Harold C. Helgeson

Harold C. (Hal) Helgeson (November 13, 1931 – May 28, 2007) was a professor at the University of California, Berkeley. He was widely regarded as the preeiminent practitioner of theoretical geochemistry for more than 40 years, a career he embraced after a colorful set of experiences in the military and the mining industry. He was widely known to the geochemical community for his innovation, rigor, farsightedness, and tenacity in the application of thermodynamics and kinetics to the study of geochemical processes. He was known to his friends and close colleagues for his great generosity, honesty, fierce loyalty, diverse opinions, and unconventional sense of humor. He received the most prestigious international awards in geochemistry in honor of his research contributions, including the Goldschmidt Medal from the Geochemical Society (1998) and the Urey Medal from the European Association of Geochemistry (2004). In addition to his published work, which was prodigious, he traveled and lectured extensively. His lectures were famous for their complex diagrams and clarity, and for the sheer force of their delivery. Professor Helgeson typically delivered his potent lectures after virtually no sleep because he so enjoyed extending his social and scientific interactions into the early morning hours. Few hosts could keep up with his schedule, but they never forgot the experience.

Helgeson was born in Minneapolis, Minnesota, and grew up in Saint Paul, Minnesota. As a teenager, he worked summers as a canoe trip guide in northern Minnesota and southern Ontario, where he developed a life-long love of the outdoors. After completing a degree in geology at Michigan State University, he worked for a year as an exploration geologist for Technical Mine Consultants in Athabasca, Saskatchewan, and at Blind River, Ontario (1953–1954). He then served two years in the Korean War as a photo-radar intelligence officer in the 497th Recon. Tech. Squadron of the U.S. Air Force in Wiesbaden, Germany, where he met his first wife, Velda, an American school teacher from California. After his military service he spent four years as a mining and exploration geologist in South Africa, in diamond exploration, and as an underground mining geologist, where he learned to speak Afrikaans. His son Chris was born during this time. While deep underground, he realized that he might find a different career appealing.

In 1959 Helgeson returned to graduate school at Harvard University, where he studied first with Hugh McKinstry, and then with Robert Garrels. Although Helgeson nearly dropped out due to financial troubles, Professor McKinstry loaned him sufficient money to retain him in the graduate program. Receiving his Ph.D. in 1962, Helgeson published his thesis as a book in 1964, establishing the foundations of theoretical high-temperature geochemistry. After a stint as a research chemist for Shell Development Company in Houston, where his daughter Kim was born, he accompanied Bob Garrels and Fred Mackenzie in 1965 to Northwestern University in Evanston, Illinois, where he began his teaching career. It was at Northwestern that he, Garrels, and Mackenzie developed the first path-calc theoretical numerical modeling program on a rollout of computer paper at the Bermuda Biological Station for Research in 1967. In 1970, he joined the faculty at the University of California, Berkeley, where he worked the next 37 years. During his Berkeley years, Helgeson met his second wife Suzanne, and his third wife, France. His daughter Broghan (mother France) was born in 1988. At Berkeley, he became a pioneer in the application of computer calculations that made use of his thermodynamic work, and the computer codes produced in his laboratory of theoretical geochemistry, known as "Prediction Central", were used by geoscientists and engineers around the world. A remarkable feature of Helgeson's career was his decision, early on, to freely distribute copies of his computer codes and databases generated over the course of his research. This created a legacy beyond his publication record, and encouraged a sense of community for those who worked on building up the theoretical tools.

Professor Helgeson’s interests continually evolved. Together with his many students and collaborators, he pioneered the development of a unified predictive theoretical approach to both the inorganic and the organic chemical realms, with applications in petroleum geochemistry, biogeochemistry, and the chemical interactions of minerals, microbes, and aqueous species in geochemical processes. Right into the last month of his life he was revising a seminal paper advancing a new theory for the origin of petroleum.

Helgeson died at the age of 75, after a brief battle with lung cancer, in Berkeley, California.

References

• Schulte, Mitch, 2000. A conversation with Harold Helgeson. The Geochemical News, January.

• Shock, Everett L. and Jan P. Amend, 2001. A tribute to Hal Helgeson on his 70th birthday. Geochimica et Cosmochimica Acta, Vol. 65, page 3613.

• Sverjensky, Dimitri A. 2007, Obituary. Elements, August.