文摘
The 14 February 2006 Phodong (Sikkim) earthquake of moderate magnitude (Mw 5.3) triggered several aftershocks that were recorded by a local seismic network. The thrust earthquake is part of the continuing earthquake activity in the Himalayan seismic belt region that occurs on the detachment or ramp under the Higher Himalaya. The aftershocks of the earthquake occurred in increased stress regions caused by the earthquake rupture. Triggering of aftershocks by such a moderate magnitude earthquake implies that the faults in the Himalaya are critically stressed and even a small change of stress, about 0.001–0.002 MPa, can trigger earthquakes on such faults.