Premium
Ocean noise triggering of rhythmic long period events at Deception Island volcano
Author(s) -
Stich Daniel,
Almendros Javier,
Jiménez Vanessa,
Mancilla Flor,
Carmona Enrique
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl049671
Subject(s) - volcano , microseism , geology , noise (video) , seismology , forcing (mathematics) , ambient noise level , hydrothermal circulation , event (particle physics) , geophysics , physics , climatology , oceanography , computer science , sound (geography) , quantum mechanics , artificial intelligence , image (mathematics)
We report on swarms of repeating long‐period (LP) events with remarkably periodic occurrence at Deception Island volcano, Antarctica. The LP events show dominant frequencies near 2 Hz and characteristic inter‐event times that range from ∼10 s to ∼20 s for individual swarms. We observe that LP inter‐event times are approximate integer multiples of the dominant periods of the oceanic microseism, indicating a synchronization of LP activity with the phase of ocean noise. We attribute LP periodicity to the coincidence of sustained LP activity in an unstable hydrothermal system and external forcing by ocean noise that introduces periodic pressure variations in volcano fluids. We estimate the volumetric strain change generated by the oceanic microseism at the source location and conclude that strain of order 10 −7 is sufficient to introduce clear periodicity in the LP sequences, and that periodicity increases with increasing strain.