The earthquake catalog of ‘historic’ events (those prior to May 2016) is comprised of information from three datasets. These are:
| No. | Earthquake Catalog | Period |
| 1 | GEM Historical Catalog (Global Earthquake History) (Albini, et al., 2013) | 1000-1903 |
| 2 | ISC-GEM Instrumental Catalog (Instrumental Earthquake Catalogue) (Storchak, et al., 2012) | 1900-2013 |
| 3 | U.S. Geological Survey Earthquake Catalog (see http://earthquake.usgs.gov/earthquakes/search/ ) | 2013-May 2016 |
GEM Historical Catalog
The Global Earthquake Model (GEM) Project compiled an “Historical” catalog of non-instrumentally recorded earthquakes that covers the period from 1000 to 1903. This catalog specifically focuses on earthquakes with magnitude greater than or equal to seven. A total of 825 events were identified. The identification and evaluation (location, magnitude determination, etc.) was based on an extensive archival research and historical evaluation. Figure 1 shows a map of the earthquakes in the GEM Historical catalog.
Figure 1 - Map of the 825 earthquakes in the GEM Global Historical Catalog (Albini, et al, 2013).
ISC-GEM Instrumental Catalog
The GEM Instrumental Earthquake Catalogue (1900-2009) was an effort designed to ‘improve characterization of spatial distribution of seismicity, magnitude frequency relation and maximum magnitudes’ to support the overall GEM effort (Storchak, et al., 2012). For instance, the worked to use a consistent approach to determined uniform earthquake locations and magnitudes (MW).
Where possible direct measures of MW were used or results reported in technical papers that provided estimates of seismic moment and MW. For events where measured values of MW were not available, estimates were made from regression models that made it possible to estimate MW from available magnitude measures (e.g., surface-wave magnitude).
In total there are over 30 thousand earthquakes in the instrumental catalog.
Figure 2 shows a global map of the earthquakes identified in initial instrumental catalog. This catalog was subsequently supplemented by the addition of over 5 thousand more earthquakes.
Figure 2 - Map showing the earthquakes in version 3.0 of the ISC-GEM catalogue (more than 24,000 earthquakes (Storchak, et al., 2012; ). The figure is from http://www.isc.ac.uk/iscgem/overview.php, accessed 12/5/2016).
U.S. Geological Survey Earthquake Catalog
The USGS maintains a catalog of earthquakes that occur world-wide. For the period from 2013 to May 2016 the USGS catalog was searched for earthquakes of magnitude 4.5 and greater.
Citations
Albini, P., R.M.W. Musson, A.A. Gomez Capera, M. Locati, A. Rovida, M. Stucchi, and D. Viganò (2013), Global Historical Earthquake Archive and Catalogue (1000-1903), GEM Technical Report 2013-01 V1.0.0, 202pp., GEM Foundation, Pavia, Italy, doi: 10.13117/GEM.GEGD.TR2013.01.
Storchak, D.A., D. Di Giacomo, I. Bondár, J. Harris, E.R. Engdahl, W.H.K. Lee, A. Villaseñor, P. Bormann, and G. Ferrari (2012), ISC-GEM Global Instrumental Earthquake Catalogue (1900-2009), GEM Technical Report 2012-01 V1.0.0, 128 pp., GEM Foundation, Pavia, Italy, doi: 10.13117/GEM.GEGD.TR2012.01.