Bunge, P. M., Richards, C. Lithgow-Bertelloni, B. Romanowicz and S. Grand (1998), Time scales and heterogeneous structure in geodynamic Earth models, Science, 280, 91-95.
Note the authors. Seems John Baumgardner is not listed. Hmmm....the plot thickens.
Funny, indeed! Here's the result page from a Yahoo! on the subject. Indeed, your reference shows up as one of 19. The first link up is the PubMed Abstract of the original Science article. But that one wouldn't do for you. It lists Baumgarnder.
The Science article is not directly available, but the coauthors Grand and Bunge can be seen listing Baumgardner as a fellow author. Hmmm! The plot indeed thickens. However, those data points wouldn't do for your purposes so you skipped those.
Number 5 is the one you skipped back here with, represting it as the true, canonical, and ONLY thing in the world on the subject. You didn't come back saying, "Well, one of nineteen sources lists all the other guys and not Baumgardner." That wouldn't be very impressive. The listener might assume it was some sort of clerical error, or that Baumgardner had after the fact caught some grief for the kind of schizo behavior he exhibits in simultaneously publishing articles supporting and attacking an old earth and asked to have his name removed from a listing or two. No, we don't want to distract the dummies.
So you have provided a nice model of ICR-style scholarship. Just take what's good. Whatever you do, don't say how much data you left behind on the discard heap. You just run in and say, "Look-a here what I got! No, don't look over there! Look-a here! Just look at this! Never mind that! Look at this! Did I say, 'Look at this?' What have we got here, some kind of attention deficit disorder? Look at me, Zippy! Look-a here!"
I'm reproducing the first part of the paper. My copyright agreement with AAAS forbids me from reproducing the entire article.
Time Scales and Heterogeneous Structure in Geodynamic Earth Models
Hans-Peter Bunge, * Mark A. Richards, Carolina Lithgow-Bertelloni, John R. Baumgardner, Stephen P. Grand, Barbara A. Romanowicz
Computer models of mantle convection constrained by the history of Cenozoic and Mesozoic plate motions explain some deep-mantle structural heterogeneity imaged by seismic tomography, especially those related to subduction. They also reveal a 150-million-year time scale for generating thermal heterogeneity in the mantle, comparable to the record of plate motion reconstructions, so that the problem of unknown initial conditions can be overcome. The pattern of lowermost mantle structure at the core-mantle boundary is controlled by subduction history, although seismic tomography reveals intense large-scale hot (low-velocity) upwelling features not explicitly predicted by the models.
H.-P. Bunge, Institut de Physique du Globe de Paris, Laboratoire de Sismologie, 4 place Jussieu, 75252 Paris Cedex 05, France.
M. A. Richards, Department of Geology and Geophysics, University of California, Berkeley, CA 94720, USA.
C. Lithgow-Bertelloni, Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109, USA.
J. R. Baumgardner, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87544, USA.
S. P. Grand, Department of Geological Sciences, University of Texas, Austin, TX 78713, USA.
B. A. Romanowicz, Berkeley Seismological Laboratory, and Department of Geology and Geophysics, University of California, Berkeley, CA 94720, USA.
* To whom correspondence should be addressed. E-mail: bunge@ipgp.jussieu.fr
Geodynamic Earth models were pioneered by Hager and O'Connell (1), who calculated mantle flow by imposing present-day plate motions as a surface boundary condition. With the advent of global seismic tomography (2), these models were extended to predict the geoid and dynamic topography (3). However, these Earth models are "static," because they solve for instantaneous mantle flow in response to boundary conditions, internal loads, or both.
Time-dependent Earth models are required to understand how the evolution of mantle flow affects Earth processes that occur on geologic time scales. For example, continental shelf and platform stratigraphy are controlled by vertical motions of the continental lithosphere in response to mantle convection (4). True polar wandering is caused by changes in the inertia tensor as a result of mantle convection (5), and the alternation between periods of rapid and slow magnetic field reversals is probably related to mantle-controlled changes at the core-mantle boundary (CMB).
The development of time-dependent Earth models has been delayed for several reasons: (i) Sufficient computer power to resolve the narrow thermal boundary layers in global mantle convection models has not been available; (ii) it is not obvious how the internal mantle density structure can be related to plate motion observations at the surface; and (iii) it is not known how time-dependent Earth models can be initialized at some starting point in the past, because the mantle density structure is known only for the present day (6).
Some of these difficulties have been overcome. (i) Advances in computer power allow three-dimensional (3D) spherical convection to be simulated at a resolution on the order of 50 to 100 km (7, 8). At the same time, large-scale mantle velocity heterogeneity structure has been mapped in greater detail (9, 10), and seismic tomography has imaged subducted slabs (11-13). (ii) The connection of internal mantle density structure to the history of subduction (14, 15) has allowed estimation of the internal buoyancy forces that drive plates (16). These developments allow convection models to be combined with plate motion reconstructions and such models to be tested with seismic data.
Figure 1B shows an Earth model obtained with the TERRA convection code (17, 18). More than 10 million finite elements provide an element resolution of about 50 km throughout the mantle, which allowed us to model convection at a Rayleigh number of 108 (19). The history of plate motion is imposed as a time-dependent velocity boundary condition (20) starting in the mid-Mesozoic at 119 to 100 million years ago (Ma). We chose this starting time because well-constrained reconstructions exist only as far back in time as the 119 to 100 Ma period.
(Etc.)
The fact that Baumgardner on the one hand authors papers claiming great antiquity of the earth, and on the other claims evidence for young earth creationism, is not an irrelevant matter. It bears on his credibility. How can we believe anything he writes, if he's prepared to put his name on two completely discordant pieces of scientific work?
As for HalfFull's silly insinuations, until he's willing to say what he means forthrightly, he will be ignored.
(WP, returning to off-FR status)