(a) Sapropels record from core ODP Leg 160 (site 967, Eastern Mediterranean Sea)38 together with summer insolation (June, July and August) at 25 °N (ref. 39). The AHPs—identified using the sapropels1 (except for the early Holocene AHP)—are highlighted in green. (b) Continental humidity index from grain-size measurements of core GeoB7920 (ref. 11; 20.75 °N;18.58 °W), (c) Terrigenous Flux6 of ODP658 site (20.75 °N; 18.58 °W), (d) the estimated latitudinal position of the sedimentary Sahara–Sahel boundary24 (black line) with its uncertainty (grey dashed lines). (e) Lake level status in East and North African basins25.