Caribbean Training Course in Seismology and Tsunami Warnings
25-30 June 2007, Modified for TTTSDK v3.1 distribution (Nov 2008)
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_ind [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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Caribbean Training Course in Seismology and Tsunami Warnings
25-30 June 2007, Modified for TTTSDK v3.1 distribution (Nov 2008)
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 are plotted:
1. 1867 earthquake and tsunami
a. Using a non-point source (18.0N, 65.0W, length 120km, width 30km, EW direction)
b. Using a point source (18.0N, 65.0W)
2. Puerto Rico Trench hypothetical source using non-point source
(19.2948N, 67.5734W, length 100km, width 50km, strike 85.87)
(this scenario was used as 1 for SIFT modeling efforts)
How to use:
1. Move directory to C:\Program Files\TTT Package\Examples and to sub-directory where the input files are.
Type C: to change your drive from H: to C:. (If it is already C:\, skip this step.)
2. Run software to create grid file of tsunami travel times using:
ttt_client [bathymetry grid filename] –e[epicenter filename] –T[travel-time grid filename] –VL
e.g., for Example\1_a
ttt_client ttt_topo_5m –eepicenter_carb_1867_multi.txt –Tttt_carb_1867_5m_multi.b –VL
3. Run GMT script to create contour plot
ttt_fancy [travel-time grid filename] ttt_topo_5m [epicenter filename] [ps filename]
4. ttt_fancy will ask users for map boundary, max. hours to plot, contour interval, and contour label interval.
e.g.,
ttt_fancy ttt_carb_1867_5m_multi.b ttt_topo_5m epicenter_carb_1867_multi.txt ttt_carb_1867_5m_multi.ps
The epicenter file, travel-time grid file and plots (ps and png file) are put together in C:\Program Files\TTT
Package\Examples\TTT_FANCY_hhmmss (time stamp), which is created automatically.
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Caribbean Training Course in Seismology and Tsunami Warnings
25-30 June 2007, Modified for TTTSDK v3.1 distribution (Nov 2008)
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 (Example 1_a):
1867 Virgin islands EQ and tsunami, 18.0N, 65.0W, length 120km, width 30km, EW direction
epicenter file: epicenter_carb_1867_multi.txt
2. Run GMT script to create contour plot
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Caribbean Training Course in Seismology and Tsunami Warnings
25-30 June 2007, Modified for TTTSDK v3.1 distribution (Nov 2008)
For this case,
map area is 100W – 20E, 60S – 60N.
stop plotting after 12 hours ------ input only INTEGER from 1 to 30 .
contour interval is 1 hour, and contour label interval is 4 hours .
Map made using example above:
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