The influence of seismotectonics on precursory changes in groundwater composition for the 1995 Kobe earthquake, Japan |
| |
| Authors: | Jens Hartmann Jason K Levy |
| |
| Institution: | (1) Institute for Applied Geosciences, Darmstadt University of Technology, Schnittspahnstrasse 9, 64287 Darmstadt, Germany;(2) Department of Applied Disaster and Emergency Studies, Brandon University, Brandon, Manitoba, R7A 6A9, Canada |
| |
| Abstract: | It is shown that temporal variation in hydrochemistry may be attributed, in part, to continuous seismotectonic activity occurring before the onset of the 1995 “Kobe” earthquake, Japan, challenging the “one earthquake–one signal” hypothesis with respect to potential precursory signals to this devastating event. A possible continuous seismotectonic influence on chloride and sulphate ion-concentration is evaluated with aggregate earthquake-information by transforming a multivariate earthquake time series (including coordinates and magnitude) into a one-dimensional time series (considering geometric relationships between earthquakes and the well-site). A piecewise analysis of ion-concentration and seismotectonic-activity time series compares trends and change points between the two time series: a positive correlation (before the proposed onset of the preparation stage) is followed by a negative correlation (during the proposed preparation stage) which, in turn, is succeeded by a positive correlation (after the heaviest aftershock sequences). This suggests that seismotectonic processes occurring before the Kobe earthquake dynamically influenced aquifer characteristics, leading to temporal variations in the hydrochemical time series. Accordingly, a dynamic change in the mixing ratios of waters with different hydrochemical characteristics is proposed as a mechanism for explaining observed variation. The research can be extended by considering vectors in the stress field that lead to changes in the aquifer-well system.The influence of seismotectonics on precursory changes in groundwater composition for the 1995 Kobe earthquake, Japan. |
| |
| Keywords: | Hydrochemistry Tectonics Kobe Time series Earthquake |
| 本文献已被 SpringerLink 等数据库收录！ |
|
