Dr. Johan Gilchrist

NSF EAR Postdoctoral Fellow

University of Oregon

My name is Johan Gilchrist (a.k.a. Yoshi) and I'm a National Science Foundation Earth Sciences Postdoctoral Fellow at the University of Oregon. I use a combination of field-, laboratory- and computer-based methods to improve our understanding of volcanic eruptions, landslides, glaciers, and wildfires. My expertise focuses on multiphase turbulent flow and explosive eruption dynamics, however, my current research interests are expanding to supraglacial landslides, wildfire plumes, and methane river flows on Titan.

Research Highlight

Our research featured in the May 2023 issue of Nature Geoscience explores how the terraced slopes of submarine caldera volcanoes, such as Santorini, Greece, can be used to estimate elusive eruption source conditions. We show that fountain physics causes caldera-forming eruption columns to collapse periodically as doughnut shaped sedimentation waves that impact the sea surface to generate tsunamis, surfing hot rock avalanches, and submarine pyroclastic density currents that build terraced deposits on the seafloor. Our results may help explain why large caldera-forming eruptions, like the Jan 15, 2022 eruption of Hunga Tonga Hunga-Ha'apai, can have surprisingly little impact on climate.

Listen to my overview of our work on CBC Radio's Quirks and Quarks:

https://www.cbc.ca/radio/quirks/quirks-and-quarks-april-22-2023-1.6817336