LOW-MODERATE SEISMICITY IN THE VICINITY OF PALGHAT GAP, SOUTH-INDIA AND ITS IMPLICATIONS

Low-moderate seismicity has been detected within the Palghat Gap, a la rge physiographic feature in south India. An M(L) 4.3 earthquake that occurred on 2 December 1994 near Wadakkancheri in Trichur district, Ke rala was also located within the confines of this feature. A few small tremors have previously been reported from the source region of the 1 994 earthquake as well, Historic records show the occurrence of two ea rthquakes near Coimbatore, on the northern extremity of the gap. Conti nued low level seismic activity, originating from this area is recorde d by the stations of the Gauribidanur Seismic Array (GBA). Thus, regio nal seismicity points to the presence of active structures and enhance d stress concentration within the Palghat Gap. On the basis of these o bservations, we suggest a reevaluation of this regional feature in ter ms of its potential to generate larger earthquakes in the future.