4.1 SEISMOGENESIS OF EARTHQUAKES IN THE INDIAN PENINSULAR SHIELD AND SUBDUCTION PROCESSES IN THE BURMESE ARC REGION

The broadband stations in the Peninsular shield located at Kothagudem, Cuddapah and Dharwar since 1999, have improved the detection threshold of local earthquakes with smaller magnitudes. Local earthquakes recorded at these stations have been located using single station as well as multi station methods. Some of the prominent seismically active regions (Fig.4.1) inferred from this study are the south eastern part of the Godavari graben and south of Nellore (Venkatagiri and Gudur) in Andhra Pradesh. Regional earthquakes from Koyna, Dhule and Amaravti from Maharashtra and Bhuj from the northwestern part of India have been located. Also Khandwa in Madhya Pradesh, Bangalore and Idduki from the south are a few other prominently active regions. The broadband stations data was used for determining the attenuation values from local earthquake coda waves. Site response at Dharwar, Cuddapah and Kothagudem stations has been estimated. These studies will serve as one of the qualitative inputs in future microzonation studies especially in the moderate seismicity regions like Godavari graben, regions along the east coast of India like Ongole, Nellore etc. Average velocity structure for the South Indian shield region which is path specific using surface wave dispersion is in progress