Deep long-period earthquakes generated by second boiling beneath Mauna Kea volcano

Area of Science:

• Volcanology
• Seismology
• Geophysics

Background:

• Deep long-period earthquakes (DLPs) are volcanic seismic events, often observed at quiescent volcanoes.
• DLPs are characterized by low-frequency seismic waves and originate deep within the Earth's crust.
• Their precise cause and relationship to volcanic activity remain subjects of ongoing research.

Purpose of the Study:

• To investigate the cause of a unique, long-lived sequence of DLPs beneath Mauna Kea volcano.
• To explore the potential link between magma crystallization processes and DLP generation.
• To reassess the implications of widespread DLP activity for volcanic unrest.

Main Methods:

• Analysis of seismic data from Mauna Kea volcano over a 19-year period.
• Correlation of DLP event frequency and characteristics with geological models of magma behavior.
• Application of fluid dynamics and petrology principles to interpret seismic observations.

Main Results:

• A sequence of over one million near-periodic DLPs was identified beneath Mauna Kea.
• The DLP sequence is attributed to repeated volatile exsolution from crystallizing, stalled magma.
• This process, termed "second boiling," is proposed as the primary driver for the observed DLPs.

Conclusions:

• The study provides a novel explanation for DLP generation, linking it to magma crystallization and volatile exsolution.
• DLP activity may commonly indicate stagnant, cooling magma rather than pre-eruptive conditions.
• These findings necessitate a re-evaluation of how DLP seismicity is interpreted in volcanic monitoring.