Title: Nuclear reactor at the core of the Earth! - A solution to the riddles of relative abundances of helium isotopes and geomagnetic field variability
Author(s): Rao KR
Source: CURRENT SCIENCE 82 (2): 126-127 JAN 25 2002
Document Type: Editorial Material
Title: Substructure of the inner core of the Earth
Author(s): Herndon JM
Source: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 93 (2): 646-648 JAN 23 1996
Document Type: Article
Language: English
Cited References: 29 Times Cited: 13
Abstract: The rationale is disclosed for a substructure within the Earth's inner core, consisting of an actinide subcore at the center of the Earth, surrounded by a subshell composed of the products of nuclear fission and radioactive decay. Estimates are made as to possible densities, physical dimensions, and chemical compositions. The feasibility for self-sustaining nuclear fission within the subcore is demonstrated, and implications bearing on the structure and geodynamic activity of the inner core are discussed.
Title: Thermal and magnetic evolution of the Earth's core
Author(s): Labrosse S
Source: PHYSICS OF THE EARTH AND PLANETARY INTERIORS 140 (1-3): 127-143 NOV 28 2003
Document Type: Article
Language: English
Cited References: 55 Times Cited: 13
Abstract: The magnetic field of the Earth is generated by convection in the liquid-core and the energy necessary for this process comes from the cooling of the core which provide several buoyancy sources. The thermodynamics of this system is used to relate the Ohmic dissipation in the core to all energy sources and to model the thermal evolution of the core. If the same dissipation is maintained just before the onset of inner-core crystallization, and the associated compositional convection, as at present, a much larger heat flow at the core mantle boundary (CMB) is necessary which, if extrapolated backward, may require a very high initial temperature. Two solutions to that problem are studied: either the Ohmic dissipation was smaller then, which could be maintained with the same heat flow as at present or an important radioactivity is present in the core. The presence of radioactivity in the core makes the inner core only a few hundred million years (Ma) older than non-radioactive cases with the same dissipation, because the low efficiency of radioactive heating requires a much larger heat flow at the core mantle boundary. Although the age of the inner core is controlled by the heat flow at the CMB, the Ohmic dissipation to be maintained is the constraint that makes it low.