Henry Elderfield. 25 April 1943—19 April 2016

Abstract

Henry (always known as Harry) Elderfield was a marine geochemist whose pioneering measurements of strontium and its isotopes, rare earth elements and manganese in seawater and sediment pore waters gave him insights into the circulation of fluids into, through and out of the oceanic crust and marine sediments and their control of the chemical composition of the oceans. He provided the basis for proxies of past ocean temperatures, pH and water mass distributions. These he used to reveal changes in global temperature and sea-levels on timescales spanning the last 50 million years (Myr) with emphasis on the last 1 Myr of glacial/interglacial history. His work on a proxy for pH, coupled with understanding of the dissolved carbon system in seawater, allowed examination of problems of ocean acidification caused by past changes of atmospheric CO 2 . His manner of gentle persuasion underpinned by rigorous chemistry was passed on to more than 40 research students, and his proxy methods are in daily use by hundreds worldwide.