Uncertainty Quantification of Eruption Source Parameters Estimated From Tephra Fall Deposits

R. Constantinescu , J. T. White , C. B. Connor , A. Hopulele-Gligor , S. Charbonnier , J. -C. Thouret (1) , J. M. Lindsay , D. Bertin

1 LMV - Laboratoire Magmas et Volcans

Uncertainty quantification (UQ) in eruption source parameters, like tephra volume, plume height, and umbrella cloud radius, is a challenge for volcano scientists because tephra deposits are often sparsely sampled due to burial, erosion, and related factors. We find that UQ is improved by coupling an advection-diffusion model with two Bayesian inversion approaches: (a) a robust but computationally expensive Generalized Likelihood Uncertainty Estimation algorithm, and (b) a more approximate but inexpensive parameter estimation algorithm combined with first-order, second-moment uncertainty estimation. We apply the two inversion methods to one sparsely sampled tephra fall unit from the 2070 BP El Misti (Peru) eruption and obtain: Tephra mass 0.78-1.4 × 10¹¹ kg; umbrella cloud radius 4.5-16.5 km, and plume height 8-35 km (95% confidence intervals). These broad ranges demonstrate the significance of UQ for eruption classification based on mapped deposits, which has implications for hazard management.

Keywords: eruption source parameters; uncertainty quantification; eruption magnitude; tephra fallout modeling; tephra inversion

Domains: Sciences of the Universe [physics]

R. Constantinescu, J. T. White, C. B. Connor, A. Hopulele-Gligor, S. Charbonnier, et al.. Uncertainty Quantification of Eruption Source Parameters Estimated From Tephra Fall Deposits. Geophysical Research Letters, 2022, 49, ⟨10.1029/2021GL097425⟩. ⟨insu-03708903⟩