Macroseismic and aftershock studies reveal a major seismic fault in Madhya Pradesh THE analysis of last year's Jabalpur earthquake has shown a "deep-rooted" seismogenic fault" located within the Narmada south fault zone, says J R Katyal, deputy director-general of the Geological Survey of India (GSI).

The fault has been traced to the south of labalpur. Katyal says that the main shock and the aftershocks occurred at a depth range of 35-40 km at the crust-mantle boundary. These were generated by a "reverse fault mechanism with a left lateral strike slip motion along this fault".

According to him, this possibly occurred by a north-northeast to south-southeast directed compressive regime that was induced because of post-collisional northward movement of the Indian plate. The intensity of the earthquake in Jabalpur on May 22, 1998, was measured six points on the Richter scale. The quake had caused massive destruction in a radius of 350 km.