In Memoriam: Craig Glenn, sedimentologist and pioneer on submarine groundwater 

Craig Glenn with a thermal imaging UAV/ drone.

Craig Richard Glenn, professor of Earth Sciences at University of Hawai‘i (UH) at Mānoa, passed away on September 5, 2024 after a four-year battle with severe health problems. Glenn is known worldwide for his pioneering research on submarine groundwater discharge in Hawaiʻi, especially in developing and applying remote sensing techniques. Additionally, he was a key instructor in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST) for essential and famous courses in sedimentology, stratigraphy and marine geology, and he was heavily engaged in service to the scientific community. 

Glenn joined the department (formerly the Department of Geology and Geophysics) at the UH Mānoa in the late 1980’s and served for over 35 years. He obtained his bachelor’s and Master’s degrees in Earth Science at University of California – Santa Cruz, and his doctoral in Marine Geology at the University of Rhode Island, and then spent a year as a Research Fellow at the Swiss Federal Institute of Technology (ETH) in Zurich. 

During his early career, Glenn’s research focused on modern and ancient paleoproductivity and marine authigenic mineral formation. In the early 2000’s he led a National Science Foundation (NSF)-funded project to use aerial thermal infrared imagery to map submarine groundwater discharge along the Kona coast of Hawai‘i. The project produced numerous high-resolution, spatially extensive images illustrating the leaky nature of the coastal zone and abundant groundwater discharge into the ocean. The images have not been surpassed in quality and extent since, and are proudly displayed in the hallway of NSF’s Virginia headquarters.

More recently, Glenn led the Department of Health and Army Corps of Engineering-funded landmark study titled the “Lahaina Groundwater Tracer Study”, which became the basis of a U.S. Supreme Court decision about the vital role of groundwater on the health of the nation’s oceans, rivers, and lakes. “The court found that point source discharges to navigable waters through groundwater are regulated under the Clean Water Act. ” (reference link). Justice Breyer is cited in expressing how impressed he was with the science articulated about groundwater pollution, “The scientists really convinced me they’re geniuses and they can trace all kinds of things…” (reference link). 

The Department of Earth Sciences in memoriam story noted, “This is an example of Professor Glenn’s excellence in bringing together scientists and stakeholders to address tough problems in water resources. He has since continued to advance our understanding of submarine groundwater discharge via source tracking of nutrients and recharge, and improved remote sensing techniques.”

Glenn was an incredibly dedicated mentor, having served as primary advisor to more than twenty Master’s and doctoral students, many of whom are leaders in environmental services and/or research. In service to the scientific community, he was a member of the Society for Sedimentary Geology, the International Association of Sedimentologists, and the American Geophysical Union. Craig participated in five UNESCO-IUGS International Geological Correlation Programs, was the Co-Chair and founder of the SEPM Research Group on Marine Authigenesis, FRiends Of Marine AuthiGEsis (FROMAGE), and chaired the 2017 Geological Society of America Cordilleran Section Meeting in Honolulu. He became a Fellow of the Geological Society of America in 2000.

Glenn has been a highly valued collaborator, colleague, and good friend. He was blessed to have had the loving support of his two daughters and good friends.

Content courtesy of Department of Earth Sciences.