London: 1999. 1st Edition. FIRST EDITION IN ORIGINAL WRAPS OF A SERIES OF COMPUTER SIMULATIONS OF THE EARTH’S DYNAMO illustrating “how the thermal structure of the lowermost mantle might affect convection and magnetic-field generation in the fluid core” (Glatzmaier et al., Nature 401, 6756, 1999, p.885). “Their model differs from all other geodynamo models by solving the equations of motion within the anelastic approximation instead of the Boussinesq approximation. That is, in their model, the variation of density with depth is taken into account and both compositional and thermal buoyancy are computed” (Elsevier, Treatise on Geophysics, 290).
This paper follows Glatzmaier and Roberts significant 1995 paper in which they presented one of the first self-consistent dynamo models to graphically present the dynamics of the interior of the earth. The important computer generated graphics that they derived from the computer model they created are among the most famous in the field. Their model was the first to “successfully reproduce the intensity of Earth’s field, its dipole character… its present westward drift” and the spontaneous geomagnetic reversals of the north and south poles that emerge from the underlying dynamics they elucidate (Penn State Department of Geosciences). We offer the 1995 paper also. This paper continues their work on geomagnetic reversals and mantle manipulations.
In the 1999 paper, Glatzmaier et al present “eight different patterns of heat flux from the core to the mantle are imposed over the core–mantle boundary. Spontaneous magnetic dipole reversals and excursions occur in seven of these cases, although sometimes the field only reverses in the outer part of the core, and then quickly reverses back. The results suggest correlations among the frequency of reversals, the duration over which the reversals occur, the magnetic-field intensity and the secular variation. The case with uniform heat flux at the core–mantle boundary appears most ‘Earth-like’.
“This result suggests that variations in heat flux at the core–mantle boundary of the Earth are smaller than previously thought, possibly because seismic velocity anomalies in the lowermost mantle might have more of a compositional rather than thermal origin, or because of enhanced heat flux in the mantle’s zones of ultra-low seismic velocity” (Glatzmaier et al). Item #549
CONDITION & DETAILS: First edition in original wraps. Complete. 4to. 11 x 8.5 inches (275 x 213mm). The Glatzmaier paper is inclusive of two extensive figures, one of which is colored and very well known. Mailing address label on front wrap; near fine condition inside and out.