2D Electrical resistivity imaging for geothermal groundwater characterization and rejuvenation of the Gaurikund hot spring in the Main Central Thrust (MCT) zone of the Garhwal Himalaya, Uttrakhand, India

Abstract

Gaurikund is a famous geothermal spring near the Kedarnath Dham in the central Himalaya, Uttarakhand, India. During the Kedarnath Disaster in 2013, the thermal spring and most of the areas surrounding the Kedarnath temple lies ruined and covered by debris. In the present study, an effort has been made to image the debris covered source of the geothermal groundwater potential zones for rejuvenating the Gaurikund thermal spring and to understand the mechanism for enhancing the continuous recharge and flow of this hot spring. We have carried out hydrogeological measurements with these objectives at four locations (points 1–4). The obtained data indicates that spring water temperature varies from 35 to 58 °C and point-2 was observed to be the main source of the spring, situated adjacent to the Gauri Mata temple. Besides this, we performed 2D electrical resistivity imaging (ERI) profile with different configurations in the vicinity of the spring along the right bank of the Mandakini River. ERI reveals two distinct low resistivity horizons with resistivity variation from 20 to 50 Ωm within the depth of 5–15 m. The low resistivity zones have been interpreted to be the thermal spring's potential source, which occurs either along the fractured zones with channelized groundwater flow or along highly weathered zones. The study suggests that the source of the Gaurikund hot spring is located in the hanging-wall of the Vaikrita Thrust, a northerly dipping major structural unit and weak zone that can play a significant role in reviving the Gaurikund geothermal spring.