Winds of change: meteorological influences on Strokkur’s geyser eruptions, Iceland

Geothermal eruptions are among the most spectacular phenomena in nature. However, the regularity of the eruptions and the internal or external driving factors of eruptions remain unclear due to the scarcity of long-term data. Our study fills this gap by presenting an unprecedented 4.5-year catalog of 650,000 water fountains observed at Strokkur geyser, Iceland. Our findings reveal a correlation between the wind speed and the recurrence interval of eruptions. Specifically, as the wind speed increases, the recurrence interval increases quadratically. This represents the most significant external modulator, influencing the system at least down to the bubble reservoir at a depth of 24 m. A secondary modulator is the temperature, with a linear increase in the recurrence interval as the temperature decreases. A heat loss model that accounts for the wind speed and temperature differences between water and air does not fully predict the observed behavior. However, the model does not account for heat loss during fountaining or for water loss from the catchment during eruption. The aim of this study is to quantify the relationship between the weather and the geyser to enable a correction and to focus on other internal and external drivers in future studies.