One of the world's most accomplished yet perhaps least well-known geochemists was Katsuko Saruhashi, who broke the glass ceiling several times in her long career.

She was born in 1920 in Tokyo, to Kuniharu and Kuno Saruhashi. Kuno, especially, thought that women needed to achieve technical competence in order to get ahead in the world, and she encouraged her introverted daughter to explore the world.

A shy yet curious child, Katsuko wondered what cause raindrops to fall, among many other things. That curiosity fired her studies at the Imperial Women's College of Science, from which she graduated in 1943.

After graduating, she joined the Meteorological Research Institute. She would work there for her entire career.

Saruhashi, who lived through the dropping of two atomic bombs on her home country, did extensive research into nuclear radiation, after the U.S. tested nuclear weapons near the Marshall Islands just one year after the end of World War II.

A 1954 nuclear test on Bikini Atoll in 1954 caused medical difficulties in Japanese fishermen who were within 80 miles of the blast zone. When they showed signs of radiation sickness three weeks after the explosion, the Japanese government moved to investigate. Saruhashi was part of the team at the Meteorological Research Institute that found nuclear residue as far away as 620 miles from the blast zone. The work of especially Saruhashi but also the rest of the team led to a 1963 curtailing of oceanic nuclear experimentation.

She also showed through meticulous research that the Pacific Ocean releases twice as much carbon dioxide into the atmosphere as it absorbs. At the time, few scientists were studying carbon dioxide levels in water, so she had to invent her own techniques for measuring it. Part of her research into the levels of carbonic acid in seawater led to Saruhashi's Table, which she included as part of a 1955 research paper and later became a standard measurement base for oceanographers for three decades, until computers became standard issue.

In 1957, her earned a doctorate in chemistry from the University of Tokyo. She was the first woman to do so. The next year, the established the Society of Japanese Women Scientists. When she retired, in 1980, she founded the Saruhashi Prize, which recognizes female scientists working in the natural sciences, and the Association for the Bright Future of Women Scientists. She was the first woman to win the Miyake Prize for geochemistry, taking the prize in 1985; she was also the first woman elected to the Science Council of Japan.

"I wanted to highlight the capabilities of women scientists. Until now, those capabilities have been secret, under the surface."