Parameters Controlling the Eruption Frequency of Long-Lived Felsic Magmatic Systems: An Example From the Milos Volcanic Field (Greece)

The mechanism controlling the volcanic eruption frequency is yet poorly understood. The key to a better understanding this mechanism comes from integrating accurate geochronology with numerical models. In many silicic volcanic systems, the eruption frequency is studied for short timescales of <500 kyr. Here, we combine two published numerical models (Caricchi et al., 2014, https://doi.org/10.1038/ngeo2041; Degruyter & Huber, 2014, https://doi.org/10.1016/j.epsl.2014.06.047) to improve our understanding of the eruption frequency in a long-lived (>3 Ma) felsic magmatic system, the Milos volcanic field. We use the published Milos geochronological data as input into the Caricchi et al. (2014, https://doi.org/10.1038/ngeo2041) model to derive average magma supply rates (Q_av) and eruptible volumes. These two parameters are then used in the Degruyter and Huber (2014, https://doi.org/10.1016/j.epsl.2014.06.047) model to compute the chamber growth rate (G_mc) for the Milos magmatic system. The results of the Caricchi et al. (2014, https://doi.org/10.1038/ngeo2041) model indicate that the time intervals between magma pulses into the subvolcanic reservoir (t_i) and Q_av are the key parameters controlling the eruption frequency. During the time intervals of 1.48–1.04 and 0.97–0.63 Ma the t_i is longer than 1000 years and the volcanic quiescence periods are longer than 350 kyr. Furthermore, these periods are characterized by low values for Q_av (≤0.001 km³ · yr⁻¹) and G_mc (<0.0001 km³ · yr⁻¹). In contrast, during the time intervals of 2.0–1.5 and 0.60–0.06 Ma, the t_i is shorter (<0.5 kyr) and the values for Q_av (>0.001 km³ · yr⁻¹) are higher corresponding to frequent eruptions.