New Clues to Untangle the Question: Was the Volcanic Eruption Triggered by the Earthquake?

Understanding the cause/effect relationship between tectonic earthquakes and volcanic eruptions is a striking topic in Earth Sciences. Volcanoes may erupt due to the impact of seismic waves (i.e. dynamic stress) and changes in the stress field (i.e. static stress) with variable reaction times. In 2012, three large (Mw≥7.3) subduction earthquakes struck Central America within ten weeks; some volcanoes in the region erupted days after, meanwhile for others it took months to years to erupt. Here we show that the three earthquakes contributed to the increase in the number of volcanic eruptions during the seven years that followed. We found out that only those volcanoes that were already in a critical state of unrest effectively erupted, indicating that the earthquakes only prompted the eruptions. We recommend the permanent monitoring of active volcanoes to reveal which are more susceptible to culminate into eruption when the next large-magnitude earthquake hits a region.