Changes

==Mapping two-way time==

==Mapping two-way time==

Most two-dimensional seismic reflection lines are presented in the format of horizontal distance versus two-way traveltime (time sections). Using interpreted time sections and a geographic base map, one can draft structure contour maps.

Most two-dimensional seismic reflection lines are presented in the format of horizontal distance versus two-way traveltime (time sections). Using interpreted time sections and a geographic base map, one can draft structure [[contour]] maps.

===Preparation for mapping===

===Preparation for mapping===

===Contouring===

===Contouring===

After the misties are adjusted, the revised two-way times can be plotted on the final base map. Finally, the points can be contoured at an interval that you deem appropriate.

After the misties are adjusted, the revised two-way times can be plotted on the final base map. Finally, the points can be [[contour]]ed at an interval that you deem appropriate.

==Other types of maps==

==Other types of maps==

==Computer-aided mapping==

==Computer-aided mapping==

Interpretations derived from seismic lines can be mapped efficiently with the help of a computer workstation, which performs repetitive calculations very quickly. First, the interpretations must be entered into a workstation, either by interactive (on-screen) interpretation or by digitizing interpretations that exist on printed lines. Mistie corrections are then performed by the computer. Two-way times and time intervals can then be posted on a base map. Contouring time and time interval maps can be done by the workstation, but the result usually requires some hand editing (see [[A development geology workstation]]).

Interpretations derived from seismic lines can be mapped efficiently with the help of a computer workstation, which performs repetitive calculations very quickly. First, the interpretations must be entered into a workstation, either by interactive (on-screen) interpretation or by digitizing interpretations that exist on printed lines. Mistie corrections are then performed by the computer. Two-way times and time intervals can then be posted on a base map. [[Contour]]ing time and time interval maps can be done by the workstation, but the result usually requires some hand editing (see [[A development geology workstation]]).

Constructing depth maps is possible once hand-drawn time and velocity maps are digitized into the workstation. The computer grids and multiplies the time and velocity maps, and the resultant values can then be contoured.

Constructing depth maps is possible once hand-drawn time and velocity maps are digitized into the workstation. The computer grids and multiplies the time and velocity maps, and the resultant values can then be contoured.