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Trifonov, V.G., 2010. Tectonic and climatic
rhythms and the development of society. In: Florinsky, I.V. (Ed.), Man and the Geosphere. Nova Science Publishers, New
York, pp. 257–305. The author discusses the short-period (years
to decades) and medium-period (hundreds to thousands years) variations of
climatic and tectonic activity and their influences on the human history and
recent life. At a regional scale, it is demonstrated that for the last 170
years periodic changes of the Caspian Sea level are the combined result of
the water balance variations (mainly caused by climatic changes) and the
recent tectonic activity partly manifested by seismicity. The influence
of active tectonics consists in the integral effect of various deformations producing changes in the Caspian
reservoir volume. Phases of the sea-level fall correspond to the growth of
seismicity under the Caspian basins that indicates the extension and sinking
of the reservoir. Phases of the sea-level rise correspond to the growth of
seismicity under the adjacent uplifts and their slopes that indicates
transverse shortening of the reservoir and a decrease in its volume. The
climatic and tectonic processes influence the Caspian level mainly in the
same direction. The global observations show that the 11-yr and
multiple-of-11-yr cyclicity is the most significant among the recent
short-period variations of climatic and tectonic activity. This cyclicity
influences the economic activity of the society. The ~1,200-yr (~1,800-yr in one case)
cycles are the most important among the medium-period variations of climatic
and tectonic activity (i.e., fault movements, earthquakes, and volcanism) in
the Middle and Late Holocene. These cycles contributed to the historical
crises, which were characterized by social unrest and mass migrations, and
changed the balance of political forces. On the other hand, the crises determined breakthroughs to
new technologies and new forms of economic and political relations. The
crises were manifested in the Alpine–Himalayan orogenic belt and East
European Platform. Perhaps they covered the entire Northern hemisphere. Synchronism of climatic and
tectonic events in both short- and medium-term oscillations is possibly
caused by the difference in the rotational velocity of the liquid outer core
and mantle (the dominant factor), periodic changes in the Earth’s orbital
parameters, as well as solar activity. Multiple-of-11-yr cycles correlate
with the periodic changes in solar activity, whereas the 1,200-yr cycle is
associated with the precession of the geomagnetic axis around the Earth’s
rotational axis. The short- and medium-period variations of climatic and
tectonic activity should be considered in planning the sustainable
development of the society.
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