Gwen Macpherson has studied water-rock interactions, water resources and groundwater CO2 dynamics in shallow limestone aquifers in an unplowed tallgrass prairie (NSF LTER site) for the past two decades. She also studies the modern sustainability of 1000-year old water-supply systems in water-scarce regions in southeast Asia and northern Africa, and non-traditional light stable isotopes as tracers of fluid movement and water-rock reactions in deep sedimentary basins.
Gwen Macpherson teaches Oceanography (undergraduate), and graduate/undergraduate courses in Aqueous Geochemistry, Field Methods in Chemical Hydrogeology, Analytical Methods in Geochemistry, as well as various topical seminars for graduate students.
All life depends on water. With population growth and climate warming, water resources are strained, especially in water-scarce regions where groundwater may provide 100% of the supply. Water purity is threatened by urban development, industrial spills, and agricultural practices; increasing demand for energy, necessary for economic growth, may strain already limited water resources and has the potential to contaminate them. Gwen Macpherson uses the Konza Prairie Long-Term Ecological Research Site as a study area characterizing baseline processes in a relatively unspoiled area, finding that, even there, groundwater CO2 is increasing, acidifying the water. She also is interested in water resource sustainability, focussing on especially vulnerable third-world countries with scarce water supply and unstable governments. On another front, she uses unconventional, light stable isotopes, in particular lithium, because of the potential they have in tracing the movement of water in deep sedimentary basins. Understanding the dynamics of fluid movement in sedimentary basins will help clarify processes of diagenesis, petroleum migration, and natural discharge of deep saline waters to the earth's surface.
Gwen Macpherson serves as Graduate Director in Geology and Departmental, Undergraduate Honors and Research-Experience-Program Coordinator. She is a longstanding member of AGU, GSA, GS, IAGC and AWG.