Open AccessEmpirical Equations of State for the Earth's Lower Mantle and Core
Author(s) -
Bullen K. E.
Publication year - 1968
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.1968.tb00219.x
Subject(s) - outer core , geology , inner core , quadratic equation , geophysics , mantle (geology) , moment of inertia , earth model , structure of the earth , representation (politics) , mathematics , physics , geometry , classical mechanics , law , politics , political science
Summary A quadratic representation of the incompressibility k in terms of the pressure p for the materials of the Earth inside the pressure range 0.4 < p < 3.2 × 10 12 dyn/cm 2 was empirically derived some years ago on the basis of seismic and other evidence. The numerical coefficients in the representation have been revised in the present paper, taking account of recent observational evidence. The revised quadratic law applies to the whole Earth below 1000 km. The new evidence includes the recently revised estimate of the Earth's moment of inertia, revised seismic evidence on the lower core, and data from free Earth oscillations. The quadratic model is compared with linear models derived for the lower mantle and core separately. Attention is drawn to errors made when any of these models is applied at pressures less than 0.4 × 10 12 dyn/cm 2 . It is pointed out that unqualified application of Birch's finite‐strain formulae leads to some results for the Earth's deeper interior that are somewhat discordant with the empirical evidence here used.