Volcanic eruptions are triggered in static dilatational strain fields generated by large earthquakes

Area of Science:

• Geosciences
• Volcanology
• Seismology

Background:

• The relationship between large earthquakes and volcanic eruptions is established but the precise triggering mechanism remains debated.
• Previous studies confirmed a correlation, necessitating a deeper understanding of the underlying processes.

Purpose of the Study:

• To investigate the specific seismic parameters that trigger volcanic eruptions.
• To quantify the increased likelihood of eruptions following significant seismic events.

Main Methods:

• Analysis of recent earthquake and volcanic data spanning the last 35-55 years.
• Evaluation of static dilatational strain and ground motion effects on volcanic systems.

Main Results:

• Volcanic eruption likelihood increases two to three times in the 5-10 years after large earthquakes if static dilatational strain exceeds 0.5 µ.
• Strong ground motion alone does not significantly increase eruption likelihood.
• Static dilatational strain may activate gas bubble growth, increasing magma buoyancy.

Conclusions:

• Static dilatational strain, not just ground motion, is a key factor in earthquake-triggered volcanic eruptions.
• This research provides a quantifiable method to assess eruption risk following major seismic events.
• Findings will improve preparedness for volcanic activity after large earthquakes.