A multidisciplinary approach for the study of the effects of active tectonics along the North Anatolian fault zone: possibilities for the application of the electrical self potential method

Abstract

The aims of this joint interdisciplinary project “Marmara” of ETH Zurich and the Istanbul Technical University (ITO) are to study the effects of active tectonics as evidenced by geology, geodesy and seismology on hydrogeology and geothermics in selected areas along the North Anatolian fault zone. Within the framework of this project thermal water systems in seven different areas have been investigated or are under investigation up to now (SchindIer et al., 1993). For three study areas along the North Anatolian fault zone (from east to west) of Kuzuluk/Adapazari, Bursa and of Canakkale the investigations with respect to the geological and hydrogeological features are complete. The now possible hydrogeological characterisation shows encouraging possibilities for the application of new methods like the electrical self potential method for the following reasons: 1) a fully interdisciplinary approach, including seismic survey with especially conceived network, geodetic survey to investigate tectonic movements by the GPS method, geothermic survey combined with geological mapping and hydrogeological investigations of normal mineral and thermal waters; 2) groundwaters of very different chemical and isotopical composition e.g.: Ca-HCO3-type thermal waters of up to 82 °C temperature and total mineralisation of 500 mg/I to 1500 mg/I in the Bursa area, Na-HCO3-type cold mineral waters of up to 2500 mg/I to thermal waters of same mineralisation of up to 80 °C temperature, containing large amounts of CO2 of up to 1 l per 1 kg of water (at surface conditions) in the Kuzuluk area and Na-Cl-type waters presenting real thermal brines of up to 65 000 mg/I of total mineralisation and temperatures of up to 100 °C in the Canakkale area; 3) distinct types of hydrodynamic flow regime in areas of different geological and tectonic structure. Based on the results of the investigations within these areas the possibilities of further studies including self potential methods are discussed.