Effects of the Cinarcik - Ismit August 17, 1999 earthquake on the composition of thermal and mineral waters as revealed by chemical and isotope investigations

Effects of the August 17, 1999 Ismit earthquake include to short-term changes in the composition of thermal and mineral waters in the areas of Kuzuluk, Bursa, and Yalova/Gemlik along the North Anatolian Fault Zone. We report the results of groundwater sampling campaigns before and after the earthquake. For these three areas changes of isotopic composition in ²H and ¹⁸O of the water, and in ¹³C of the dissolved species of inorganic carbon, as well as changes of some chemical constituents and physical parameters, were observed. These changes are most probably related to the active tectonics of the area and to induced groundwater circulation.