Accurate depth determination of VLF events of the ongoing seismo-volcanic crisis in Mayotte - Archive ouverte HAL Access content directly
Poster Communications Year : 2021

Accurate depth determination of VLF events of the ongoing seismo-volcanic crisis in Mayotte

Abstract

VLF (Very Low Frequency) events of the ongoing seismovolcanic crisis of Mayotte are detected through a single-station time-frequency detector with data that comes from local and regional stations around Mayotte. The correction of the OBH (Ocean Bottom Hydrophone) pressure data into acceleration allow us to perform analysis like location, modelling and observe the complexity of the source mechanism in the VLFs signal. After corrections, waveforms, frequency content and duration of VLFs shows the same history, it's an effect of the source. Event location is performed though spatial 3D back-projection of station-pair cross-correlation functions, assuming a velocity of 3.5 km/s. Well constrained horizontal location is set in the middle of the proximal swarm, depth resolution is poor. We explore depths through synthetics seismograms generated using a simple 1D model and an isotropic focal mechanism. They provide a good fit with the observed signals. We compared 75 detected VLF with synthetics : cross-correlation time delay and amplitude ratio are analysed in function of the epicentral distance. VLF possible depth range is reduce to 10-25 km.
Fichier principal
Vignette du fichier
Poster_LAURENT_good_size.pdf (12.33 Mo) Télécharger le fichier
Origin Files produced by the author(s)

Dates and versions

hal-03481002 , version 1 (15-12-2021)

Identifiers

  • HAL Id : hal-03481002 , version 1

Cite

Angèle Laurent, Claudio Satriano, Pascal Bernard. Accurate depth determination of VLF events of the ongoing seismo-volcanic crisis in Mayotte. 5èmes Rencontres Scientifiques et Techniques Résif, Nov 2021, Obernai (67210), France. ⟨hal-03481002⟩
54 View
20 Download

Share

Gmail Mastodon Facebook X LinkedIn More