The main difference of the EDEIS from other databases on impact structures, such as well-known Earth Impact Database maintained by the Planetary and Space Science Centre of the University of New Brunswick (Canada), is that the EDEIS contains the data not only on the validated craters, whose impact origin was confirmed by the full set of criteria, but also the data on probable or apparent structures. The cosmogenic genesis of these structures has not been confirmed yet, however, they have some typical impact features and therefore are promising for further study. The degree of confidence to the impact origin of a structure is characterized by its validity index V that varies from 0 to 4 depending on the number of criteria (morphological, structural, mineralogical, chemical) that are met for a particular structure in favor of its cosmogenic origin.
The validity index value roughly means the following:
4 – definite (all four types of criteria are confirmed)
3 – apparent (any three of four confirmed)
2 – promising (any two of four confirmed))
1 – possible (based mostly on crater morphology)
0 - a false entry
Distribution of the current database content over the validity index is as follows:
208 structures with V=4
186 structures with V=3
342 structures with V=2
35 structures with V=1
60 structures with V=0
Petrenko, V.E. (1998) Catalogs and data banks for the Earth impact structures, Trudy of the ICMMG SD RAN, Series: Mathematical Modeling in Geophysics, Vypusk 5, Novosibirsk, 161-180.
Petrenko, V.E. and Z.A.Lyapidevskay (1998) Data bank for the impact structures on the Earth, Trudy of the ICMMG SD RAN, Series: Mathematical Modeling in Geophysics, Vypusk 7, Novosibirsk, 161-185.