Springwater chemical anomalies prior to the mw = 7.2 Van Earthquake (Turkey)

We performed chemical analyses of commercially bottled spring water (EREK Spring water) emanating from a location less than 20 kilometer from the epicenter of the Mw = 7.2 Van Earthquake of October 23rd 2011. The available water samples cover the period from September 8th 2011 to January 11th 2012. The pre-earthquake anomaly is characterized by a slight but clear increase in Ca²⁺, Mg²⁺, K⁺ and Cl^- contents and decrease in Na+ and SO₄^2- contents compared to the background. Post-seismic samples show decreasing trends in Ca²⁺, Mg²⁺, K⁺ and Cl^- and increasing trends in Na⁺ and SO₄^2-. All ion concentrations reach stability approximately one month after the earthquake. These results indicate that spring water chemical anomalies may be monitored as potential geochemical pre-earthquake indicators.