Modeling source parameters of quasi-periodic tremor

Abstract

Modeling harmonic tremor recorded at volcanoes is an essential practice in improving eruption forecasting methods and warning systems. We model the conduit dynamics of quasi-periodic tremor (chugging) recorded at Karymsky, Tungurahua, and Fuego volcanoes to estimate its source characteristics. Chugging mechanisms are estimated using two theoretical models originally derived in Garcés [1997, doi: https://doi.org/10.1029/1999JB900096] and Girona et al. [2019, doi: https://doi.org/10.1029/2019JB017482], respectively. Comparisons of the conduit and fluid output parameters suggests that chugging is primarily limited to near-surface oscillations and outgassing due to an accumulation of gas between eruptive episodes. The modeled results indicate clustered release of volatiles exsolved from a deeper magma conduit region, triggered by an initial explosion. This interpretation is consistent with both infrasonic and seismic observations at each volcano.