It is an honor and a great personal pleasure to introduce Miriam Kastner as the recipient of the 2008 AGU Maurice Ewing Medal. Her major contributions to understanding the marine sediment record and ocean chemistry have resulted from tireless fieldwork at sea combined with thoughtful experiments and exacting analytical and theoretical studies.
Miriam gained her first degree at the Hebrew University, Jerusalem, followed by her Ph.D. at Harvard and postdoctoral research at Chicago before moving to the Geoscience Research Division of the Scripps Institution of Oceanography.
Her earliest major work focused on the origin of authigenic feldspars and of zeolites in oceanic sediments. Next she explained the diagenetic transformations of opal-A to opal-CT and quartz, of crucial importance to the formation of siliceous marine deposits. She showed that dolomite formation is controlled by its associated pore-fluid geochemistry, solving what had been a nagging problem in carbonate mineral science. Her groundbreaking work on the Sr distribution coefficient was crucial in establishing strontium concentrations in calcite as a widely used indicator for carbonate recrystallization, and a fundamental indicator for all paleoclimate studies that depend on carbonate proxies. Her work on phosphate deposits completely revised ideas on the stability of P-O bonds in the phosphate ions in apatite and led to a recalculation of the ocean residence time of phosphorus. Her use of barite to evaluate processes in Cenozoic climate change is a further example of the combination of mineralogical and geochemical expertise she brings to solving important scientific problems.
Miriam published the first paper on the hydrothermal system in the Guaymas Basin on ocean drilling, and was involved in the expedition that found the first hydrothermal springs at 21°N East Pacific Rise. She described the formation of talc at Guaymas and calculated a 300°C fluid temperature and positive δ18O of the fluid. Her work on the mineralogy and genesis of hydrothermal marine deposits is unsurpassed.
In technology and instrumentation she has been an important advocate of in situ experiments on a grand scale in her research on fluid transport in the oceanic lithosphere and the formation of gas hydrates at convergent margins. She was involved in development of the Osmo sample flowmeter that was successfully deployed in the Costa Rica decollement.
Her dedication, persistence, and passion for her work are exemplary. Miriam's tireless commitment and her insistence on the highest standards have become legendary. Current geologic folklore associated with the ocean drilling programs is full of stories about Miriam's commitment and diligence. Her service to the marine geoscience community is equally remarkable. She has served on dozens of key national and international advisory panels and editorial boards for prestigious journals, acting as an outspoken advocate for science of the highest quality. She has acted as role model for young scientists, promoting excellence.
For her long-standing record of research excellence and productivity, for her leadership roles in scientific ocean drilling and in marine geosciences overall, and for her resulting profound influence on the field of marine geochemistry from her influential publications, Miriam Kastner is a most worthy recipient of the Maurice Ewing medal for 2008.
—HENRY ELDERFIELD, University of Cambridge, Cambridge, UK
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