73-15 Correlation between Plinian eruption column height and pyroclastic density current runout distance

Session: Using Volcanic Deposits to Help Us Understand Volcanic and Magmatic Processes (Posters)

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Abstract:

Previous research has shown that the height of Plinian eruption columns is dependent on the discharge at erupting volcanic vents according to a power law (Carey and Sigurdsson, 1989). Additionally, other research has shown that the runout distance of pyroclastic density currents (PDCs) is also dependent on eruption discharge according to a power law (Roche et al, 2021). This dependence of PDC runout distance and Plinian eruption column height on vent discharge led us to investigate the potential for correlation between Plinian eruption column height and PDC runout distances. Whereas previous research investigated the ratio between total vertical descent distance and runout distance of small-volume PDCs, the so-called H/L ratio, the relationship between Plinian and/or sub-Plinian eruption column height and PDC runout distance is not well-constrained.  We therefore investigate dozens of Pleistocene-to-present Plinian and sub-Plinian eruptions described in volcanological literature for well-constrained eruption column heights and PDC runout distances. Our analysis includes both data from witnessed eruptions and eruptions known only from deposits. We find a statistically-significant power law relationship between pre-collapse eruption column height and the runout distance of the PDCs that resulted from eruption-column collapse. The correlation between column height and PDC runout distance is stronger for “dilute” PDCs than for “concentrated” PDCs, as described in the volcanological literature. Our work further substantiates that eruption discharge controls both Plinian eruption column height and PDC runout distance. Additionally, this relationship also provides scientists who are monitoring and responding to ongoing Plinian/sub-Plinian eruptions a potential means of estimating possible PDC runout distance prior to column collapse using real-time data collected from vent or satellite observations of ongoing eruptions.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-6561

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