On the use of earthquake multiplets to study fractures and the temporal evolution of an active volcano
| Autor: | Georges Poupinet, A. Ratdomopurbo, O. Coutant |
|---|---|
| Přispěvatelé: | Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Laboratoire Central des Ponts et Chaussées (LCPC)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 1996 |
| Předmět: |
010504 meteorology & atmospheric sciences
Magma chamber Fault (geology) lcsh:QC851-999 010502 geochemistry & geophysics 01 natural sciences Coda Waveform Cross-spectrum Seismogram relocation of events temporal monitoring 0105 earth and related environmental sciences geography geography.geographical_feature_category lcsh:QC801-809 Azimuth lcsh:Geophysics. Cosmic physics Geophysics Volcano 13. Climate action [SDU]Sciences of the Universe [physics] volcanic earthquake lcsh:Meteorology. Climatology Geology Seismology |
| Zdroj: | Annals of Geophysics, Vol 39, Iss 2 (1996) Annals of Geophysics Annals of Geophysics, Istituto Nazionale di Geofisica e Vulcanologia (INGV), 1996, 39 (2), ⟨10.4401/ag-3968⟩ |
| ISSN: | 1593-5213 |
| DOI: | 10.4401/ag-3968⟩ |
| Popis: | International audience; Multiplets, i.e. events with similar waveforms, are common features on active volcanoes. The seismograms of multiplets are analyzed by cross-spectrum techniques: this procedure improves by a factor of about 10 the precision of differential P-arrival times and therefore the accuracy of the relative location of earthquakes. Long period events which cannot be located because of the impossibility to pick up P-waves on individual seismograms can be located with a precision of about 10 m. Such a precision permits fault planes to be mapped inside a volcanic edifice and the azimuth and strike of fractures to be defined. Seismograms of the two events (of a doublet) that occur on different dates are analyzed by the Cross Spectrum Moving Window technique (CSMW) for measuring the time delay between waves in the coda. The pattern of the delays in the coda is a function of the temporal changes of seismic velocity that occurred inside the volcano during the time interval that separates the two events of a doublet. We illustrate the potential of the doublet technique for detecting temporal changes inside a volcano by performing computations of synthetic seismograms. The case of a dyke injected inside the volcano is considered as well as that of the replenishment of a superficial magma chamber and of a general increase in velocity in the summit of the volcano. Data from Merapi volcano (Indonesia)illustrate a possible temporal velocity change inside the volcano several months before the 1992 eruption. |
| Databáze: | OpenAIRE |
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