Receiver Function and SKS automatic measurement - Seismological Tools Automated Download, processing & Imaging Using Mostly Python (STADIUM - Py)

• By Cédric P Legendre (@cplegendre) and Utpal Kumar (@utpalrai)
• Based on RF analyses by: Tom Eulenfeld (@trichter); https://github.com/trichter/rf
• Based on SKS analyses by: Jack Walpole (@JackWalpole); https://github.com/JackWalpole/splitwavepy
• Based on ObsPy: https://github.com/obspy/

The User's manual for STADIUM-Py can be downloaded from here.

Installation

Install the anaconda Python 3 environment rfsksenv by running the following command (Note: It requires preinstalled anaconda)

• OSX:

conda env create -f environment_osx_10_14_6.yml

• Linux:

conda env create -f environment_UbuntuXIX.yml

• Windows:

requires installation of Anaconda Python followed by packages in the environement.

To activate the anaconda environement:

conda activate rfsksenv

PS:

• All these libraries can be installed separately in "non-anaconda" environment as well.

• If having some issues with Cartopy, one simple fix may be:

pip uninstall shapely; pip install --no-binary :all: shapely

• In Ubuntu, there were conflicts in the different required libraries. Therefore, some of the necessary dependencies needed to be installed manually:

  • cartopy -- conda install -c conda-forge cartopy
  • h5py -- conda install h5py
  • obspyh5 -- pip install obspyh5 or -- conda install obspyh5
  • rf -- pip install rf
  • splitwavepy -- pip install splitwavepy

Run:

python stadium.py

User's input:

A total of four files controls the run of STADIUM-Py:

• input_file.yaml (select region)
• Settings/stepwise.yaml (toggle the steps)
• Settings/advRFparam.yaml (fine tune the RF parameters)
• Settings/advSKSparam.yaml (fine tune the SKS parameters)

Below, you will find a list of the parameters, with possible values and its description.

input_file

• project\_name |default| Define the name of the project directory where all results will be stored.
• fresh_start | 0/1 | Delete the 'default' folder and start fresh
• makeRF | 0/1 | Run the code to calculate the Reciever Functions
• makeSKS |0/1 | Run the code to calculate the shear-wave splitting of SKS phase

In addition, 4 boundary parameters are used to select the region of interest:

1. mnlong |-130 | Minimum longitude of the region of interest
2. mxlong |-60 | Maximum longitude of the region of interest
3. mnlat |35 | Minimum latitude of the region of interest
4. mxlat |50 | Maximum latitude of the region of interest

stepwise

This file is provided in case user want to run specific part of the code (for testing or parameters adjustments).

data settings

• client |IRIS | Enter all the clients for data download separated by commas. List of ObsPy clients: https://docs.obspy.org/packages/obspy.clients.fdsn.html . Current list -- 24 items: BGR, EMSC, ETH, GEONET, GFZ, ICGC, INGV, IPGP, IRIS, ISC, KNMI, KOERI, LMU, NCEDC, NIEP, NOA, ODC, ORFEUS, RASPISHAKE, RESIF, SCEDC, TEXNET, USGS, USP.
• network |* | List of networks (default = all)
• station |* | List of stations (default = all)
• locations |"","00"| List of locations (default = "","00")

plot settings

• plot_stations |0/1 | Create a stations map
• plot_events |0/1 | Create an events map
• plot_all_retrieved_events_stations |0/1 | Create a stations and event map

RF stepwise

• obtain_inventory_RF | 0/1 | List all the stations available
• download_data_RF | 0/1 | Download the waveforms to calculate the Reciever Functions
• compute_plot_RF | 0/1 | Plot receiver functions?
• plot_ppoints |0/1 | Plot the piercing points (for Reciever Functions)
• plot_RF_profile |0/1 | Plot the vertical profiles (for Reciever Functions)

SKS stepwise

• obtain_inventory_SKS |0/1 | List all the stations available (for SKS)
• download_data_SKS |0/1 | Download the waveforms to calculate the shear-wave splitting of SKS phase
• plot_traces_ENZ |0/1 | Plot the waveforms (for SKS)
• plot_traces_RTZ |0/1 | Plot the rotated waveforms (for SKS)
• plot_SKS_measure |0/1 | Plot the grid search for phase and delay time.
• plot_SKS |0/1 | Plot the results (for SKS)
• picking_SKS |0/1 | Picking of the SKS phase
• plot_traces |0/1 | Plot the traces that may contain SKS phase
• plot_trigger |0/1 | Plot the automatic picking of the SKS phase

advRFparam.yaml: RF parameters

filenames

• invRFfile |rf_stations.xml | station xml
• RFsta |all_stations_RF.txt | station text catalog
• retr_stations |all_stations_rf_retrieved.txt | retrived stations list file
• data_rf_suffix |rf_profile_data | rf data file name: {net}-{stn}-rf_profile_data.h5
• events_map_suffix |RF-events_map | events map filename suffix {net}-{stn}-RF-events_map.png
• retr_station_prefix |RF_stations | retrieved stations prefix
• rf_compute_data_suffix |rf_profile_rfs | rf computation result file name: network-station-rf_profile_rfs.h5
• rfprofile_compute_result_prefix |rf_profile_profile | rf profile computation result file name: rf_profile_profile{azimuth}_*.h5

H - K settings

• h_kappa_res_file |h-kappa-values.txt | File name for the H-K results
• plot_h |0/1 | Plot Moho map
• plot_kappa |0/1 | Plot Vp/Vs ratio

RF profile settings

• num_profile_divs_lat |2 | Amount of EW profiles
• num_profile_divs_lon |3 | Amount of NS profiles
• ppdepth |70 | Chosen depth for piercing point calculation

RF event search settings

• minradiusRF |30 | Minimum epicentral distance (for Reciever Functions)
• maxradiusRF |90 | Maximum epicentral distance (for Reciever Functions)
• minmagnitudeRF |5.5 | Minimum magnitudes of events (for Reciever Functions)
• maxmagnitudeRF |9.5 | Maximum magnitudes of events (for Reciever Functions)

RF filter settings

• minfreq |0.5 | stream minfreq for bandpass
• maxfreq |2.0 | stream maxfreq for bandpass

RF display settings

• trace_height |0.1 | height of one trace in inches
• trim_min |-5 | trim stream relative to onset before plotting
• trim_max |20 | trim stream relative to onset before plotting
• rf_info |default| additional axes for RF plot, None for no additional axes

advSKSparam: SKS parameters

File names

• invSKSfile |sks_stations.xml | station xml
• SKSsta |stations_SKS.txt | station text catalog
• retr_stations |all_stations_sks_retrieved.txt | retrived stations list file
• data_sks_suffix |sks_profile_data | sks data file name: {net}-{stn}-sks_profile_data.h5
• events_map_suffix |SKS-events_map | events map filename suffix {net}-{stn}-SKS-events_map.png
• retr_station_prefix |SKS_stations | retrieved stations prefix
• sks_meas_indiv |sks_measurements.txt | sks measurements file suffix for individual stations
• sks_measure_map |SKS_station_Map | filename of sks measurements map

SKS event search settings

• minradiusSKS |90 | Minimum epicentral distance (for SKS)
• maxradiusSKS |120 | Minimum epicentral distance (for SKS)
• minmagnitudeSKS |5.5 | Minimum magnitudes of events (for SKS)
• maxmagnitudeSKS |9.5 | Maximum magnitudes of events (for SKS)

SKS filter settings

• minfreq |0.01 | stream minfreq for bandpass
• maxfreq |0.6 | stream maxfreq for bandpass

SKS picking

• trimstart |30 | trim the traces for sks picking trace starttime+trimstart to starttime+trimend
• trimend |110 | trim the traces for sks picking trace starttime+trimstart to starttime+trimend

SKS picking algorithm

• sks_picking_algo |recursive_sta_lta | picking algorithm for sks phase...other options are classic_sta_lta, z_detect, carl_sta_trig, delayed_sta_lta
• sks_picking_algo_thr0 |2.5 | starting threshold for sks picking algorithm
• sks_picking_algo_thr1 |0.65 | end threshold for sks picking algorithm

SKS measurements constraints

• sel_param: lam12 #options: snr, lam12; selection parameter of the measurements: either use signal to noise ratio, snr or use the eigenvalue ratio (lambda1/lambda2), lam12

sel_param_settings:

• snr_ratio |2 | minimum signal to noise ratio of the traces for filtering good measurements
• lam12fast_threh |1.1 | threshold for the lambda1/lambda2 for fast direction pick
• lam12lag_threh |1.1 | threshold for the lambda1/lambda2 for lag time pick

lag_settings:

• minlag |0 | minimum allowed lag time in sks measurements
• maxlag |3 | maximum allowed lag time in sks measurements
• maxdlag |1.5 | maximum allowed error in the lag time

fast_dir_settings:

• maxdfast |7 | maximum allowed error in the fast direction

error_plot_toggles:

• error_plot_indiv |0 | make 1 to plot the error profiles of fast direction and lag time for each measurements
• error_plot_all |1 | make 1 to plot the error profiles of fast direction and lag time for each measurements

PS: These parameters should be modified with caution by the users.

Procedure:

• Search the events that satisfy some critera (defined input_file.yaml).

• Search all stations for which data are available (defined input_file.yaml).

• Download the waveforms.

• This is an automated procedure that may be time consuming if a large dataset is selected.

Process the data following:

RF

• Filter and rotate the trace into the LQ domain.
• Deconvolve the radial and tangential components by the vertical component.
• Calculate the piercing points for each event.
• Stacks the reciever functions before plotting.
• Plot the reciever functions for L and Q components, sorted by back azimuth (or distance).
• Create some vertical profile for all stations in selected regions.

SKS

• Filter and rotate the trace into the radial/tangential referencial.
• Minimize the energy on the transverse components.
• Automatically pick the SKS phase.
• Invert for phase and delay time.
• Plot the results.

Display parameters:

Station Map

Events Map

For RF:

For SKS:

Reciever Functions

• Single event RF

• Piercing points

• Single station profile

Reciever Functions - Multiple station profile

Reciever Functions - H - Kappa measurements on individual RF

Reciever Functions - H - Kappa maps

SKS

• Read the station HDF5 file containing all the seismic traces recovered for this station.

• Filter and rotate the trace into the radial / tangential referencial. trace1.rotate('NE->RT')

• Minimize the energy on the transverse components.

• Automatically pick the SKS phase. We implemented several picking options from ObsPy to attempt to pick the SKS phase.

• Invert for phase and delay time. measure = sw.EigenM(data)

• Get all the potential SKS measurements for each station

• Plot the results.

Cite as

Kumar, Utpal, & Legendre, Cédric P. (2021, January 16). STADIUM-Py: Python Command-line Interface for automated Receiver Functions and Shear-Wave Splitting Measurements (Version 1.0). Zenodo. http://doi.org/10.5281/zenodo.4686103