Browsing by Author "Natt, A"

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    Preliminary paleolimnological data from a Santiago island coastal lagoon, Galapagos Archipelago, Ecuador
    (Elsevier, 2007-07) Natt, A; Haberle, SG; Jacobsen, GE
    The Galapagos Islands are arguably the most famous islands in the world. This fame derives from the Islands’ rich biological history and unique locality that provides opportunities for research in the fields of evolution, geomorphology and biodiversity. Furthermore, the unique geographical location of the archipelago has in the past and continues to provide excellent potential for palaeoclimatology, palaeolimnology and palaeoecology. In particular the location of the islands within what is essentially the heart of the ENSO region ensures the islands are frequently influenced by El Niño driven precipitation events. These El Niño precipitation events are extremely influential, given that the islands location within the Pacific Dry Zone (PDZ) ensures the islands have a semi-arid climate (< 500 m asl). Due to the influential nature of El Niño variability in the Galapagos, the numerous saline to hyper-saline coastal lagoons throughout the archipelago have the potential of recording past hydrological changes associated with El Niño-related climate variability. Furthermore, the influence of humans via the introduction of goats and burning may have influenced erosion rates in the catchment. The Preliminary multi-proxy analysis of a laminated sediment sequence raised from Espumilla 2 lagoon, Santiago Island, will be presented. The data include a 14C AMS radiocarbon chronology, fossil diatom analysis, magnetic susceptibility and mineralogical analysis. This research is also part of a larger collaborative project, which will be briefly summarised, and the potential for comparison discussed. © 2007 Published by Elsevier Ltd.
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    Preliminary paleolimnological data from a Santiago island coastal lagoon, Galapagos Archipelago, Ecuador
    (Vacuum Society of Australia, 2007-11) Natt, A; Haberle, SG; Jacobsen, GE; Tibby, J
    The Galapagos Islands are arguably the most famous islands in the world. This fame derives from the Islands’ rich biological history and unique locality that provides opportunities for research in the fields of evolution, geomorphology and biodiversity. Furthermore, the unique geographical location of the archipelago has in the past and continues to provide excellent potential for palaeoclimatology, palaeolimnology and palaeoecology. In particular the location of the islands within what is essentially the heart of the ENSO region ensures the islands are frequently influenced by El Niño driven precipitation events. These El Niño precipitation events are extremely influential, given that the islands location within the Pacific Equatorial Dry Zone (PEDZ) ensures the islands have a semi-arid climate (<500 m above sea level). Due to the influential nature of El Niño variability in the Galapagos, the numerous saline to hyper-saline coastal lagoons throughout the archipelago have the potential of recording past hydrological changes associated with El Niño-related climate variability. Furthermore, the influence of humans via the introduction of goats and burning may have influenced erosion rates in the catchment. Preliminary multi-proxy analysis of a laminated sediment sequence raised from the Espumilla lagoon system, Santiago Island, will be presented. The data includes a 14C AMS radiocarbon chronology, fossil diatom analysis, magnetic susceptibility and 2mm resolution ITRAX x-ray fluorescence geochemistry. The preliminary results show that the sediment core raised from this site has vast potential for reconstructing El Niño driven rainfall over the past 2500 calibrated years BP, while at the same time revealing a detailed and interesting history of the evolution of this ecologically significant lagoon system.