Eur. Phys. J. B 15, 551-555 (2000)
https://doi.org/10.1007/s100510051159

New evidence of earthquake precursory phenomena in the 17 January 1995 Kobe earthquake, Japan

¹ Institute of Geophysics and Planetary Physics, UCLA, Los Angeles, CA 90095-1567, USA
² Department of Physics, University of Southern California, Los-Angeles, CA 90089-0484, USA
³ Department of Earth and Space Sciences, UCLA, Los Angeles, CA 90095-1567, USA
⁴ LPMC, CNRSUMR 6622 and Université de Nice-Sophia Antipolis, 06108 Nice Cedex 2, France

Received: 21 January 2000
Published online: 15 June 2000

Abstract

Significant advances, both in the theoretical understanding of rupture processes in heterogeneous media and in the methodology for characterizing critical behavior, allows us to reanalyze the evidence for criticality and especially log-periodicity in the previously reported chemical anomalies that preceded the Kobe earthquake. The ion (Cl^-, K⁺, Mg⁺⁺, NO and SO) concentrations of ground-water issued from deep wells located near the epicenter of the 1995 Kobe earthquake are taken as proxies for the cumulative damage preceding the earthquake. Using both a parametric and non-parametric analysis, the five data sets are compared extensively to synthetic time series. The null-hypothesis that the patterns documented on these times series result from noise decorating a simple power law is rejected with a very high confidence level.