African monsoon precipitation experienced a dramatic change in the course of the Holocene.The pace with which the African monsoon shifted from a strong early to middle to a weak late Holocene is critical for our understanding of climate dynamics, hydroclimate-vegetation interaction, and shifts of prehistoric human settlements, yet it is controversially debated. On the basis of planktonic foraminiferal Ba/Ca time series from the eastern Mediterranean Sea, here we present a proxy record of Nile River runoff that provides a spatially integrated measure of changes in East African monsoon (EAM) precipitation. The runoff record indicates a markedly gradual middle to late Holocene EAM transition that lasted over 3500 years. The timing and pace of runoff change parallels those of insolation and vegetation changes over the Nile basin, indicating orbitally forced variation of insolation as the main EAM forcing and the absence of a nonlinear precipitation-vegetation feedback. A tight correspondence between a threshold level of Nile River runoff and the timing of occupation/ abandonment of settlements suggests that along with climate changes in the eastern Sahara, the level of Nile River and intensity of summer floods were likely critical for the habitability of the Nile Valley (Egypt).

We present the first tephroanalysis based on geochemical fingerprinting of volcanic glass shards from eastern Apulian shelf sediments in the Gulf of Taranto (Italy). High sedimentation rates in the gulf are ideal for high-resolution paleoclimate studies, which rely on accurate age models. Cryptotephrostratigraphy is a novel tool for the age assessment of marine sediment cores in the absence of discrete tephra layers. High-resolution quantitative analysis of glass shard abundance in the uppermost 45 cm of a gravity core identified two cryptotephras. Microprobe analysis of glass shards supported by an accelerator mass spectrometry 14C–based age model identified the pronounced primary cryptotephra at 36 cm bsf (below sea floor) as the felsic AD 776 Monte Pilato Eruption on the island of Lipari, whereas the thinner, mafic tephra layer at 1.5 cm bsf is associated with the AD 1944 eruption of Somma-Vesuvius. Identifying these tephra layers provides an additional, 14C-independent, stratigraphic framework for further paleoclimatic studies allowing us to link Mediterranean climate and hydrology to orbital variation and large-scale atmospheric processes. Our results underline the importance of qualitative tephrostratigraphy in a highly geodynamic region, where solely quantitative approaches have demonstrated to bear a high potential for false correlations between tephra layers and eruptions.

Interactive comment on "Combined North Atlantic and anthropogenic forcing of changes in the marine environments in the Gulf of Taranto (Italy) during the last millennium" by Valerie Menke et al. Valerie Menke et al.

Interactive comment on "Combined North Atlantic and anthropogenic forcing of changes in the marine environments in the Gulf of Taranto (Italy) during the last millennium" by Valerie Menke et al. Valerie Menke et al.

Abstract.This study examines the multi-decadal to centennial variability of benthic ecosystems, depositional environments and biogeochemical processes in the Gulf of Taranto (Italy) over the last millennium. Our study is based on sediment cores from two sites in the eastern Gulf of Taranto (Mediterranean Sea), and benthic foraminifera data of 43 surface sediment samples from the western Adriatic Sea reflecting modern conditions. We use the data to 20 unravel relative contributions of natural and anthropogenic forcing to conditions at the sediment-water interface in a marine setting with a long history of human impacts in river catchments. High abundances of infaunal foraminifera in surface sediments trace the nutrient-rich Po river outflow and display an area of high organic matter deposition in the north-eastern Gulf of Taranto. Decreasing Ca/Ti ratios suggest increasing terrigenous fluxes at ~1300 AD driven by wetter conditions during persistent negative phases of the North Atlantic 25 Oscillation (NAO). A strong NAO connection is also evident in high-resolution clay mineral data. The smectite/illite ratio reflects variable Po river runoff, and correlates well with NAO strength for the past 300 years. Benthic ecosystem variability as reflected by foraminifera is closely linked to the Northern Hemisphere temperature evolution during the past millennium. Spectral analysis reveals a quasi-periodic variability of ~50 to Clim. Past Discuss., https://doi