pySAC

This script processes seismic event data from a CSV file using the obspy library and FDSN web services. Users can filter events by date and magnitude, select a specific event, and retrieve waveform data for a specified seismic phase at a given station. The retrieved waveform data is then saved in SAC (Seismic Analysis Code) format.

README

Seismic Data Extraction and Processing Script

This script is designed to extract seismic event data from a CSV file, filter events based on user-defined criteria, select a specific event, and retrieve waveform data for a given seismic phase at a specified station. The retrieved waveform data is then saved in SAC (Seismic Analysis Code) format. The script leverages the obspy library for seismic data processing and FDSN web services for data retrieval.

Prerequisites

Before running the script, ensure you have the following installed:

• Python 3.x
• obspy library
• Access to a jan76_dec20.csv file containing seismic event data

You can install the required libraries using pip:

pip install obspy

Global Centroid-Moment-Tensor (CMT) Catalog File

The jan76_dec20.csv is a small version of Global Centroid-Moment-Tensor (CMT) catalog file and contains the following columns in the specified order:

1. Event ID
2. Year
3. Month
4. Day
5. Hour
6. Minute
7. Second
8. Latitude
9. Longitude
10. Depth
11. Magnitude

Script Usage

1. Specify the Path to the CSV File:

   Replace the placeholder path in the script with the actual path to your jan76_dec20.csv file:

   csv_file = "path/to/your/jan76_dec20.csv"

2. Run the Script:

   Execute the script in your Python environment. You will be prompted to enter various inputs:

   • Event Date Range:
     • Start year, month, and day
     • End year, month, and day
   • Magnitude Range:
     • Minimum magnitude
     • Maximum magnitude
   • Event Selection:
     • Index number of the event you wish to select
   • Phase, Network, and Station:
     • Phase name (e.g., "P", "S")
     • Network name (e.g., "IU")
     • Station name (e.g., "ANMO")

3. Retrieve and Save Waveform Data:

   The script will retrieve the waveform data for the specified phase at the selected station and save it in SAC format. The filename will follow the convention:

   EventID.Network.Station.Component.SAC
   

Example

Here's an example of how the script can be run and interacted with:

Enter start year: 2020
Enter start month: 1
Enter start day: 1
Enter end year: 2020
Enter end month: 12
Enter end day: 31
Enter minimum magnitude: 5.0
Enter maximum magnitude: 7.0
Events within the specified time period and magnitude range:
[0] Event: 1, Time: 2020-01-02T12:34:56, Magnitude: 5.5, Latitude: -10.0, Longitude: 110.0, Depth: 10.0
...
Enter the index number of the event you want to choose: 0
Selected Event: (1, UTCDateTime(2020, 1, 2, 12, 34, 56), 5.5, -10.0, 110.0, 10.0)
Enter phase name: P
Enter network name: IU
Enter station name: ANMO

Important Notes

• Ensure that the CSV file path and the station/network details are correct.
• The script assumes that the CSV file does not contain a header row or that the header is skipped using next(reader).
• Adjust the time window for waveform data retrieval (start_time and end_time) as needed.
• The script uses the iasp91 model for travel time calculations. You can change this to another model if needed.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Contributions

Contributions are welcome. Please open an issue or submit a pull request for any improvements or bug fixes.

Acknowledgements

This script uses the obspy library, which is an open-source project for processing seismological data. Thank you to the developers and contributors of obspy!