Palaeoenvironmental change in tropical Australasia over the last 30,000 years - a synthesis by the OZ-INTIMATE group
- Reeves, Jessica, Bostock, Helen, Ayliffe, Linda, Barrows, Timothy, De Deckker, Patrick, Devriendt, Laurent, Dunbar, Gavin, Drysdale, Russell, Fitzsimmons, Kathryn, Gagan, Michael, Griffiths, Michael, Haberle, Simon, Jansen, John, Krause, Claire, Lewis, Stephen, McGregor, Helen, Mooney, Scott, Moss, Patrick, Nanson, Gerald, Purcell, Anthony, van der Kaars, Sander
- Authors: Reeves, Jessica , Bostock, Helen , Ayliffe, Linda , Barrows, Timothy , De Deckker, Patrick , Devriendt, Laurent , Dunbar, Gavin , Drysdale, Russell , Fitzsimmons, Kathryn , Gagan, Michael , Griffiths, Michael , Haberle, Simon , Jansen, John , Krause, Claire , Lewis, Stephen , McGregor, Helen , Mooney, Scott , Moss, Patrick , Nanson, Gerald , Purcell, Anthony , van der Kaars, Sander
- Date: 2013
- Type: Text , Journal article
- Relation: Quaternary Science Reviews Vol. 74, no. (2013), p. 97-114
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- Description: The tropics are the major source of heat and moisture for the Australasian region. Determining the tropics' response over time to changes in climate forcing mechanisms, such as summer insolation, and the effects of relative sea level on exposed continental shelves during the Last Glacial period, is an ongoing process of re-evaluation. We present a synthesis of climate proxy data from tropical Australasia spanning the last 30,000 years that incorporates deep sea core, coral, speleothem, pollen, charcoal and terrestrial sedimentary records.Today, seasonal variability is governed largely by the annual migration of the inter-tropical convergence zone (ITCZ), influencing this region most strongly during the austral summer. However, the position of the ITCZ has varied through time. Towards the end of Marine Isotope Stage (MIS) 3, conditions were far wetter throughout the region, becoming drier first in the south. Universally cooler land and sea-surface temperature (SST) were characteristic of the Last Glacial Maximum, with drier conditions than previously, although episodic wet periods are noted in the fluvial records of northern Australia. The deglacial period saw warming first in the Coral Sea and then the Indonesian seas, with a pause in this trend around the time of the Antarctic Cold Reversal (c. 14.5ka), coincident with the flooding of the Sunda Shelf. Wetter conditions occurred first in Indonesia around 17ka and northern Australia after 14ka. The early Holocene saw a peak in marine SST to the northwest and northeast of Australia. Modern vegetation was first established on Indonesia, then progressively south and eastward to NE Australia. Flores and the Atherton Tablelands show a dry period around 11.6ka, steadily becoming wetter through the early Holocene. The mid-late Holocene was punctuated by millennial-scale variability, associated with the El Niño-Southern Oscillation; this is evident in the marine, coral, speleothem and pollen records of the region. © 2012.
- Description: 4 Earth Sciences
- Description: 21 History And Archaelogy
- Description: 2003011213
- Authors: Reeves, Jessica , Bostock, Helen , Ayliffe, Linda , Barrows, Timothy , De Deckker, Patrick , Devriendt, Laurent , Dunbar, Gavin , Drysdale, Russell , Fitzsimmons, Kathryn , Gagan, Michael , Griffiths, Michael , Haberle, Simon , Jansen, John , Krause, Claire , Lewis, Stephen , McGregor, Helen , Mooney, Scott , Moss, Patrick , Nanson, Gerald , Purcell, Anthony , van der Kaars, Sander
- Date: 2013
- Type: Text , Journal article
- Relation: Quaternary Science Reviews Vol. 74, no. (2013), p. 97-114
- Full Text:
- Reviewed:
- Description: The tropics are the major source of heat and moisture for the Australasian region. Determining the tropics' response over time to changes in climate forcing mechanisms, such as summer insolation, and the effects of relative sea level on exposed continental shelves during the Last Glacial period, is an ongoing process of re-evaluation. We present a synthesis of climate proxy data from tropical Australasia spanning the last 30,000 years that incorporates deep sea core, coral, speleothem, pollen, charcoal and terrestrial sedimentary records.Today, seasonal variability is governed largely by the annual migration of the inter-tropical convergence zone (ITCZ), influencing this region most strongly during the austral summer. However, the position of the ITCZ has varied through time. Towards the end of Marine Isotope Stage (MIS) 3, conditions were far wetter throughout the region, becoming drier first in the south. Universally cooler land and sea-surface temperature (SST) were characteristic of the Last Glacial Maximum, with drier conditions than previously, although episodic wet periods are noted in the fluvial records of northern Australia. The deglacial period saw warming first in the Coral Sea and then the Indonesian seas, with a pause in this trend around the time of the Antarctic Cold Reversal (c. 14.5ka), coincident with the flooding of the Sunda Shelf. Wetter conditions occurred first in Indonesia around 17ka and northern Australia after 14ka. The early Holocene saw a peak in marine SST to the northwest and northeast of Australia. Modern vegetation was first established on Indonesia, then progressively south and eastward to NE Australia. Flores and the Atherton Tablelands show a dry period around 11.6ka, steadily becoming wetter through the early Holocene. The mid-late Holocene was punctuated by millennial-scale variability, associated with the El Niño-Southern Oscillation; this is evident in the marine, coral, speleothem and pollen records of the region. © 2012.
- Description: 4 Earth Sciences
- Description: 21 History And Archaelogy
- Description: 2003011213
- Roberts, Georgia, Towers, Jacqueline, Gagan, Michael, Cosgrove, Richard, Smith, Colin
- Authors: Roberts, Georgia , Towers, Jacqueline , Gagan, Michael , Cosgrove, Richard , Smith, Colin
- Date: 2019
- Type: Text , Journal article
- Relation: Palaeogeography, Palaeoclimatology, Palaeoecology Vol. 523, no. (2019), p. 97-115
- Full Text: false
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- Description: Archaeologists and palaeoecologists are increasingly turning to stable isotope analysis (δ 13 C, δ 18 O) of fossil bioapatite to examine interactions of human and animal populations. However, relatively few investigations have focussed on the identification of natural variation in comparable modern populations, particularly within the Australian context. In this paper, we present the first modern isotopic reference dataset for Tasmanian bare-nosed wombat teeth (Vombatus ursinus tasmaniensis). Samples for δ 13 C bioapatite and δ 18 O bioapatite measurements were recovered sequentially at sub-monthly resolution from all tooth types. δ 13 C bioapatite showed little variation within a seasonal sinusoidal pattern within the sample set (n = 24 wombats; 35 teeth) due to the homogeneous C 3 distribution of plants in Tasmania. In contrast, δ 18 O bioapatite profiles varied seasonally, representing time periods of between 0.9 and 2.1 years in 95% of the sample. Significant differences between tooth types were found from intra-individual to inter-regional scales for both dental growth rates and isotopic values. The accuracy of season-of-death assessments differed across the island; those in eastern Tasmania were accurate in all instances whereas those in the west showed substantial inaccuracies. We suggest that this may be due to the elodont form of wombat dentition and the ecologically influenced seasonally varied diet in western Tasmania. As the rate of dental growth is positively correlated with the proportion of coarse vegetation within the diet, this seasonal variation is therefore likely to change how annual isotopic signals are incorporated into the enamel. These results highlight the need to understand the degree of species-specific isotopic variation at a range of scales before applying this technique to archaeological or palaeontological assemblages.
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