Rachel Breunig

Glaciers are powerful and efficient agents of topographic change, and warming climatic conditions mark a juncture in the way many landscapes are evolving as they re-emerge from beneath retreating glaciers. Active volcanic environments are uniquely impacted by conditions deep within Earth's crust— these conditions control how often, how explosively, and how much mass is erupted. Can surface processes impact crustal conditions that control eruption traits? How do glacial and interglacial cycles play a part? My collaborators and I have taken to the Southern Volcanic Zone in Chile as a natural laboratory to answer these questions.

The Critical Zone is Earth's thin skin that hosts interactions between life, water, rock, and the atmosphere. Water movement in and through the Critical Zone is governed in part by surface and subsurface structure. Water reacts with minerals in the soil and rock as it flows through a hillslope, altering chemistry and structure in a process called weathering. How do changes in the shape of hillslopes affect patterns of weathering within the hillslope? Does a hillslope with a uniform interior weather the same as one with mixed composition? I am investigating these questions in my work at Wyalusing State Park. (photo by Sally Stevens)

Where does water reside in first-order hillslopes, and how was the storage capacity that accomodates that water generated? During my undergraduate research at the Jackson School of Geosciences, I worked on projects addressing these questions. My undergraduate thesis focused on developing a new approach to mass-balance derived weathering indices that account for bedrock heterogeneities in sedimentary rock. I also worked with a team to physically and chemically characterize cores of rock that traversed the Critical Zone at Rancho Venada and Antelope Valley Ranch (Eel River Critical Zone Observatory, Northern California) and further interpret the controls of chemical erosion, topography, and climate on the distribution of water in the subsurface.