Seismic gap have occurred in previously-identified seismic gaps. Prior to the 1989 Loma Prieta earthquake, that segment of the San Andreas fault system recorded much less seismic activity than other parts of the fault. The main shock and aftershocks of the 1989 event occurred within the previous seismic gap. Immediately following the 2004 Indian Ocean earthquake, a seismic gap analysis of the seismic zones around the Pacific Ocean identified the Central Kuril segment of the Kuril-Kamchatka Trench subduction zone as the most likely to give rise to a major earthquake. This zone, 500 km in length, at that time had experienced no
Seismic inversion the success of any seismic inversion. The inferred shape of the seismic wavelet may strongly influence the seismic inversion results and, thus, subsequent assessments of the reservoir quality. Wavelet amplitude and phase spectra are estimated statistically from either the seismic data alone or from a combination of seismic data and well control using wells with available sonic and density curves. After the seismic wavelet is estimated, it is used to estimate seismic reflection coefficients in the seismic inversion. When the estimated (constant) phase of the statistical wavelet is consistent with the final result, the wavelet estimation converges more quickly than