5.10.1.2. eqcorrscan.utils.mag_calc.amp_pick_sfile

eqcorrscan.utils.mag_calc.amp_pick_sfile(sfile, datapath, respdir, chans=[‘Z’], var_wintype=True, winlen=0.9, pre_pick=0.2, pre_filt=True, lowcut=1.0, highcut=20.0, corners=4, min_snr=1.0, plot=False, remove_old=False, velocity=False)[source]

Function to pick amplitudes for local magnitudes from NORDIC s-files.

Reads information from a SEISAN s-file, load the data and the picks, cut the data for the channels given around the S-window, simulate a Wood Anderson seismometer, then pick the maximum peak-to-trough amplitude.

Output will be put into a mag_calc.out file which will be in full S-file format and can be copied to a REA database.

See docs for eqcorrscan.utils.mag_calc.amp_pick_event() for methods used here for stabilisation.

Parameters:
  • sfile (str) – Path to NORDIC format s-file
  • datapath (str) – Path to the waveform files - usually the path to the WAV directory
  • respdir (str) – Path to the response information directory
  • chans (list) – List of the channels to pick on, defaults to [‘Z’] - should just be the orientations, e.g. Z,1,2,N,E
  • var_wintype (bool) – If True, the winlen will be multiplied by the P-S time if both P and S picks are available, otherwise it will be multiplied by the hypocentral distance*0.34 - derived using a p-s ratio of 1.68 and S-velocity of 1.5km/s to give a large window, defaults to True
  • winlen (float) – Length of window, see above parameter, if var_wintype is False then this will be in seconds, otherwise it is the multiplier to the p-s time, defaults to 0.5.
  • pre_pick (float) – Time before the s-pick to start the cut window, defaults to 0.2
  • pre_filt (bool) – To apply a pre-filter or not, defaults to True
  • lowcut (float) – Lowcut in Hz for the pre-filter, defaults to 1.0
  • highcut (float) – Highcut in Hz for the pre-filter, defaults to 20.0
  • corners (int) – Number of corners to use in the pre-filter
  • min_snr (float) – Minimum signal-to-noise ratio to allow a pick - see note in amp_pick_event on signal-to-noise ratio calculation.
  • plot (bool) – Turn plotting on or off.
  • remove_old (bool) – If True, will remove old amplitude picks from event and overwrite with new picks. Defaults to False.
  • velocity (bool) – Whether to make the pick in velocity space or not. Original definition of local magnitude used displacement of Wood-Anderson, MLv in seiscomp and Antelope uses a velocity measurement.
Returns:

Picked event

Return type:

obspy.core.event.event.Event