Question 21. Would a ring of cold material in the earth’s upper mantle that was on the verge of catastrophic runaway, as you postulate, if part of God’s original construction of the earth, be consistent with God’s declaration at the end of creation Day 6 that all He had made was ‘very good’?
Response: This is certainly a valid concern. Involved with this issue is the reality that God has purposes and plans about which we have little or no inkling. “For as the heavens are higher than the earth, so are My ways higher than your ways and My thoughts than your thoughts,” He declares to us in Isaiah 55:8. Furthermore, God has, and has always had, perfect foreknowledge. “For I am God, and there is no other; I am God, and there is no one like Me, declaring the end from the beginning and from ancient times things which have not been done, saying, ‘My purpose will be established, and I will accomplish all My good pleasure.’” (Isaiah 46:9-10) So the certainty of the Flood as well as its precise timing were without any doubt in God’s mind as He was in the process of creating the earth and filling it with plants and animals, with birds and fish, and with Adam and Eve. To be sure, there was no sin or death in the world that existed at the end of Day 6. I personally suspect strongly that the earth was so constructed that the processes that would eventually unleash the Flood cataclysm were not already in motion at that point in time, that is, at the end of creation Day 6. I strongly suspect (but cannot demonstrate) that it was not until Adam sinned that any preexisting mechanism was potentially set into motion. So would the inclusion of a ring of cold material in the upper mantle in the originally created earth necessarily be in conflict with a creation God could declare to be “very good”? I personally do not think so, especially if this aspect of the earth’s structure were created in a stable initial state.
Therefore, an important related question is whether or not the presence of a ring of cold material in the earth’s upper mantle that was on the verge of catastrophic runaway could actually be stable for an indefinite period of time. I can imagine the answer to be yes. The mineralogical phase boundary at about 660 km depth in the earth—the boundary that separates the upper mantle from the lower mantle—provides a moderate barrier to flow crossing it. The main reason is that the main phase changes are endothermic, that is, they require energy from the surrounding environment in order to take place. So it is at least conceivable that God could have designed things such that the cold material in the upper mantle was in a mechanically and thermodynamically stable state requiring some sort of trigger, such as some radiogenic heat, to become unstable.