This can be illustrated roughly in the following way. The ellipsoid of the Earth is subdivided into the series of levels referred to above. The surface of the ionosphere forms one of the outermost levels. Below it, or deeper into the Earth, is the surface of the troposphere, and beneath the latter lies the combined surface of the hydrosphere and the lithosphere. Finally, the barysphere, the mantle, and the core lie even closer to the Earth's center. It must be taken into account that all these envelopes represent, as it were, levels of ellipsoids. The hydrosphere-lithosphere level, which was just discussed above, we assume to be the most important level and the one which most determines the interaction of the envelopes.
Ocean currents have for a long time been explained as being a conse quence of the winds which furrow the surface of the ocean. The currents follow the directions of the winds. In this case the contact between the troposphere and the hydrosphere produces currents. Exactly the same thing occurs at the contact boundaries of the other envelopes: lithosphere and barysphere, and barysphere and mantle.
Other interactions exist between the hydrosphere and the lithosphere. Here there is a contact more intimate than just a contiguity of inner and outer surfaces. This contact, so it seems to us, extends into the depths of the Earth, gradually weakening from higher levels to lower ones, but even at great depths exerting an influence on the relation between the contacting envelopes. Consequently, the central element or link in the interaction of the envelopes is the action of the oceans on the continents, which determines the main features of the entire interaction (namely its direction and rate). Accordingly, the action of the oceans on the continents (the relationship between the two largest megastructures of the planet) is a central phenomenon which determines all the main aspects of the inter action of the envelopes. In other words, the tide-producing processes must be counted as a basic manifestation of this interaction.
In a report presented at the Geographical Society on 27 February 1961, T. D. Reznichenko made use of several examples to show very convincingly that during the warm phases of periods measured in millenia the estuary regions, and also the channels, of rivers flowing latitudinally become shifted toward the north. During periods of cold, on the other hand, the mouths and channels of such rivers shift to the south.
In relation to this, we should also keep in mind Gerenchuk's recent observation that "tectonic disturbances are the primary means for the natural discharge of ground water which ensures the constancy of runoffs required for river formation" (Gerenchuk, 1960, p. 172).
As Gerenchuk has pointed out, rivers do not appear just anywhere. Rather, they always come into being in places where the structure of the land permits their creation. It is not possible to make a river out of any given gully, but only out of gullies which occupy definite places in ancient synclines. Large river systems are always associated with artesian basins and are in fact inseparable from them. This means that tectonic structures determine where river valleys will be located, and that the evolution of the valleys must be affected by the evolution of the structures enclosing them. As Davydov (1955), L'vovich (1938), and others have pointed out, ground water is a very important supply source for rivers. For example, on the Russian plain, ground water supplies on the average over 30% of the total amount of water fed into the rivers. There is some basis for assuming that a shifting of the channels takes place not only for the river and ground water of the alluvium but also for the actual ground water as well.
Gerenchuk notes that "the presence of tectonic structures, as indicated by synclines, faults, upheavals, and folds, with a prevalence of jointing, is a necessary condition for the formation of river valleys" on the Russian Platform (p. 177).
Structural disturbances, together with the outflows of ground water accompanying them, are a prerequisite for rearrangement of the river system plan. In general, the tectonic forces which appear under the conditions of river erosion are the prime cause of the rearrangement of river systems. River.valleys usually form along lines of tectonic disturbances (Gerenchuk, 1960). Consequently, it is quite likely that the shifting of these valleys to new places is also related to the appearance of such disturbances.
On the basis of the foregoing we may state that, when during the course of the Earth's rotation the water of the oceans is shifted first in one direction and then in another, both latitudinally and longitudinally, analogous shiftings of the ground water and the water in rivers take place simultaneous ly on the continents. Tectonic phenomena contributing to this change also appear. This is a cogent example of the unity and inseparability of the waters of our planet.