Advances in Conception about Earthquakes - Earthquake Engineering for Structural Design - page 104

Figure 4.3 Seismoscope invented by Zhang Heng in 132 AD
(USGS, nd, RMS, 2006)
Using this instrument, the Chinese scientists evaluated the intensity of a
documented earthquake for over 3000 years. Therefore, earthquakes in China have
been recorded in the period from 1830 BC to the present. These records account for
the damage effects of an earthquake by using an intensity scale which is similar to
the Modified Mercalli Scale today (Bolton and Cole, 2006).
4.1.2Period of Early Scientific Explanations
The classical period coincides with the Greek civilization, when the Greek
philosophers attempted to give scientific explanations for all natural phenomena.
Thales (624-546 BC ) believed that an agitation of the great sea, which the Earth is
floating on, is responsible for earthquake generation. Pythagoras (570-496 BC )
considered that the heat of the Earth's interior as the cause of the earthquakes and
Epicur (341-270 BC ) believed that the erosion and transportation action of water
generates earthquakes. The most influential explanations belong to Aristotle (384-
323 BC ) who attributed earthquakes to the wind blowing in underground caverns.
The Aristotelian view of earthquakes remained the primary theory during the
medieval periods of the countries of both Europe and Islam (Agnew, 2002).
The main period of the science development corresponds to the Renaissance,
when a new spirit dominates and the scientists are basically interested in
observational researches. The science moves from Greece to Western Europe. The
new technology of chemical explosives suggested that earthquakes might be
explosions in the Earth. Agricola (1494-1555) formulated the hypothesis that