Buckle-controlled seismogenic faulting in peninsular India

As intraplate earthquakes are often not associated with major known faults their location as well as their timing is unpredictable. In peninsular India the larger (M5.0) events occur mainly on reverse faults in a series of belts 400–800 km apart which are aligned roughly normal to the azimuth of convergence between the Indian and Eurasian plates. The location of the belts is controlled largely by the buckling wavelength of the lithosphere, and the seismogenic faults do not generate folding and sometimes result from it. There is consequently no need to postulate the creation of regularly spaced normal faults in an antecedent extensional phase, and the deformation is consistent with a plate-driving force such as gravity glide which is unlikely to reverse its polarity and which creates structures that are influenced by plate geometry at the leading edge. The thesis is potentially of value to seismic hazard mitigation as it identifies the zones that are most at risk.