Geophysical Research Letters · 2007 · 64 citations · 24 references
Natural SciencesEarth SciencesGeophysicsExploration GeophysicsGeodesySeismologyEarthquake Source ProcessesGeophysical InversionGeophysical Signal ProcessingSeismic ExplorationSeismic InterpretationSeismic TomographyFull-waveform InversionMoment Tensor InversionNear-surface Velocity StructureNumerical Wave SimulationSeismic Source InversionSeismic Source Time FunctionSeismic Tensor InversionSeismic Velocity Structure
The persistent occurrence of long period (LP) events at Mt Etna became apparent with the installation of the first fixed broad‐band seismic network in late 2003. Repeating similar LP events from Nov. ‘03 to Sept. ‘04 indicate a non‐destructive source process. We perform moment tensor (MT) inversions on a stacked high S/N ratio representative LP signal, conducting a grid search for the source geometry and L2‐inversion for the source time function. Results indicate a NNW‐SSE oriented resonating sub‐vertical crack as the most probable source. This result is consistent with deformation and GPS observations. Crucial to this result are constraints imposed by detailed 3D full waveform numerical simulations in a heterogeneous tomographic model with topography, and in particular a detailed assessment of the influence of very near surface velocity structure on LP signals. Pulsating gas injection is hypothesised as the most likely LP trigger.
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Bernard Chouet, Phillip Dawson, Takao Ohminato et al. · Journal of Geophysical Research Atmospheres · 2003 · 417 citations · Full text