The European Geosciences Union (EGU) has awarded the 2010 Milutin Milankovitch Medal to Professor Emeritus Jim Hays "for his pioneering, fundamental and continuous work on the reconstruction of Cenozoic climates and for his Science 1976 seminal paper on the astronomical theory of palaeoclimates." In the latter, Hays, along with colleagues John Imbrie and Nick Shackelton, proved that the timing of major ice ages is controlled by variations in Earth's orbit around the sun.
As noted in the EGU announcement, Hays' early research focused on the development of a chronostratigraphic framework for deep-sea sediments which ultimately "established a near-global, Plio-Pleistocene chronology for deep-sea sediments and recognized and dated for the first time the 100,000 -year climate cycle." But it was Hays' and Lamont colleagues' work with Imbrie and Shackleton on the CLIMAP project that lead to the seminal 1976 Science paper: "Variations in the Earth's Orbit: Pacemaker of the Ice Ages." The project combined the marine-chronostratigraphy with estimates of past sea surface temperature and an oxygen isotope record, both based on the study of marine microfossils in Lamont's extensive deep-sea core collection. The oxygen isotope record was found to be influenced by the waxing and waning of ice sheets. These estimates and findings eventually allowed the construction of global maps of past sea surface temperature at specific times. More importantly, as the EGU announcement states, "this careful pre-CLIMAP and early CLIMAP chronostratigraphic work ... allowed Hays, Imbrie, and Shackelton to show, through analyses in both the frequency and time domains, that Earth's orbital variations control the timing of climate change on ice age time scales, proving the theory that Milankovitch contributed so much to developing." Hays' current research focuses on measuring past changes in the efficiency of the ocean's biological pump using deep- and shallow-living radiolarians.
The Milankovitch Medal was established by the EGU Division on Climate: Past, Present & Future in recognition of the scientific and editorial achievements of Milutin Milankovic, and honors scientists for their outstanding research in long term climatic changes and modeling.
Denis-Didier Rousseau, President of the EGU Division on Climate: Past, Present & Future, will present the award at at the EGU General Assembly in Vienna, Austria, on May 4, 2010. Hays will then deliver the Milutin Milankovic Medal Lecture entitled The biological consequences of a cold, stratified, high latitude, glacial ocean.