Computer-based self-organized tectonic zoning revisited: Scientific criterion for determining the optimum number of zones

As multivariate numerical classification become increasingly available to Earth Scientists, there is a corresponding need to introduce a scientific criterion or stopping rule to determine the optimum number of classifications. The increasing interest in comparative, experimental numerical zoning makes such a criterion highly desirable. In this research multivariate data comprising new and updated geological and geophysical characteristics of Iran have been used to construct Automatic Integrated Self-Organized Optimum Zoning (AISOOZ) maps. The Wilk's Lambda Criterion and the relative discrepancy of Wilk's Lambda have been applied for the first time as stopping rules to measure the relative usefulness of zoning maps. The application of these criteria has eventually led to an optimum map with 11 zones.Our AISOOZ map reveals some remarkable features that cannot be observed on conventional tectonic maps of Iran. For example: contrary to the conventional maps, the AISOOZ map reveals the much disputed extent and rigidity of the microplate in the central and eastern parts of Iran and makes a clear distinction between the Makran ranges and the eastern Iran mountains. The AISOOZ method is a new approach to zoning, organized in a hierarchy of increasing complexity, and developed from reductionist approach. Based on this logic, the AISOOZ method casts an interesting light on the connection between the zoning hierarchy and the geodynamic evolution of the study area. It also helps to estimate the likelihood of earthquake occurrence for each zone. The AISOOZ map not only can be re-assessed quite often, but also provides us with a means for on-line information availability. The information can be tailored to the user's specific needs and down-loaded to the user's computer. Furthermore, the general approach presented in this paper could readily be adapted to pattern recognition and zoning maps of any space, regardless of context or scale.

► In the past, geologists have primarily dealt with conventional maps on the basis of their appearance.
► The development of sophisticated technology to collect data has outpaced geologists ability to use it to full potential.
► This paper aims at closing the gap and rid map construction of its traditionally non-quantitative and subjective nature.
► For this purpose Automatic Integrated Self-Organized Optimum Zoning (AISOOZ) method has been introduced for the first time.
► The application of stopping rule in AISOOZ method offers a novel approach to produce optimum zoning maps.