Commemorating what would've been her 98th birthday, Google paid tribute to Japanese geochemist Katsuko Saruhashi on Thursday.

The honour took in the form of a Doodle, featuring a sketch of the scientist, clipboard in hand, as water fills the background.

Saruhashi is best known for developing a groundbreaking method for measuring carbonic acid in natural waters based on its temperature, pH level and chlorinity. This methodology was dubbed "Saruhashi’s Table," and proved to be indispensable to oceanographers for decades.

In 1954, she examined the prevalence of radioactive materials in seawater and how far it spread due to fallout in the Pacific.

The U.S. conducted nuclear tests around the Marshall Islands, and Saruhashi's evidence of radioactive contamination spreading across oceans helped lead to above-ground nuclear tests being banned in 1963.

Saruhashi was the first woman to earn a doctorate in chemistry from the University of Tokyo in 1957, and in 1980 was elected to the Science Council of Japan -- also a first for a woman.

In 1981, she established the Saruhashi Award, which is granted every year to female scientists to recognise their distinguished research in natural sciences.

"There are many women who have the ability to become great scientists. I would like to see the day when women can contribute to science and technology on an equal footing with men," she once said.

Saruhashi died in 2007 aged 87.