|Ground Truth Database|
The Ground Truth Database contains a collection of events of ground truth (GT) quality to support location calibration studies. The database includes nuclear and chemical explosions, mine blasts, rock bursts and earthquakes. The database contains only shallow focus (less than 40 km focal depth) earthquakes, because deep focus earthquakes are of less interest for nuclear test monitoring. Every event is accompanied with arrival data as well as references to document the source of information.
The current release of the Ground Truth Database (Bondar et al, 2001) represents major changes and additions relative to earlier versions. Reference events compiled by the Group 2 Consortium (McLaughlin et al, 2002) are now incorporated in the ground truth database. Furthermore, the most recent version of the groomed ISC bulletin of Engdahl et al. (1998) was subjected to the GT5 selection criteria of Bondár et al. (2004a) and events passing the GT5 criteria were added to the database. All events in the ground truth database were carefully vetted and quality controlled, following the procedures described in Bondár et al. (2004b).
At present, the ground truth database holds 13,379 GT0-15 events ( map) with some 900,000 associated phases (of which some 810,000 are defining) recorded at 3,771 stations (map). Residuals in the bulletins refer to IASP91 (Kennett and Engdahl, 1991) predicted travel times with the source fixed to the GT location. For details see Bondár et al. (2004b), Engdahl and Bergman (2001), and Engdahl et al. (2002). The GT15 events ( Pan et al., 2002) are only included to provide coverage on mid-oceanic ridge events in the mid-Atlantic ridge, the Carlsberg ridge and the Gulf of Aden
Please select the GT bulletin from the menu below (for more information you can check these explanations).