Macro Seismic Survey of 4th December 2024 Mulugu Earthquake, Telangana, India

ABSTRACT An earthquake event of magnitude 5.3M rocked near the Ilapur village of the Mulugu District of Telangana on 4th December 2024. A macrocosmic survey was carried out in parts of the States of Telangana, Andhra Pradesh, Chhattisgarh, Maharashtra, and Odisha. A wide spectrum of data encompassing effects on the person, surroundings and damage to structures, etc., was collected from 216 points through a set of questionnaires. To avoid bias, people of different ages and genders were interviewed and factored for inferring the macroseismic intensity in the MSK-64 scale. The post-disaster studies of the earthquake event revealed a NW-SE trend of isoseismals, which is suggestive of the fact that the said event was caused by movement along a linear surface. The focal plane solution given by the National Centre of Seismology (NCS) interpreted a normal faulting with a minor strike-slip component. The NCS data revealed that the trend of the Nodal Plane (NP1) striking 347° and dipping 49°, which is almost parallel to the NW-SE trend of the Godavari valley fault, and hence is considered as the causative fault source for this event. The macroseismic intensity range was found to vary within the range of III to VI. The trend of isoseismals and interpretation of damage pattern reflect that, besides the reactivation of Godavari valley fault, rock rheology has played a pivotal role in influencing the propagation of seismic waves. The maximum felt effect was represented by macroseismic intensity of VI covering areas like Ilapur, Eturnagaram, Tadvai, Medaram, Narlapur of Mulugu District, Telangana and some parts of eastern Maharashtra (Gadchiroli District) and the southern part of Chhattisgarh (Bijapur District). Damage up to grade 2 in the form of widening of pre-existing cracks, construction joints, peeling off of fairly thick chunks of plaster from the roof, was observed from the meizoseismal zone.