Changes

==Other types of maps==

==Other types of maps==

<gallery mode=packed heights=200px widths=200px>

<gallery mode=packed heights=250px widths=250px>

mapping-with-two-dimensional-seismic-data_fig3.png|{{figure number|3}}Illustration showing effect of lateral differences in velocity on conversion of time and depth. If a single velocity function of 8300 ft/sec were used, errors of +6 ft at A and -440 ft at B would appear on the depth map.

mapping-with-two-dimensional-seismic-data_fig3.png|{{figure number|3}}Illustration showing effect of lateral differences in velocity on conversion of time and depth. If a single velocity function of 8300 ft/sec were used, errors of +6 ft at A and -440 ft at B would appear on the depth map.

mapping-with-two-dimensional-seismic-data_fig4.png|{{figure number|4}}(a) Illustration of ray paths, intervals, and interfaces used to help explain the Dix formula. (b) The Dix formula for calculating interval velocities, which assumes that interfaces are flat and smooth.

mapping-with-two-dimensional-seismic-data_fig4.png|{{figure number|4}}(a) Illustration of ray paths, intervals, and interfaces used to help explain the Dix formula. (b) The Dix formula for calculating interval velocities, which assumes that interfaces are flat and smooth.