Decadal Timescale Correlations Between Global Earthquake Activity and Volcanic Eruption Rates

Abstract

AbstractAt the global scale, large tectonic earthquakes and volcanic eruptions are believed to be random and independent events. Here, we compare global time‐series of large earthquakes ( 7) and explosive volcanic eruptions (VEI 2) spanning 1960–2019. Both time‐series exhibit decadal timescale trends, over which annual earthquake and eruption rates vary by a factor of 2. Moreover, global seismic moment release is positively correlated with global eruption rate, with Monte Carlo permutation tests showing that this correlation is significant with a ‐value of 0.05. Although large earthquakes can trigger eruptions at nearby volcanoes, the magnitude of this effect is insufficient to cause the observed global correlation. Other mechanisms, such as triggering of distant eruptions (>1000 km) by earthquake‐induced dynamic stress changes, modulation of global earthquake and eruption rates by variations in Earth's rotational velocity, or natural synchronization of events over repeating cycles, are therefore required to explain the correlation.