Geochemical Journal, Vol. 46 (No. 1), pp. e11-e16, 2012EXPRESS LETTER
Sedat İnan,1 Werner Paul Balderer,2 Fanny Leuenberger-West,2 Hakan Yakan,1 Ali Özvan3 and Friedemann T. Freund4,5,6
1TÜBİTAK Marmara Research Center, Earth and Marine Sciences Institute, 41470, Gebze-Kocaeli, Turkey
2ETHZ, Engineering Geology, Sonneggstrasse 5 ETH Zentrum, CH 8092 Zürich, Switzerland
3Van 100. Yıl University, Department of Geology, 65040, Van, Turkey
4NASA Ames Research Center, Earth Science Division, Code SGE, MS 242-4, Moffett Field, CA 94035-1000, U.S.A.
5Carl Sagan Center, SETI Institute, 189 Bernardo Ave. Mountain View, CA 94043, U.S.A.
6Department of Physics, San Jose State University, San Jose, CA 95192-0106, U.S.A.
(Received December 6, 2011; Accepted January 27, 2012; Online published February 13, 2012)
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 SO42- contents compared to the background. Post-seismic samples show decreasing trends in Ca2+, Mg2+, K+ and Cl- and increasing trends in Na+ and SO42-. 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.
Key words: geochemical anomalies, spring water, earthquake precursors, Van, Turkey