Open AccessRelaxation and free modes of a self‐gravitating planet
Author(s) -
Caputo Michele
Publication year - 1984
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1984.tb02222.x
Subject(s) - planet , relaxation (psychology) , rheology , hydrostatic equilibrium , stress relaxation , geology , stress field , stress (linguistics) , geophysics , physics , mode (computer interface) , gravitational field , mechanics , classical mechanics , thermodynamics , astrophysics , astronomy , computer science , psychology , social psychology , linguistics , philosophy , finite element method , kinetics , operating system
Summary The relaxation and purely radial free modes of a planet subject to a non‐hydrostatic pre‐stress are studied. The non‐hydrostatic pre‐stress considered is caused by gravity and is obviously present and relevant to a certain depth in the Earth as the presence of large mountain ranges and abyssal plains imply. The relaxation of this stress field is studied and it is shown that there is an infinite set of rheological models of the same type which have the same relaxation time. Only other information on the behaviour of the material, such as the Q ‐1 , allows us to specify better the rheological model. It is also shown that the pre‐stress shifts the period of each purely radial free mode of the planet, however in the case of the Earth this effect is not relevant with the present accuracy of determination of the periods of the free modes.