was a Japanese-American

professor Professor (commonly abbreviated as Prof.) is an academic rank at universities and other post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a "person who professes". Professors ...

Geophysics Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' so ...

at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

(MIT), and then at the

University of Southern California , mottoeng = "Let whoever earns the palm bear it" , religious_affiliation = Nonsectarian—historically Methodist , established = , accreditation = WSCUC , type = Private research university , academic_affiliations = , endowment = $8.1 ...

(USC), seismologist,

author An author is the writer of a book, article, play, mostly written work. A broader definition of the word "author" states: "''An author is "the person who originated or gave existence to anything" and whose authorship determines responsibility f ...

and

mentor Mentorship is the influence, guidance, or direction given by a mentor. A mentor is someone who teaches or gives help and advice to a less experienced and often younger person. In an organizational setting, a mentor influences the personal and p ...

. He and Paul G. Richards coauthored "Quantitative Seismology: theory and methods".

Biography

Aki was born in

Yokohama is the second-largest city in Japan by population and the most populous municipality of Japan. It is the capital city and the most populous city in Kanagawa Prefecture, with a 2020 population of 3.8 million. It lies on Tokyo Bay, south of T ...

, Japan. He received his bachelor's degree in 1952 and doctoral degree in 1958, both from the

University of Tokyo , abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project b ...

. Until 1960, he conducted research at that university's

Earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

Research Institute. He then did post-doctoral research at the Caltech Seismological Laboratory, where he worked with

Frank Press Frank Press (December 4, 1924 – January 29, 2020) was an American geophysicist. He was an advisor to four U.S. presidents, and later served two consecutive terms as president of the U.S. National Academy of Sciences (1981–1993). He was the au ...

."Keiiti Aki: Seismological Polymath"
Geotimes (March 2005) Press invited Aki to join him at

MIT The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the m ...

in 1966. This second visit to the United States coincided with the 1966

Parkfield earthquake Parkfield earthquake is a name given to various large earthquakes that occurred in the vicinity of the town of Parkfield, California, United States. The San Andreas fault runs through this town, and six successive magnitude 6 earthquakes occurre ...

, 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 The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...

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 The Seismological Society of America (SSA) is an international scientific society devoted to the advancement of seismology and the understanding of earthquakes for the benefit of society. Founded in 1906, the society has members throughout the wo ...

, and Chair of the

NAS Nas (born 1973) is the stage name of American rapper Nasir Jones. Nas, NaS, or NAS may also refer to: Aviation * Nasair, a low-cost airline carrier and subsidiary based in Eritrea * National Air Services, an airline in Saudi Arabia ** Nas Air ( ...

Committee on Seismology. He was instrumental in the creation of the

Southern California Earthquake Center The Southern California Earthquake Center (SCEC) is a collaboration of more than 1,000 scientists across 100 research institutions with a mission to: conduct research on earthquakes in Southern California and elsewhere by gathering data, conductin ...

, headquartered at the

, in 1991, he having moved to USC from MIT in 1984. In 1995, Aki moved to the seismically active island Réunion, east of

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

in the Indian Ocean, where he continued to work until his death there in 2005."In memoriam: Keiiti Aki"
, USC Trojan Magazine (Autumn, 2005) He sustained an injury to his brain from a fall while walking in the street on May 13; he fell into a coma and died on May 17. He left behind two sons (Shota and Zenta) and two daughters (Kajika and Uka).

Honors received

*Fellow of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

(1973) *Election to the U.S. National Academy of Sciences (1979) *Medal of

(1986) *

Thorarinsson Medal The Thorarinsson Medal is awarded every four years by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) for outstanding contributions to the general field of volcanology, and is the highest award given by ...

from the

International Association of Volcanology and Chemistry of the Earth's Interior The International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) is a learned society that focuses on research in volcanology, efforts to mitigate volcanic disasters, and research into closely related disciplines, such ...

(2000) *

William Bowie Medal The William Bowie Medal is awarded annually by the American Geophysical Union for "outstanding contributions to fundamental geophysics and for unselfish cooperation in research". The award is the highest honor given by the AGU and is named in honor ...

of the

American Geophysical Union The American Geophysical Union (AGU) is a 501(c)(3) nonprofit organization of Earth, atmospheric, ocean, hydrologic, space, and planetary scientists and enthusiasts that according to their website includes 130,000 people (not members). AGU's a ...

(2004) * Beno Gutenberg Medal of the

European Geosciences Union The European Geosciences Union (EGU) is a non-profit international union in the fields of Earth, planetary, and space sciences whose vision is to "realise a sustainable and just future for humanity and for the planet." The organisation has hea ...

(2005)

Selected publications

* *

References

* *
AKI, Keiiti
International Who's Who. accessed September 3, 2006. {{DEFAULTSORT:Aki, Keiti Japanese emigrants to the United States People from Yokohama University of Tokyo alumni California Institute of Technology alumni University of Southern California faculty American seismologists American academics of Japanese descent 1930 births 2005 deaths Japanese seismologists Fellows of the American Academy of Arts and Sciences Fellows of the Seismological Society of America Southern California Earthquake Center Members of the United States National Academy of Sciences Thorarinsson Medalists