~.ttou Files
~.ttou files are produced by the ttou command, which can be used up to six times in a run of mloc. Each instance of the command specifies a phase for which all corresponding data will be printed to a file named ~_phasename.ttou. These files are carried in a subdirectory of the cluster series directory named ~_tt.
The most common use of this output file is to create a dataset of Lg arrivals that can be quickly analyzed to obtain a model for Lg arrivals (implemented by the lgtt command). Lg travel times can be well-predicted by a model that is linear in epicentral distance with a y-intercept close to zero. The default model in mloc is 31.500 sec/degree with intercept = 0. The format of ~.ttou files is designed for easy import into a data-modelling program, and the Lg travel-time model is estimated by a simple linear least-squares fit. Here is an example, from a cluster near Hutchinson, Kansas (a row of headers has been added for this display):
No Event name Depth MNF Station Delta Az Obs. TT Res. Read Error Flag 5 20170730.0013.45 5.0 56 TUL3 2.755 139 86.40 -1.16 0.22 6 20180301.2026.59 5.0 91 ANMO 7.464 248 232.87 1.17 1.12 6 20180301.2026.59 5.0 95 TXAR 9.859 210 308.62 3.57 0.86 6 20180301.2026.59 5.0 98 PDAR 10.001 302 308.60 -0.78 1.14 6 20180301.2026.59 5.0 99 TKL 11.649 97 363.34 3.50 0.10 x 6 20180301.2026.59 5.0 102 ULM 12.322 6 376.40 -4.03 2.21 7 20180308.1048.21 5.0 122 TUL3 2.750 139 85.98 -1.40 0.22 7 20180308.1048.21 5.0 130 BGNE 3.393 358 105.74 -1.33 4.00 7 20180308.1048.21 5.0 146 OGNE 4.273 315 132.35 -1.66 4.00 7 20180308.1048.21 5.0 170 ANMO 7.461 248 232.25 0.64 1.12 7 20180308.1048.21 5.0 173 TXAR 9.853 210 308.95 4.10 0.86 7 20180308.1048.21 5.0 175 PDAR 10.004 302 308.00 -1.48 1.14 7 20180308.1048.21 5.0 178 TKL 11.649 97 359.70 -0.13 0.10 7 20180308.1048.21 5.0 181 ULM 12.329 6 373.45 -7.19 2.21 12 20180414.0246.34 5.0 136 TXAR 9.860 210 302.15 -2.91 0.86 x 12 20180414.0246.34 5.0 142 ULM 12.323 6 380.46 -0.01 2.21 25 20190816.1259.10 5.0 245 ANMO 7.449 248 231.58 0.34 1.12 25 20190816.1259.10 5.0 252 TXAR 9.838 210 306.46 2.07 0.86 25 20190816.1259.10 5.0 255 PDAR 10.005 302 309.95 0.45 1.14 25 20190816.1259.10 5.0 262 TKL 11.655 97 360.26 0.25 0.10 25 20190816.1259.10 5.0 266 ULM 12.343 6 379.19 -1.88 2.21 25 20190816.1259.10 5.0 270 ELK 13.602 287 423.27 3.64 4.00 36 20190818.0845.29 5.0 237 ANMO 7.449 248 232.60 1.34 1.12 36 20190818.0845.29 5.0 240 TXAR 9.841 210 307.15 2.68 0.86 36 20190818.0845.29 5.0 243 PDAR 10.002 302 307.92 -1.48 1.14 36 20190818.0845.29 5.0 246 TKL 11.656 97 359.97 -0.09 0.10 36 20190818.0845.29 5.0 249 ULM 12.339 6 377.83 -3.13 2.21 37 20190901.1321.06 4.0 50 ANMO 7.455 248 231.09 -0.35 1.12 37 20190901.1321.06 4.0 53 TXAR 9.846 210 308.68 4.05 0.86 37 20190901.1321.06 4.0 55 PDAR 10.005 302 311.50 2.00 1.14 37 20190901.1321.06 4.0 57 TKL 11.651 97 359.79 -0.12 0.10 37 20190901.1321.06 4.0 60 ULM 12.335 6 377.59 -3.26 2.21
The Lg travel-time model derived from fitting a line to the TT vs. Delta columns is given in subsequent command files as:
lgtt 3.2 30.615 2.5
The fit of this model to the Lg data is shown by the turquoise symbols and line in the “Local-Regional Shear Phases” summary plot, one of the summary plots controlled by the pltt command:
