DOREL ZUGRAVESCU
Centrul de Fizica Pamantului si Seismologie, Laboratorul de Geodinamica si
Analiza Numerica,
Bucuresti
GEODYNAMIC OBSERVATORIES OF ROMANIA
(Abstract)
There are very complicated criteria which have to be taken into account for
a correct choice of the sites of the geodynamics observatories. Their arrangement
also requires very special measures and very complex works. All these are justified
by the small amplitude of the directly observable phenomena related to the
periodical deformations of the Earth body, by the possibility that the information
concerning the nonperiodical deformations can be separated in the performed
records, and especially by the necessity that the recording apparatus be set
up away from the level at a depth great enough that the thermal deformation
produced to the crust by external radiations be negligible.
The geodynamics observatories described in this paper (Caldarusani geodynamic
observatory, Underground Pades-Gorj and Craciunesti-Deva observatories) remove
the empty space to the territory of our country corresponding on the map presenting
the world distribution of the observatories where the deformations of the Earth
body are performed, assuring the detailed time monitoring of the phenomenon.
Their site has been chosen to allow an as good knowledge as possible of the
tectonic compartments of the Romanian territory and to provide quantitative
elements causally connected to the processes leading to the tensional build
up in the seismically active areas (fig. 1).
The scientific exploitation of the results has allowed to establish the existing
relations between the crust tilt as due to the baric field and the regional
tectonic as well as the triggering effect the Earth tide has on the Vrancea
earthquake, respectively the relation between the earthquake mechanism and
the Earth tide.
Key words: Geodynamic observatories, Earth tides, crust deformation, crust tilts, regional tectonics, Vrancea earthquakes, Romania.