BAUMGARDNER'S MODELING OF RAPID PLATE TECTONIC MOTION
Ben Clausen, Geoscience Research Institute
Dr. John Baumgardner's early roots are from Texas, in a family casual to the claims of the Bible. After receiving a master's degree in electrical engineering from Princeton University, he returned to Texas where he became part of a Presbyterian college Sunday school class. Through a verse-by-verse study of the Gospel of John, he was led to consider the question of who Jesus Christ is and had what he calls "a dramatic conversion experience." Having been well-schooled in evolution theory, he took a while to recognize a conflict with the Bible's portrayal of an originally perfect earth, where death and a catastrophic flood occurred only after sin.
While giving university lectures on creation/evolution topics, he became keenly aware of the need for creationists to provide a geological model to account for the large-scale motion of the earth's surface, i.e., plate tectonics.
In 1983 Baumgardner completed his Ph.D. in geophysics from the University of California, Los Angeles (UCLA) with a thesis entitled, A Three-Dimensional Finite Element Model for Mantle Convection. He now continues his modeling of plate tectonics as well as other geophysical fluid dynamics research as a staff member of the Theoretical Division, Fluid Dynamics Group, Los Alamos National Laboratory.1,2
FIGURE. John Baumgardner in his lab at the Los Alamos National Laboratory in New Mexico. Photo courtesy Public Affairs Office, Los Alamos National Laboratory.
To model the motion of the earth's plates (roughly equivalent to the continents), Baumgardner uses a Fortran program called TERRA3, developed originally as part of his Ph.D. research, that must be run on a supercomputer because of its size and complexity. It divides the earth's mantle (a 3000 km layer of rock that surrounds the earth's core) into millions of three-dimensional hexagonal cells, each with a variable value for its temperature, pressure, density, velocity, and material properties. These variables change through time in a calculation based on a small set of basic principles. TERRA is one of four models in the world capable of modeling the earth in a global manner. Results from this computer program have been presented at the American Geophysical Union meetings4 as well as being described in scientific journals.5
Baumgardner's simulation of the Genesis Flood begins with an original single supercontinent that breaks up because the surrounding ocean floor is colder, and thus denser, than the rock below it. The more dense surface rock follows the natural tendency to sink into the hotter, less dense mantle rock beneath it. The drag of the sinking ocean floor pulls the more buoyant continental plates outwards from the center of the supercontinent resulting in the drift of North and South America away from Europe and Africa still seen today. Runaway subduction, first proposed in the 1960s by a physicist at General Electric, allows this movement of the tectonic plates to happen rapidly and is a consequence of the fact that silicate minerals weaken dramatically with increasing temperature and deformation rate. By omitting some of the physics of rock deformation, TERRA can model the scientifically standard slow rates of plate motion. However, when the more detailed physics is included, Baumgardner finds the model predicts much more rapid motion. Details of his model for the Genesis Flood were presented at the Third International Creation Conference.6
Baumgardner recognizes that there are legitimate questions about the physical processes needed to obtain these rapid rates:7 (1) The time frame for the Flood requires an effective mantle viscosity [resistance to fluid flow] almost one billion times smaller than the estimated present viscosity. Since viscosity decreases exponentially with increasing temperature and also in a strongly nonlinear manner with increasing deformation rate, he believes [and recently has demonstrated in numerical calculations] that such decreased viscosity naturally occurs throughout large volumes of the mantle as the runaway process unfolds. (2) The short time scale for plate motion conflicts with the long time scale implied by radiometric dating, which requires all radioactive decay since the Cambrian [where the lowest major fossil bearing rocks appear] to have taken place since the beginning of the Flood. Baumgardner believes the nuclear decay rates likely have not been constant during the earth's history and were orders of magnitude higher during the Flood event. (3) Based on the normal rate at which rocks conduct heat, millions of years seem to be required for the cooling of the oceanic lithosphere from near the molten state to its current thermal regime. Baumgardner believes that enhanced cooling rates, as a consequence of hydrothermal circulation of ocean water through the lithospheric layer, are insufficient to solve the problem. In addition, a much faster transfer of heat from the crust into oceans would seemingly produce a temperature for the ocean and atmosphere that is too hot for life.8 Baumgardner concludes that "an enhanced rate of nuclear decay during the [Flood] event and a loss of thermal energy afterward" "cannot be understood or modeled in terms of time-invariant laws of nature". He believes that "intervention by God in the natural order during and after the catastrophe appears to be a logical necessity."
In the Los Alamos community, Dr. Baumgardner is known as a Christian activist, concerned for example with the dogmatic teaching of evolution as fact in the public schools, but he does not push his religious views on his colleagues. Brad Hager, a geophysicist at Massachusetts Institute of Technology, says it would require a miracle to increase the thermal diffusivity [rate at which rocks conduct heat] to a level where the lithosphere could have cooled in a few thousand years.
However, Hager has only respect for Baumgardner's computer program. Gerald Schubert, of the UCLA Department of Earth and Space Sciences, agrees that "As far as the code goes, Baumgardner is a world-class scientist." "Indeed, there is universal agreement that TERRA, created to prove the Bible literally true, is one of the most useful and powerful geological tools in existence."
http://www.grisda.org/georpts/gr26.htm
