Browsing by Author "Horrocks, M"

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    Holocene environmental change in northern New Zealand: the view through the lens of Lake Spectacle
    (Australasian Quaternary Association Inc, 2014-06-29) Augustinus, PC; Horrocks, M; Munro, H; Gadd, PS; Linnell, T
    During 30th anniversary Australasian Quaternary Association (AQUA) Biennial Conference Professor Jim Bowler and Professor Roger Jones delivered public lectures to a full house at the Grand Ball Room, Mildura. This event was introduced by Glenn Milne, Mayor, Mildura rural city council, and conducted by Dr. Jessica Reeves, former president of AQUA. In the first lecture Jim engaged us with his passionate talk on “Journey to Discover, Who are we”, where he focussed on his lifelong research at Lake Mungo. Jim reminded us about the six decades of scientific research at Mungo, including a vivid description of the day he discovered Mungo Man’s skeleton in the dunes at Joulni, which was to go on to change our understanding of Aboriginal occupation of Australia. However, his emphasis then moved onto the challenges for future research. This included the key role that the current traditional owners have in managing and facilitating science, their potential role in researching their history, and the need to establish a keeping place onsite at Mungo to repatriate the archaeological finds, both past and future. Jim finished by encouraging young researchers to engage with the site, particularly given the continued erosion of the dunes and destruction of cultural and natural heritage, especially given the world heritage listing. In the second lecture Roger focused on our future world in the face of climate change, and how we will experience it. Roger began by highlighting the dominance of uniformitarianism over catastrophism in scientific thinking during the past few centuries. He described how this trend in thought has shaped our perspective, and narratives on trends in present and future climates, highlighting the overall gradual increases in temperature with time. Roger contended that this is only part of the story, and that we miss the importance of non-linearity in the climate system – or alternatively stochastic variation along with a gradual change. He described the importance of this variability in influencing the lived experience and response of people to climate change, with particular focus on how we feel an abrupt shift given the step changes in the nature of extreme events. I think this fact should be communicated properly to make people concerned about possible future abrupt change for proper adaptation and better management. Along with all the conference attendees, many non-scientists, indigenous people and local electronic and print media reporters attended the public lecture. People were engaged by the lectures and posed some interesting questions. Both lecturers were happy to answer questions and share their practical and research experience. The public lecture got media attention and huge public interest. I think it was a great idea to arrange a public lecture during the AQUA conference as it is the best way to engage some of the community and let them know our scientific findings. I hope it will continue at all AQUA events in future. © 2014, AQUA Biennial Meeting Mildura.
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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.
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    Reciting the layers: evidence for past tsunamis at Mataora-Wairau Lagoon, Aotearoa-New Zealand
    (Elsevier B.V., 2017-07-01) King, DN; Goff, JR; Chagué-Goff, C; McFadgen, BG; Jacobsen, GE; Gadd, PS; Horrocks, M
    Sedimentary, geochemical, microfossil and geochronological analyses were carried out on 10 sediment cores across the south-eastern corner of Mataora-Wairau Lagoon (M-WL), South Island, Aotearoa-New Zealand. This multi-proxy approach provides strong evidence for three late Holocene palaeotsunamis (two previously unreported) and a historical tsunami generated by rupture of the Wairarapa Fault in 1855 CE. The main scientific evidence for these events consists of anomalous, high-energy marine sediment layers that overlie material of contrasting composition. These layers coincide with peaks in planktonic and benthic marine to brackish-marine diatoms and geochemical signatures indicative of sudden changes in environmental conditions. Palaeotsunami I (maximum date 2095 cal. BP) and Palaeotsunami II (maximum date 915 cal. BP - previously identified by Clark et al., 2015) appear to represent large events contemporaneous with major earthquakes inducing tectonic uplift and coseismic subsidence around the Cook Strait region. Palaeotsunami II is close to the date of the earliest settlement of the M-WL area by Māori, and a traditional narrative that references loss of life following waves over-washing the Wairau boulder bank. Given the boulder bank was likely to have been seaward of its current position during events I and II, we surmise that the inundation distances would have been greater than the most landward extent (340 m) inferred from the deposits found in this study. Palaeotsunami III (maximum date 525 cal. BP) was associated with tectonic subsidence across the study site, most likely associated with rupture of the southern Hikurangi subduction zone. We expect the ongoing refinement of the methods used in this study, and the results from future studies of analogue sites and offshore fault systems, will improve our understanding of the significant tsunami hazard facing this region. © 2017 Elsevier B.V.