enhance_catalog

This repository stores the codes that make up the workflow described in Tan et al. (2023):

Tan, D., Fee, D., Hotovec-Ellis, A. J., Pesicek, J. D., Haney, M. M., Power, J. A. & Girona, T. (2023). Volcanic earthquake catalog enhancement using integrated detection, matched-filtering, and relocation tools. doi: 10.3389/feart.2023.1158442

The codes can be used to enhance AVO earthquake catalogs using a streamlined integration of open-source catalog-enhancing tools: REDPy, EQcorrscan, HypoDD, and GrowClust. The combination of these tools offers the capability of adding seismic event detections and relocating events in a single workflow. The workflow relies on a combination of standard triggering and cross-correlation clustering (REDPy) to consolidate representative templates used in matched-filtering (EQcorrscan). The templates and their detections are then relocated using the differential time methods provided by HypoDD and/or GrowClust. Additional utilities include the incorporation of campaign and backfilled data at appropriate junctures, relative magnitude calculations, and frequency index calculations for valid events.

The general sequence to be followed is:

1. Determine the timespan of interest and download seismic data
2. Run REDPy to determine families of repeaters within the timespan
3. Read in the analyst-derived catalog and compare it with REDPy's output to consolidate representative templates
4. Create the tribe of representative templates for EQcorrscan
5. Run the matched-filter scan using EQcorrscan to obtain the temporally enhanced event list
6. Calculate frequency indices and relative magnitudes for all valid events
7. Cross-correlate relocation candidates with one another to obtain cross-correlation differential times
8. Relocate valid events to obtain the relocated, enhanced catalog
9. Plot resulting data products in time and in space

Refer to the Table S12 pdf file in the repository to access the latest, detailed recommendations for each function.

Key references and other suggested citations

Hotovec-Ellis, A. J., & Jeffries, C. (2016). Near real‐time detection, clustering, and analysis of repeating earthquakes: Application to Mount St. Helens and Redoubt volcanoes.

Chamberlain, C. J., Hopp, C. J., Boese, C. M., Warren‐Smith, E., Chambers, D., Chu, S. X., ... & Townend, J. (2018). EQcorrscan: Repeating and near‐repeating earthquake detection and analysis in Python.

Trugman, D. T., & Shearer, P. M. (2017). GrowClust: A hierarchical clustering algorithm for relative earthquake relocation, with application to the Spanish Springs and Sheldon, Nevada, earthquake sequences.

Klein, F. W. (2002). User's guide to HYPOINVERSE-2000, a Fortran program to solve for earthquake locations and magnitudes (No. 2002-171). US Geological Survey.

Waldhauser, F. (2001). hypoDD--A program to compute double-difference hypocenter locations.

Quickstart

1. Clone and enter directory

git clone https://github.com/darren-tpk/enhance_catalog
cd enhance_catalog

2. Create conda environment

conda env create
conda activate enhance_catalog

3. Run example (3 day period from the Redoubt 2009 eruption)

python example.py

Dependencies

Other repositories:

• REDPy
• EQcorrscan
• GrowClust
• waveform_collection