Methods for collecting morphometric data, their processing and their analysis have not yet been adequately elaborated, but it is already possible to make some tentative recommendations.
In collecting any morphometric data one must avoid all kinds of averaged indexes, since arbitrarily chosen averaging obliterates the possible natural "peaks". Moreover, averaged data collected by one investigator in a certain region are difficult to compare with those from other regions collected by other investigators. The numerical characteristics (length, width, height of uplifting, depth of subsidence, etc.) of the relief structures and forms must be given on a very detailed scale for every relief form and every tectonic structural form, and they must be measured with the maximum accuracy possible in this kind of work.
Working with the neotectonic map, we used an interval of 5 km for plan measurements, corresponding to 1 mm on the map.
In the tables presented in this paper this interval was sometimes changed where structures of the corresponding dimensions were absent from the territory under consideration (the USSR territory). For instance, we did not discover any structures with length of 505, 510, 515, 545 km, nor structures with a width of 155, 165 km, nor several others. The intervals were not shortened in the plotting of graphs (see Figures 2, 3, and 4).
In determining morphometric indexes it is important to establish the level with respect to which the measurements are to be performed. These levels may differ for relief forms of different origins; they must be deter mined for every specific case, and must be precisely indicated in records, tables, and graphs. In processing vast numbers of homogeneous data, the base level can be established statistically with a sufficient degree of accuracy as the mean of a large number of measurements, even when some of the latter involve errors.
In the course of measurements an index card should be made out for every measured form, and this card should include all the morphometric characteristics recorded in a definite sequence. Such cards make it possible to process the collected data by means of modern computers.
The work done thus far (a brief summary of which has been provided in this paper) leads to the following conclusions: 1. Systematic collection and analysis of morphometric data is an important method of studying relief forms and the tectonic structures of the Earth.
2. The general morphometric series which we established as a result of the preliminary processing of a tremendous amount of data still requires further checking, since our data were incomplete and of insufficient accuracy. However, this series must now be accepted as the numerical expression of natural regularities.
3. At the present time the morphometric series can be employed in the construction and analysis of geological, tectonic, geomorphological, and other specialized maps, in drawing the contours of tectonic structures, in collecting and processing morphometric data, and for other scientific and practical purposes.
4. The pattern expressed by the morphometric series delineates a new approach to studies of the problem of the development of tectonic structures and relief forms.
5. Final checking of the patterns observed calls for further collection and processing of sufficiently accurate morphometric data on a mass scale and according to a uniform program; this will require joint efforts of geologists, geophysicists, and geomorphologists.