Isotope Geochemistry (ePub)

for exchange to occur and serve as a control of the geochemistry of ocean water.

Karl was a major player in a revolutionary marine geochemistry campaign known as the Geochemical Ocean Section Study (GEOSECS). GEOSECS was part of the International Decade of Ocean Exploration in the 1970s, and it took aim at measuring and understanding the distribution of geochemical tracers for circulation and biogeochemistry in the world’s oceans.. It was also within this same time period that another large-scale ‘geochemical’ sampling program known as Apollo 11 came along. Here Karl utilized his INAA techniques to examine some of the first returned lunar samples for their trace elements. Karl was particularly proud of being the holder of the Silliman Chair and being curator of the Yale meteorite collection. In a continuation of Karl’s foray into cosmochemistry, Andy Davis came to Yale to study with Karl and Sydney Clark.

Equally important to the legacy of what Karl did for science in his research contributions on and across the planet was his influence on scientists. His legendary daily coffee hours were a training ground for many generations of students, postdocs, and visitors, as well as a proving ground for Karl’s own ideas. He had a great love for vigorous scientific debate. Karl loved to question and be questioned. Nothing was sacred and, in the act of questioning as in exploring, new science arises. He was extraordinarily supportive of people, always had time to discuss and listen, and helped everyone from students to his fellow faculty at Yale. Karl was twice department chair and even when not chair, a steadying influence in times of departmental difficulty.

Andrew M. Davis, Lawrence Grossman and Albert S. Colman

University of Chicago, Chicago, IL, USA

Mark H. Thiemens

University of California at San Diego, La Jolla, CA, USA

This Obituary was first published in PNAS, Vol. 110, No. 41, 16290–16291, 10th October 2013 © 2013

Proceedings of the National Academy of Sciences of the United States and is reproduced with permission.