NCEDC Daily Catalog Snapshots

Information about earthquakes is updated over time, as we review and reprocess the data used to locate them and determine their magnitudes. To scientifically evaluate and compare seismicity, it is important to be using the same catalog.

The NCEDC is pleased to announce the availability of daily snapshots for the earthquake parameters catalog of the Northern California Seismic System through GitHub. This means that at any time the catalog can be retrieved as it was on a given date. The catalog repository is available at:

https://github.com/NCEDC/NCSS-catalogs

The files contain information from 1966 to present and are available in the EHP CSV format. For documentation on the format, please go to:

https://earthquake.usgs.gov/earthquakes/feed/v1.0/csv.php

A current snapshot of these files can also be found at:

http://ncedc.org/ftp/pub/catalogs/NCSS-catalogs/

In the GitHub repository, a file 'index.txt' is provided that contains the mapping between the commit times and the hash keys. It can be used to retrieve a version of the catalog at a given time.

How to use the index file

This file contains entries similar to the following:

...
NCSS catalogs as of 2017-03-13 01:00:02 --> 4f3c8891402c14c260350afcde15f55d46f36974
NCSS catalogs as of 2017-03-12 01:00:01 --> 84e6697c9f7f482cc47751fada331dc1b360d4b3
NCSS catalogs as of 2017-03-11 01:00:01 --> 5a14aebedc36c05339d511ae9ae6190c37ff73b4
NCSS catalogs as of 2017-03-10 01:00:02 --> d1a3f36bd71b04dc175c7711409c5b9c2fc20454
...

For example, a snapshot of the catalog on 2017/03/11 13:00:00 would be available at:

https://github.com/NCEDC/NCSS-catalogs/tree/5a14aebedc36c05339d511ae9ae6190c37ff73b4

Specific snapshots are available at:

https://github.com/NCEDC/NCSS-catalogs/tree/<HASH_KEY>