Publications by authors named "Annette Hahn"

Article Synopsis
  • Despite extensive fossil discoveries in eastern Africa, the environmental context of hominin evolution remains unclear due to insufficient continuous records, particularly for the Pleistocene epoch.
  • A new 620,000-year environmental record from Chew Bahir in southern Ethiopia reveals how climate variability may have impacted hominin biological and cultural changes, highlighting significant shifts in habitats.
  • The study identifies key climatic phases that correlate with major technological and social advancements in hominins, suggesting that environmental conditions played a crucial role in their evolution and eventual dispersal.
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Richards Bay Harbour (RBH) is situated in the industrialized area on the northeast coast of South Africa. To decipher recent human activities and accompanying environmental degradation, surface sediment was collected across RBH and analysed for granulometric and elemental composition, microfaunal assemblages, and microplastics. Microplastics occur most abundantly near recreational areas, whereas metal contamination relates to activities at bulk goods terminals from which they are imported or exported.

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We present calibration models for the detection of two types of plastic (LDPE, PET) in sediments, developed from analysis of synthetic sediment mixtures and application of Fourier transform infrared spectroscopy (FTIRS) and partial least squares regression (PLSR) modeling. Synthetic sediment mixtures were produced using ground plastic particles mixed with various different sediment matrixes yielding LDPE and PET contents ranging from 0 to 5 wt%. The resulting PLSR calibration models between the FTIRS spectral information and the defined plastic concentration of the synthetic sediment mixtures show strong cross-validated correlations (R = 0.

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Fourier transform infrared spectroscopy (FTIRS) can provide detailed information on organic and minerogenic constituents of sediment records. Based on a large number of sediment samples of varying age (0-340,000 yrs) and from very diverse lake settings in Antarctica, Argentina, Canada, Macedonia/Albania, Siberia, and Sweden, we have developed universally applicable calibration models for the quantitative determination of biogenic silica (BSi; n = 816), total inorganic carbon (TIC; n = 879), and total organic carbon (TOC; n = 3164) using FTIRS. These models are based on the differential absorbance of infrared radiation at specific wavelengths with varying concentrations of individual parameters, due to molecular vibrations associated with each parameter.

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