Sea margin has several features that make it a useful naturallaboratory for studying the effect of surface processes on deep Earth. Theseinclude strong orographic rainfall, convex channel profiles versus concaveswath profiles on the west side of the divide, morphological disequilibrium influvial channels, and systematic morphological changes from north to souththat relate to depth changes of the central Red Sea. Here we show that thesefeatures are well interpreted with a cycle that initiated with the onset ofspreading in the Red Sea and involves feedbacks between orographic precipitation,tectonic deformation, mid-ocean spreading and coastal magmatism.It appears that the feedback is enhanced by the moist easterly tradewinds that initiated largely contemporaneously with sea floor spreading in theRed Sea.