A Scientist's Life: Miriam Kastner

Pioneering geochemist on a career spent breaking through seafloor and breaking through in a male-dominated field

Miriam Kastner is a distinguished professor at Scripps Institution of Oceanography at UC San Diego. She received a master’s degree in geology and a minor in chemistry at Hebrew University in Jerusalem in 1964 and a PhD in geosciences from Harvard University in 1970. Kastner came to Scripps in 1972, becoming the second female professor at the institution, only two months after geophysicist Tanya Atwater joined the faculty. Her research touches on many aspects of geochemistry from the effects of fluids at subduction zones on ocean chemistry to the abundance and distribution of methane hydrates, stores of frozen methane that exist in conditions of low temperature and high pressure below the seafloor. Methane hydrates have attracted widespread interest both as potential contributors to global warming and as a potential energy source.

In September 2014, Kastner’s four decades of research and teaching were recognized during a symposium in her honor at Scripps that included dozens of her colleagues and former students. Their gift to her was an engraved drill bit used to extract cores of seafloor materials. These same colleagues also came together to establish the Dr. Miriam Kastner Endowed Student Prize Fund to support Scripps marine geochemistry graduate students. 

explorations now: Describe what you do for a living.

Miriam Kastner: Primarily geochemistry. I have focused on subduction zones, on the role of fluids in subduction zones; on the effects of these fluids on seawater chemistry and other processes, such as their role in earthquakes. For these objectives, colleagues and I have established observatories for monitoring fluids in subduction zones. Other related topics are chemical paleoceanography, and gas hydrates, what is their role in the carbon cycle, climate, their potential for CO2 sequestration and as an energy source?

en: How did you select geochemistry as a career?

MK: I wanted to be a mathematician. In the first year at university, I studied mathematics but wondered, “What can I do with mathematics?” Once every few years there is a true genius in mathematics, the rest are very good or good and they end up being teachers in high schools or colleges. I decided that as much as I liked mathematics, I didn’t think that is what I want to do with my life. Since childhood, I always knew that I would be in the sciences, but I never had any role model in my life; there were not any women scientists around me. It seems that this desire was always within me. While at Harvard I got exposed to oceanography through contacts with Woods Hole Oceanographic Institution.

In my field, the leading scientists are working on original research and are advancing the understanding of the important processes on Earth. New questions always arise and none of us will ever answer all of them; there is a driving force to learn and understand more and when one problem is solved, 10 others evolve; that’s one of the beauties in being an active scientist.

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en: Why did you choose Scripps?

MK: When I was a postdoctoral fellow at the University of Chicago I received a call for an interview. I didn’t know that a job was available at Scripps. I did, however, know several of the Scripps faculty that came to Harvard for a sabbatical or just for visits. While visiting, they got to know me. One of them suggested that I should be interviewed, that’s how it happened. I was excited about the opportunity, accepted the invitation to come for the interview, gave a talk, and was offered the job.

en: What are some of the major questions in your field?

MK: Most of the gas hydrates on Earth are in continental margins, and on Earth methane is the prime gas in these hydrates. The stability of hydrates is a function of temperature, pressure and the amount of methane present. The convergent margins (subduction zones) contain at least half of the gas hydrates in the oceans. An enormous amount of carbon is sequestered in gas hydrate mineral formations and if they decompose the question is the fate of the carbon released, and certainly of the associated methane, a potent greenhouse gas. The potential impact on seawater chemistry and on climate of methane release to the ocean and particularly atmosphere from gas hydrates comprises an important focus of this research. Some scientists focus on the role of methane hydrates on slope stability, especially during glacial/interglacial fluctuations, because these hydrates cement the slope sediments and when they decompose, it is suggested that landslides may be triggered. This research on natural methane hydrates has emerged only in the last 30 years so it’s relatively a young science.

I’m also very interested in how seawater chemistry has changed over geologic time. The study depends on proxies, and there are different types of proxies for the various properties of seawaters, such as temperature, or pH. (Proxies are indirect indicators of ocean properties in the present or past.) What interests me is to study the reliability of some of the existing proxies and to develop new proxies. For example, we developed a proxy for the history of seawater sulfate using the sulfate sulfur isotopes with implications for oxygen and carbon fluctuations. Having a larger range of proxies permits the study of more properties of seawater.

en: What are some of the tools and methods that you use to do your research?

MK: In my research we are using a large range of tools at sea- and shore-based laboratories. Often, depending on the research, new tools have to be developed. For example, when sediment cores containing gas hydrates are recovered from beneath the ocean floor, they immediately begin to decompose at surface temperature and pressure unless they are stored in liquid nitrogen. We had to learn how to deal with such an unstable substance, and that evolved over time. At present, rather sophisticated tools exist to study gas hydrates at in situ conditions. Especially in the last five to seven years, this technology has evolved exponentially. One of the international interests in gas hydrates is their potential as a source of energy. Japan, for example, is investing at least 10 times more funds on gas hydrate research than the United States; Japan has very few other natural sources of energy.

en: Describe the working environment for female researchers when you entered the field as compared to the present day.

MK: For three years, I was the only woman student in my department at Harvard. Overall, it was not a very encouraging environment for women. Women were not taken seriously by many of the faculty members. However, there were others more enlightened, and I was lucky to have a supportive forward-looking PhD committee. At that time at Harvard, women students were told from time to time that Harvard’s mission is to educate the future leaders of the country and women will not be such leaders, therefore why bother to educate them. Most of the faculty members did not expect much from women students; the perception was that the few women present would be there until they found a husband.

When I joined Scripps and tried to get funding for my research, some program directors regarded funding women as a waste of funds; they openly expressed their opinion about funding women scientists.

The young women scientists of today do not realize that this is how it used to be. I am delighted to see the significant progress and the changes over the past 30 years or so in how women are perceived and in the support for young women scientists. In recent years women have been encouraged to pursue their careers and are given resources to do so. Young women do not realize that they wouldn’t be where they are without many of us “fighting” for the improvement of the status of women over the years; however, there is still much to be done.

My philosophy was to do what I do well and eventually it would be appreciated. I was very confident that if I would do the best possible, I would prevail; self-confidence is most important. My advice is that aspiring young women scientists should do the best they can and should not expect special favors.

Related Image Gallery: A Scientist's Life Photo Gallery: Miriam Kastner

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