As part of the second and final SZNet US/Chile field pilot projects, there will be a field trip to Mount Hood in 2026. Mount Hood is one of the most hazardous volcanoes in the continental US and represents an outstanding opportunity for interdisciplinary geohazard science of the type advocated by the SZ4D initiative. Active processes associated with all three pillars of the SZ4D science program (Landscapes and Seascapes, Faulting and Earthquake Cycles, and Magmatic Drivers of Eruption) are on display here. This field trip - organized by Leif Karlstrom (U. Oregon), Scott Bennett (USGS), Adam Kent (Oregon State U.), Ian Madin (DOGAMI), and Brian Yanites (Indiana U.)- will investigate interacting hazards on Mount Hood by focusing on multiscale sediment dynamics. We expect to host a team of ~25 scientists spanning career stages and disciplines, who will apply traditional field techniques, aerial drone surveys, and geophysics, to collect new data and discuss outstanding science questions. Potential field targets include a near-summit pyroclastic surge deposit, sediment aggradation and fluvial dynamics associated with recent eruption deposits, sediment impoundment by active faults and its use in Holocene earthquakes, debris flows and landslides in the Columbia river gorge, and monogenetic volcanic processes. The trip will be organized with office days to enable processing and analysis of data and involve projects that all participants can contribute to, with the goal of developing research products, new ideas, and new collaborations.  

This trip aims to demonstrate the advantages of a multidisciplinary research approach to understand interacting processes associated with geohazards at subduction zones, providing interactions and training to accelerate research at Mount Hood and analogous volcanic systems elsewhere. Tentatively planned for July 2026, participants (fully funded by SZNet, with international applicants welcome) will be selected on the basis of an application that will be open starting in January 2026. 

(A) Coarse sediment in the White River - photo by Leif Karlstrom

(B) Top of a Twin Lakes fault scarp - photo by Leif Karlstrom

(C) Steep volcanic stratigraphy associated with the Columbia River Gorge - photo by Brian Yanites

(D) Early season snow on an unmapped pyroclastic surge deposit - photo by Leif Karlstrom

Figure: Photos from scouting trips in October 2025 around Mount Hood. (A) Coarse sediment in the White River from Old Maid+Timberline eruptive deposits that have subsequently aggraded and continue to be mobilized by atmospheric rivers. (B) The top of a Twin Lakes fault scarp, which exhibits 2m offset from two ~M6-7 Holocene ruptures and that impounded sediment locally, (C) Steep volcanic stratigraphy associated with the Columbia River Gorge on the north side of Mount Hood, (D) Early season snow on an unmapped pyroclastic surge deposit and the source region for block-and-ash flows from recent eruptions. All photos by Leif Karlstrom except for (C) by Brian Yanites.