Seismic Coda Waves Observed on a Sedimentary Basin

Phase statistics of seismic coda waves.

We report the analysis of the statistics of the phase fluctuations in the coda of earthquakes recorded during a temporary experiment deployed at Pinyon Flats Observatory, California. The observed distributions of the spatial derivatives of the phase in the seismic coda exhibit universal power-law decays whose exponents agree accurately with circular Gaussian statistics. The correlation function...

Antipodal focusing of seismic waves observed with the USArray

We present an analysis of the Mw = 5.3 earthquake that occurred in the Southeast Indian Ridge on 2010 February 11 using USArray data. The epicentre of this event is antipodal to the USArray, providing us with an opportunity to observe in details the antipodal focusing of seismic waves in space and time. We compare the observed signals with synthetic seismograms computed for a spherically symmet...

Robust estimation of seismic coda shape

Helium flux from a sedimentary basin.

The tritium-3He ages of groundwaters collected from the Saijo Basin in Japan were measured. The ages vary between 11.7 and 16.3 years. The 4He flux of >3 x 10(4) atoms/cm2 s is calculated by the 4He concentrations and ages. In addition the helium flux of 8.3 x 10(5) atoms/cm2 s is calculated at the Higashi-Niigata gas field in Japan. The above two estimates are consistent with the continental h...

Energy partition of seismic coda waves in layered media: theory and application to Pinyon Flats Observatory

L. Margerin, M. Campillo, B.A. Van Tiggelen, R. Hennino, 1 Centre Européen de Recherche et d’Enseignement de Géosciences de l’Environnement, Université Aix Marseille, C.N.R.S., Europôle Méditerranéen de l’Arbois, BP 80, 13545 Aix en Provence, France 2 Laboratoire de Géophysique Interne et Tectonophysique, Université Joseph Fourier, C.N.R.S., B.P. 53, 38041 Grenoble, France 3 Laboratoire de Phys...