Giants in History: Katsuko Saruhashi

Measuring the oceans' capacity to protect the planet 

Katsuko Saruhashi (22 March 1920 - 29 September 2007)


Japanese geochemist Katsuko Saruhashi (22 March 1920 – 29 September 2007) developed the first method and tools for measuring carbon dioxide in seawater, which became known as Saruhashi’s Table. Her work showed that the Pacific Ocean releases twice as much carbon dioxide as it absorbs, indicating that global warming could not be substantially mitigated by seawater’s capacity to absorb carbon dioxide.Saruhashi also developed a sensitive method for measuring the amounts of radioactive isotopes Cesium-137 and Strontium-90 in seawater. Her research on the radioactive fallout from nuclear testing at Bikini Atoll helped to determine limits for oceanic nuclear testing. Her childhood fascination with rain coupled with her parents' encouragement towards technical knowledge and financial independence led to her earning a degree from the Imperial Women's College of Science, now known as Toho University. Later, she was the first woman to obtain a Ph.D. in chemistry from the University of Tokyo and the first woman elected to the Science Council of Japan, she was a strong proponent of equal opportunities for women in science. She established the Society of Japanese Women Scientists as well as the Saruhashi Prize, which is awarded yearly to a female scientist who serves as a role model for younger women scientists. (Photo provided by Toho University)

Toho University
University of Tokyo
Academic disciplines: 
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