Velocity Analysis of Early Results: Reflected Wave Fields
Seismic Reflection Geometry
Ray-path diagrams for:
1. Data Acquisition
2. CMP - assumes isotropy
3. Reflection velocity analysis
S-Wave Reflection (Sr): detail
S-Wave Reflection (Sr): with NMO
The figure above left shows semblance and gathers plots with a possible S-wave reflection event (Sr) flagged. The figure above right shows the same data with Normal Move Out (NMO) correction applied at constant 1,100 m/s S-wave velocity. Note the changes in Amplitude Versus Offset (AVO).
The figure lower left shows a second data set acquired with a smaller (2.5 mm) trace interval to avoid the spatial aliasing seen in the upper plots. The lower right figure shows the semblance and 'CMP' gather for the new data set.