Hyderabad: Telangana, largely considered safe from major seismic activity as it falls predominantly in Zone 2 on the seismic map, witnessed a rare 5.3 magnitude earthquake on Dec 4. The quake struck the Mulugu district, with its epicentre near Medaram, which is part of the Godavari rift zone classified as Zone 3.
According to seismologists, the Godavari rift zone is prone to moderate earthquakes. The recent quake was caused by the release of strain energy along the fault system, occurring at a depth of 40 kilometres. “The current earthquake falls in the Godavari rift seismic zone 3. The entire state of Telangana, barring this patch, is in Zone 2, which is a safe seismic zone,” said Prakash Kumar, director of CSIR-NGRI.
In the last six decades, Telangana recorded four significant earthquakes: A 5.3 magnitude earthquake in Bhadrachalam in June 1969, a 4.5 magnitude earthquake in Medchal in 1983, a 4.8 magnitude quake near Pulichintala in Jan 2021 and Wednesday’s quake in Medaram.
Prakash Kumar said: “We cannot predict whether there will be further earthquakes in the region, but we are sending strong motion accelerometers to Mulugu to record aftershocks. Instruments are being set up to monitor microquakes in the area.”
He mentioned that the tremors were recorded by eight instruments in Mulugu, as well as at observatories in Choutuppal and on NGRI campus in Hyderabad.
Sri Nagesh, former chief seismologist of NGRI and a faculty member in IIT Madras, said the region is prone to earthquakes of moderate magnitude. “We saw a similar quake in 1969 and smaller magnitudes occurred between Medaram and other areas since then,” he said.
Allaying speculations, Nagesh said: “This earthquake is tectonic in nature and has nothing to do with the Kaleshwaram irrigation project.” Nagesh also said that aftershocks are likely, recalling how Bhadrachalam experienced aftershocks for a decade following its 1969 quake.
Seismologists emphasised the importance of earthquake-resilient constructions in the region. “Authorities should promote earthquake-proof construction methods and protocols. It is critical to ensure resilience in buildings based on the seismic requirements of the area,” said Prakash Kumar.
