TY - JOUR
T1 - Assessing the likelihood and magnitude of volcanic explosions based on seismic quiescence
AU - Roman, Diana C.
AU - Rodgers, Mel
AU - Geirsson, Halldor
AU - LaFemina, Peter C.
AU - Tenorio, Virginia
N1 - Funding Information:
This study was supported by the National Science Foundation grants EAR-0911366 to D.C.R. and EAR-0911546 to P.C.L. Work undertaken at Oxford by M.R. was completed while funded on NERC STREVA grant NE/J020001/1 . We acknowledge the assistance for this study from Polaris Energy (Magdalena Perez), Nuevas Esperanzas, and the residents at Telica. We thank the staff at INETER for on-going assistance and support during deployment of this network. In particular we thank Allan Morales (INETER) and Jim Normandeau (UNAVCO) for assistance in network installation and Molly Witter (PSU) for additional assistance in visual observation of the 2011 eruption. We are extremely grateful to two anonymous reviewers for carefully reviewing this manuscript and providing constructive and thought-provoking criticism of our approach and interpretations. The raw continuous seismic data analyzed in this paper are archived and accessible through the IRIS Data Management Center.
Publisher Copyright:
© 2016
PY - 2016/9/15
Y1 - 2016/9/15
N2 - Volcanic eruptions are generally forecast based on strong increases in monitoring parameters such as seismicity or gas emissions above a relatively low background level (e.g., Voight, 1988; Sparks, 2003). Because of this, forecasting individual explosions during an ongoing eruption, or at persistently restless volcanoes, is difficult as seismicity, gas emissions, and other indicators of unrest are already in a heightened state. Therefore, identification of short-term precursors to individual explosions at volcanoes already in heightened states of unrest, and an understanding of explosion trigger mechanisms, is important for the reduction of volcanic risk worldwide. Seismic and visual observations at Telica Volcano, Nicaragua, demonstrate that a) episodes of seismic quiescence reliably preceded explosions during an eruption in May 2011 and b) the duration of precursory quiescence and the energy released in the ensuing explosion were strongly correlated. Precursory seismic quiescence is interpreted as the result of sealing of shallow gas pathways, leading to pressure accumulation and eventual catastrophic failure of the system, culminating in an explosion. Longer periods of sealing and pressurization lead to greater energy release in the ensuing explosion. Near-real-time observations of seismic quiescence at restless or erupting volcanoes can thus be useful for both timely eruption warnings and for forecasting the energy of impending explosions.
AB - Volcanic eruptions are generally forecast based on strong increases in monitoring parameters such as seismicity or gas emissions above a relatively low background level (e.g., Voight, 1988; Sparks, 2003). Because of this, forecasting individual explosions during an ongoing eruption, or at persistently restless volcanoes, is difficult as seismicity, gas emissions, and other indicators of unrest are already in a heightened state. Therefore, identification of short-term precursors to individual explosions at volcanoes already in heightened states of unrest, and an understanding of explosion trigger mechanisms, is important for the reduction of volcanic risk worldwide. Seismic and visual observations at Telica Volcano, Nicaragua, demonstrate that a) episodes of seismic quiescence reliably preceded explosions during an eruption in May 2011 and b) the duration of precursory quiescence and the energy released in the ensuing explosion were strongly correlated. Precursory seismic quiescence is interpreted as the result of sealing of shallow gas pathways, leading to pressure accumulation and eventual catastrophic failure of the system, culminating in an explosion. Longer periods of sealing and pressurization lead to greater energy release in the ensuing explosion. Near-real-time observations of seismic quiescence at restless or erupting volcanoes can thus be useful for both timely eruption warnings and for forecasting the energy of impending explosions.
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U2 - 10.1016/j.epsl.2016.06.020
DO - 10.1016/j.epsl.2016.06.020
M3 - Article
AN - SCOPUS:84975849764
VL - 450
SP - 20
EP - 28
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
SN - 0012-821X
ER -