In seismology an earthquake source is described in terms of a fault with a particular rupture size. The faulting process of large earthquakes has been investigated in the last two decades through analyses of long-period seismo grams produced by advanced digital seismometry. By long-period far-field approximation, the earthquake source has been represented by physical parameters such as s ismic moment, fault dimension and earthquake mag nitude. Meanwhile, destruction often results from strong ground motion due to large earthquakes at short distances. Since periods of strong ground motion are...