Seismic intensity scales as fill) can amplify seismic waves, often at a considerable distance from the source, while sedimentary basins will often resonate, increasing the duration of shaking. This is why, in the 1989 Loma Prieta earthquake, the Marina district of San Francisco was one of the most damaged areas, though it was nearly 100 km from the epicenter. Geological structures were also significant, such as where seismic waves passing under the south end of San Francisco Bay reflected off the base of the Earth's crust towards San Francisco and Oakland. A similar effect channeled seismic waves between the other major faults in
Seismic attribute AVO gradient, intercept multiplied by gradient, far minus near, fluid factor, etc. The anelastic attenuation factor (or Q) is a seismic attribute that can be determined from seismic reflection data for both reservoir characterisation and advanced seismic processing. A post-stack attribute that measures the continuity between seismic traces in a specified window along a picked horizon. It can be used to map the lateral extent of a formation. It can also be used to see faults, channels or other discontinuous features. Although it should be used along a specified horizon, many software packages compute this attribute along arbitrary time-slices. A