Abstract
The Killari Earthquake (Moment magnitude 6.1) of September 30, 1993, occurred in the state of Maharashtra, India, has an epicenter (18°03′ N, 76°33′ E) located at ~ 40 km SSW of Killari Town. The ~ 125 km long basin of Tirna River, close to the Killari Town, currently occupies the area that has witnessed episodic intra-cratonic earthquakes, including the Killari Earthquake, during last 800 years. The anisotropy of magnetic susceptibility (AMS) study was performed on ~ 233 soft sedimentary core samples from six successions located in the upper to lower stream of the Tirna River basin in the present study in order to evaluate the effects of earthquake on the river flow dynamics and its future consequence. The AMS Kmax orientations of the samples from the upper reach of the river section suggest that the sedimentation in this part of the river was controlled by a N–S to NNW–SSE fluvial regime with a low or medium flow velocity. In the middle reaches of the basin, an abrupt shift in the palaeo-flow direction occurred to W–E with low velocity flow. However, a NW–SE higher palaeo-flow regime is identified in the following central part of the basin in down-stream direction, followed by a low-velocity palaeo-flow regime at the lower reach of the Tirna basin. We attribute the sudden high flow velocity regime in the central part of the river basin to an enhanced gradient of the river that resulted from the reactivation of a NW–SE fault transecting the Tirna River basin at the Killari Town. As the NW–SE faulting in regional scale is attributed as the main cause of Killari Earthquake, the reactivation of this fault, thus, could enhance the further possibility of an earthquake in near future, and hence leading to devastating flood in the almost flat-lying downstream part of the Tirna River.
Highlights
A devastating earthquake [Moment magnitude ( Mw): 6.1] occurred close to Killari town (18°03′ N, 76°33′ E) in Maharashtra state, India[1,2] (Fig. 1), on September 30, 1993
A 17 km long, NW–SE reverse fault that extends from Talni to Killari Town with a dip 45°SW was suggested to have produced from the focal mechanism of the main shock (Fig. 1)[5,14], an elaborate structural analyses of this fault is awaited
In the present paper, we have attempted to identify the possible changes in palaeo-flow pattern of the Tirna River due to the earthquake using the technique of Anisotropy of Magnetic Susceptibility (AMS) of soft sediment cores collected from its floodplains, and tried to evaluate its future impact on the surrounding environment
Summary
A devastating earthquake [Moment magnitude ( Mw): 6.1] occurred close to Killari town (18°03′ N, 76°33′ E) in Maharashtra state, India[1,2] (Fig. 1), on September 30, 1993. The ~ 125 km long Tirna River, the subject of present study, is currently flowing towards the east along a channel that occupies ~ 10 km long WSW–ENE trending fault zone in the vicinity of the earthquake epicenter (Fig. 1). Several subsurface faults trending mainly NW–SE, and a few in N–S, NE–SW and ENE–WSW are identified in satellite imageries crosscutting the Tirna River b asin[13]. The main course of Tirna River is found to be controlled by a combination of NW–SE and WSW–ENE fault systems (Fig. 1). The NW–SE fault, is found to be still active
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
