Age, biomarker, sea surface temperature, and stable isotopic records of sediment core GeoB20616-1

DOI

We present a continuous and well-resolved record of climatic variability for the past 100,000 yrs from a marine sediment core taken in Delagoa Bight, off southeastern Africa. In addition to providing a sea surface temperature reconstruction for the past ca. 100,000 yrs, this record also allows a high-resolution continental climatic reconstruction. Climate sensitive organic proxies, like the distribution and isotopic composition of plant-wax lipids as well as elemental indicators for fluvial input and weathering type provide information on climatic changes in the adjacent catchment areas (Incomati, Matola, and Lusutfu rivers). At the transition between glacials and interglacials, shifts in vegetation correlate with changes in sea surface temperature in the Agulhas current. The local hydrology, however, does not follow these orbital-paced shifts. Instead, precipitation patterns follow millennial scale variations with different forcing mechanisms in glacial versus interglacial climatic states. During glacials, southward displacement of the Intertropical Convergence Zone facilitates a transmission of northern hemispheric signals (e.g. Heinrich events) to the southern hemispheric subtropics. Furthermore, the southern hemispheric westerlies become a more direct source of precipitation as they shift northward over the study site, especially during Antarctic cold phases. During interglacials, the observed short-term hydrological variability is also a function of Antarctic climate variability, however, it is driven by the indirect influence of the southern hemispheric westerlies and the associated South African high-pressure cell blocking the South Indian Ocean Convergence Zone related precipitation. As a consequence of the interplay of these effects, small scale climatic zones exist. We propose a conceptual model describing latitudinal shifts of these zones along the southeastern African coast as tropical and temperate climate systems shift over glacial and interglacial cycles. The proposed model explains some of the apparent contradictions between several paleoclimate records in the region.

Identifier
DOI https://doi.org/10.1594/PANGAEA.910537
Related Identifier IsSupplementTo https://doi.org/10.5194/cp-17-345-2021
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.910537
Provenance
Creator Hahn, Annette (ORCID: 0000-0002-3647-473X); Schefuß, Enno (ORCID: 0000-0002-5960-930X); Groeneveld, Jeroen ORCID logo; Miller, Charlotte ORCID logo; Zabel, Matthias ORCID logo
Publisher PANGAEA
Publication Year 2020
Funding Reference Federal Ministry of Education and Research https://doi.org/10.13039/501100002347 Crossref Funder ID 03F0798A https://foerderportal.bund.de/foekat/jsp/SucheAction.do?actionMode=view&fkz=03F0798A Tracing Human and Climate impacts in South Africa
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Resource Type Bundled Publication of Datasets; Collection
Format application/zip
Size 5 datasets
Discipline Earth System Research
Spatial Coverage (33.334 LON, -25.589 LAT)