NERC Research Fellow
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The purpose of my research is to understand how the changing global temperatures affect the permafrost and desert regions of the world, especially during the periods when global temperatures were warmer than pre-industrial Holocene. I use Neogene/Quaternary record of carbonate cave deposits (speleothems) to access the paleoenvironmental conditions.
Speleothems form in caves when rain/snow waters seep from the surface, dissolve carbonate rocks above the cave, which is then re-deposited as secondary CaCO3 inside the cave. No speleothem deposition can occur without flowing water, i.e. when the mean annual temperature is below 0°C, or in arid climate. Therefore, speleothems which are found in presently permafrost or arid regions must be relicts from earlier warmer/wetter periods.
Speleothems can be accurately dated using U-Th and U-Pb methods. Speleothem deposition periods show when warm periods occurred in regions that are presently permafrost, and when the humid periods occurred in present-day desert.
My present research includes paleoclimate of Siberia and Mongolian Gobi Desert. My purpose is to find when mean annual temperatures in Siberia were above 0°C and when the Gobi Desert in Mongolia was humid. The study improves our understanding of the relationship between the climates of central Asia to the cold/warm cycles of the global climate and the results could assist in modeling the future climate change (i.e. desertification or permafrost degradation processes).
During my PhD I used dating of speleothems and their stable-isotope composition to reconstruct the patterns and history of past humid/dry conditions across the portion of the Saharan Arabian Desert found in southern Israel (Negev Desert).
Vaks, A., Gutareva, O. S., Breitenbach, S. F. M. Avirmed, E., Mason, A. J., Thomas, A. L., Osinzev, A. V., Kononov, A. M., Henderson, G. M. (2013) Speleothems Reveal 500,000-Year History of Siberian Permafrost., Science, 340, 6129, pp. 183-186.
Vaks, A., Woodhead, J., Bar-Matthews, M., Ayalon, A., Cliff, R.A., Zilberman, T., Matthews, A., Frumkin, A. (2013) Pliocene–Pleistocene climate of the northern margin of Saharan–Arabian Desert recorded in speleothems from the Negev Desert, Israel., Earth and Planetary Science Letters, 368, pp. 88–100.
Vaks, A., Bar-Matthews, M., Matthews, A., Ayalon, A., Frumkin, A., (2010) Middle-Late Quaternary paleoclimate of northern margins of the Saharan-Arabian Desert: reconstruction from speleothems of Negev Desert, Israel, Quaternary Science Reviews, 29, 19-20, pp. 2647-2662.
Lisker, S., Vaks, A., Bar-Matthews, M., Porat, R., Frumkin, A., (2010) Late Pleistocene palaeoclimatic and palaeoenvironmental reconstruction of the Dead Sea area (Israel), based on speleothems and cave stromatolites, Quaternary Science Reviews, 29, 9-10, pp. 1201-1211.
Lisker, S., Vaks, A., Bar-Matthews, M., Porat, R., Frumkin, A. (2009) Stromatolites in caves of the Dead Sea Fault Escarpment: Implications to latest Pleistocene lake levels and tectonic subsidence, Quaternary Science Reviews, 28, 1-2, pp. 80-92.
Vaks, A., Bar-Matthews, M., Ayalon, A., Matthews, A., Halicz, L., Frumkin, A. (2007) Desert speleothems reveal climatic window for African exodus of early modern humans, Geology, 35, 9, pp. 831-834.
Vaks , A., Bar-Matthews, M., Ayalon, A., Matthews, A., Frumkin, A., Dayan, U., Halicz, L., Almogi-Labin, A. and Schilman, B., (2006) Paleoclimate and location of the border between Mediterraneanclimate region and the Saharo-Arabian Desert as revealed by speleothems from the northern Negev Desert, Israel., Earth and Planetary Science Letters, 249, 3-4, pp. 384-399.
Vaks, A., Bar-Matthews, Ayalon., A., Schilman, B., M., Gilmour, M., Hawkesworth, C. J., Frumkin, A., Kaufman, A., Matthews, A. (2003), Paleoclimate reconstruction based on the timing of speleothem growth, oxygen and carbon isotope composition from a cave located in the “rain shadow”, Israel., Quaternary Research, 59, 2, pp. 182-193.
Last updated: Friday 22nd November 2013