Detection, classification, and location of seismovolcanic signals with
multi-component seismic data, example from the Piton de la Fournaise
volcano (La Reunion, France)
- Cyril Journeau,
- Nikolai M. Shapiro,
- Jean Soubestre,
- Valérie Ferrazzini,
- Aline Peltier
Nikolai M. Shapiro
Institut Physique du Globe de Paris, Institut Physique du Globe de Paris
Author ProfileJean Soubestre
Instituto Volcanológico de Canarias, Instituto Volcanológico de Canarias
Author ProfileAline Peltier
Institut De Physique Du Globe De Paris, Institut De Physique Du Globe De Paris
Author ProfileAbstract
We apply three different methods based on the analysis of the
multi-component seismic data to detect seismovolcanic tremors and other
seismovolcanic signals, to propose an approach to classify them and to
locate their sources. We use continuous seismograms recorded during one
year by 21 stations at the Piton de la Fournaise volcano (La Réunion,
France). The first method allows to detect seismovolcanic signals based
on stability in time of the inter-components cross-correlations
function. Two other methods based on the simultaneous analysis of the
whole network can be used to detect seismovolcanic signals and to locate
their sources. In a second approach, the seismic wavefield is analyzed
by calculating the width of the network covariance matrix eigenvalue
distribution. The third method consists in performing the 3D
back-projection of the inter-stations crosscorrelations in order to
calculate the network response function. Simultaneous analysis of the
parameters measured by the three different methods can be used to
classify different types of seismovolcanic tremors. Our results
demonstrate that all three methods efficiently detect seismovolcanic
tremors accompanying the 2010 eruptions and the preceding pre-eruptive
seismic swarms. Furthermore, methods 2 and 3 based on simultaneous
analysis of the whole network detect a large number of volcanic
earthquakes. Our location results show that each seismovolcanic tremor
is located in a distinct region of the volcano, close to the eruptive
site at a shallow depth and the preceding seismic crisis is located
deeper at about the sea level under the summit crater.