Inequalities persist in the geosciences. Women and people of color remain underrepresented at all levels of the academic faculty, including positions of power. The proportion of women among geoscience faculty has been catalogued in previous studies but there has yet to be research considering the effects of institutional practices on the under-representation of women. Here, we compile a dataset of 2,531 tenured and tenure-track geoscience faculty from 62 universities to evaluate the proportion of women by rank, discipline, and type of institution. We find that 27% of faculty are women. The fraction of women in the faculty pool decreases with rank, as women comprise 46% of assistant professors, 34% of associate professors, and 19% of full professors. We quantify the attrition of women in terms of a fractionation factor, which describes the rate of loss of women along the tenure track and allows us to move away from the metaphor of the ‘leaky pipeline’. Given significant disparities in race, this work is most applicable to white women, and our use of the gender binary does not represent gender diversity in the geosciences. Our results support previous work that shows tackling the diversity problem at the student level is insufficient to ensure gender parity at the faculty level. Rather, efforts to address inequities in institutional culture and biases in promotion and hiring practices over the past few years may provide insight into the recent positive shifts in fractionation factor.