Fig.1: map showing the earthquakes listed in the version 6.0 of the ISC-GEM catalogue (more than 36,000 earthquakes, see Fig.2). The symbols are plotted according to Agnew (2014) and colour coded according to the ISC-GEM depth.
On the 7 of March 2019, the version 6.0 of the ISC-GEM Catalogue was publicly released. The release marked the end of the first year of the Advancement Project.
During this year we added to the catalogue a) 623 earthquakes that occurred in 2015 with magnitude 5.5 and above plus continental earthquakes with magnitude 5.0-5.5; b) 7012 earthquakes during the periods 1964-1979 and 2000-2014 that include both continental events with magnitude 5.0-5.5 and events around the magnitude cut-off threshold of 5.5 that were not selected before (i.e., earthquakes not included in the catalogue’s previous versions).
In addition, we expanded the catalogue files to include also the nodal planes for earthquakes with GCMT solution as well as source mechanism from the literature for those earthquakes with direct M0 from the bibliographic search of reliable seismic moments (see Lee and Engdahl, 2015). In total, we added 385 source mechanisms from the literature. The list of publications used to retrieve direct seismic moments and source mechanisms is available at http://www.isc.ac.uk/iscgem/mw_bibliography.php. Additional changes to the catalogue are listed in the update log.
Fig. 1 shows the ISC-GEM locations with symbols according to Agnew (2014) as obtained from the procedure described in Bondár et al. (2015). One feature that makes the ISC-GEM Catalogue a unique product is that the locations are achieved by the same location technique and velocity model (ak135) and comes with uncertainties for each focal parameter.
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Fig.1: map showing the earthquakes listed in the version 6.0 of the ISC-GEM catalogue (more than 36,000 earthquakes, see Fig.2). The symbols are plotted according to Agnew (2014) and colour coded according to the ISC-GEM depth. |
Fig. 2 shows the current time-magnitude distribution of the ISC-GEM Catalogue (1904-2015).
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Fig. 2: Top: cumulative annual number of earthquakes with Mw ≥ 5.5 (red), ≥ 6.5 (blue) and ≥ 7.5 (yellow); Bottom: time-magnitude distribution color-coded in cells of 0.1 units of Mw for each year of the ISC-GEM main catalogue. The earthquakes processed in 2015 exhibit the same distribution we can observe in recent years and add significant earthquakes to the catalogue. The biggest difference with previous versions occurs during 1964-1979 and 2000-2014, where, in the past versions, nearly no earthquake below Mw 5.5 was included. For comparison with the original version see Fig. 20 in Di Giacomo et al. (2015b), or Figure 25 in Di Giacomo et al. (2018) for the comparison with Version 5.0. |