The co-incidence of earthquakes and volcanoes: assessing global volcanic radiant flux responses to earthquakes in the 21st century

The temporal and spatial co-incidence of earthquakes and volcanoes has been documented for many years with recent reports suggesting that instances of earthquake-induced volcanic activity often occur following high magnitude seismic events. Using data extracted from the MODVOLC algorithm, this paper compares global volcanic radiant fluxes with large magnitude earthquakes to investigate temporal co-incidences between earthquakes and volcanic activity and to identify the thermal response of volcanoes to 14 large magnitude (M _w ≥ 8.0) earthquakes that occurred between 2001 and 2011. Results indicate that, on the basis of statistical testing, 3 events were associated with a statistically significant increase in global volcanic radiant flux by more than half and, 2 events experienced a statistically significant decrease in global volcanic activity. In the remaining 9 cases, global volcanic activity remained unchanged. These findings indicate that (1) at a global scale, there are instances of a temporally co-incident relationship between large magnitude earthquakes and global volcanic radiant flux, (2) modified thermal activity following an earthquake is short-lived, often reflected in changes in the number of thermally active volcanoes and/or global volcanic radiant flux and, (3) under favourable conditions, volcanoes with long repose periods may be more susceptible to triggering.