# GET /greens_function¶

Note

Some parts of this route require an advanced server setup. Please view the Advanced Server Configuration for details. The parts that don’t will keep working even with a normal configuration.

Description

Returns Instaseis Greens’s function, that is seimograms for contraction with the decomposition of the Momenttensor as in Minson & Dreger (2008). Several convenience function of the /seismograms route are replicated here to make it suitable to be queried by any program able to use HTTP.

 Minson, Sarah E., and Douglas S. Dreger (2008) Stable Inversions for Complete Moment Tensors. Geophysical Journal International 174 (2): 585–592. http://dx.doi.org/10.1111/j.1365-246X.2008.03797.x
Content-Type
• application/zip (if zipped SAC data is requested)
• application/vnd.fdsn.mseed (if MiniSEED data is requested)
Instaseis-Mu: This transports the mu of the model for the given seismogram which is needed for some finite source calculations. Please make sure your proxy does not filter it.
Filetype

Returns a ZIP archive with SAC files or MiniSEED files encoded with encoding format 4 (IEEE floating point).

SAC files will have the following user defined variables set:

• KUSER0: “InstSeis”
• KUSER1: The first eight letters of the used velocity model.
• KT7: The first seven letters of the AxiSEM version number used to generate the model. Prefixed with A.
• KT8: The first seven letters of the Instaseis version number used to generate the seismogram. Prefixed with I.
• USER0: The scale factor used to generate the waveforms.
Parameter Type Required Default Value Description
sourcedepthinmeters Float True   The source depth in meters.
sourcedistanceindegrees Float True   The epicentral disctance of source - receiver in degrees (computed on the surface of a sphere).
Output parameters
format String False saczip Specify output file to be either MiniSEED or a ZIP archive of SAC files, either miniseed or saczip.
label String False greensfunction Specify a label to be included in file names and HTTP file name suggestions.
units String False displacement Specify either displacement, velocity or acceleration for the synthetics.
dt Float False   If given, seismograms will be resampled to the desired sample spacing.
kernelwidth Integer False 12 Specify the width of the sinc kernel used for resampling to requested sample interval in terms of the original sampling interval.
Time Parameters
origintime Datetime False 1900-01-01T00:00:00.000000Z Specify the source origin time. This must be specified as an absolute date and time. This time coincides with the peak of the source time function.
starttime Datetime False

Specifies the desired start time for the synthetic trace(s). This may be specified as either:

• an absolute date and time
• a phase-relative offset
• an offset from origin time in seconds

If the value is recognized as a date and time, it is interpreted as an absolute time. If the value is in the form phase[+-]offset it is interpreted as a phase-relative time, for example P-10 (meaning P-wave arrival time minus 10 seconds). If the value is a numerical value it is interpreted as an offset, in seconds, from the origin time.

endtime Datetime False

Specifies the desired end time for the synthetic trace(s). This may be specified as either:

• an absolute date and time
• a phase-relative offset
• an offset (duration) from start time in seconds

If the value is recognized as a date and time, it is interpreted as an absolute time. If the value is in the form phase[+-]offset it is interpreted as a phase-relative time, for example P-10 (meaning P-wave arrival time minus 10 seconds). If the value is a numerical value it is interpreted as an offset, in seconds, from the start time.