I guess there is literary license for any document to use terminology such as "every" and "all" and "whole" for emphasis, rather than universality. The words can be used relatively rather than absolutely. Therefore some people believe the account of Noah's flood may have been intended to be understood as regional rather than global.
If the flood was regional, a high ring of mountains would be necessary to act as a catchment for the large body of water. If such a ring of mountains didn't already exist before the flood, perhaps it could have been formed through sudden tectonic upheaval, then gradually defaced in the aftermath of the flood.
Keep in mind however that the creation story begins with the whole world covered in water:
"And the Spirit of God moved upon the face of the waters".The New Testament also mentions, "…the earth standing out of the water and in the water…”
So from a Biblical point of view, from the very beginning there was enough water on earth to completely cover the whole surface.
I was taught during High School Physics that Mass is constant. Therefore whatever happened after Day One of creation, there must always have remained enough water on earth to cover the entire surface.
On the Second Day God made a "firmament" which separated the body of water above it from the water below it. If this "firmament" is the same firmament in which birds were later said to fly, then I guess it refers to earth's atmosphere. I don't know what state the water was in that was placed above the firmament. But whatever state it was in, the total volume of water above the firmament combined with the water below the firmament, remained constant.
And the volume of water that remained below the firmament was itself still enough to cover the whole surface of the earth even after the waters above had been separated by the firmament.
It was not until Day Three that God caused the waters below the firmament to be gathered together into places called "seas" enabling dry land to appear for the first time.
Perhaps God did this by raising hills and mountains, making trenches for the seas or by causing some of the water to go underground.
The water for Noah's flood came from three sources:
- The fountains of the great deep were broken up
- The windows of heaven were opened
- It rained for 40 days
The world's oceans cover 71% of the earth's surface to an average depth of 3,711m. That's enough water to cover the whole surface of the earth to a depth of 2.7km if all the land was level. But could Mt Everest at 8,848m have been submerged?
That would require an extra body of water only 2.277037 times the volume of the oceans. If that much water exists, where could it be?
The Bible says the flood waters "returned". Some of it was "assuaged" by means of a special wind, whilst the rest ran off the land. Is it possible for the earth's internal structure to contain that much water?
Well since 80% of what comes out of volcanoes is water vapor; since scientists believe the earth's outer core to be liquid; and since the deepest that mankind has drilled beneath the earth's sea-bed so far is still only 2,111m - I guess we can't rule-out the possibility that there may be water beneath the earth's crust.
Anyway the volume of subterranean water required to submerge Mt Everest would be a mere 0.0029044% of the earth's total volume of 1.083 207 3×1012 km³. If Mt Ararat (5,137m) was the highest peak back in Noah's days, the figure is reduced to a mere 0.0024343% of earth's internal structure needing to contain water.
But keep in mind that many of the world's peaks are getting higher and may not have been as high during Noah's day. The Himalayas and the Rockies may not have even existed at all before the flood. In fact Mt Everest, which is moving upwards at a faster rate than any other group of mountains in the world, may actually have been formed as a direct result of events that occurred in the aftermath of the Flood. According to a NASA website (NB not a Creationist website) Mt Everest contains marine fossils and is made-up of sediment that was once a seabed. What better explanation for this than the Flood.
About four or five generations after the Flood, a son was born to the line of Shem, whom they named Peleg because "in his days the earth was divided". This probably means the people were divided socially as a result of patriarchy or the Babel dispersion. However there could be another meaning.
The name Peleg פָּלֶג means earthquake, or division, and is related to a word meaning water. Several English words are phonetically related to it such as archipelago and pelagic. So is it possible during Peleg's day that the earth and not just the people was divided?
Tectonic shifts, earthquakes, volcanoes, rising sea levels, deepening oceans, continental drift, continental collision and rising mountain peaks (such as Mt Everest and the Himalayas) may all have been part of this. This may even have contributed to the present-day height of Mt Ararat.
In other words, the present-day condition of colliding continents pushing up such high peaks as the Himalayas and the Rockies (the Rockies is also a major fossil field) may be a condition that was forged only in the aftermath of the Flood, with dramatic geophysical activity being noticed particularly around 99 years after the Flood in the fifth generation - hence the name Peleg.
Therefore the volume of water that exists in today's oceans (even without looking for further volumes of subterranean water), could have been sufficient to submerge all the high hills and mountains that probably existed in Noah's day.
If so, it's possible that only one large land mass existed before the earth was divided, which could explain why Noah had to build an ark to survive rather than migrate away from the Flood region; and which could explain how people, languages, animals and flora were able to migrate easily.
If the original Pangaea was not yet broken up into the current continents, then it could be said that the Flood was both regional (because there would have been only one region!) and at the same time, global.
So to respond to the questions:
"Was the Flood regional or worldwide?"
"Is there enough water?"
Absolutely, all ways considered.
Nevertheless, Paul reminded us that if a man thinks he knows anything, he doesn't know anything yet as he ought to know it. Therefore there's merit in adopting David's attitude, "I don't exercise myself in matters too high for me."
Our faith is based not on flesh and blood nor wisdom of words, but in the power of God.
(POSTSCRIPT: The concepts in this post have been disputed, by a good friend whose scientific education is infinitely broader than mine)