2024 Mulugu Earthquake: Reactivation of a deep-seated crustal fault in Godavari Graben (India)

Indian subcontinent has been experiencing intraplate seismicity since historical times having witnessed a number of damaging earthquakes.Recently, on December 4, 2024, Godavari graben was rocked by a moderate earthquake (M=5.0)close to Mulugu town in Telangana state of India.It has a focal depth of around 10 km.Earlier too, this graben has experienced a number of moderatemagnitude destructive earthquakes.We have analyzed high-resolution satellite gravity data over this region in order to identify the active faults and genesis of this intraplate earthquake.The residual gravity anomaly, deduced using Finite Element Method, broughtout a clear expression over different geologic and tectonic features.Eastern flank of Godavari graben is seen to be characterized by extremely high-gradient gravity anomalies corresponding to a deep-seated crustal-level fault, over which the hypocenter of the Mulugu earthquake lies.Similarly, western flank is also associated with high gravity gradients, corresponding to a fault structure which also reaches to mid-crustal depth.These seismogenic faults are getting reactivated due to neo-tectonic activities caused possibly by underlying thermal anomaly.It appears that all the major intra-plate earthquakes of Indian shield have occurred along the prominent rift structures, which are associated with high heat flow and thin lithosphere, and have undergone quaternary uplifting and crust-mantle thermal interaction.