Browsing by Author "Dudley, W"

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    Multi-proxy evidence for trans-Pacific tsunamis in the Hawai'ian Islands
    (Elsevier, 2012-03-01) Chagué-Goff, C; Goff, JR; Nichol, SL; Dudley, W; Zawadzki, A; Bennett, JW; Mooney, SD; Fierro, D; Heijnis, H; Dominey-Howes, D; Courtney, C
    The origin of two sand layers buried in Pololū wetland, on the northeast coast of the island of Hawai'i, was investigated using a multi-proxy approach, including radiometric dating, sedimentology, geochemistry, micropalaeontology, palynology and historical records. Based on 210Pb, 137Cs and pollen data, the lower sand unit extending 250 to 350 m inland is attributed to the 1946 Aleutian tsunami, while the upper sand unit was laid down by the 1957 Aleutian tsunami. Chronological information does not appear to support any link between these deposits and historical storm events. Furthermore, sedimentological, geochemical, diatom and pollen results suggest deposition of marine and near-beach sediments under high energy conditions typically associated with tsunami inundation. This work presents the first conclusive sedimentary evidence for distantly-generated tsunamis on the Hawai'ian Islands, opening the way for more comprehensive historical and palaeotsunami studies. Indeed, a brief review of archaeological data suggests that the Hawai'ian coast may have experienced similar large magnitude events in the past, from both local and distant sources. © 2012 Elsevier
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    Palaeotsunamis in the Pacific Islands
    (Elsevier, 2011-07-01) Goff, JR; Chagué-Goff, C; Dominey-Howes, D; McAdoo, B; Cronin, S; Bonté-Grapetin, M; Nichol, SL; Horrocks, M; Cisternas, M; Lamarche, G; Pelletier, B; Jaffe, BE; Dudley, W
    The recent 29 September 2009 South Pacific and 27 February 2010 Chilean events are a graphic reminder that the tsunami hazard and risk for the Pacific Ocean region should not be forgotten. Pacific Islands Countries (PICs) generally have short ( < 150 years) historic records, which means that to understand their tsunami hazard and risk researchers must study evidence for prehistoric events. However, our current state of knowledge of palaeotsunamis in PICs as opposed to their circum-Pacific counterparts is minimal at best. We briefly outline the limited extent of our current knowledge and propose an innovative methodology for future research in the Pacific. Each PLC represents a point source of information in the Pacific Ocean and this would allow their palaeotsunami records to be treated akin to palaeo-DART (R) (Deep-ocean Assessment and Reporting of Tsunamis) buoys. Contemporaneous palaeotsunamis from local, regional and distant sources could be identified by using the spatial distribution of island records throughout the Pacific Ocean in conjunction with robust event chronologies. This would be highly innovative and, more importantly, would help provide the building blocks necessary to achieve more meaningful disaster risk reduction for PICs. (C) 2010 Elsevier B.V.