TTTSDK v3.1 distribution (Dec 2008, ITIC)
Hands-on exercise: Tsunami Travel Times (TTT software)
Sample Instructions for Tsunami Travel Time Plots
This handout provides information on sample scripts and sessions for creating plots of Caribbean region tsunami
travel times using the TTT software. Technical information on the calculation of tsunami travel times is
provided in TTTSDK3.1_Reference_Document.pdf (in C:\Program Files\TTT Package\Software\TTT\doc) and
Annex V: Methods for Tsunami Travel Time Calculation used by PTWC, WC/ATWC, and JMA of the PTWS
Operational Users Guide (draft, December 2007, in C:\Program Files\TTT Package\TTT_GMT_otherdocs).
Another tool that can be used to create tsunami travel time plots is the ITDB software (Interactive Tsunami
Database); the numerical calculation method is similar and the results are comparable.
Accuracy is most dependent on the accuracy of the bathymetry file used for the calculations, e.g., the finer grid
size of the bathymetric file, the more accurate the estimate - at the same time, however, computation time
increases significantly as finer grid size bathymetric files are used (e.g., calculation using 2-min (distance, ~2
mile grid interval) bathymetry grid takes 10 minutes (time) or more to complete.)
The TTT software works on a Windows PC using a Windows command window.
The TTT program is executed to calculate the tsunami travel times over the specified map boundaries (e.g.,
create a grid file of tsunami travel times). Then the GMT software is used to make a postscript plot of the travel
times, and to create raster image (png format). The GMT software is a general plotting software that can be
customized to produce many types of plots.
Using TTT
Producing TTT plots is a two stage process:
1. The TTT program (ttt_client.exe) is executed to calculate the tsunami travel time to each point on a grid.
This calculation is made using input files giving 1) the earthquake epicenter (or a series of point
locations representing a long fault rupture) 2) the water depth, which is extracted from the bathymetric
file. TTT is run with the following command (text in square brackets, i.e. [ ], should be replaced with
the appropriate file name):
ttt_client [bathymetry grid filename] -e[epicenter filename] -T[travel-time grid filename] -VL
The travel-time grid is the output file. The bathymetric grid name is given without the .i2 extension, all
other filenames should be given with the file extensions.
2. The output is then plotted using GMT (Generic Mapping Tools), which is a general command line
controlled graphics tool. To simplify the plotting stage, 4 basic hardwired scripts are provided to plot
individual oceans (ttt_fancy_atl.bat, ttt_fancy_ind,bat, ttt_fancy_pac.bat, ttt_fancy_world.bat), and an
interactive script (ttt_fancy.bat) to plot any desired region. However, plots are entirely customizable if
GMT is learnt (which is outside the scope of this exercise). All the scripts have a similar command to
run them, for the interactive script, e.g.:
ttt_fancy [travel-time grid filename] [bathymetry grid filename] [epicenter filename] [ps filename]
ttt_fancy_pac [travel-time grid filename] [bathymetry grid filename] [epicenter filename] [ps filename]
Files to create plots and their locations:
ttt_client.exe… C:\Program Files\TTT Package\Software\TTT\bin (executable to calculate tsunami travel time)
ttt_fancy_(atl/ind/pac/world).bat
… C:\Program Files\TTT Package\Software\TTT\bin (GMT script to produce contour plot)
ttt_fancy.bat … C:\Program Files\TTT Package\Software\TTT\bin (GMT script to produce contour plot)
ttt1.cpt to ttt30.cpt…C:\Program Files\TTT Package\Software\TTT\bin\CPT (color pallet files for ttt_fancy.bat)
ttt_topo_(1/2/5/10/15/20/30/60)m.i2
… C:\Program Files\TTT Package\Software\TTT\share\ttt (bathymetry grid files)
epicenter file… C:\Program Files\TTT Package\Examples
(user-created)
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TTTSDK v3.1 distribution (Dec 2008, ITIC)
Latitude and longitude conventions:
Longitude: The western hemisphere can be either negative or greater than 180, e.g.,
Longitude West = negative (for 100W, it can be -100 or 260).
Be sure to make East edge value than West edge, e.g.,
For 140E – 160W, the West edge is 140 and the East edge should be 200, not -160
Latitude: The Southern hemisphere = negative, e.g., 20 S = -20
This exercise allows 2 scenarios to be plotted:
1960 Chile earthquake and tsunami
a. Using a non-point source (38.0S, 73.5W, length 1000km from Lebu to Puerto Aisen)
b. Using a point source (38.0S, 73.5W)
(Note: Source Location is approximate.)
Example Plot (Pacific line source)
How to use (overview):
1. Move directory to C:\Program Files\TTT Package\Examples.
Type C: to change your drive from H: to C:. (If it is already C:, skip this step.)
Type cd “Program Files\TTT Package\Examples” to move your directory.
2. Run software to create grid file of tsunami travel times using:
ttt_client ttt_topo_5m –eepi_Pacific_mu.txt –Tttt_Pacific_5m_mu.b –VL
3. Run GMT script to create contour plot
ttt_fancy ttt_Pacific_5m_mu.b ttt_topo_5m epi_Pacific_mu.txt ttt_Pacific_mu.ps
Input files: Epicenter file (epi_Pacific_mu.txt), Bathymetry file (ttt_topo_5m.i2)
In detail, instructions for creating the travel time grid and plot:
1. Make sure an epicenter file for multiple sources is in C:\Program Files\TTT Package\Examples.
Sample file is in EXAMPLE_PACIFIC\Data Files
2. Open a command window and go to C:\Program Files\TTT Package\Examples.
3. Run TTT for multiple source by typing the command:
ttt_client ttt_topo_5m –eepi_Pacific_mu.txt –Tttt_Pacific_5m_mu.b –VL
This makes the output travel time grid called ttt_Pacific_5m_mu.b
4. Run the plotting script to create a hardwired plot of the Pacific Ocean region:
ttt_fancy_pac ttt_Pacific_5m_mu.b ttt_topo_5m epi_Pacific_mu.txt ttt_Pacific_mu_woGrid.ps
5. Plot a personalized version of the map with a restricted geographical area and maximum plotted travel-time
contour:
ttt_fancy ttt_Pacific_5m_mu.b ttt_topo_5m epi_Pacific_mu.txt ttt_Pacific_mu.ps
west edge = 120E, east edge = 295E, south edge = -55, north edge = 50, maximum time plotted = 12 hours.
6. Make sure an epicenter file for point source is in C:\Program Files\TTT Package\Examples.
Sample file is in EXAMPLE_PACIFIC\Data Files
7. Run TTT for point source by typing the command:
ttt_client ttt_topo_5m –eepi_Pacific_pt.txt –Tttt_Pacific_5m_pt.b –VL
This makes the output travel time grid called ttt_Pacific_5m_pt.b
8. Run the plotting script to create a hardwired plot of the Pacific Ocean region:
ttt_fancy_pac ttt_Pacific_5m_pt.b ttt_topo_5m eepi_Pacific_pt.txt ttt_Pacific_pt_woGrid.ps
9. Plot a personalized version of the map with a restricted geographical area and maximum plotted travel-time
contour:
ttt_fancy ttt_Pacific_5m_pt.b ttt_topo_5m epi_Pacific_pt.txt ttt_Pacific_pt.ps
west edge = 120E, east edge = 295E, south edge = -55, north edge = 50, maximum time plotted = 12 hours.
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TTTSDK v3.1 distribution (Dec 2008, ITIC)
Screen captures of usage (there may be slight variations depending on your installation):
1. Run software to create grid file of tsunami travel times using:
1960 Chile EQ and tsunami, 38.0S, 73.5W, length 1000km, epicenter file: epi_Pacific_mu.txt
2. Run GMT script to create contour plot using ttt_fancy_pac.bat
3. Run GMT script to create contour plot using ttt_fancy.bat
Example:
map area is 120E – 295E, 55S – 50N.
stop plotting after 12 hours ------ input only INTEGER from 1 to 30 .
contour interval is 1 hour, and contour label interval is 4 hours .
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TTTSDK v3.1 distribution (Dec 2008, ITIC)
1. Run software to create grid file of tsunami travel times using:
1960 Chile EQ and tsunami, 38.0S, 73.5W, epicenter file: epi_Pacific_pt.txt
2. Run GMT script to create contour plot using ttt_fancy_pac.bat
3. Run GMT script to create contour plot using ttt_fancy.bat
Example:
map area is 120E – 295E, 55S – 50N.
stop plotting after 12 hours ------ input only INTEGER from 1 to 30 .
contour interval is 1 hour, and contour label interval is 4 hours .
Notes:
1. When you run ttt_fancy_pac(atl/ind).bat, output files are created in C:\Program Files\TTT
Package\Examples.
2. When you run ttt_fancy.bat, input files (epicenter and bathymetry grid) and output files (plots) are put
together under C:\Program Files\TTT Package\Examples\TTT_FANCY_hhmmss (hr min sec of computer
clock when script run), which directory is automatically created.
3. You may also run the scripts anywhere under C:\, but ttt_fancy_atl/ind/pac.bat creates the outputs in
C:\Program Files\TTT Package\Examples. This can easily be changed by editing the .bat files.
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TTTSDK v3.1 distribution (Dec 2008, ITIC)
Maps made using example above:
Using ttt_fancy_pac with multiple sources (line source)
Using ttt_fancy for multiple source
Using ttt_fancy for point souce
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