Preseismic Groundwater Ion Content Variations: Observational Data in Flowing Wells of the Kamchatka Peninsula and Conceptual Model

Abstract

Repeated manifestations of hydrogeochemical anomalies in groundwater ion content variations before local strong earthquakes were recorded in three flowing wells of the Petropavlovsk-Kamchatsky test site. A model of changes in chemical composition of groundwater is considered using observational data and modeling of two waters mixing with contrasting composition in a zone of increased permeability in aquifer. Hydrodynamic parameters of the model—relaxation time of water pressure impulses and the time of mixed water movement in aquifer and wellbore—can vary from days to hundreds of days in individual wells. These parameters determine the duration and morphological features of anomaly in mixed water from a well. Using observational data from self-flowing well M-1, an assessment was made of chemical composition and mineralization of two mixing waters and their ratio in mixed water under background conditions and during the preparation of earthquake on 2 March 1992, Mw = 6.9.

Water Geochemistry and Stable Isotope Changes Record Groundwater Mixing After a Regional Earthquake in Northeast India

“…These signals need to be assessed relative to time‐series of earthquake‐induced changes in groundwater geochemistry data that require continuous, long‐term monitoring systems and usually manual sampling, alongside expensive and time‐consuming laboratory analyses (Woith et al., 2013; Xiang & Peng, 2023). To this end, there are recent and ongoing programs (Martinelli, 2020; Ouzounov et al., 2018) to monitor the hydrogeochemical properties of groundwater to search for precursors and document earthquake‐geochemical correlations for example, Russia (Kopylova & Boldina, 2019, 2020, 2021; http://www.emsd.ru/lgs/observations), China (Chen & Liu, 2023; Chen & Wang, 2021; Shi et al., 2013, 2020; Wang et al., 2018; Xiang & Peng, 2023; Yu et al., 2023), USA (Wang & Manga, 2015), Japan (Hosono & Masaki, 2020; Hosono et al., 2020; Itaba et al., 2010; Koizumi et al., 2019; Matsumoto & Koizumi, 2013; Nakagawa et al., 2020; Uyeda, 2013; https://gbank.gsj.jp/wellweb/GSJ_E/index.shtml), Iceland (Andren et al., 2016; Barbieri et al., 2021; Claesson et al., 2007; Skelton et al., 2019), Korea (Kaown et al., 2021; Kim et al., 2019, 2020; Lee et al., 2021), and Italy (Barberio et al., 2017, 2020; Binda et al., 2020; De Luca et al., 2018; Franchini et al., 2021; Martinelli et al., 2021; Rosen et al., 2018).…”