Open AccessEstimation of the Rigidity of the Earth by Earth Tide Studies
Author(s) -
Balakrishna S.
Publication year - 1967
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1967.tb06239.x
Subject(s) - rigidity (electromagnetism) , geology , moment of inertia , geodesy , geophysics , mantle (geology) , tidal acceleration , earth's rotation , homogeneous , physics , classical mechanics , astrophysics , planet , thermodynamics , quantum mechanics
Summary The determination of the mechanical properties of Earth in the study of the nature of the Upper Mantle in this region by rigidity measurements has been carried out from the last few years (1960–65) in the observatory at Hyderabad. The study of elastic deformation of the Earth due to gravitational attraction of Sun and Moon (earthtide) is a problem which is of great interest to geophysicists. Because of its rigidity, the Earth will not quite reach the equipotential surface as an ideal body of rigidity would do but will assume intermediate height which will depend upon the elastic properties and density of the materials constituting the Earth. The measurement of this deformation and estimation of characteristic tidal constants and rigidity of the Earth as a new means of understanding the nature of the Upper Mantle. The discussion is mainly restricted to M 2 Tidal component as it is found to be most reliable and consistent because it is the largest and the most important one. The tidal elastic constants for M 2 component at Hyderabad for over a period of five years are reported in this paper. Gravimetric factor 1.17 obtained for M 2 component at Hyderabad is as expected for a mid‐continental station. The value obtained for the rigidity of the Earth for this region, assuming that the Earth has a homogeneous constitution with mean density of 5.52 is of the order of 1.13 × 10 ‐12 dyn/cm 2 . This is indicative of the fact that the Upper Mantle region in this part of the world is compact and highly rigid.