Keiiti Aki

Who was Keiiti Aki?

Keiiti Aki was a Japanese-American professor of Geophysics at the Massachusetts Institute of Technology, seismologist, author and mentor. He co-authored with Paul G. Richards, "Quantitative Seismology: theory and methods".

Aki was born in Yokohama, Japan. He received his bachelors degree in 1952 and doctoral degree in 1958, both from the University of Tokyo. Until 1960, he conducted research at that university's Earthquake Research Institute. He then did post-doctoral research at the Caltech Seismological Laboratory, where he worked with Frank Press.

Press invited Aki to join him at MIT in 1966. This second visit to the United States coincided with the 1966 Parkfield earthquake, noteworthy for its so-called coda waves, reverberations of seismic energy due to multiple scattering from subsurface inhomogeneities. Aki “developed a passion for using those waves to investigate Earth,” according to Bill Ellsworth, Aki's former student who was later head of the USGS seismology group. “He came from Japan as a statistically oriented seismologist, but he was not afraid to transform himself.”

Aki was very active in his field and was the president or chair of many organizations. He was the president of Seismological Section of the AGU, president of the Seismological Society of America, and Chair of the NAS Committee on Seismology. He was instrumental in the creation of the Southern California Earthquake Center, headquartered at the University of Southern California, in 1991, he having moved to USC from MIT in 1984.