Q. 94: How could the ‘high mountains’ of Gen. 7 be covered, if sea level rose by only 100-200 m?

CPT Q. #94 – 101 Q&A on Catastrophic Plate Tectonics

Question: 94. In your response to question 31, you said you thought the rise of sea level might be only 100-200 m during the Flood. However, how can this be consistent with Gen. 7:19 and 20, where it says the waters prevailed and all the high mountains were covered to a depth of 15 cubits? The word “prevailed” sounds to me like it cannot refer to intermittent tsunami-like waves. The word for “mountains” (har) is the same word used for Mount Sinai, for example. If there were no high mountains before the Flood, why would the Hebrew word for “high” (gabowahh) be used to modify the word “mountain”? Also another Hebrew word for “hill” was available (gibah) if what was covered during the Flood was not the equivalent of post-Flood mountains, which were familiar to Moses’ audience.

Response: I am persuaded these Hebrew words do indeed mean ‘high mountains’. Furthermore, evidence from the geological record suggests that the Appalachian Mountains formed during the earlier part of the Flood were possibly as high as today’s Himalayas but were beveled flat by subsequent intense erosion. Incredibly thick sequences of sedimentary rock in the basins to the west of the Appalachians testify to the huge volume of these mountains and the ferocity of the erosive processes. Moreover, in most of the continental shield areas of the world it is common to find root zones of former high mountains with thousands of meters of rock formerly present apparently beveled completely away. Given these observations it seems likely to me that the waters of the Flood had extreme erosive power, sufficient to erode away huge mountain ranges in a matter of days. If water velocities are sufficiently high for cavitation to occur, the water depth does not need to be that great to degrade topographical features that significantly exceed the mean water depth.

I want to be forthright here in saying that I have no means by which I can with any degree of confidence put tight quantitative constraints on the water depth over the continents during the Flood. Generally speaking, however, water current speed varies inversely with water depth. Sustaining high water velocities seems to require relatively modest water depths. High water velocities seem to be needed to accomplish all the erosion which seems to have occurred during the Flood, especially to erode away the mountain belts which appeared during cataclysm. High water velocities also seem to be needed to abrade rock down to silt-sized particles and transport it over large distances as the sediment record appears to indicate. For these reasons I conclude that water depths of only a few hundred meters are more likely than those of one or two kilometers or more. It is particularly this requirement for so much erosion of crystalline rock and its physical abrasion to small particles that now pushes me toward smaller water depths over the continents during the Flood cataclysm.