Syee Weldeab

Learn More
A detailed reconstruction of West African monsoon hydrology over the past 155,000 years suggests a close linkage to northern high-latitude climate oscillations. Ba/Ca ratio and oxygen isotope composition of planktonic foraminifera in a marine sediment core from the Gulf of Guinea, in the eastern equatorial Atlantic (EEA), reveal centennial-scale variations(More)
A sediment core from the western tropical Atlantic covering the last 21,000 yr has been analysed for centennial scale reconstruction of sea surface temperature (SST) and ice volume-corrected oxygen isotopic composition of sea water (d18Oivc-sw) using Mg/Ca and dO of the shallow dwelling planktonic foraminifer Globigerinoides ruber (white). At a period(More)
We investigated five time-equivalent core sections (180^110 kyr BP) from the Balearic Sea (Menorca Rise), the easternmost Levantine Basin and southwest, south, and southeast of Crete to reconstruct spatial patterns of productivity during deposition of sapropels S5 and S6 in the Mediterranean Sea. Our indicators are Ba, total organic carbon and carbonate(More)
[1] A Holocene Gulf of Guinea record of riverine runoff, based on Ba/Ca in tests of a shallow-dwelling planktic foraminifer, and sea surface temperature (SST), based on Mg/Ca, reveals centennial-scale instabilities in West African monsoon (WAM) precipitation and eastern equatorial Atlantic (EEA) thermal conditions. The long-term Holocene climate trend is(More)
[1] Sea surface temperature (SST) for the central equatorial Indian Ocean, has been reconstructed over the last 137 kyr, from Mg/Ca of the planktonic foraminiferal species Globigerinoides ruber. According to our record the equatorial Indian Ocean SST was 2.1 C colder during the last glacial maximum as compared to present times. The data further shows that(More)
Sediment cores from the Western Mediterranean Sea (WMS) have been analyzed for their bulk element composition, N18O values of planktic foraminiferal tests, and 87Sr/86Sr and 143Nd/144Nd ratios of their bulk lithogenic components. The investigated time interval comprises the last 215 kyr. Si/Al and Ti/Al ratios as well as radiogenic isotope compositions(More)
Here we present evidence that the Holocene African monsoon system (AMS) varied in response to the eastern equatorial Atlantic sea-surface temperature (SST). Several short-term episodes of decreased moisture availability as a result of low eastern equatorial Atlantic SST are suggested by planktonic foraminiferal Mg/Ca ratios. These episodes promoted a(More)
We established a multi-proxy time series comprising analyses of major elements in bulk sediments, Sr and Nd isotopes, grain size of terrigenous fraction, and δ18O and δ13C in tests of Neogloboquadrina pachyderma (sinistral) from a marine sediment sequence recovered off the Orange River. The records reveal coherent patterns of variability that reflect(More)
Time series of planktonic foraminiferal d18O and Ba/Ca-based sea surface salinity (SSS) estimates from the eastern Gulf of Guinea (eastern equatorial Atlantic) indicate changes in runoff that reflect variability of spatially integrated precipitation over the equatorial West African monsoon area. Millennial-scale and recurring runoff-induced SSS rises and(More)
[1] In this study we utilize two organic geochemical proxies, the U37 k′ index and TEX86, to examine past sea surface temperatures (SST) from a site located near the Nile River Delta in the eastern Mediterranean (EM) Sea. The U37 k′ and TEX86 records generally are in agreement and indicate SST ranges of 14°C–26°C and 14°C–28°C, respectively, during the last(More)