Environmental change: a view from downunder.

Abstract ‘Downunder???in the title refers to both the underground and the Southern Hemisphere. The talk will be in two parts.

The first part explains how evidence for environmental change can be obtained from caves. The emphasis will be on the interpretation of the climatic archive contained in speleothems (stalagmites etc) and will be illustrated by examples drawn from studies around the world. A case will be made that speleothem archives are on track to supersede ice cores and marine cores in their importance, because they can be much better dated, are of much higher resolution, and contain more information. They are also available from every continent that is free of ice cover. The U/Th dating limit of ~0.5Ma has recently been extended by U/Pb and so dated speleothem records are now potentially obtainable for many millions of years.

The second part presents the evidence for climatic change obtained from New Zealand speleothems. It compares our palaeoclimate records with those obtained from elsewhere, and concludes that at the multi-millenial scale we appear to be in step with climate change on the planet, but at the millennial scale we show a marked independence with climate change in New Zealand sometimes leading that observed in the Northern Hemisphere by centuries and sometimes even thousands of years. Finally, a possible view of the future is offered by projecting forwards in time the climate cycles identified in speleothems ???but would human-induced changes exacerbate or suppress the natural swings of climate?

Supporting lecture (University centres)

New Zealand cave archives: palaeo-hydrology, -tectonics, -seismicity, and -climate.

Abstract
Limestone caves are amongst our oldest landforms; some certainly over one million and possibly three million years old. They are also protected environments in which deposits from the surrounding region of physical, chemical and biological nature accumulate. For these reasons they are natural archives of environmental change, often containing dateable evidence that complements and extends that found on the surface.

Examples will show how information can be obtained from caves on rates of water-table lowering, valley incision, flood history, uplift and tilting, seismic events, glacial and climatic history.. 

Biographical notes

Paul's interests range from geomorphology through hydrology to environmental change. He has a special research interest in caves and limestone (karst) terrains. Pure research is balanced with applied research wherever possible and he has had past involvement in projects concerned with catchment management, minimization of environmental impacts of tourist cave operations, assessment of the hydrological impacts of limestone quarrying, and evaluation of several World Heritage Park proposals for IUCN/UNESCO. He is a member of the World Council for Protected Areas of IUCN. He is currently serving as a member of the executive of the International Speleological Union and is a past member of the executive of the International Association of Geomorphologists.

Paul's current research is focused on the evidence for past climate change. He is obtaining this information from Nature's time vaults: caves. Stalagmites contain high resolution, quantitative records of past temperatures (from their oxygen isotopes). The records produced from this source are verified against palaeoclimate time series derived independently from tree-rings (by Dr Anthony Fowler and others). This is the first international attempt to cross-check quantitative palaeoclimate information obtained from these two natural archives, and the research is funded by the NZ Foundation for Research Science and Technology. He is a contributor to the INQUA core programme INTIMATE (INTegration of Ice, Marine and TERrrestrial records - see the Alloway et al. (2007) publication listed below.

Paul's teaching interests mirror and draw on his research experience, which has involved fieldwork in China, Papua New Guinea, Nuie, Australia, western Europe, USA and throughout New Zealand.

Paul's formal qualifications include degrees from Durham, Dublin and Cambridge (PhD, ScD) Universities. Before joining the staff at Auckland, he was a member of staff at the Australian National University and at the University of Dublin (TCD). He has served as Head of Department and Deputy Dean of Science.

Some publications

'Karst Hydrogeology and Geomorphology', Chichester, Wiley, 2007: 555 pp. (with Ford, D.C.).

'Towards a climate event stratigraphy for New Zealand over the past 30 000 years (NZ-INTIMATE project).' Journal of Quaternary Science 22(1), 2007: 9-35 (with Alloway, B. and members of the NZ-INTIMATE project).

'Late Pleistocene to Holocene composite speleothem chronologies from South Island, New Zealand - did a global Younger Dryas really exist?' Earth and Planetary Science Letters, 230(3-4), 2005: 301-17 (with King, D.N.T., Zhao, J.-X. and Collerson, K.D.)

'The evolution of the mountains in New Zealand '. In Mountain Geomorphology, (Owens, P. and Slaymaker, O. eds), London , Arnold , 2004: 89-106.

'Speleothem master chronologies: combined Holocene 18O and 13C records from the North Island of New Zealand and their palaeo-environmental interpretation'. The Holocene 14(2): 194-208, 2004 (with King D., Zhao J.-X. and Collerson K.).

'Polygonal karst and palaeokarst of the King Country, North Island, New Zealand', Zeitschrift für Geomorphologie, Suppl.-Vol. 136, 2004: 45-67

'Karst Systems'. In Freshwaters of New Zealand Harding, (Mosley, J., Pearson, P., Sorrell, B. (eds.), Christchurch, NZ Hydrological Society, 2004: 31.1- 31.20.

'The epikarst: evolution of understanding'. In Epikarst (Jones, W.K., Culver, D.C. and Herman, J.S. eds) . Charles Town WV, Karst Waters Institute, Special Publication 9, 2004: 8-15.

'Relationship between oxygen isotopes in rainfall, cave percolation waters and speleothem calcite at Waitomo, New Zealand. New Zealand Journal of Hydrology, 41(1), 2002: 53-70 (with Fowler, A.).

Christian Gottlieb Ferdinand von Hochstetter (1829-1884)

Hochstetter was born in Esslingen in the Kingdom of Wurttemberg and joined the Austrian Geological Survey in 1853. Four years later he was appointed geologist on the Austrian frigate Novara that undertook a global scientific cruise. The Novara berthed in Auckland, then the capital of New Zealand, on 22 December 1858. At the request of the New Zealand Government and supported by the Auckland Provincial Council, Hochstetter, accompanied by Julius Haast and others, surveyed the Drury Coal Field to the south of the capital.

This was accomplished so successfully that the provincial council persuaded the commander of the Novara to allow Hochstetter to remain in New Zealand so that he could undertake further work in the province. Over the next five months Hochstetter and Haast, and a support team, visited much of southern part of Auckland Province, including the volcanic region and the gold diggings at Coromandel Harbour.

On completion of his Auckland mapping, Hochstetter was commissioned by the Nelson Provincial Council to report on the mineral wealth of the province. Hochstetter, accompanied by Haast, arrived in Nelson, after brief stops at New Plymouth and Wellington, on 4 August 1859. In Nelson, they examined Dun Mountain, and from which he collected and subsequently named dunite, the Aorere Gold Field and other places of interest. While Hochstetter visited the Wangapeka Gold Field in the west and Lake Roto-it, Haast geologically examined the eastern part of the province . Hochstetter left Nelson for Sydney on 1 October 1859, on the first leg of his return voyage to Europe.

His geological maps of Auckland and Nelson were the first of their kind in New Zealand.

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Website editor's note: the "o" in Hochstetter definitely does not carry an umlaut (ö)