Advances in Conception about Earthquakes - Earthquake Engineering for Structural Design - page 114

slipping and the rupture processes which would have been impossible to see ten
years ago.
Based on GPS observations, one can notice that the drift of continents will
continue. In the frame of Wilson's Cycle Theory, a new conformation of continents
must be considered. In the future, after 50 million years, the Atlantic and Indian
oceans will extend their surfaces, in detriment of the Pacific Ocean, where the
tendency of closeness of North American plate to Eurasian plate could be
observed. In the next future, the Californian area will separate from the North
American plate along the San Andreas fault; a part of Eastern African plate will
move towards East; the Mediterranean area will be reduced, but the Arabian plate
will move away from the African plate. Finally, Australia will move in the North
direction, finishing its travel by a collision with the Eurasian plate. A new great
continent will rise by the collision of the existing ones. After this, a new separation
will occur, in the frame of the cyclic evolution of the Earth.
4.2 TOWARDS ANEW VIEWIN SEISMOLOGY
4.2.1EarthScienceas aFundamental Interdiscipline
Earth Science explores the different processes and transformations which have
produced the Earth and looks at how this world is likely to evolve in the future.
This science is fundamentally interdisciplinary, because it requires the basic
disciplines of physics, chemistry, mathematics and biology for its scope, which can
be pursued only by the simultaneous application of various mixtures of these
different modes of understanding. In fact the Earth Science, more than any other
science, is the embodiment of the emerging new sciences, where the focus is on
Complex Systems. Complex Systems is a science which focuses on systems in their
entirety, rather than upon only one of the system's component parts. In the past, the
primary goal of the Earth Science has been to understand the form and function of
individual parts of the Earth System. In contrast, a major goal of the modern Earth
Science is to more fully understand the Earth System as a whole, so that it may
accurately predict its future evolution (Peltier, 2000).
What does it mean these general aspects for the development of Seismology?
First of all, one can consider the Earth crust as a Dynamical System composed by
many sub-systems, which interact in dynamical processes. Second, one can
consider that the laws governing the other parts of Earth System (such as
Meteorology) can be used also in Geophysics. Therefore, the following new
theories about the systems must be considered:
- SystemTheory.
- Self-Organized Dissipative System Theory.
- Bifurcation Theory.
- Chaos Theory.
In the following, the main aspects of these theories, in relation to Seismology
Science, will be presented.