Was the flood over the whole world or just part of it?
I have previously answered a similar enough question that I will copy and past below.  Let me add just a couple of thoughts.  The Old Testament is not a careful, scientific analysis of events in the past.  We should begin discussing such topics by asking what clear historical and theological material seems to be contained in the story.  Here is what I see to be essential to the Genesis flood story:
1. The reason the flood happened was the blatant rebellion and out-of-control sin in the world at that time.
2. The flood was a judgment by God, on the sinful world of that time.
3. There was an actual flood, and its impact was massive.
4. Some, including at the very least Noah and his family, survived the flood–a symbol of salvation for those who put their faith in God.
Personally, I am comfortable with any explanation of the flood which is consistent with this theological and historical information.  To me, personally, a global flood fits the picture better than a local one.  I cannot “prove” that this flood happened, but, as you will see below, there is some important evidence (NOT primarily scientific in nature) supporting that it happened.  I do not find the local flood explanation to be untenable, but I do not prefer it for reasons you will see below.
John Oakes
Did the flood in Genesis 6-9 really happen?   If so, was it a world-wide flood, or just a local phenomenon in
Mesopotamia? Is there any evidence for the flood happening?

This question has certainly brought about a lot of debate over the years.
Many have scoffed at the “myth” of the flood in the time of Noah. The
principle reason for intellectuals to scoff at the story of the flood is a
predisposition to assume that supernatural events cannot and do not
happen. It is easy to see that if one assumes before even examining the
question that miraculous, supernatural events do not happen, one will end
by assuming that the flood never happened.

However, the flood is an inescapable part of the inspired word of God–the
Bible. Jesus did not hesitate to accept it as a literal event which
actually happened (Matthew 24:38). Neither did Peter (2 Peter 2:5) or the
writer of Hebrews (Hebrews 11:7). Should we?

Well, yes, we should at least be open-minded enough to check out the
evidence. If the world-wide flood recorded in Genesis actually happened,
there might be some evidence of the event which one could point to. If one
were to search for evidence for the flood, what could one expect to find?

Some would claim that the flood created most of the sedimentary layers on
the earth–up to twenty-five thousand feet thick in places. They would
claim, for example that all the layers which can be observed at the Grand
Canyon were laid down in a single, universal flood, and that the canyon
itself was carved out as the waters of that single flood receded. This
claim is not credible at all. If fact, if a universal flood occurred, it
would at most redistribute a significant part of the top soil, sand and
gravel at the surface of the earth, leaving perhaps as much as a few dozen
feet of mud in some places, and eroded top soil in others. Therefore the
physical signs of a great, world-wide flood would be similar to those of a
major local flood. In Mesopotamia, for example, flood layers up to 15 feet
thick have been discovered, which some have attributed to the flood in the
days of Noah. This may well be, but it is difficult to prove, as major
floods occur naturally in Mesopotamia from time to time.

If physical evidence may be unconvincing, what evidence can one look for,
to confirm the flood described in Genesis? One significant fact is that
nearly every very ancient culture has a record of a great flood.
Traditions of a singularly massive flood are found in cultures in
Australia, China, Egypt, Sub-Saharan Africa, Mesopotamia, North, Central
and South America and Europe. No other ancient event is remembered in
every part of the globe. This fact is very strongly suggestive that some
sort of great, world-wide flood actually happened. Due to their
presupposition against the possibility of a supernatural event, most
intellectuals are extremely unlikely to accept this hypothesis.

Although the common record of a great flood from every region of the globe
is quite suggestive, it is worth remembering that ultimately, for the
Bible believer, faith in the account of the flood in Genesis is based
primarily on belief that the entire Bible is inspired by God. The Old
Testament has every conceivable mark of inspiration by the creator. Peter
reminded his readers, in 2 Peter 3:5-7 that the grounds for belief in the
return of Jesus is the same as for belief in the flood. Both are based on
the Word of God.

Another common question about the flood is whether it was truly
world-wide. One answer is that the account in Genesis certainly implies
that it was. In Genesis seven one can find the words every and all
throughout. Besides, as already pointed out, there is a similar record of
a great flood found in every part of the globe, lending credence to its
being world-wide in its effect. Some have proposed the “Local Flood
Theory” to explain the Genesis flood account. The idea is that the flood
of Noah was a massive flood in the Mesopotamian area only. The problem
with this theory is that there is no way the water could rise so high for
one hundred and fifty days, just in Mesopotamia, without spreading to
surrounding areas. Others have proposed pseudo-naturalistic explanations
of the flood such as the “Canopy Theory.” This is the theory that in the
early earth there was a massive canopy of water in the upper atmosphere
which was released in the flood. This theory is easily dismissed as it
defies several well-known physical laws.

In the final analysis, the flood described in Genesis is clearly a
miraculous event. It is plainly described as a judgment for mankind’s
sins. Any attempt to find some sort of “natural” explanation is bound to
fail. Exactly how God did it we do not know. Unfortunately, many possible
questions about the flood will probably remain unanswered. Did literally
every kind of animal come to the ark? What happened to the water? Could
the flood have been world-wide in effect, but leave at least some
creatures behind in various parts of the world? Did God recreate certain
species after the flood? Because the Bible does not provide specific
answers to some of these questions, one can speculate, but it is unwise to
be dogmatic about one specific opinion.

A more thorough treatment of this question is found in the article at this
web site entitled, “Will it Be Fire Next Time??

Comments are closed.