Was Noah's Flood Global or Local?
The most detailed account of Noah's Flood is given in the Book of Genesis. Here there seems little doubt that the Flood had to be truly global and not just "global" in the minds of one minor tribe of people:
All the high hills under the whole heaven were covered…the mountains were covered. And all flesh died…All in whose nostrils was the breath of the spirit of life, all that was on the dry land, died. So He destroyed all living things…the waters were on the face of the whole earth (Gen. 7:19-23; 8:9).
If these verses are referring to just a local flood, then Noah was a fool to have spent 120 years building an enormous vessel to save himself, his family and the animals. It would have been far simpler to have moved out of the area. But Jesus and Peter were equally as foolish, since they both spoke of Noah and the Flood (Matt. 24:37; 2 Pet. 2:5; 3:1-10).
Moreover, after the Flood, God made a covenant promise with Noah and all mankind that the waters would never again become a flood to destroy all flesh (Gen. 9:11-15). There have been many local floods since, so either God has broken His covenant promise or the Genesis Flood was global.
There are 138 other accounts of a great flood of long ago in the traditions of widely diverse cultures from around the world. The details vary, but the story is essentially the same. It relates how the gods were angry with humans and destroyed them all with a flood – but allowed one man, his family, and some animals to be saved on a large vessel. These accounts existed prior to the introduction of Christianity; they are well documented and rather difficult to explain unless the event actually happened.
The physical evidence of the global nature of this Flood is abundant. The surface of the earth consists mostly of sedimentary rocks; that is, layers of rock that were at one time sediment in water. These layers contain fossils, which are the remains of once-living creatures. It is now well known that many of these sedimentary layers extend in continuous bands, some of which encircle more than half the earth. Clearly, this means that at some time in the past, half the earth's continental land masses were covered in water at the same time. The problem is referred to as "the persistence of facies."
Geology textbooks show each stratum or layer cleanly separated from the layer beneath it. But on-site inspection will often show the two strata blending together at the interface. This is known as "interbedding." The straightforward conclusion here is that strata were not laid down in sequence, with millions of years between one deposit and the next. Rather, they were laid down in rapid succession or even simultaneously. Recent laboratory work that is observable and repeatable has shown that simultaneous deposition under flood conditions does indeed leave stratified layers.