********** USERS GUIDE: COMPLOC EARTHQUAKE LOCATION PACKAGE ********** This describes the programs included in the COMPLOC package, which are designed for local earthquake locations. They have been tested on data from the Southern California Seismic Network (SCSN) and Northern California Earthquake Data Center. Before beginning, it is necessary to have the following: (1) A one-dimensional velocity vs. depth model for the region. Here is the format: z or r Vp Vs (DON'T INCLUDE THIS HEADER LINE!) 0.0 4.0 2.31 (START WITH THIS LINE) 6.0 6.2 3.58 32.0 6.8 3.93 32.0 7.8 4.50 60.0 7.9 4.56 The spacing is arbitrary in the file; a fixed column format is not required. The first column can be either depth or radius in km. The next two columns are the P and S wave velocities in km/s. A linear velocity gradient is assummed between model points. In this case there is a velocity discontinuity at 32 km. For crustal models such as this one, a slight velocity gradient should be used for the upper mantle to assure that Pn and Sn arrivals will be obtained. Notice that one can also input a "layer cake" model such as the Hadley-Kanamori model for southern California: 0.0 5.5 3.18 5.5 5.5 3.18 5.5 6.3 3.64 16.0 6.3 3.64 16.0 6.7 3.87 32.0 6.7 3.87 32.0 7.8 4.50 40.0 7.83 4.52 Notice, however, that a slight velocity gradient is put into the lowermost layer so that the program will generate rays for Pn and Sn. (2) A list of station names, their locations and station corrections if available. Example: CI BAR EHZ 32.68005 -116.67215 496.0 0.00 0.00 CI BRG EHZ 33.17139 -116.17470 205.0 0.00 0.00 CI CAH EHZ 33.49296 -116.72386 1313.0 0.00 0.00 CI COY EHZ 33.36296 -116.31114 218.0 0.00 0.00 CI CPM EHZ 34.15442 -116.19771 897.0 0.00 0.00 The station location file format is: col len format name comment --- --- ------ ---- ------- 1 2 a2 net network id 4 4 a4 stname station name 9 3 a3 comp component (but not used in our location programs) 13 10 f10.5 slat station latitude 23 12 f12.5 slon station longitude 35 10 f10.1 selev station elevation (but not used in our programs) 45 16 2f8.2 stterm(2) prior station corrections at each station (1 for P, 2 for S) This is a fixed column format; you MUST put everything in the correct columns. The program uses only the network id and station name to identify and locate stations. This file should have no more than 5000 lines. It is not required that the file be in alphabetical order but this is recommended for your own convenience. (In UNIX, just enter "sort -name filename -print filename.srt" to obtain a sorted version.) (3) Phase pick data for the events to be located These can be in one of three possible formats: (a) BED3, our own special binary format (b) SCSN STP phase data (c) NCEDC HYPOINVERSE phase data For large data sets, we recommend that formats (b) and (c) be converted to (a) using our conversion programs (see below) because the BED3 format is much faster to read. However, if desired (b) and (c) can be used directly in the location program. The programs are as follows: VZFILLIN resamples velocity model to finer depth intervals (should be run before DEPTABLE) DEPTABLE computes tables of travel time, ray angle, ray parameter and vertical slowness at source as a function of source depth for both local and global seismic velocity models. These output tables are designed to be read with the GET_TTS subroutine. PHASE2BED3 converts from SCSN STP or Hypoinverse to BED3 format for storing pick data COMPLOC performs locations using grid search method Implements "shrinking box" source-specific station term (SSST) method (if desired). Results are output into one of five possible formats. Recommended user sequence: (1) Create vz model and run VZFILLIN to resample to 1-km (or 0.5-km) depth interval (2) Run DEPTABLE to create tables necessary for COMPLOC (3) Use PHASE_TO_BED3 to convert phase pick data to BED3 format (4) Run COMPLOC to compute locations ------------------------------------ VZFILLIN -------------------------------- vzfillin.f is a utility program that reads (z, Vp, Vs) model files and resamples them at any desired finer depth interval. This is done with linear interpolation. It also permits generating S velocities that are a specified fraction of the P velocities. Example: shearer@katmai 14> vzfillin Enter input model file name vz.shlk1 Enter output file name vz.shlk1.1km Enter Vp/Vs ratio if Vs=0 in input (e.g., 1.732) 1.76 Enter output dz spacing (e.g. 1) 1 turns 0.0 4.0 0.0 6.0 6.2 0.0 32.0 6.8 0.0 32.0 7.8 4.50 60.0 7.9 4.55 into 0.000 4.0000 2.3094 1.000 4.3667 2.5211 2.000 4.7333 2.7328 3.000 5.1000 2.9445 4.000 5.4667 3.1562 5.000 5.8333 3.3679 6.000 6.2000 3.5796 7.000 6.2231 3.5929 8.000 6.2462 3.6062 9.000 6.2692 3.6195 10.000 6.2923 3.6329 11.000 6.3154 3.6462 12.000 6.3385 3.6595 13.000 6.3615 3.6728 14.000 6.3846 3.6862 15.000 6.4077 3.6995 etc. ----------------------------------- DEPTABLE ------------------------------- deptable.f is a f77 program that computes tables of travel time, ray angle, ray parameter, and vertical slowness at the source as a function of source depth and source-receiver distance. It can be used for both local and global seismic models because an Earth flattening transformation is applied to the velocity model prior to the ray tracing. The output tables are designed to be read with the GET_TTS subroutine. An input velocity model is required in the following format: z or r Vp Vs 0.0 4.0 2.31 6.0 6.2 3.58 32.0 6.8 3.93 32.0 7.8 4.50 60.0 7.9 4.56 The first column can be either depth or radius in km. The next two columns are the P and S wave velocities in km/s. A linear velocity gradient is assummed between model points. In this case there is a velocity discontinuity at 32 km. For crustal models such as this one, a slight velocity gradient should be used for the upper mantle to assure that Pn and Sn arrivals will be obtained. Notice that one can also input a "layer cake" model such as the Hadley-Kanamori model for southern California: 0.0 5.5 3.18 5.5 5.5 3.18 5.5 6.3 3.64 16.0 6.3 3.64 16.0 6.7 3.87 32.0 6.7 3.87 32.0 7.8 4.50 40.0 7.83 4.52 Notice, however, that a slight velocity gradient is put into the lowermost layer so that the program will generate rays for Pn and Sn. IMPORTANT: deptable will only give results for source depths that correspond to a specified depth in the input model. These example input files are not finely sampled in depth and thus are not suited for the example shown below in which results are output at 1 km depth intervals. Use the VZFILLIN program to resample your input model to a finer depth sampling before running deptable. Here is an example of running the deptable program: --------------------------------------------------------------------------------- shearer@katmai 9> deptable Enter input velocity model vz.shlk1_1km First column of input: 1=depth, 2=radius 1 finished reading model Depth points in model= 126 ************************* Table of Model Interfaces ********************** Depth Top Velocities Bot Velocities -----Flat Earth Slownesses----- vp1 vs1 vp2 vs2 p1 p2 s1 s2 0.5 1 4.00 2.31 2 4.18 2.42 0.25000 0.23903 0.43301 0.41401 6.0 13 6.20 3.58 14 6.20 3.58 0.16114 0.16114 0.27910 0.27910 32.0 66 6.80 3.93 67 6.80 3.93 0.14632 0.14632 0.25343 0.25343 32.0 67 6.80 3.93 68 7.80 4.50 0.14632 0.12756 0.25343 0.22111 60.0 124 7.90 4.55 125 7.90 4.55 0.12539 0.12539 0.21771 0.21771 60.0 125 7.90 4.55 126 7.90 4.55 0.12539 0.12539 0.21771 0.21771 Enter maximum depth (9999 for none) 9999 Source depths: (1) Range, (2) Exact 1 Enter source dep1,dep2,dep3 (km)(min,max,spacing) 0 28 1 (1) P-waves or (2) S-waves 1 pmin, pmax = 0. 0.25 Enter number of rays to compute 5000 Enter min p at long range (.133 = no Pn, .238 = Sn) .133 Completed ray tracing loop (1) del in km, t in sec or (2) del in deg., t in min 1 Enter output file for ray table (or none) none Enter del1,del2,del3 (min, max, spacing) 0 150 1 Enter output file name for travel times out.tt Enter output file name for source ray angles out.ang Enter output file name for ray parameters out.ray Enter output file name for vertical slowness at source out.eta ------------------------------------------------------------------------------------- Comments: The maximum depth input can be used if a reflected phase, such as PmP or PcP, is desired. Source depths can either be specified exactly or as a range of equally spaced depths. IMPORTANT: ALL OF THESE DEPTHS MUST CORRESPOND TO A LINE IN THE INPUT VELOCITY MODEL (use the vzfillin program to add lines to your input velocity model) The minimum ray parameter is always set to zero so that vertically travelling rays from events at depth are included. The maximum value is set to the reciprocal of the surface velocity in the model. Unless speed is important, a large number of rays should be used. The program maximum is 40000 rays. If desired, the ray table output file gives the surface-to-surface x and t results for all values of the ray parameter. This may be useful in some case for debugging and other purposes. The output ray angles at the source are from vertical, 0 is upgoing vertical, 90 is horizontal, 135 is downgoing at a 45 degree angle, etc. The output values of ray parameter are negative for upgoing rays from the source and positive for downgoing rays from the source. The program sets zero values of Vs in the input velocity model to Vp. This kluge means that a specified core S phase will automatically generate SKS. The program only outputs the first-arriving branches of triplicated phases. Because Pn and Sn are so weak in most local earthquake data sets, these phases can be supressed by giving a suitable value for the minimum p at long range (as in the above example). This results in tables that include Pg out to ranges beyond the Pg/Pn cross-over distance. The results are only approximate for layer cake (constant velocity layer) models because the results are interpolated between adjacent values of ray parameter p. However, when a large number of rays are used, the inaccuracies are relatively small. ------------------------------------ PHASE_TO_BED3 -------------------------------- We recommend converting phase data file from the network into our BED3 file which is a binary file. It is much faster to read phase data in BED3 format than the direct phase format, especially for large data sets. We provide phase_to.bed3.f which is a f77 program that can convert SCSN catalog phase data and NCSN HYPOINVERSE phase data into BED3 format. Examples: (1) SCSN STP phase data to bed3 file >> phase_to_bed3 Enter output file name for bed3 file SDC.bed3 Enter input file name with phase data (or none) phaselist.stp Enter phase data format (1) SCSN STP (2) HYPOINVERSE 1 ! SCSN STP phase data format Enter file name with phase data (or none) none nq,npickall = 304 2172 ! number of quakes and picks (2) NCSN HYPO71 phase data to bed3 file >> phase2bed3 Enter output file name for bed3 file SIMEON.bed3 Enter file name with phase data (or none) phaselist.simeon Enter phase data format (1) SCSN (2) HYPOINVERSE 2 ! NCSN HYPOINVERSE phase data format Enter file name with phase data (or none) none nq,npickall = 1621 46772 ! number of quakes and picks Phase data files phaselist.scsn and phaselist.ncsn are in this directory. NOTE: Be aware of that there should be only one line following the last pick in the phaselist.stp file. ------------------------------------ COMPLOC -------------------------------- comploc is the f77 program that implements the source-specific location method. Before running comploc, you must already have the P and S travel time table files, the station location file, and the phase pick file. Note that you must have starting locations for the events in the phase pick file; comploc is not designed to locate events without any prior location estimates. Because of the number of required inputs, we recommend always running comploc using a UNIX script (command file). In the examples, these are the "do" files. Here is an example of running the program, followed by a more detailed explanation of the various inputs: comploc Enter P-TT file name tt.socal.pg Enter S-TT file name tt.socal.sg Phase file format (1) BED3 (recommended) (2) SCSN (STP) (3) HYPOINVERSE 1 Enter phase file name Valle.bed3 Enter stlist file name for station locations stlist.scsn Output Location format: (1) SCSN format (2) HYPOINVERSE (Y2K) (3) NCEDC readable (4) HYPO71 format (5) Our Format 5 Enter output file name for locations outbox.L1.loc Enter delmax (km) !distance cutoff delmax (km) 100 Enter npick_min !min number of pick of each event to be relocated 5 Enter flat1,flat2,flon1,flon2 window for quakes !min and max latitude, longitude window for quakes -999 999 -999 999 Enter: (0) normal or (1) fixed loc kluge 0 Enter: (0) catalog depth or (1) qdepref !initial location depth 1 Enter the reference starting depth 10.0 Enter max event number to read (999999 for all) 999999 Enter random frac of events to get (2 for all) !random frac of events to get (2 for all) 2 Enter number of iterations for static station terms 5 Enter number of iterations for ssst 10 Enter starting nmed, dismax for SSST !starting number of nearby events and distance cutoff for station terms calculation 1000 20 Enter ending nmed, dismax for SSST !ending number of nearby events and distance cutoff for station terms calculation 20 5 Enter NORM id (1) L1, (2) L2 or (3) ROBUST MEAN 1 Enter number of iterations !number of iterations that location box shrinks for each event and fraction for Grid-search !fraction that location box shrinks relative to the previous box 15 0.67 First, the program asks for the required input file names. The phase data are permitted in one of three different formats, including the binary bed3 format. Five different output formats for the locations are permitted, including our own special format (option 5). The distance cutoff permits rejection of phase data from stations beyond a maximum distance (km) from the event. Often data at longer distances are less reliable due to Pg/Pn ambiguities or defects in the velocity model. We have generally used a 100 km cutoff for our California location work. Comparing results using different distance cutoffs is a good test of the velocity model. If the event depths change significantly when a 50 km cutoff is used compared to a 100 km cutoff, then the mid to lower crustal velocities in the model are likely too fast or too slow. A clue that this may be happening is when a mainshock locates at a different depth from its aftershocks; larger events typically have phase picks extending to larger distances than smaller events. npick_min sets a mininum number of phase picks in order to locate an event. Obviously at least four picks are required to solve for (x,y,z,t). We recommend setting this to at least five. Larger numbers will restrict the locations to only the better recorded events. A lat/lon window options permits locating a geographic subset of your dataset. Units are decimal degrees. Use negative numbers for west longitudes, i.e. California is at -120 longitude. Normally, the fixed loc kluge option should not be used as it does not produce new locations. The fixed location kluge option permits keeping the location fixed at the (x,y,z) location given in the phase file. The program will then only vary the origin time of the events to achieve the best fit. This option can be useful to compute station terms for a given set of locations with respect to a particular 1-D velocity model. For example, if one has locations available from a joint-hypocenter velocity (JHV) inversion that are believed to be accurate, this option can be used to compute a set of station terms that will yield similar absolute locations using the comploc program (this will require a separate run of comploc using the station terms as input). The advantage is that additional events (not in the JHV catalog) can be located and the SSST method should improve the relative location accuracy of all of the events. The starting reference depth is the center point for the grid search method. If a fixed depth is used (as in this example), then another input line is required to specify the depth. Except for rare, pathological events that confuse the grid search approach, the location results should not be sensitive to this depth. 10 km is a good starting depth because the grid search method starts with a box of +- 10 km. For testing purposes, one can locate fewer than the total number of events by specifying a maximum number of events to locate. One can also specify a random fraction of the total events to locate. For example, entering 0.1 for the random fraction would cause the program to randomly select 10% of the input events. The program works by performing a number of iterations of event location and station term calculation. There are two types of stations terms. Static station terms are a single number for each station and phase (P or S). They are computed as the mean (or median) of the residuals for each station. The source-specific station terms (SSST) are specific to each event and are computed by smoothing the residuals over adjacent events. The best results are generally obtained by first solving for static stations terms and then solving for source-specific station terms using a residual smoothing box that decreases in size with each iteration. The program permits the user to vary the number of iterations used at each step and the size of the smoothing box for the SSST calculation. In this example, 5 iterations are used to compute the static station terms and 10 are used for the SSST. At each SSST iteration the terms are computed by smoothing over nmed adjacent events, located within a distance dismax of each target event. In this example, nmed = 1000 and dismax = 20 (km) at the first iteration. At the last (10th iteration), nmed = 20 and dismax = 5 (km). nmed and dismax are set to intermediate values for iterations 2 to 9 (these are evenly spaced in log(nmed) and log(dismax)). The parameters used here work pretty well for our California locations but users may wish to experiment with different choices. The general strategy is to gradually decrease the number of events used in smoothing the residuals for the SSST calculation. The longer wavelength structure in the residual field helps to improve the absolute location accuracy; the shorter wavelength structure provides the best relative location accuracy among nearby events. Even if the primary control on the SSST smoothing is provided by nmed, suitable choices for dismax can make the program run faster. This is because sorting by distance is required to identify the closest nmed events. Sorting is a computer intensive process for large data sets (> 100,000 events) so using dismax to restrict the number of events to be sorted is a good idea. The grid search location method searches for the smallest residuals as defined by the (1) the L1-norm (median), (2) L2-norm (least squares, mean), or (3) robust mean (L2 with outlier suppression). We generally recommend the use of (1) or (3) because they are relatively insensitive to gross picking and timing errors, unless you are confident that your picks are outlier free. For consistency, this choice of norm also controls how the station terms are computed (1=median residual, 2= mean residual, 3=robust mean residual). Note: the robust mean estimates the mean uses L2 for residuals less than 0.1 s and L1 for residuals greater than 0.1 s. The grid search location method is iterative. At each iteration, it checks 27 locations in a 3x3x3 cube centered on the current best location. The location with the smallest residual becomes the new current location and the cube shrinks by a user specified fraction (0.67 in this example). The starting cube is 20 km across (+- 10 km from the starting location). The nominal location precision is determined by the number of iterations and the fractional reduction parameter. In this case, this precision is 10*0.67^15 = 0.0246 km = 25 m. Faster results can be obtained by using 0.5 rather than 0.67 and a smaller number of iterations; however the grid search performs somewhat less reliably in this case for "problem" events (if the misfit function is very elongated, the minimum may fall between grid points and the program may not converge to the true minimum residual solution). Note: (1) Travel time tables, ray parameter tables and vertical slowness tables are generated using deptable.f program. (2) We give users choices of output location file format. (2a) SCSN catalog format ======================================================================== col len format name comment --- --- ------ ---- ------- 1 4 a4 cyr YYYY 6 2 a2 cmon MM 9 2 a2 cdy DD 13 2 a2 chr HH (UTC time: 16 2 a2 cmn mm 7 hours ahead of Pacific Daylight Time 19 5 f5.2 fsc SS.ss 8 hours ahead of Pacific Standard Time) 25 3 i3 lat degrees 29 5 f5.2 lat minutes 34 4 i4 lon degrees 39 5 f5.2 lon minutes 45 1 a1 quality location quality 'A' +- 1 km horizontal distance +- 2 km depth 'B' +- 2 km horizontal distance +- 5 km depth 'C' +- 5 km horizontal distance no depth restriction 'D' >+- 5 km horizontal distance 'Z' no quality listed in database 47 3 f3.1 magnitude 54 6 f6.2 depth kilometers 60 3 i3 nph number of picked phases 67 5 f5.2 rms root mean square of travel times 73 8 i8 eventid event ID ======================================================================== (2b) HYPOINVERSE (Y2K) ======================================================================== col len format name comment --- --- ------ ---- ------- 1 4 I4 iyr Year. 5 2 I2 imon Month. 7 2 I2 idy Day. 9 2 I2 ihr Hour. 11 2 I2 imn Minute. 13 4 F4.2 fsc Origin time seconds. 17 2 F2.0 ilat Latitude (deg). 19 1 A1 S for south, blank otherwise. 20 4 F4.2 elat Latitude (min). 24 3 F3.0 ilon Longitude (deg). 27 1 A1 E for east, blank otherwise. 28 4 F4.2 Longitude (min). 32 5 F5.2 qdep Depth (km). 37 3 F3.2 Magnitude from maximum S amplitude from NCSN stations 40 3 I3 Number of P & S times with final weights greater than 0.1. 43 3 I3 Maximum azimuthal gap, degrees. 46 3 F3.0 Distance to nearest station (km). 49 4 F4.2 rms RMS travel time residual. 53 3 F3.0 Azimuth of largest principal error (deg E of N). 56 2 F2.0 Dip of largest principal error (deg). 58 4 F4.2 Size of largest principal error (km). 62 3 F3.0 Azimuth of intermediate principal error. 65 2 F2.0 Dip of intermediate principal error. 67 4 F4.2 Size of intermediate principal error (km). 71 3 F3.2 Coda duration magnitude from NCSN stations. 74 3 A3 Event location remark. (See table 7 below). 77 4 F4.2 Size of smallest principal error (km). 81 2 2A1 Auxiliary remarks (See note below). 83 3 I3 Number of S times with weights greater than 0.1. 86 4 F4.2 Horizontal error (km). 90 4 F4.2 Vertical error (km). 94 3 I3 Number of P first motions. 97 4 F4.1 Total of NCSN S-amplitude mag weights ~number of readings. 101 4 F4.1 Total of NCSN duration mag weights ~number of readings. 105 3 F3.2 Median-absolute-difference of NCSN S-amp magnitudes. 108 3 F3.2 Median-absolute-difference of NCSN duration magnitudes. 111 3 A3 3-letter code of crust and delay model. (See table 8 below). 114 1 A1 Last authority for earthquake N=NCSC (USGS), B=UC Berkeley. 115 1 A1 Most common P & S data source code. (See table 1 below). 116 1 A1 Most common duration data source code. (See cols. 68-69) 117 1 A1 Most common amplitude data source code. 118 1 A1 Coda duration magnitude type code 119 3 I3 Number of valid P & S readings (assigned weight > 0). 122 1 A1 S-amplitude magnitude type code 123 1 A1 "External" magnitude label or type code. 124 3 F3.2 "External" magnitude. 127 3 F3.1 Total of the "external" magnitude weights (~ number of readings). 130 1 A1 Alternate amplitude magnitude label or type code (i.e. L for ML calculated by Hypoinverse from Wood Anderson amplitudes). 131 3 F3.2 Alternate amplitude magnitude. 134 3 F3.1 Total of the alternate amplitude mag weights ~no. of readings. 137 10 I10 Event identification number 147 1 A1 Preferred magnitude label code chosen from those available. 148 3 F3.2 Preferred magnitude, chosen by the Hypoinverse PRE command. 151 4 F4.1 Total of the preferred mag weights (~ number of readings). 155 1 A1 Alternate coda duration magnitude label or type code (i.e. Z). 156 3 F3.2 Alternate coda duration magnitude. 159 4 F4.1 Total of the alternate coda duration magnitude weights. 163 1 A1 Version number of information: 0=25 pick; 1=Final EW with MD; 2=ML added, etc. 0-9, then A-Z. Hypoinv. passes this through. 164 1 A1 Version # of last human review. blank=unreviewed, 1-9, A-Z. ======================================================================== (2c) NCEDC readable ======================================================================== col len format name comment --- --- ------ ---- ------- 1 4 i4 iyr Year. 6 2 i2 imon Month. 9 2 i2 idy Day. 12 2 i2 ihr Hour. 15 2 i2 imn Minute. 18 5 f5.2 fsc second. 23 9 f9.4 qlat Latitude. 32 10 f10.4 qlon Longitude. 42 7 f7.2 qdep Depth (km). 49 6 f6.2 qmag Magnitude. 58 2 a2 magt magnitude type. 60 5 i5 nst Number of stations used to compute the location. 65 4 i4 gap Maximum Azimuthal gap (unavailable from our location program). 69 5 i5 clo Distance of closest station to event (unavailable from our location program). 74 5 f5.2 rms RMS travel time residual. 80 4 a4 src Source of event info The reporting source for the solution. Our solution's source is SHLK. 85 10 i10 id Event ID (2d) HYP71 ======================================================================== col len format name comment --- --- ------ ---- ------- 1 4 i4 iyr Year. 5 2 i2 imon Month. 7 2 i2 idy Day. 10 2 i2 ihr Hour. 12 2 i2 imn Minute. 14 6 f6.2 fsc Original time seconds. 20 3 f3.0 ilat Latitude in minutes. 24 5 f5.2 qlat Latitude. 29 4 f4.0 ilon Longitude in minutes. 34 5 f5.2 qlon Longitude. 38 7 f7.2 qdep Depth. 47 5 f5.2 qmag Magnitude. 52 3 i3 npspick Number of picks (P+S). 55 4 f4.0 maxazi maximum azimuth. 59 5 f5.1 mindis minimum source-receiver distance. 64 5 f5.2 rms RMS residual for each earthquake. 69 5 f5.1 errx Horizontal error. 74 5 f5.1 errz Vertical error. 83 10 i10 idcusp Cuspid (2e) Our own format ======================================================================== col len format name comment --- --- ------ ---- ------- 1 4 i4 iyr Year. 5 3 i3 imon Month. 8 3 i3 idy Day. 11 3 i3 ihr Hour. 14 3 i3 imn Minute. 17 7 f7.3 fsc Original time seconds. 24 8 f8.4 qlat Latitude. 32 10 f10.4 qlon Longitude. 42 6 f6.2 qdep Depth. 48 6 f6.2 errx Location error in x. 54 6 f6.2 erry Location error in y. 60 6 f6.2 errz Location error in z. 66 6 f6.2 errt Original time error. 72 11 i11 cuspid Event ID. 83 4 f4.1 qmag Magnitude. 87 4 i4 nppick number of P-phases used to compute the location. 91 4 i4 nspick number of S-phases used to compute the location. 95 6 f6.2 rms RMS travel time residual. ========================================================================