People
Dr. Melissa Berke (she/her)
I am an Associate Professor in the Department of Civil and Environmental Engineering and Earth Sciences at the University of Notre Dame. Prior to my time at Notre Dame, I was a postdoctoral researcher in the Global Change and Sustainability Center at the University of Utah. I earned my PhD from the University of Minnesota at the Large Lakes Observatory, my master’s degree from the University of California Riverside, and my bachelor’s degree from Oberlin College. I am broadly interested in understanding paleoclimate and paleoenvironmental change, using isotopic and organic geochemical proxies from lacustrine and marine sediments over a wide range of timescales and locations, but am particularly captivated by the tropical water cycle and associated landscape variability. In my free time, I love to travel, hike/backpack, and enjoy live music.
Lab Manager Scientist
Dr. Ross Williams
Dr. Ross Williams is a Laboratory Manager Scientist in the Department of Civil and Environmental Engineering and Earth Sciences. He joined Notre Dame in the Spring of 2022 after spending five years at NASA Goddard Space Flight Center as a postdoc in the Solar System Exploration Division. There, he worked primarily on the Mars Curiosity Rover's Sample Analysis at Mars instrument (SAM) preparing experiments and analyzing mass spectrometry results in the search for evidence of Martian organic processes. Prior to that, he received his Ph.D in Geochemistry from Massachusetts Institute of Technology reconstructing past terrestrial environmental conditions in extreme climates using a biomarker approach, When not in a lab, he is an avid photographer and enjoys exploring the outdoors.
Postdoctoral Researchers
Dr. Claire Rubbelke
Originally from Wisconsin, Dr. Claire Rubbelke received her undergraduate degree in 2020 from the University of Wisconsin-Madison, where she majored in Atmospheric and Oceanic Science, Geoscience, and Geography. She recieved her Ph.D. in Earth Sciences from Syracuse University in 2025. Her past research used leaf waxes extracted from marine sediment cores taken off the Southwestern coast of Africa in order to learn about hydroclimate during the Plio-Pleistocene. She utilizes in proxy-model integration methods to understand the dynamic and thermodynamical mechanisms which influence Southern African rainfall over various timescales. She is currently interested in the global and regional drivers of hydroclimate change over the Mid-Pleistocene Transition. When she's not on campus, there's a very good chance she's either walking her dog, talking about her dog, or at home, hanging out with her dog.
Dr. Venanzio Munyaka
Vena is a postdoctoral researcher with the Environmental Change Initiative (ECI) at the University of Notre Dame. Originally from Nyeri, Kenya, he earned his bachelor’s degree in Natural Resource Management from the University of Eldoret. He later interned with the National Museums of Kenya for three years, where his interest in paleoecosystems began to develop. He then moved to Texas, where he obtained his doctorate in Geology from Baylor University. His research focused on the paleoclimate and paleoecology of Miocene primate habitats in eastern Africa. At Notre Dame, he collaborates with Professors Melissa Berke (CEEES) and Ryan Sensing (Biology) on a project examining how soil organic carbon responds to the interaction of fire and grazing. On the weekends you will catch Vena enjoying hiking, camping, mountain biking, just about anything outdoors.
Graduate Students
Yangzhuang Li
Yangzhuang is a PhD student from China. He completed his B.S. degree at Lanzhou University. Then, he participated in some research training at China Academy of Sciences. During his academic journey, Yangzhuang became deeply interested in paleoclimate studies, dedicating his research to reconstructing ancient climates. He utilized biomarkers such as PAHs to investigate the history of wildfires and their impact on the Earth's climate millions of years ago. Now, Yangzhuang is working on samples from IODP Expedition 401 to investigate water exchange dynamics during Messinian Salinity Crisis based on salinity and temperature records. Beyond his academic pursuits Yangzhuang enjoys playing video games, traveling and cooking.
Bethany Kettleborough
Bethany is a PhD student who received her B.S. in Environmental Geoscience from Purdue University. As an undergraduate researcher, Bethany studied water stable isotopes in agricultural porewater from the Midwest and in precipitation from Peru. Through this work, she became interested in using isotopes and organic geochemistry to research ecosystem responses to climate and environmental changes. Bethany’s PhD involves using biomarkers and compound specific isotopes on samples from Lake Izabal (Guatemala). When not in the lab, Bethany likes reading, crocheting, and watching the Golden Girls.
Group alumni
Graduate Students
Dr. Kayla Hollister (Ph.D. 2026)
Dr. Mirko Alessandro Uy (Ph.D. 2026)
Beatriz Alejandra Aguilar Enriquez (M.S. 2023, Ph.D. candidate at University of South Florida)
Dr. Alejandra Cartagena Sierra (Ph.D. 2023, Engineer at Elementar Americas)
Dr. Audrey Taylor (Ph.D. 2022, Program Analyst at Bureau of Ocean Energy Management)
Dr. Keith O’Connor (Ph.D. 2020, Senior Scientist in Reactor Plant Chemistry, Nuclear Naval Lab)
Dr. Darren Cheah (M.S. 2016, Ph.D. from Curtin University)
Undergraduate Students
Teresa Elfrink (Dept. of CEEES), 2024 - present
Josie Humbert (Dept. of CEEES), 2022 - 2026
Caroline Collins (Dept. of BIOS), 2022-2023
Megan Staley (Dept. of CEEES), 2021 - 2023
Erin Ludwig (Dept. of CEEES), 2020-2021
Sydney Brady (Dept. of BIOS), 2019-2020
Kyle Walker (Dept. of BIOS), 2019-2020
John Keenan (Dept. of CEEES), 2019
Floyd Nichols (REU student), Summer 2018
Andrew Copp (Dept. of CEEES), 2018
Joshua Horn (Dept. of BIOS), 2017-2019
Ellison Rooney (Science Business), 2017-2019
Katherine Conese (Dept. of CEEES), 2017-2018
Greg Campion (Dept. of CEEES), Summer 2017
Emily Najacht (St. Mary’s/Dept. of CEEES), 2016-2017
Meagan Hughes (Dept. of BIOS), 2015-2017
Adrienne Bruggeman (St. Mary’s/Dept. of CEEES), 2015-2018
Teresa Muldoon (Dept. of CEEES), 2014-2016
Michael Tillema (Dept. of CEEES), 2014-2016
Christa Costello (St. Mary’s/Dept. of CEEES), 2014-2016
Katelyn Frierott (Dept. of CEEES), 2014
Postdoctoral Researchers
Dr. Imogen Browne (2024-2026, now at the New Zealand Royal Society Te Apārangi, Kaiarotake Rangahau/Research Assessor)
Dr. Rosemary Bush (2014-2015, now Weinberg College Adviser/Assistant Professor of Instruction at Northwestern University)