"Close monitoring" of faults neighbouring in the 7.6 magnitude, earthquake is essential as the Indian plate boundary has become seismically "very active", according to top Indian seismologists. The wave of strong earthquakes since the Sumatran quake last December, that triggered the Tsunami suggest that the Indian plate boundary has become "seismically very active" and needs watching, they warned. The Indian plate is one of the 14 major plates that is locked on to the surface of the earth like a jigsaw puzzle. Strain built up along the boundaries due to motion of the rigid plates, when released, manifest as earthquakes.