Guide

Introduction

This is a collection of maps created for a variety of research projects conducted here at the Institute for Crustal Studies (ICS). The maps were generated with set of UNIX mapping programs called Generic Mapping Tools (GMT). The purpose of the catalog is not only to archive and distribute maps to the ICS researchers who use them, but also to provide examples and resources for mapping with GMT. Local users (those with accounts on quake) can easily regenerate a PostScript file for printing (see below). If you are viewing this site from elsewhere, everything you need to reproduce these maps is freely available on the Internet, including the software and most of the data that is used. In addition you are free to copy any of the scripts used to make each map.

History and Site Maintenance

1997 Geoff Ely - Created and maintained this site until he left for grad school at IGPP/SIO. You may be able to track him down there with questions. In the meantime GMT has been pretty stable and should continue to work.

1999 Geoff Ely - updates a few things on the site during a visit to ICS.

2004 Aaron Martin creates the "Other Resources" section below after working on getting some new topo data for a project map.

2006-01-17 Joe Mount - I have updated this website, mainly the procedure for Generating PostScript on both Sun and Mac boxes and the cal_tutorial script. I have also tested each script. I was able to get most of them working; 'syv2' and 'vb2' are not exactly working ('syv2' is missing the landmass/coast -- see pscoast -- and 'vb2' has data circles that are too small -- zooming in shows that the data points are correct but need to be scaled larger -- see psxy -- the 3rd column for the scsn19* files is the size of the circles, which is too small).

2006-01-23 Aaron Martin - Updated the html just a bit trying to increase the aesthetics.

2006-02-13 Joe Mount - Added some documentation to clarify script-generating procedures after user had problems.

2012-08-28 Aaron Martin - ICS and ICESS (another ORU) merged to create Earth Research Institute (ERI). The projects website has been migrated to ERI infrastructure some time ago. Finally reassembled the mapcat-data project directory referenced just below. Have updated the pathfile reference to reflect its new location within the ERI infrastructure. That directory will NOT be available on all systems, but contact IT staff if its not available on a system capable of running GMT.

Generating PostScript (local ERI users only)

NOTE: must create a file called "pathfile" with the single line "/home/gmt/data/mapcat-data". This specifies the location of the data files used by GMT.
NOTE2: "pathfile" must be in the same directory as the gmtscripts that you wish to generate.

From a Sun workstation:
Find the map that you want to generate from the website.
(For this example we will use the map "cal".)
Hold the shift key down and click the left
mouse button on "GMT Script".
(This will let you save a copy of the script in your directory.)
In a UNIX terminal window go to your directory and type "sh cal".
(This will generate a PostScript file called "cal.ps".)
You can view the map with the command "gv cal.ps".
You can print the map with the command "lp -d printername cal.ps".

From a Macintosh:
Find the map that you want to generate from the website.
(For this example we will use the map "cal".)
Save the linked file to your directory.
Open a terminal and log into a Sun machine.
Use scp to copy the map file to the Sun box.
Go to the directory with the downloaded map file and type "sh cal".
(This will generate a PostScript file called "cal.ps").
Use scp to copy cal.ps back to your local Mac directory. Use Adobe Illustrator to open and print cal.ps. You can also use Preview. (NOTE: "lab" can only be properly viewed using Ghostview... see the lab script for explanation).
(If your Mac does not have Illustrator, you may need to scp the .ps file to a Mac that does have it)
NOTE: All scripts have primarily been regenerated and tested on the Mac
using the Preview program.

Writing GMT scripts

In GMT, separate commands are executed to create each feature of a map. All the commands for a certain map can be combined into a "script". Then simply running the script will generate the complete map. All of the scripts in the catalog are fairly similar in structure. Here the map called "cal" is used as a tutorial. It is earthquake and fault map of California and Nevada.
Tutorial GMT script: cal_tutorial
JPEG image: cal.jpeg

GMT software

Generic Mapping Tools is available from the GMT home page. at the University of Hawaii.

Other Resources

http://seamless.usgs.gov Interactive source for topographical data collections.
http://www.geos.ed.ac.uk/it/howto/GMT Handy tutorial.
90 m (3 arc-second) data for all of North America
ftp://edcftp.cr.usgs.gov/pub/data/srtm/North_America_3arcsec/3arcsec
30 m (1 arc-second) data for the United States
ftp://edcftp.cr.usgs.gov/pub/data/srtm/United_States_1arcsec/1arcsec
The ftp site contains a list of files that look like this -

N15W094.hgt.zip
where N 15, W 94 is the lower left corner of the file. The files contain 1 degree by 1 degree blocks of elevation data (so the upper right corner of this file would be N 16, W 93).
The data is in bil format. In ArcInfo, I unzip the file, change .hgt to .bil, and write a .hdr file to import the data.
The data is in geographic coordinates (decimal degrees, I think) so you may need to project the data to UTM for use in GMT.