TITLE:
Conventional and Fractal Variogram Based on Time—Space Analysis of Seismicity Distribution—Case Study: Algeria Seismicity (1673-2010)
AUTHORS:
Moh-Amokrane Aitouche, Mabrouk Djeddi
KEYWORDS:
Algeria, Seismicity, Catalog, b-Value, Geostatistics, Semiv Variogr, Am Fractal
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.6 No.11,
November
30,
2018
ABSTRACT: Geostatistics belongs to the wide class of statistical methods. It is used and applied
to analyze and predict the values associated with spatial or spatio-temporal
phenomena such as seismological events. Thus, in addition to its adaptability
to perform spatial data analysis based on the principles of variography, many
other methods more representative of the spatial distributions of the epicentres
have been experimented. The unidirectional or isotropic fractal variogram associates
the criterion of variance with the fractal dimension which is a better
descriptive parameter of the spatial organization of events. The same analysis
procedure carried out through a directional or azimuthal variogram introduces
the context of a preferential direction of earthquake evolution. Moreover, b-value is a privileged seismological parameter that can be studied alone
or in combination with other more advanced geostatistical analysis factors
such as fractals, fractal dimensions and the anisotropic variogram. All these
concepts were used as methodology for a protocol of analysis of the catalog of
the Algeria seismicity including 1919 events for the period extending from
1673 to 2010. This catalog is provided by the compilation of partial catalogs
synthesized by the CRAAG (Research Centre in Astronomy, Astrophysics
and Geophysics).