Holocene climate variability in south east Australia; inferred from oxygen isotopes in sedimentary cellulose at Lake Surprise, Victoria

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dc.contributor.authorDharmarathna, Aen_AU
dc.contributor.authorTyler, JJen_AU
dc.contributor.authorBarr, Cen_AU
dc.contributor.authorTibby, Jen_AU
dc.contributor.authorJones, MDen_AU
dc.contributor.authorAnjor, MJen_AU
dc.contributor.authorCadd, Hen_AU
dc.contributor.authorGadd, PSen_AU
dc.contributor.authorHua, Qen_AU
dc.contributor.authorChild, DPen_AU
dc.contributor.authorZawadski, Aen_AU
dc.contributor.authorHotchkis, MACen_AU
dc.contributor.authorZolitschka, Ben_AU
dc.date.accessioned2023-10-20T02:25:49Zen_AU
dc.date.available2023-10-20T02:25:49Zen_AU
dc.date.issued2022-05-23en_AU
dc.date.statistics2023-02-02en_AU
dc.description.abstractSouth east Australia experienced periods of multi-year droughts particularly within the last 2 millennia. However, given the limited evidence from smaller number of sites and scarcity of quantitative, high-resolution climate records, it is largely unknown whether these droughts are a feature of climate through the Holocene and the extent to which they are experienced throughout the region. Where conditions are suitable, oxygen isotopes preserved in lake sediments are a useful tool for reconstructing past climate and environmental conditions. Here, we present preliminary results of a Holocene length record from Lake Surprise in western Victoria, from which we analysed δ18O of aquatic cellulose as a proxy for lake-water δ18O, complemented by organic carbon/nitrogen ratios, organic carbon isotopes and XRF (ITRAX) inferred elemental composition. Our interpretation of the palaeo-data is supported by ~3 monthly monitoring of water and sediment geochemistry to track the modern hydrology of the lake. Our preliminary results show a strong positive correlation between precipitation and sedimentary calcium (carbonate deposition) over the last 150 years, likely linked to changes in primary productivity. The aquatic cellulose δ18O record through Holocene is also correlated with carbonate concentration, reinforcing our interpretation of CaCO3 deposition in the lake during wet periods. The cellulose δ18O record indicates a trend of gradually increasing aridity from early to late Holocene, with a notable extremely dry phase over the last 2 ka. Comparison of the cellulose δ18O record with high-resolution Holocene climate records indicates that multiple climate drivers such as ENSO intensification and Antarctic warming are strongly linked to increasing aridity of the region. Further work will focus on both increasing the resolution of the record to better identify the frequency and duration of key events and on quantifying natural hydroclimate variability, particularly via lake hydrologic modelling to better constrain the paleoclimate record. © Author(s) 2022. Creative Commons Attribution 4.0 Licence.en_AU
dc.identifier.articlenumberEGU22-10775en_AU
dc.identifier.citationDharmarathna, A., Tyler, J., Barr, C., Tibby, J., Jones, M., Ankor, M., Cadd, H., Gadd, P., Hua, Q., Child, D., Zawadski, A., Hotchkis, M., & Zolitschka, B. (2022). Holocene climate variability in south east Australia; inferred from oxygen isotopes in sedimentary cellulose at Lake Surprise, Victoria. Presentation to the EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10775. Retrieved from: https://doi.org/10.5194/egusphere-egu22-10775, 2022.en_AU
dc.identifier.conferenceenddate2022-05-27en_AU
dc.identifier.conferencenameEGU General Assembly 2022en_AU
dc.identifier.conferenceplaceVienna, Austriaen_AU
dc.identifier.conferencestartdate2022-05-23en_AU
dc.identifier.urihttps://meetingorganizer.copernicus.org/EGU22/EGU22-10775.htmlen_AU
dc.identifier.urihttps://apo.ansto.gov.au/handle/10238/15160en_AU
dc.language.isoenen_AU
dc.publisherEuropean General Assemblyen_AU
dc.relation.urihttps://meetingorganizer.copernicus.org/EGU22/EGU22-10775.htmlen_AU
dc.subjectQuaternary perioden_AU
dc.subjectClimatesen_AU
dc.subjectAustraliaen_AU
dc.subjectDroughtsen_AU
dc.subjectVictoriaen_AU
dc.subjectOxygen isotopesen_AU
dc.subjectSedimentsen_AU
dc.subjectLakesen_AU
dc.subjectEnvironmenten_AU
dc.subjectEcologyen_AU
dc.subjectCelluloseen_AU
dc.titleHolocene climate variability in south east Australia; inferred from oxygen isotopes in sedimentary cellulose at Lake Surprise, Victoriaen_AU
dc.typeConference Abstracten_AU
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