Near real-time b -value analysis for volcano traffic light alert systems and eruption forecasting

Area of Science:

• * Seismology
• * Volcanology
• * Geophysics

Background:

• * Volcanic eruptions are often preceded by rock failures around magma pathways.
• * A decreasing seismic b-value signifies increased stress and a higher likelihood of eruption.
• * Analyzing b-value time series is crucial for understanding volcanic unrest.

Purpose of the Study:

• * To analyze b-value time series from eight well-monitored volcanoes globally.
• * To introduce and evaluate a 'Volcano Traffic Light Alert System (VTLAS)' for eruption forecasting.
• * To assess the effectiveness of b-value drops in predicting volcanic eruptions within 10 days.

Main Methods:

• * Analysis of seismic data b-value time series from volcanoes in Iceland, USA, and Japan.
• * Development of the Volcano Traffic Light Alert System (VTLAS) with a 'red light' threshold (b-value drop >10%).
• * Examination of eruption occurrences within 10 days of identified 'red light' events.

Main Results:

• * Of 25 identified cases, 39% were followed by eruptions; 61% were not.
• * Non-eruptive 'red light' events (71%) were often linked to large earthquakes.
• * The VTLAS demonstrated a forecasting success rate comparable to other geophysical methods.

Conclusions:

• * The proposed VTLAS, based on b-value analysis, shows potential for anticipating volcanic eruptions.
• * Combining b-value monitoring with other geophysical data (InSAR, GNSS, thermal) is recommended for enhanced reliability.
• * Further research is needed to distinguish volcanic unrest from imminent eruptions more effectively.