CPT Q. 037: Was runaway subduction restricted to the first forty days of the Flood?

Q. 37. CPT offers an interesting explanation for the 40 days of rain at the beginning of the Flood. It proposes that runaway subduction created supersonic steam jets at the MORs which carried significant amounts of water into and above the atmosphere which was precipitated back as the global rain. However, the current version of CPT seems to imply two episodes of runaway subduction. How could another period of extensive rain have occurred during the middle of the Flood when the Bible clearly notes that the last 221 days of the Flood were a time of wind and isostasy returning the waters to their new basins? If there were two periods of rain of such magnitude, why is the second not mentioned in the biblical text?

Response: Nowhere that I am aware have I suggested that there were two separate episodes of runaway subduction. The inference that there were two episodes likely arises from the fact that the 3D computer modeling I have done up until now has been a simplified version of the runaway subduction history, which begins, not with the pre-Flood continent assemblage, but with a Pangean assemblage instead. In answers to earlier questions I outlined my reasons for concluding that a supercontinent configuration corresponding roughly to Pannotia in the secular literature, but centered approximately on the equator and similar to Pangea, existed prior to the Flood. Evidence suggests that early during the interval of geological history known as Paleozoic, corresponding to the early part of the Flood, the continental blocks often referred to as Laurentia (basically North America), Baltica (basically western Europe), and Siberia broke away and migrated from this supercontinent’s northwestern margin. Later during the Paleozoic interval, however, these blocks approximately reversed their paths and rejoined what remained of the earlier supercontinent (basically Gondwana) to form Pangea.

I have stressed in the past and want to emphasize once again that mantle rock, in the absence of some process occurring to weaken it, is exceedingly strong. Currently observed plate speeds on the order of only centimeters per year testify to this strength. Five centimeters of plate motion per year, for example, is equivalent to one kilometer of displacement in 20,000 years. The only way that the large tectonic displacements which the geological record requires to have occurred during the brief few months of the Flood is for the strength of the mantle to have been reduced by roughly nine orders of magnitude during the entire time these large displacements were taking place.

Laboratory studies on how silicate minerals deform at high temperatures under stress reveal that they weaken by many (at least nine) orders of magnitude under the levels of stress that can arise inside a planet with the mass and hence the gravity of the earth. As I have shown in my papers, this intrinsic weakening behavior in mantle minerals implies the potential for catastrophic runaway of both cold material from above and hot material from below in the earth’s mantle. An important result from the 2D modeling in my 2003 ICC paper is just how widespread throughout the mantle the weakening becomes once runaway begins.

In light of the physical processes involved, is it likely or even possible for more than one episode of runaway to have occurred? The short answer is no, else the mantle strength would rise and the time scale would be much longer than the few months implied by the Genesis text. Thus, the Paleozoic plate displacements, as well as the Mesozoic and Cenozoic ones, must all be part of a single runaway episode. In other words, for CPT to be viable and logically account for the large-scale tectonic changes documented for the metazoan fossil-bearing portion of the geological record there can be only one runaway episode.

Although I have stressed this before, I want to emphasize again that CPT as a candidate mechanism for the Flood has almost nothing to do with computer modeling. CPT’s essential support comes from geological and geophysical observations together with laboratory measurements relating to how silicate minerals deform under mantle conditions. Thus its central tenets can be evaluated apart from any computer calculations. CPT is primarily anchored in the observational data that testifies powerfully that the present-day seafloor is all younger than the Paleozoic portion of the geological record. This logically implies that all present-day ocean floor has been generated since the onset of the Flood cataclysm. Given the overwhelming evidence that subduction is real, the absence of pre-Mesozoic ocean floor on the earth today suggests strongly that all the pre-Flood ocean floor as well as all the Paleozoic ocean floor must have been recycled into the mantle by subduction during the brief span of the year of the Flood. That, in a nutshell, is CPT–apart from any computer calculation whatever.

Nevertheless, what are the prospects of including the Paleozoic portion of the cataclysm in a computer simulation? Although I have commented on this several times before, the reason I have not yet included the Paleozoic is simple. It is because finding an initial condition that is close enough to the actual one to produce a continent configuration which resembles the present one is exceedingly difficult. It involves, for one thing, guessing the temperature distribution inside the mantle at the onset of the Flood with a moderate degree of correctness. Only with lots of trial and error and many 3D computer calculations was I able to do this for a Pangean starting condition. But to go back further in time and find an initial condition that first causes Laurentia, Baltica, and Siberia to break away from a Pannotia-like supercontinent and then causes these blocks to reverse direction and return to close to their original places to form Pangea is an even more daunting task. My present guess is that a viable initial condition will likely involve an upwelling plume beneath the northwestern part of the initial supercontinent plus some zones of cold material sequestered in the upper mantle, probably around much of the supercontinent’s perimeter. But the possibilities are vast. Thankfully, the viability of CPT does not depend on the success of that enterprise. Nevertheless, I welcome anyone who wants to help in undertaking it.