Springwater chemical anomalies prior to the Mw = 7.2 Van Earthquake (Turkey)
Sedat İnan, Werner Paul Balderer, Fanny Leuenberger-West, Hakan Yakan, Ali ?zvan and Friedemann T. Freund
(Received December 6, 2011; Accepted January 27, 2012; Online published February 13, 2012)
CONCLUSIONS
We conducted chemical analyses of commercially
bottled spring water (EREK Spring water) emanating from
a location less than 20 km distance from the epicenter of
the Mw = 7.2 Van Earthquake of October 23rd 2011 in
search of geochemical precursors, if any. The available
water samples cover the period from September 8th 2011
to January 11th 2012. The pre-earthquake anomaly is characterized
by increase in Ca2+, Mg2+, K+, Cl? content and
decrease in Na+ and SO4
2? of the water samples bottled
before the earthquake. Post-seismic dated samples (covering
about three months after the earthquake) show decreasing
trends in Ca2+, Mg2+, K+, Cl? and increasing
trends in Na+ and SO4
2?, respectively. About one month
after the earthquake, ion contents of the spring water have
attained stability. These results indicate that spring water
chemical anomalies may be monitored as potential
geochemical pre-earthquake indicators. In order to be able
to suggest the mechanism(s) leading to the reported preearthquake
geochemical anomalies, more work needs to
be conducted, especially multi-disciplinary (seismological,
geodetical, geochemical) and continuous earthquake
monitoring networks must be established.
