zmap a tool for analyses of seismicity patterns typical applications ...

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Importing data into ZMAP CHAPTER VI ASCII columns – the most simple way Importing data is often the first major hurdle that users have in running ZMAP. Within ZMAP, data are stored internally in the Matrix ‘a’ in the following format: Column 1 2 3 4 5 6 7 8 9 Longitude Latitude Year Month Day Magnitude Depth Hour Minute The trick is to get your data into ‘a’. The most stable and easy solution is to create an ASCII file with exactly these columns, separated by at least one blank or tab. Note that zeros in column 4 and 5 will create errors. Western Longitudes are by convention negative. Such a file could look like this: -120.819 36.251 1980 1 1 3.7 6.60 2 9 -120.825 36.249 1980 1 1 3.6 7.80 2 9 -120.809 36.251 1980 1 2 1.5 6.54 0 54 -120.817 36.255 1980 1 2 2.8 6.44 10 39 -120.615 36.048 1980 1 3 0.5 4.58 12 19 -120.815 36.265 1980 1 4 1.3 4.97 19 49 -120.470 35.925 1980 1 7 0.8 4.62 7 39 -120.565 36.016 1980 1 9 0.9 6.48 1 51 -120.472 35.928 1980 1 9 2.9 10.35 17 54 -120.643 36.083 1980 1 10 0.9 3.19 22 54 -120.951 36.371 1980 1 15 1.9 8.44 2 39 -120.934 36.357 1980 1 16 2.0 5.87 10 2 You can test if it is an acceptable file by loading it into Matlab. Lets assume the file is stored in the filename mydata.dat, then typing load mydata.dat should create a variable mydata in the workspace, with 9 columns and as many row as earthquakes in you catalog. Quite frequently, you will encounter the following message: ??? Error using ==> load Number of columns on line 6 of ASCII file C:\ZMAP6\out\park.dat must be the same as previous lines. You should check line 6 for inconsistencies and try again. Once this file can be loaded into Matlab, there are three ways to load it into ZMAP: • Using the ASCII file import option. From the ZMAP menu, select the “Create or Modify *.mat file’ option, the “EQ Datafile” option ASCII columns. 54
• First rename mydata into a: a = mydata; then start zmap and type: startwitha • Use the ‘Import Filter’ option from the ZMAP menu, and select the ASCII import filter. To get your data into ASCII column format, you can use various tools. On a PC, I often use textpad (http://www.textpad.com/). In block selection mode, you can delete columns, and by copying and pasting a blank column, you can add blanks between dates. On a UNIX workstation, cut and paste work well: cut –c4-8 catalog.dat > year cut –c9-10 catalog.dat > month … paste long lat year month … > mydata.dat which will be a tab separated file that can be readily read into Matlab. Other options to import your data: Writing your own import filters A second option to import your data is to write your own import filter. A number of existing filters are listed in the ./importfilters directory. When you choose “Import Data” from the ZMAP menu, an window will list all available filters: Select a filter and choose “Import”, then select the name of the file to be imported. The filters generally will try to read the entire data matrix at once. If this fails, it will read line by line and report lines that could not be imported. To design a filter that fits you data format is relatively easy. Lets assume that you would like to read in the SCEC DC earthquake catalog for 2001 (http://www.scecdc.scec.org/ftp/catalogs/SCEC_DC/2001.cat). The first few lines are shown below. 2001/01/01 01:16:25.7 le 1.0 h 35.123 -118.538 5.2 A 9172298 0 0 0 0 2001/01/01 01:21:55.9 le 1.6 h 35.047 -119.083 10.9 A 9172300 0 0 0 0 55
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ZMAP A TOOL FOR ANALYSES OF SEISMIC
Page 3 and 4: INTRODUCTION This cookbook is aimed
Page 5 and 6: Figure 2: Seismicity map of the ent
Page 7 and 8: Save new mat-file: At this point it
Page 9 and 10: Narrowing the target of investigati
Page 11 and 12: Figure 11: Resolution map with the
Page 13 and 14: Articles in which tools discussed i
Page 15 and 16: Figure 2.2: Genas1 window. The cumu
Page 17 and 18: Figure 2.5: Comparison of the rates
Page 19 and 20: this case, the routine found that a
Page 21 and 22: cumulative number curve for M>1. ev
Page 23 and 24: Second: One may want to know the am
Page 25 and 26: Figure 3. 5: Z-menu window. Choosin
Page 27 and 28: each node and calculates for every
Page 30 and 31: Again the grid is chosen by using t
Page 33 and 34: Articles in which tools discussed i
Page 35 and 36: Figure 4.2: b-value maps of souther
Page 37 and 38: Figure 4.5: (a) Magnitude of comple
Page 39 and 40: Changes of b-values as a function o
Page 41 and 42: CHAPTER V Stress Tensor Inversions
Page 43 and 44: Inverting for the best fitting stre
Page 45 and 46: of S1 as a bar, and color codes the
Page 47 and 48: Using Gephart’s code An alternati
Page 49 and 50: #define VARIANCE_30 30 change to: #
Page 51 and 52: depicts the misfit value f. Please
Page 53: Lu, Z., M. Wyss, and H. Pulpan, Det
Page 57 and 58: CHAPTER VII Tips an tricks for maki
Page 59 and 60: Now lets change the axes setup. Sel
Page 61 and 62: Alternatively, you can print from t
Page 63: Working with interpolated color map
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