File Formats

Trace formats

SourceSpec can read all the trace formats supported by ObsPy.

Two very common choices are:

The SAC format can carry additional information in its header, like event location and origin time, phase picks, instrument sensitivity.

Input trace files can be provided –through the -t option– as a list of files, as a directory containing the files, or as a TAR(GZ) or ZIP archive containing the files.

Event formats

SourceSpec can read event information (event ID, location, origin time) in the following formats:

  • SourceSpec Event File: this file can contain additional event information, such as magnitude, moment tensor or focal mechanism

  • QuakeML: this file can contain additional event information, such as magnitude, moment tensor or focal mechanism. If phase picks are available, they will be read as well

  • HYPO71

  • HYPOINVERSE-2000: if phase picks are available, they will be read as well

Event information can also be stored in the SAC file header (header fields: EVLA, EVLO, EVDP, O, KEVNM).

Phase pick formats

Phase picks for P and S waves can be read from one of the following formats:

Phase picks can also be stored in the SAC file header, using the header fields A and T0 through T9. A pick label can be specified (header fields KA and KT0 through KT9) to identify the pick; the pick label can be a standard 4-characters SAC label (e.g., "IPU0", " S 1") or a label starting with "P" or "S" (lowercase or uppercase, e.g., "P", "pP", "Pg", "S", "Sn"). Picks with labels that cannot be parsed by SourceSpec will be ignored. If no label is specified, then SourceSpec will assume that A is the P-pick and T0 is the S-pick.

Station metadata formats

Station metadata (coordinates, instrumental response) can be provided in one of the following formats:

Note that SEED RESP and PAZ formats do not contain station coordinates, which should therefore be in the trace header (traces in SAC format).

The station metadata file name or file directory is provided in the configuration file through the parameter station_metadata.

Alternatively, instrument sensitivity can be provided in the SAC header or as a constant in the configuration file. In both cases, use the configuration parameter sensitivity.

Output files

The SourceSpec main code, source_spec will produce the following output files (EVID is replaced by the actual event ID):

  • EVID.ssp.yaml: YAML file containing the estimated spectral parameters (summary values and per station values)

  • EVID.ssp.out (deprecated): text file containing the estimated spectral parameters (summary values and per station values)

  • EVID.ssp.log: log file in text format (including the command line arguments, for reproducibility)

  • EVID.ssp.conf: the input config file (for reproducibility)

  • EVID.residuals.hdf5: station residuals in HDF5 File Format

  • EVID.spectra.hdf5: (optional) spectra in HDF5 File Format

  • EVID.ssp.h: hypocenter file in HYPO71 format with the estimated moment magnitude (only if an input HYPO71 file is provided)

  • EVID.xml: updated QuakeML file with the results of the SourceSpec inversion (only if an input QuakeML file is provided)

The following plots will be created, in png, pdf or svg format:

  • EVID.traces.png[.pdf,.svg]: trace plots

  • EVID.ssp.png[.pdf,.svg]: spectral plots

  • EVID.sspweight.png[.pdf,.svg]: spectral weight plots

  • EVID.boxplot.png[.pdf,.svg]: box plots for the earthquake source parameters retrieved at each station

  • Misfit plots, when using “grid search” or “importance sampling” for the spectral inversion

As an option, station maps can be created (requires Cartopy):

  • EVID.map_mag.png[.pdf,.svg]: station map with symbols colored by estimated moment magnitude

  • EVID.map_fc.png[.pdf,.svg]: station map with symbols colored by estimated corner frequency

As an option, the retrieved source parameters (per station and average) can be appended to a SQLite database, whose path is defined in the configuration file.

Finally, always as an option, source_spec can generate a report in HTML format.