[Aqualist] Potential PhD project

[Chris Turney]

Hi Everyone,

Would you mind circulating the following PhD project to any potential  
students?   Sorry for any cross-posting.

Best wishes,

Chris
TESTING HYPOTHESES OF SYNCHRONOUS INTERHEMISPHERIC CLIMATIC CHANGE  
(60,000 YEARS AGO – PRESENT)

Kliti Grice, Curtin University of Technology, WA
Chris Turney, University of Wollongong, NSW
Peter Kershaw, Monash University, VIC

ABSTRACT

Over much of the past 60,000 years, climate in the North Atlantic  
region was characterised by a series of millennial-scale  
oscillations. A key question in Quaternary climate change is the  
extent to which these changes were experienced globally and the role  
the North Atlantic might have played in generating and transmitting  
these signals. Elucidating past processes is crucial as Australia is  
highly sensitive to change with the northern part of the country  
being in the immediate proximity of a major source of global latent  
heat release (the West Pacific Warm Pool) which is moderated by the  
El Niño-Southern Oscillation (ENSO). The high-resolution sequence  
Lynch's Crater (Queensland) (Turney et al. 2004) has been identified  
as ideal to for investigating changes in ENSO. Due to the relatively  
high aridity, palaeoenvironmental reconstructions are largely based  
on pollen. An alternative approach is to utilise stable carbon and  
hydrogen isotope ratios of individual molecular fossils (biomarkers)  
and their abundances to provide a quantification of climatic change.  
Chronological control will be attained using the latest state of the  
art radiocarbon dating techniques devised by Turney et al. (2001).

This project will utilise the latest developments in isotopic  
analysis and radiocarbon dating to test hypotheses concerning the  
timing and synchroneity of climate change between the hemispheres  
during this period.

SCIENTIFIC RATIONALE

Future changes in climate and the environment have the potential to  
increase both in amplitude and frequency relative to the recent past.  
A potential analogue for this future climate change scenario is the  
last 60,000 years. Within the North Atlantic region, this period  
includes a series of rapid and severe millennial-scale climatic  
oscillations referred to as Dansgaard-Oeschger and Heinrich events  
(Bond et al., 1993) that have been identified in oceanic, ice and  
terrestrial records throughout the Northern Hemisphere (Voelker et  
al., 2002).

Interpretations are complicated in Australia by the extent to which  
ENSO and the associated WPWP was in operation during this period.  
Recently, millennial-scale and semi-precessional changes in  
‘moisture’ in northern Australia imply increased frequency of warm  
phases of ENSO correlated to Dansgaard-Oeschger interstadials and  
Heinrich Events in the North Atlantic region, consistent with a  
tropical Pacific role in forcing high-latitude climate changes  
(Turney et al., 2004). Thus, precise correlation of quantified  
climate estimates is critical to gain a better understanding of the  
exact timing and mechanisms of past global change. Distributions of  
biomarkers and their isotopic signals derived from algae, bacteria  
and land plants preserved in lacustrine and peat deposits will be  
studied.

Extensive work has now been undertaken demonstrating the potential of  
this approach for reconstructing palaeoenvironmental and –climatic  
reconstructions (e.g. Street-Perrott et al., 1997) though these have  
largely remained qualitative in nature.

This project will utilise isotopic analyses of specific compounds in  
strategically identified sequences to achieve the following:

1. Climatic calibration of isotopic values obtained from contemporary  
plant components

2. Extraction of suitable specific compounds from high-resolution  
sequences spanning the last 60,000 years and representing changes in  
climatically-sensitive locations

3. Test hypotheses of synchronous climate change between the hemispheres


METHODS

Extending the work of Turney et al. (1999) who calibrated  
contemporary plant d13C against atmospheric moisture content, this  
project will undertake a comprehensive collection program of  
different plant samples obtained from sites across the climatic range  
of Australia and adjacent to meteorological stations. Following  
standard extraction procedures, a range of different specific  
compounds for stable isotopic analysis will be examined using the  
stable isotopic facilities at the University of Wollongong. The  
results will be calibrated against contemporary climatic parameters  
and allow quantitative estimates. The high-resolution sequence  
Lynch’s Crater will be the focus of this project, already having  
multiproxy investigations (including pollen) undertaken on it. Using  
the specific compounds identified from the contemporary study, this  
project will comprehensively analyse the sediments to quantify past  
changes. The biomarker and isotopic work will be carried out in the  
Stable isotope and biogeochemistry group in the Department of Applied  
Chemistry at Curtin University of Technology under the guidance of  
Kliti Grice. Funding for 14C AMS ages will be made through AINSE and  
an ARC Discovery Grant held by Chris Turney.



APPLICATION DETAILS

The PhD student will be based at Curtin University of Technology.  
Students wishing to apply for this project must hold an Australian  
Postgraduate Award (APA) or a CUPS (Curtin scholarship). Deadline for  
award applications is 31 October 2006. Application forms for these  
awards can be obtained at http://scholarships.curtin.edu.au/ 
scholarship.cfm?id=3. The successful applicant will be eligible for a  
top-up scholarship to assist with research costs. Candidates  
interested in applying are welcome to contact Kliti Grice  
(K.Grice at curtin.edu.au) or Chris Turney (turney at uow.edu.au).

REFERENCES

Bond, G. et al. (1993) Nature, 365, 143-147.
Kershaw, A.P. (1986) Nature, 322, 47-49.
Kershaw, A.P. (1995) Antiquity, 69, 656-675.
Pancost, R.D. et al. (2003) The Holocene, 13, 921-932.
Street-Perrott, F.A. et al. (1997) Science, 278, 1422-1426.
Turney, C.S.M. et al. (1999) J. Quat. Sci., 14, 437-442.
Turney C.S.M. et al. (2001) J. Quat. Sci, 16, 767-771.
Turney, C.S.M., et al. (2004) Nature, 428, 306-310.
Voelker, A.H.L. et al. (2002) Quaternary Science Reviews, 21, 1185-121



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Dr. Chris Turney

Bones, Rocks and Stars: The Science of When Things Happened.
Published by Macmillan Science in June 2006:
www.macmillanscience.com/1403985995.htm
Popular science website: www.christurney.com

Journal of Quaternary Science Asian and Australasian Regional Editor (
www.interscience.wiley.com/journal/jqs)
President to the INQUA Sub-Commission for Tephrochronology and Volcanism
(SCOTAV)
Web page: www.gns.cri.nz/inquatephra/

See images of Homo floresiensis ('the Hobbit') at www.uow.edu.au/
science/eesc/geoquest/hf/hf_images.html

Australian Research Council Queen Elizabeth II Fellow
School of Earth and Environmental Sciences
University of Wollongong
Wollongong
NSW 2522
Australia

Home page: www.uow.edu.au/science/eesc/staff/cturney/ct.html
E-mail: turney at uow.edu.au
Office Tel.: +61 2 4221 3561
Lab. Tel.: +61 2 4221 5906
Fax.: +61 2 4221 4250

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Slartibartfast:  Science has achieved some wonderful things of  
course, but I'd far
rather be happy than right any day
Arthur Dent:  And are you?
Slartibartfast:  No.  Thats where it all falls down of course.
Arthur Dent:  Pity.  It sounded like quite a good lifestyle otherwise.

The Hitchhikers Guide to the Galaxy, Douglas Adams

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