Thomas L. Henyey (Tom), former chair of the USC Earth Sciences Department and former SCEC director (1996-2002), passed away on October 10, 2023, at the age of 82.

Tom was born in New York City on March 7, 1941, while his father (a famous astrophysicist) was spending a year as a Guggenheim fellow at Columbia University. He spent his early years in Wisconsin while his father was a professor at Yerkes Observatory. In 1947 his father was hired as a professor in the Astronomy Department at UC-Berkeley and the family moved to the East Bay area of San Francisco.

After high school, Tom studied geophysics at UC Berkeley, graduating in 1962. He then did his Ph.D. in geophysics at Caltech under the guidance of Gerald Wasserburg and James Brune, graduating in 1968. His dissertation research focused on the thermomechanics of the San Andreas fault and the thermal regime of southwestern North America. Important papers by Henyey and Wasserburg (1971) and Brune, Henyey and Roy (1969) used the results of heat-flow observations to estimate the magnitude of shear stress on the San Andreas fault. These studies led to the well known “heat flow paradox” that stimulated considerable follow up research.

After graduating from Caltech, Tom was hired as a professor at the University of Southern California where he and Leon Teng were given the assignment of developing a geophysics program. His early years at USC were spent continuing his thermal studies applied to tectonic problems of the continental margin of southwestern U.S. and the Gulf of California.  In the early 1980s he worked with colleagues in New Zealand on studies of heat flow in Fiordland on the South Island there. 

The focus of Tom’s research then changed to the application of reflection seismology to crustal structure and evolution in the southwestern U.S. He was PI in the late 1980s of a multi-institution consortium known as CALCRUST that acquired and processed seismic reflection data from many areas in southern California. Following the Landers and Northridge earthquakes he was Co-PI on the LARSE I and II transects across the Los Angeles Basin and adjacent areas. A related major research project in the 1990s of Tom as PI was a geotectonic transect project across the Southern Alps of New Zealand with primary focus of imaging the Alpine fault at depth. 

Tom twice served as chair of the USC Earth Sciences Department, once from 1989 to 1991 and again from 2003-2006 before his retirement in the summer of 2006.

At a meeting organized by the USGS of earthquake scientists from around the U.S. at Lake Arrowhead in early 1989, he and Kei Aki were chosen to prepare a proposal to the NSF Science and Technology Centers program for an earthquake research center in southern California. A team led by Tom and Kei (with major contributions from Dave Jackson, Bernard Minster, Lynn Sykes, and John McRaney) spent six months writing the successful proposal to fund SCEC as an NSF Science and Technology Center, co-funded by the U.S. Geological Survey.

Tom’s role in SCEC began as Executive Director in 1991. When Kei Aki retired as PI and Science Director in 1996, Tom was elected as PI and SCEC Director. He served in that position until early 2002. In addition to his leadership of SCEC’s research activities, Tom was a champion of SCEC’s Knowledge Transfer and Education programs. When SCEC was refunded as a stand-alone center in 2002, Tom served as Deputy Director for Planning until the fall of 2003 when he stepped down to resume his role as USC Earth Sciences Department chair.

Tom played a key role in the funding of the original EarthScope program. He had been working with NSF on how to continue funding of SCEC in late 1998 and early 1999. That effort led to a meeting with NSF officials in the spring of 1999 including representatives of the USArray, PBO, SAFOD, and InSAR initiatives, with NAS joining and Tom representing SCEC. The meeting led to NSF appointing the ad hoc EarthScope Working Group that worked with the geoscience community for four years to develop the science goals and plans for EarthScope. Tom chaired that working group from 1999 until EarthScope was finally funded in 2003.

Tom Jordan (SCEC DIrector, 2022-2017):  “Tom Henyey was a scientific leader with a quiet but effective management style who chalked up some remarkable organizational achievements: CALCRUST in the 1980’s, SCEC in the 1990’s, and EarthScope in the 2000’s. Gardening was his hobby, and his approach to scientific organization was similarly organic—bring good scientists together, feed them adequate resources, and let their collaborations grow in the bright California sunshine!”

Yehuda Ben-Zion (SCEC Director): Tom Henyey made profound contributions to the development of the geophysics program at USC and large collaborative organizations including SCEC and EarthScope. His broad perspectives, openness to ideas and people, keen strategic planning, and management skills prepared the conditions for generations of scientists to conduct research that significantly advanced the knowledge about the dynamics of faults and the crust.

Graduate students at USC that Tom advised include Jeff Bannon, Dan Brandsma, Joyjeet Bhowmik, Avijit Chakraborty, Robb Clayton, Tim Fogarty, Gil Fry, Michael Forrest, Tim Jenkinson, John Landry, Calvin Lee, Tien Lee, Steve Pike, Rex Pilger, Jeff Plescia, and Hugh Robertson. Tom also provided mentorship to USC post-doc and early career scientists including Nicola Godfrey, Joseph Kruger, and David Okaya.

Upon his retirement in 2006, Tom devoted himself to hobbies he had always enjoyed, photography and gardening. He had a special way with orchids and his house was always full of orchids he grew in his backyard greenhouse.

Tom met his wife of 57 years, Sally, when he was a graduate student at Caltech. She survives him, as well as daughter Erika Parker and her husband Tim, and grandchildren Austin and Ivy.