Physical Characteristics of Pyroclasts from the 2023 Eruption of Shishaldin Volcano, Alaska

This report includes analyses of physical characteristics, such as particle size distribution, density, clast dimensions, and measured area mass, for samples collected from the 2023 eruption of Shishaldin Volcano, Alaska. Reported samples include 8 samples collected by an Alaska Volcano Observatory (AVO) field team during August 20–22, 2023, 12 distal samples collected by the public during or after ashfall events between August 25 and October 15, 2023, and 9 samples collected by another AVO field team following the eruption on July 25 and July 30, 2024 (fig.1). The 2023 Shishaldin Volcano eruption included 13 paroxysmal ash-producing events with ash clouds that reached 46,000 feet above sea level (Loewen et al., 2026). These analyses are intended to help inform topical studies on that eruption and document the physical character of its erupted pyroclastic products. Loewen, M. W., Gomez-Patron, A., Fee, D., Lopez, T., Mota, R., Saunders-Shultz, P., Merritt, K., Dietterich, H., Brewster, I., & Wallace, K., 2026, Shishaldin Volcano 2019–2020 and 2023 Eruption Chronology Data: Alaska Division of Geological & Geophysical Surveys Raw Data File 2026-xx. https://doi.org/10.14509/32077