Publication Date:
2013-05-22
Description:
Reconstructed Holocene lake-level curves from two saline, hydrologically closed maar crater lakes in southwestern Victoria, Australia, show near synchronous lake-level changes throughout the Holocene. We show that lake levels, reconstructed from sediment particle size and ostracod valve chemistry ( 18 O and Sr/Ca) have undergone rapid (〈100 yr), large (〉10 m) fluctuations throughout the Holocene. Finer sampling resolution shows a more sensitive response to Holocene climate than was previously presented for Lake Keilambete. Both maar crater lakes show a short-lived maximum in Holocene lake levels around 7.2 ka. The period of lake filling leading to peak lake levels matches the phase of most effective precipitation (7.4–7.0 ka) reconstructed from a high-resolution speleothem record from northern Tasmania. Water levels declined in both lakes during the mid Holocene, with a more substantive decline after ~5 ka which coincides with the end of the Southern Hemisphere hypsithermal. Water levels continued to oscillate with a periodicity of around 300–700 years, before reaching a late-Holocene nadir around 1.8 ka (Keilambete) and 1.3 ka (Gnotuk). The trend and periodicity of oscillations in the maar water levels show commonalities to D in the Dome C ice core, and suggest that temperature may be a significant component in influencing the Precipitation/Evaporation (P/E) ratio in southeastern Australia during the Holocene.
Print ISSN:
0959-6836
Electronic ISSN:
1477-0911
Topics:
Geography
,
Geosciences
Permalink
