Julio Sepúlveda

Julio Sepúlveda is an Associate Professor in the Department of Geological Sciences and Associate Director of Community and Belonging at the Institute of Arctic and Alpine Research (INSTAAR) at the University of Colorado Boulder. His research spans biogeochemistry, geobiology, and paleoclimate studies, with a focus on microbial roles in carbon cycling, oxygen minimum zones, and extreme climate events.

• PhD (Marine Geosciences): University of Bremen, Germany (2008)
• MS (Oceanography): University of Concepción, Chile (2005)
• BS (Marine Biology and Oceanography): University of Concepción, Chile (2001)

His research group investigates microbial lipid biomarkers to reconstruct:

• Modern systems: continental margins, marine oxygen minimum zones, and extreme environments
• Ancient systems: mass extinction events, greenhouse climates, and glacial-interglacial transitions

Key article trends include:

• Validating brGDGTs as paleotemperature proxies in Arctic lakes
• Quantifying microbial responses to ocean deoxygenation via lipid analysis
• Applying machine learning (BIGMaC) to improve paleoenvironmental reconstructions
• Reconstructing Arctic vegetation during interglacial periods via ancient DNA

Scientific Awards:

• School of Science Infinitive Kilometer Award, MIT (2012)
• MARUM Research Prize for Best PhD Thesis (2010)
• Best Undergraduate Thesis in Marine Biology, Chile (2000)
• Best Student Presentation in Biological Oceanography, Chile (1999)

Current advisees and postdocs include:

• PhD Students: Harry Allbrook, Robert Kelleher
• Grad Students: Muhammad Haikal Ezhar bin Abu Bakar, Robert Bourque
• Postdoctoral Scholars: Edgart Flores, Jonathan Raberg, Maria Luisa Sánchez Montes

He leads the Organic Geochemistry Lab and contributes to the AllSTAARs Task Force. Courses taught include GEOL 4700/5700: Organic Geochemistry and GEOL 3040: Global Change.