Southern African hydroclimate during the Late Quaternary: integrating source to sink and multi-archive studies

2020 ◽  
Author(s):  
Annette Hahn ◽  
Hayley Cawthra ◽  
Green Andrew ◽  
Humphries Marc ◽  
Schefuß Enno ◽  
...  
Keyword(s):  
Southern Africa ◽  
Late Quaternary ◽  
Global Climate ◽  
Climatic Variability ◽  
Environmental Indicators ◽  
Ocean Current ◽  
Temperate Climate ◽  
Small Scale ◽  
Quaternary Climate ◽  
Source To Sink

<p>Southern Africa is located at the interface of sub-tropical and temperate climate zones as well as between two major warm and cold ocean current systems (Agulhas and Benguela), respectively. This makes it a key region for understanding global climate dynamics and highly sensitive to future climatic change. A growing number of paleo-archives have revealed small-scale climatic dipoles in this region and the driving mechanisms of the complex climatic variability often in this region remain unclear. Several regional studies have suggested a synchronicity with the southern hemisphere and thus inferred a direct insolation forcing while others have observed a synchronicity with northern hemispheric climate and associated this with a teleconnection mechanism. In order to decipher the complex climatic processes affecting this region it is necessary to integrate on- and offshore paleo-archives as well as various paleo-environmental indicators (proxies). For the correct interpretation of the various proxies a source to sink approach is necessary determining the origin of the different terrestrial sedimentary components and their potential alterations during transport and deposition. With a focus on marine and lacustrine sedimentary archives along the west, south, and east coast of southern Africa we are now able to reconstruct Late Quaternary climate variability on regional scales. We propose a new conceptual model describing latitudinal shifts of rainfall zones as tropical and temperate climate systems shift over glacial and interglacial cycles. New insights allow us to resolve some of the apparent contradictions between paleoclimate records from the region. </p><p> </p>

scholarly journals Geoarchaeological and paleoenvironmental reconstruction of the Late Quaternary climate- environmental-human nexus in the Kurdistan region of Iraq

2020 ◽  
Author(s):  
Luca Forti ◽  
Eleonora Regattieri ◽  
Anna Maria Mercuri ◽  
Ilaria Mazzini ◽  
Andrea Pezzotta ◽  
...  
Keyword(s):  
Land Use ◽  
Late Quaternary ◽  
Climatic Variability ◽  
Archaeological Sites ◽  
Paleoenvironmental Reconstruction ◽  
Human Land Use ◽  
Quaternary Climate ◽  
Geochemical Analyses ◽  
Sandy Sediments ◽  
Origin Of Agriculture

<p>During the late Quaternary, Iraqi Kurdistan was the scenario of several fundamental human-related<br>events including the dispersion of Homo in Asia and Europe, the origin of agriculture, the beginning<br>of urbanization, and the formation of the first state entities. We present the initial results of a<br>geoarchaeological investigation in this area, which aims to reconstruct a detailed framework of the<br>relationship between climatic changes, landscape responses, human adaptation, and settlement<br>distribution during the Late Quaternary. Paleoenvironmental and paleoclimatic data were collected<br>from two key areas: the territory of the Navkur and Faideh plains, in northern Kurdistan, and a portion<br>of the Erbil plain, in southern Kurdistan. In the two regions, the Land of Niniveh and MAIPE<br>archaeological missions are operating. Remote sensing, GIS analyses, and geomorphological survey<br>are the tools used for the geomorphological reconstruction of ancient hydrology (fluvial pattern) and<br>the evolution of distinct landforms. Geochemical and geochronological analyses on speleothems from<br>the Zagros piedmont caves of same region provide information on Holocene climatic variability in<br>the area. Whereas environmental settings and human land use are investigated on the basis of<br>sedimentological, palynological, micropaleontological, and geochemical analyses of a fluvio-<br>lacustrine sequences preliminary dated between 40 and 9 ka BP. The lacustrine sequence is composed<br>by clayey and silt-sandy sediments alternating calcareous and organic matter-rich layers.<br>Environmental and geomorphological data have been compared with archaeological information<br>(mostly the chronological distribution of the archaeological sites) to interpret exploitation of natural<br>resources, the settlement dynamics and shift in land use. </p>

Terrestrial biomarker isotope records of late Quaternary climate and source-to-sink sediment transport processes in southwestern Taiwan

2021 ◽  
Vol 321 (4) ◽  
pp. 393-423
Author(s):  
Queenie Chang ◽  
Michael Hren ◽  
Andrew T. Lin ◽  
Clay Tabor ◽  
Shun-Wen Yu ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Late Quaternary ◽  
Transport Processes ◽  
Quaternary Climate ◽  
Source To Sink ◽  
Southwestern Taiwan

scholarly journals Glacial to interglacial climate variability in the southeastern African subtropics (25–20° S)

2021 ◽  
Vol 17 (1) ◽  
pp. 345-360
Author(s):  
Annette Hahn ◽  
Enno Schefuß ◽  
Jeroen Groeneveld ◽  
Charlotte Miller ◽  
Matthias Zabel
Keyword(s):  
Climate Variability ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Climatic Variability ◽  
Sea Surface ◽  
Temperate Climate ◽  
Small Scale ◽  
Convergence Zone ◽  
The Past ◽  
Catchment Areas

Abstract. We present a continuous and well-resolved record of climatic variability for the past 100 000 years 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 years, 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 of 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 orbitally paced shifts. Instead, precipitation patterns follow millennial-scale variations with different forcing mechanisms in glacial vs. 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.

Place, space and time: resolving Quaternary records

2021 ◽  
Vol 124 (4) ◽  
pp. 1107-1114
Author(s):  
J. Knight ◽  
J.M. Fitchett
Keyword(s):  
Southern Africa ◽  
Late Quaternary ◽  
Radiometric Dating ◽  
Future Research ◽  
Research Directions ◽  
Space And Time ◽  
Quaternary Climate ◽  
Time Period ◽  
Future Research Directions

Abstract Principles of place, space and time can frame an understanding of the context and interpretation of Quaternary palaeo-records, and this is particularly the case for the varied proxies used for late Quaternary climate and environmental reconstruction in southern Africa. Place refers to the specific topographic setting or context of any one record, which has implications for the operation of physical processes in the landscape that control the accumulation of different records. Space refers to the spatial scale or footprint of any one record or proxy, and this varies from one proxy to another. Time refers to not only the time period covered by individual records, but also the temporal resolution of the record, which depends on accumulation rates and availability and quality of any radiometric dating. These three principles are discussed specifically in the context of the Quaternary of southern Africa and through the papers that form this special issue, but are also relevant globally. Future research directions in Quaternary research in southern Africa are identified, including opportunities for refining regional chronostratigraphies.

scholarly journals Glacial to interglacial climate variability in the southeastern African subtropics (25–20° S)

2020 ◽  
Author(s):  
Annette Hahn ◽  
Enno Schefuß ◽  
Jeroen Groeneveld ◽  
Charlotte Miller ◽  
Matthias Zabel
Keyword(s):  
Climate Variability ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Climatic Variability ◽  
Sea Surface ◽  
Temperate Climate ◽  
Small Scale ◽  
Convergence Zone ◽  
The Past ◽  
Catchment Areas

Abstract. 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.

Modelling of late Quaternary climate over Asia: a synthesis

Boreas ◽  
2004 ◽  
Vol 33 (2) ◽  
pp. 155-163 ◽  
Author(s):  
Andrew Bush
Keyword(s):  
Late Quaternary ◽  
Quaternary Climate

Carnivore Size and Quaternary Climatic Change in Southern Africa

1986 ◽  
Vol 26 (1) ◽  
pp. 153-170 ◽  
Author(s):  
Richard G. Klein
Keyword(s):  
South Africa ◽  
Southern Africa ◽  
Late Quaternary ◽  
Geochemical Data ◽  
Mathematical Relationship ◽  
Carnivore Species ◽  
Quantitative Estimates ◽  
The Relationship ◽  
Problematic Aspect ◽  
Cool Conditions

The relationship between carnassial length and latitude south is analyzed for 17 African carnivore species to determine if individuals tend to be larger in cooler climates, as predicted by Bergmann's Rule. With modern data in support, middle and late Quaternary temperatures might then be inferred from mean carnassial length in fossil samples, such as those from Equus Cave, Elandsfontein, Sea Harvest. Duinefontein, and Swartklip in the Cape Province of South Africa. One problematic aspect of the study is the use of carnassial length and latitude as necessary but imperfect substitutes for body size and temperature, respectively. For some species, another difficulty is the relatively small number of available modern specimens, combined with their uneven latitudinal spread. Still, in 14 of the species, carnassial length does tend to increase with latitude south, while mean carnassial length in the same species tends to be greater in those fossil samples which accumulated under relatively cool conditions, as inferred from sedimentologic, palynological, or geochemical data. Given larger modern samples from a wide variety of latitudes, refinement of the mathematical relationship between carnassial length and latitude in various species may even permit quantitative estimates of past temperatures in southern Africa.

scholarly journals The Benefits of Combining Global and Local Data—A Showcase for Valuation and Mapping of Mangrove Climate Regulation and Food Provisioning Services within a Protected Area in Pará, North Brazil

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 432
Author(s):  
Robin Gutting ◽  
Ralf-Uwe Syrbe ◽  
Karsten Grunewald ◽  
Ulf Mehlig ◽  
Véronique Helfer ◽  
...  
Keyword(s):  
Global Climate ◽  
Structural Parameters ◽  
Management Strategies ◽  
Small Scale ◽  
Mangrove Forests ◽  
Food Provisioning ◽  
Local Data ◽  
Climate Regulation ◽  
North Brazil ◽  
Species Specific

Mangrove forests provide a large variety of ecosystem services (ES) to coastal societies. Using a case study focusing on the Ajuruteua peninsula in Northern Brazil and two ES, food provisioning (ES1) and global climate regulation (ES2), this paper proposes a new framework for quantifying and valuing mangrove ES and allow for their small-scale mapping. We modelled and spatialised the two ES from different perspectives, the demand (ES1) and the supply (ES2) side respectively. This was performed by combining worldwide databases related to the global human population (ES1) or mangrove distribution and canopy height (ES2) with locally derived parameters, such as crab catches (ES1) or species-specific allometric equations based on local estimates of tree structural parameters (ES2). Based on this approach, we could estimate that the area delivers the basic nutrition of about 1400 households, which equals 2.7 million USD, and that the mangrove biomass in the area contains 2.1 million Mg C, amounting to 50.9 million USD, if it were paid as certificates. In addition to those figures, we provide high-resolution maps showing which areas are more valuable for the two respective ES, information that could help inform management strategies in the future.

The sensitivity of Neotoma to climate change and biodiversity loss over the late Quaternary

2021 ◽  
pp. 1-15
Author(s):  
Catalina P. Tomé ◽  
S. Kathleen Lyons ◽  
Seth D. Newsome ◽  
Felisa A. Smith
Keyword(s):  
Body Size ◽  
Late Quaternary ◽  
Climatic Variability ◽  
Isotope Analysis ◽  
Biodiversity Loss ◽  
Bone Collagen ◽  
Cam Plants ◽  
The Holocene ◽  
Carbon And Nitrogen ◽  
Terminal Pleistocene

Abstract The late Quaternary in North America was marked by highly variable climate and considerable biodiversity loss including a megafaunal extinction event at the terminal Pleistocene. Here, we focus on changes in body size and diet in Neotoma (woodrats) in response to these ecological perturbations using the fossil record from the Edwards Plateau (Texas) across the past 20,000 years. Body mass was estimated using measurements of fossil teeth and diet was quantified using stable isotope analysis of carbon and nitrogen from fossil bone collagen. Prior to ca. 7000 cal yr BP, maximum mass was positively correlated to precipitation and negatively correlated to temperature. Independently, mass was negatively correlated to community composition, becoming more similar to modern over time. Neotoma diet in the Pleistocene was primarily sourced from C3 plants, but became progressively more reliant on C4 (and potentially CAM) plants through the Holocene. Decreasing population mass and higher C4/CAM consumption was associated with a transition from a mesic to xeric landscape. Our results suggest that Neotoma responded to climatic variability during the terminal Pleistocene through changes in body size, while changes in resource availability during the Holocene likely led to shifts in the relative abundance of different Neotoma species in the community.

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