Keynote speakers and public science talks
AQUA Conference keynote speaker bios and presentation abstracts.
Professor Atholl Anderson FRSNZ is descended from Maori-Pakeha families on Rakiura. He has undertaken a lifetime of archaeological research spanning the entire Indo-Pacific from Madagascar, Seychelles and Diego Garcia, through the Batanes (Philippines), Yaeyama (Japan) and Palau islands, to New Caledonia, Fiji, Niue, Kiribati, French Polynesia, and the Juan Fernandez and Galapagos groups. His main interest has been in pre-European island colonisation, encompassing themes of seafaring, migration chronology, colonisation behaviour and environmental change. He is an Emeritus-Professor of the Australian National University where he held the chair of Prehistory in the Institute of Advanced Studies. He was Leverhulme Professor at York, Slater Fellow and Distinguished Fellow at Durham, Research Fellow at the University of Tokyo and a Visiting Fellow at Clare Hall and Corpus Christi College, Cambridge.
(Biographic details taken from the Royal Society website)
Abstract of Anderson AQUA 2016 Keynote:
The role of climate change in South Polynesian colonization and cultural development AD 1200-1800
Climatic determinism, has had a troubled history in accounting for cultural variation or change, yet at some scales of analysis, or by magnitude, various cases of climate change can be hypothesized as highly influential for cultural trajectories, notably in oceanic islands. How far might that seem plausible for the initial colonization of South Polynesia (New Zealand and its outlying islands) in the 13th century and for the cultural transformation that occurred during Maori history prior to the 19th century? Initial colonization has been understood primarily within a framework of ‘traditionalism’ in which long-distance voyaging is thought to have involved sophisticated maritime technology operating in modern oceanic climates. Recent work casts doubt on both aspects of that model and suggests that climatic change may have played an influential role. Transformation of initial Polynesian colonists into New Zealand Maori was undoubtedly an intricate process involving a diversity of variables, in which population growth is generally regarded as the primary underlying impulsion. However, cultural change was at least contextualized within the span of the LIA and that might have played a more prominent role than is generally assumed. The most conspicuous archaeological evidence of cultural transition is an expansion of agricultural sites and forts, beginning in the fifteenth century, which is skewed strongly toward the upper North Island. This new settlement pattern, less developed in central districts and virtually absent further south, marked a north-south gradient of economic opportunity that has its origins in a deteriorating climate. As evidence from tribal histories can be read as recording the concurrent emergence of a similar north-south trend in responses to warfare, including by migration, the influence of climatic change in creating the Maori social landscape might be more profound than has yet been envisaged.
Dr Matt McGlone’s Quaternary Science research has spanned more than four decades and covered most of New Zealand and the sub-Antarctic Islands. His work has provided a valuable contribution to improving our understanding of climate change, botanical, ecological, and anthropological processes. Key components of Matt’s palynology, macrofossil, and charcoal work helped to detect the timing of human arrival in New Zealand and the deforestation impacts caused by Maori and Europeans. He has also integrated a diverse set of research threads using different proxies to reveal climate changes over interglacial-glacial cycles. Matt’s work in New Zealand has also highlighted the effects of ENSO variability and seasonality on New Zealand vegetation and landscape changes, and enabled a better research platform for investigating inter-hemispheric climate change linkages.
Abstract of McGlone AQUA 2016 Keynote:
Ascarina lucida and the climatic interpretation of the NZ Quaternary
Ascarina lucida (hutu) stands out among NZ plants as an environmental indicator. A small, disturbance favoured, bird dispersed tree, it ranges virtually the whole length of the mainland and reaches the Kermadec Islands as an outlier. Nevertheless, Ascarina appears to be incredibly choosy about sites, and is not often common. A primitive, basal angiosperm, its inefficient vascular system makes it highly vulnerable to dry air but, as a disturbance specialist, it needs open canopy space. Having been derived in relatively recent times from the tropical islands to the north, it will only tolerate light frosts; nevertheless, it is most abundant in the cooler south. It therefore occupies a quite limited range of sites: in the South Island in the very wettest areas between sea level and 500 m; in the North Island on cloud-capped mountains between 250 m and 750 m.
Ascarina produces abundant, wind-dispersed pollen. However, nowhere in New Zealand does its present pollen values match those of the early to mid Holocene or, for that matter, previous interglacial peaks. It appears then, that its hyper-abundance in the past is trying to tell us something about full interglacial climates. Exactly what this message might be, and its implications for climatic patterns of the past, will be the subject of this address.
Associate Professor Phil Shane studies the eruption histories of volcanoes. A major focus is the rhyolite eruptive history of the Okataina Volcanic Centre in central North Island. This work involves using the mineralogy and geochemistry of pyroclastic deposits to gain insight to pre-eruptive mechanisms such as triggering and magma-mixing. U-Th geochronology of zircons is being used assess magma longevity. A similar study is being conducted on volcanoes in Dominica and St Lucia. At Mt Ngauruhoe, a study focussing on plagioclase crystallisation histories is being undertaken. The ascent and eruption of basaltic magmas in the Bay of Islands is a new investigation that has started. The eruptive history of the basaltic Auckland Volcanic Field using tephra layers in ancient lake sediments is another current area of study. The purpose of that study is to assess past frequency and magnitude of eruptions for hazard analysis. This also involves drilling a deep hole through Rangitoto volcano to assess its volcanic history. Other programs include the deep-sea tephra record from Kermadec arc volcanoes; and the dispersal of tephra in oceans surrounding New Zealand for the purposes of paleoceanography.
(biographic and career details taken from the University of Auckland website)
Abstract of Shane AQUA 2016 Keynote:
Long life of Rangitoto volcano revealed by drilling
Drilling through the edifice of Rangitoto, the youngest and largest volcano in the ‘monogenetic’ Auckland Volcanic Field (AVF), reveals the multi-stage eruptive and magmatic history of a small basalt shield volcano. Previously, the volcano was thought to have been constructed in one or two short episodes about 500 cal yr BP. New data indicates activity commenced up to 6000 cal years BP, involving minor effusive and pyroclastic volcanism until 650 cal yr BP. This period either represents an early, less productive phase of a single polygenetic volcano, or alternatively, Rangitoto is better described as a volcanic complex that includes one or more buried edifices concealed by the main structure. A voluminous shield building phase occurred 650-550 cal years BP, erupting isotopically-uniform sub-alkalic basalts (Mg# 60-64). Four batches of magma distinguished by trace element chemistry were erupted sequentially. Some of the temporal-compositional trends are consistent with cycles of progressive partial melting at the source. The final phase of activity (~550-500 cal years BP) was explosive and less voluminous, producing scoria cones at the summit. This phase involved more diversity in magma compositions including more mafic sub-alkalic basalt, and alkali basalt, pointing to sourcing of magmas simultaneously from different depths in the mantle. Rangitoto volcano contributes to a growing body of evidence that major periods of volcanism in ‘monogenetic’ basalt fields occur at centers that have experienced multiple eruption episodes. Changes in magma composition accompany changes in eruption style, but a lack of an obvious shared pattern in magmatic evolution at various volcanoes points to the localized mantle heterogeneity and conduit systems. Hazard scenarios for regions traditionally classified as ‘monogenetic’ need to encompass the possibility of prolonged episodes of activity and reawakening of volcanoes, a significant implication where infrastructure is built on such regions.
Public Science Talks
AQUA 2016 hosted two public science talks, held at Old Government House, University of Auckland
Lake Ohau Climate History (LOCH) project: A 17,000 year-long annually-resolved palaeoclimate record and its potential to decipher the phasing of high frequency climate modes in Southern New Zealand
Dr Marcus Vandergoes
5 December, 6.30 pm
Geological records that span millennia yet still capture paleo-environmental information at seasonal-annual resolution can make an important contribution to understanding the spatial and temporal variability of climate processes that vary at high frequency, such as the El Niño Southern Oscillation (ENSO) and the Southern Annular Mode (SAM). However, such records are scarce and are particularly rare in the southern hemisphere. In February/March 2016 two sites were double-cored by hydraulic piston corer (HPC) in Lake Ohau, New Zealand (44°17’S, 169°55’E) as part of the Lake Ohau Climate History (LOCH) project. Both sites yielded mm-scale laminated sediments representing annually-resolved accumulation in the lake basin from ~17,000 years before present to today. We outline LOCH project developments to date, including the first usage of a globally transportable HPC system. This system uses principles established by the Ocean Drilling Program and is capable of coring >100 m of unconsolidated sediment. We also report the initial results of physical properties core scanning, including computed tomography (CT) which yields whole-volume core density data at 600 micron resolution, as well as paleomagnetic and micropaleontological studies. We provide preliminary time-series analysis of annual to centennial-scale climate variability reconstructed for the past 1,300 years and highlight the potential of the complete 17,000 year long record to decipher the phasing of high frequency climate modes in southern New Zealand and the mid-latitudes of the Southern Hemisphere.
Marcus Vandergoes is a senior scientist at GNS Science specialising in environmental change, paleoecology and paleoclimatology. A particular focus of Marcus’s research is to understand the role of the Antarctic and Southern Ocean in driving past climate change in New Zealand and the Southern Hemisphere, and the natural (pre-instrumental) variability of environmental change using natural archives covering the past 150,000 years. He has a key interest in multi-proxy environmental reconstruction that integrate disciplines including paleoecology, glacial geomorphology, geochronology and organic geochemistry. A focus of this work has been to develop methods to quantify past environmental and climate change by deriving temperature estimates using ecological indicators (chironomid (midge fly larvae) and bacterial biomarkers) from New Zealand lake sediments. His field work and research experience includes working in Antarctica, New Zealand subantarctic Islands, Patagonia, and the USA.
Back to the Future: Last Interglacial Warmth and the Stability of the Antarctic Ice Sheets
Professor Chris Turney
7 December, 6.30 pm
Recent studies modelling the Antarctic ice sheet contribution to future global sea level rise range from negligible to substantial (>7m). A useful analogue in this regard is the Last Interglacial (LIG; 135-116 ka) during which reconstructed past sea levels imply a significant ice mass loss from both Greenland and Antarctic ice sheets, contributing to a global sea level 6.6 to 9.4 metres above present day. Climate reconstructions and models of the Last Interglacial, however, suggest a wide range of global temperatures, from relatively small differences compared to present day to large warming (>2˚C) at high latitudes (so-called ‘polar amplification’). This limits our understanding of the sensitivity of the ice sheets to warming. Previous work combining terrestrial and marine records spanning the LIG is challenge given chronological and seasonality biases. Marine records are arguably better constrained in these regards but recent work has highlighted the importance of ocean current drift in introducing temperature biases into palaeo-reconstructions where the offset may reach 1.5 °C for planktonic foraminifera living for a month and 3.0 °C for longer-living species. Here we exploit an updated marine record of quantified temperature estimates across the LIG d18O plateau and attempt to quantify for bias introduced by ocean current drift to generate an accurate and precise estimate of global LIG temperatures. Using the new reconstructed sea surface temperatures we drive a coupled ice-sheet/ice-shelf model to investigate the contribution of Antarctic ice sheets to global sea level rise during the LIG.
Chris Turney is a Professor of Climate Change and Earth Science at the University of New South Wales. Working across the globe, Chris is extending historic records back to 130,000 years ago to better understand the future. As part of this work, Chris co-ordinates the international Earth's Past Future Project (www.earthspastfuture.com). Chris has published more than 165 papers, 1 textbook and 3 popular science books with 2 Highly Cited Papers listed in Thomson Reuters’ Essential Science Indicators. Described by the UK Saturday Times as the ‘new David Livingstone’, Chris’ team communicate their findings in the field as Intrepid Science (intrepidscience.com), reporting discoveries when they happen, where they happen. Chris has received several awards, including the Australian Academy of Sciences Frederick Stone Award (2014), the inaugural Sir Nicholas Shackleton Medal (2007) and the Geological Society of London’s Bigsby Medal (2009). Chris is a Fellow of the Royal Society of Arts, Geological Society of London, and the Royal Geographical Society.