Our research is in the general field of low temperature geochemistry of sedimentary rocks, with paleoceanography and continental paleoclimate being at the focus of our attention. The main objective is to understand and quantify past global changes that have occurred in the oceans and the continents on different time scales. We develop, establish and apply new geochemical tools that can serve as tracers of past environmental conditions and processes in the aquatic system with the view that actual field measurements of materials that store information about natural systems in the past provide the basis for understanding climate variability and for testing models and hypotheses in the fields of Earth Science. The stable isotope content of biogenic phases provides the main instrument for the reconstruction of past variations in the climate system.
We conduct our research mainly in the following directions:
- Reconstruction of Southern Ocean surface water characteristics using oxygen, carbon and nitrogen isotopes in deep-sea cores diatoms.
- The use of oxygen isotopes in diatom from lake sediments to reconstruct continental paleoclimate.
- The buildup of the isotopic signal in the newly formed coral skeleton and the use of corals as recorders of the environment, using oxygen and carbon isotopes in the skeleton and carbon and nitrogen isotopes in the soft tissue. The response of corals to Ocean Acidification through it stables isotopes.
- Developing two new tools in paleoceanography: (a) the use of oxygen isotopes in Radiolarian and (b) the use of vermetid reefs from the Mediterranean to reconstruct past sea surface temperature, productivity, CO2 invasion and continental runoff.
Currently we study the effects of the anthropogenic stress on the marine environments by reconstructions of short-term (10-2000 yrs) conditions that were affected either by natural processes or by human activity. This involves eutrophication processes in the Gulf of Eilat (corals) and in the Mediterranean basins(vermetid reefs) and the global potential effect of Ocean Acidification.