This is a description of the formats of the files from release #2 on our anonymous FTP server. Please address all questions, comments, and suggestions on the format and content of our network database to seber@geology.cornell.edu

Figures

The PostScript files (with the ".ps" suffix) are for the figures contained in this report and can be printed on PostScript printers. These files were created by Adobe Illustrator v. 3.5 and conform to Adobe PostScript standard v. 3.

The Adobe Illustrator files (with the ".ai" suffix) are for the same figures and can be read by drawing and page layout programs that can handle Illustrator v. 3 format files, including Adobe Illustrator v. 3.5 available for Sun workstations.

Data Files

The raw data files, extracted from Arc/Info, have several different flat ASCII formats for different types of information, and the file formats are explained below and in "README" files for each type available on the FTP server.

Line files

The files with the ".line" suffix contain "arcs" or line data such as refraction line locations or crustal interfaces. These files were extracted from Arc/Info with the UNGENERATE LINE command, and can be reloaded into Arc/Info with the GENERATE and LINE commands. The lines are stored with an arc ID number for each line and a list of coordinates for the vertices along the line. The coordinates are either in "geographic" latitude-longitude coordinates in decimal degrees (denoted ".dd.line") or in distance-depth coordinates in km (denoted ".km.line"), with depth positive upward and negative below sea level. The line files look like this (italics indicates comments):

arcID (integer)
x1 (longitude or distance), y1 (latitude or elevation) (floats)
x2, y2
.
.
.
xn, yn
END (end of this line)
arcID
x1, y1
...
xn, yn
END
END (end of file)

Point files

The files with the ".point" suffix contain point data such as shot-point locations or Moho depth points. These files were extracted from Arc/Info with the UNGENERATE POINT command, and can be reloaded into Arc/Info with the GENERATE and POINT commands. The points are stored with a point ID number and coordinates for each point. The coordinates are either in "geographic" latitude-longitude coordinates in decimal degrees (denoted ".dd.point") or in distance-depth coordinates in km (denoted ".km.point"), with depth positive upward and negative below sea level. The point files look like this (italics indicates comments):

pointID (integer), x1 (longitude or distance), y1 (latitude or elevation) (floats)
pointID, x2, y2
...
pointID, xn, yn
END (end of file)

AAT files

The files with the ".aat" suffix contain arc attribute data such as velocities above and below crustal interfaces. These files are a simple ASCII listing of the AAT (Arc Attribute Table) in Arc/Info. They were created with the PRINT command in INFO, and can be loaded with the ADD FROM command of INFO. The AAT files for the 2-D crustal sections (.km.aat suffix) contain the P velocities in km/s (for refraction profiles) or densities in g/(cm^3) (for gravity profiles) for each interface (referenced according to the arcID) in the following format:

arcID (integer)  vel_above  vel_below  (floats)       for refraction profiles
arcID (integer)  dens_above  dens_below  (floats)     for gravity profiles
...

The AAT files for the contour line maps (.dd.aat) contain the depths or thicknesses for the interface or layer in km. The arcID is again used for reference, but in this case the arcID may not be unique because it is usually set to an integer version of the depth (multiplied times 10 if the contours do not have integer intervals). Depths are negative below sea level. The file has the following format:

arcID (integer)  depth (or thickness)  (float)
...