Science Ch.11 - How Big Was the Flood?

Did the waters cover the all the “mountains” of the “earth” or all the “hills” of the “land”? Interpreting the text very literally resolves these ambiguities and produces a surprising conclusion.

Cambridge, where I live, is very flat. People joke that Hills Road is named after its humpback railway bridge. Most of the surrounding countryside is reclaimed marshes, so I can easily imagine a flood covering everything as far as the eye can see. But the idea of Noah’s flood covering the whole Earth and all its mountains is much more difficult to envisage. How could millions of land species be rescued in one boat? How did river and sea life survive in mixed salt and fresh water? How did land plants survive underwater for a year? It wasn’t just seeds that survived, because the dove found a full-grown olive tree. And the Bible text itself implies some awkward questions concerning this interpretation.

       Various organizations have made valiant efforts to explain all the problems using scientific language, though many would dispute that they are really employing scientific methods. The methodology of science is to follow the facts to a conclusion, but there is a temptation in this kind of situation to find the facts that fit a predetermined conclusion. There has been a robust debate concerning the science of a worldwide flood,1 but in this chapter I will concentrate on what the text itself says.

       It would be easy to interpret the text in some kind of mythological way or to conclude that it is merely an exaggerated account of a small flood. This may, of course, be correct, but I want to take a serious look at the actual text to see what it says as a plain narrative. One problem is that we are too familiar with it – we all know the story of a worldwide flood and God’s rescue mission for every land species on the planet. In light of this, it is easy to overlook details in the Bible text itself that imply something else.

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Hebrew ambiguities

The text of the story in the Bible is not straightforward, because the Hebrew text has some important ambiguities:
• Genesis 8:9 says the flood was “over all the surface of the earth.” The word “earth” (erets) is used in the Bible to mean
   1. the planet “Earth” (e.g., Gen 1:1), or
   2. a “land,” (e.g. Gen.2:11), as in the phrase “the land of Israel” (e.g., twice in Ezek 20:38).

Genesis 7:20 says that the water rose forty-five feet above the highest har. This word is used in the Bible for anything from a “mountain” (e.g., Gen.22.14 - ‘mountain of the Lord’) to a “hill” (e.g., Gen.12:8 - the hills near Bethel). And it is even used for the small hillock on which David stood to speak so that he could be heard by his men standing at the bottom (1 Sam 26:13). So this could mean either
   1. the highest mountain on the planet, or
   2. the highest hill in the land.

Genesis 7:19 says the waters covered the area “under the entire heavens” (tachat kol hashamayim). This phrase can mean “everywhere” without limits (e.g., Deut 4:19) or “from horizon to horizon” (e.g., Job 37:3). It is used, for example, to refer to the lands bordering Palestine that had heard about Israel’s invasion (Deut 2:25). As they certainly didn’t hear about Israel’s conquests in America, in this instance it must mean “from horizon to horizon.” So the phrase can mean either
   1. all the area under the sky of the whole planet, or
   2. everywhere under the visible sky at least as far as the horizon.
Therefore, the text could describe a flood that covered every “mountain” of the “planet Earth” or one that covered every “hill” in a large “land” at least as far as the horizon. Either way, the flood was clearly awesome and devastating – it covered the equivalent of a three-story house on the highest hills as far as the eye could see. Noah could see no land even from the top of his boat, which was forty-five feet high. At that height, the horizon is only nine miles away, though the Ararat mountains are tall enough to be seen around the Earth’s curvature from a distance of 165 miles.2 In both cases, the grandeur of the language implies it was a huge flood that completely destroyed that ancient civilization.


Archaeologists in the 1930s found evidence of an amazingly widespread flood (or floods) before 3000 BC, which covered large areas around the Tigris and Euphrates rivers – the Mesopotamian plain covering 140,000 square miles. This wasn’t just a shallow flood; even the silt they found deposited by this water was six feet deep.3 The whole country is flat, with just a few small hills, so this flood would have been utterly devastating; there is simply no high ground to run to for hundreds of miles. This area was the homeland of the ancient Middle Eastern world, and the whole population living there must have been wiped out by this flood. A disaster of this proportion – wiping out a whole civilization – has never been seen anywhere since in the world.

       According to the account in Genesis 8, the rain was followed by a strong wind (v. 1), which apparently blew the ark toward the Ararat mountains, where it “came to rest on [or among] the mountains” (v. 4). Then there was a wait of three months before “the tops of the mountains became visible” (v. 5). The Hebrew text does not actually specify whether the ark rested “on” or “among” the mountains for these three months. The word “rest” (Hebrew nuach) has two meanings – “to stop” or “to have peace” – though usually it implies both, that is, no longer having to move or struggle. For example, God gave Israel “rest” in the land of Canaan (Deut 12:10; 25:19; Josh 1:13, 15, etc.), but that didn’t mean they couldn’t move about in the land.
This means there are two possible scenarios:
   1. the ark could “rest on” the top of the highest peak – that is, be grounded there until the other peak appeared three months later, or
   2. the ark could “rest among” the mountains – that is, having been becalmed when the strong wind stopped, it gradually drifted for three months until both mountain peaks were in view.

The raven and dove

The deciding factor between these two options is found in the account of the birds that were released forty days after the peaks of the mountains became visible. Genesis says that the first was a raven, who “kept flying back and forth until the water had dried up from the earth” (Gen 8:7). Presumably, being a carrion bird, it could land and feed on floating corpses even if it found no land. By contrast, the second was a dove, who “could find nowhere to perch because there was water over all the surface of the earth; so it returned to Noah in the ark” (v. 9). After a week, he sent the dove out again, and when it “returned to him in the evening, there in its beak was a freshly plucked olive leaf” (v. 11). This can help us decide between the two possible scenarios.

       The mountains of Ararat consist of two peaks: Greater Ararat, 5,140 meters high, and Little Ararat, 3,925 meters high.4 If the ark had come to rest “on” the highest, Noah would have seen no other peaks until the water receded another 1,200 meters, so this might explain why he had to wait three months before seeing the top of any mountain. However, by the time that lower peak was visible, the water would have sunk to the 3,900-meter contour line on Greater Ararat, the mountain that they were resting on, so they would have been surrounded by twenty-five square miles of dry land. After another forty days, when the first bird was released, this area would have grown considerably because the mountain has a plateau at about 3,000 meters. In this situation, it is difficult to understand why the text says the birds couldn’t find any land. Indeed, they would have had to fly many miles before they found any water.

       Therefore, the text must mean that the ark “came to rest among the mountains.” That is, the ark came to a peaceful calm in the vicinity of Ararat, from where Noah could see the mountain peaks start to appear. This would also explain why the text mentions the plural “tops” of the mountains (v. 5) – if the ark had been sitting on top of one of them, Noah wouldn’t have seen them both. It also explains why it says that the ark came to rest at “the mountains of Ararat” (v. 4) – the plural suggests the area rather than a single mountaintop.

       This meaning of “rest” introduces yet another pair of possible interpretations, because the text does not make clear where the peaks were spotted.

       It says the “tops of the mountains became visible” (v. 5).
This could mean either that:
   1. the ark was becalmed within the mountain range itself and the peaks gradually became visible as the water level dropped, or
   2. that it was becalmed some way off and the mountains became visible as the ark slowly drifted closer.
The account of the birds can help us determine between these two options as well. The mountain range is not large – the two peaks are only about seven miles apart – so if the ark became becalmed within the mountain range, it would have been a short distance to the visible peaks. The birds could have seen the peaks clearly and reached them easily, so neither of them would have returned. Therefore, the ark must have been becalmed some distance from the actual mountains.

       If the ark stopped some way distant from the Ararat mountains, this helps to explain some other details in the text. First, the dove managed to reach land the second time, though it couldn’t reach it during the previous week, even though the peaks had already been visible before the first flight (vv. 5, 8). This makes sense if the ark was floating toward those peaks. Second, the text says, “There was water over all the surface of the earth,” even though the peaks had already been visible for over a month (v. 9). This language makes sense if the mountain peaks were a long way off over the horizon (i.e., more than nine miles away), so it was still true that the ark was surrounded by water from horizon to horizon.

       Examining the text has narrowed down the possibilities. We can conclude that the ark was blown toward the Ararat mountains and was becalmed some distance from them – but how far? People who train homing pigeons (which is the same species as a dove) say that they can cover fifty or a hundred miles without training, though this can be increased to five hundred miles with training.5 So if the ark was drifting toward the visible peaks, and it was too far away for the dove but close enough a week later for the same dove, we could conclude that it was something like fifty miles away when the dove reached it. This means the mountain peaks were visible far beyond the horizon (which is only nine miles distant), so the phrase “there was water over all the surface of the earth” (v. 9) could still apply.

Global or local?

This brings us to the crucial question: did the flood cover the whole of the planet or the whole of the land?

       Surprisingly we haven’t found any details in the text that conflict with the idea that the flood covered the 140,000 square miles of the Tigris-Euphrates basin rather than covering the planet. This low-lying area has only shallow hills and is surrounded by higher land that encloses the plain, which certainly can flood. And there is archaeological evidence that this area did experience a catastrophic flood within a time period consistent with Genesis.

       It is understandable that the worldwide flood interpretation is popular because the text has two phrases that appear to imply this: “under the entire heavens” (Gen 7:19) and “over all the surface of the earth” (8:9). However, as we saw above, the former can be used with the sense of “from horizon to horizon” (Deut 2:25), and the second occurs after the mountain peaks have become visible beyond the horizon (Gen 8:5, 9) – so this phrase must mean something like “as far as the horizon.” We might complain that this isn’t the way that we understand these phrases in English, but the important issue is what these phrases mean in the Bible text – otherwise we may end up imposing our own meanings on the Bible.

       In the New Testament, the word kosmos is used to describe the “world” that Noah’s flood destroyed (Heb 11:7; 2 Pet 2:5). This word is often used in the New Testament for the evil systems of a corrupt society (John 15:19; 17:16; 1 Cor 2:12; Gal 6:14; Jas 1:27; 4:4; 2 Pet 1:4; 1 John 5:4). That meaning explains why Hebrews says that Noah “condemned the world.” Clearly the planet of animals, plants, and rocks weren’t morally evil, so the word “condemned” couldn’t refer to them. However, the civilization that Noah lived among was condemned as evil, and the Greek kosmos often refers to a corrupt system. This suggests that the “world” that was drowned in Noah’s day refers to the evil civilization he lived among, and not the planet they lived on.

       The details about Noah in the Bible text are therefore compatible with the interpretation that this flood covered all the hills in the land that Noah and his civilization lived in, leaving his family as the only survivors, floating in a boat on water that stretched as far as the eye could see. What about the other interpretation – that the waters covered the whole planet?

       The Bible text presents a serious problem with the idea that the whole planet was flooded: the olive leaf brought by the dove. In the timetable of the text, the peaks of the mountains appeared only seven weeks before the leaf was found (Gen 8:5-11). This means there was a very short period for a tree that had been drowned for seven months to rejuvenate and sprout new leaves. Actually, the time available is much less, because olive trees don’t grow above 1,000 meters,6 and the highest peak of the Ararat mountains is 5,140 meters, and the next is about 4,000 meters. Therefore, the water had to drop 3.000 meters (over two miles) after “the tops of the mountains became visible” (v. 5) before the olive trees would have been uncovered.

       The Jewish rabbis, who took the Bible text very seriously, found a way to interpret the text so that the flood could cover the whole world and leave a healthy olive tree to provide this leaf. They reasoned that the Lord loved the land of Israel, so he would protect it from flooding.7 Therefore the dove must have flown to the Mount of Olives and returned with a fresh leaf – a round trip of about two thousand miles. Protecting Israel from floodwaters would, of course, require a wall as tall as Everest around the whole country, but once this is granted, it is possible to reconcile the Bible text with the idea of a worldwide flood.

Literal meaning

Therefore, while it is possible to conclude that the Bible text refers to a flood covering the whole planet, the text actually implies a flood that covered the land in which Noah was living. Reading the text as actually found in the Bible suggests that waters covered all the “hills” in the “land.” The civilization of Noah’s day occupied the huge, low-lying Tigris-Euphrates plain. The text implies that the ark was blown by “a strong wind” until the two “mountain tops” of Ararat became visible. When the dove was released, it reached the higher land that had not been flooded, where living trees were still growing. When the floodwaters retreated, Noah was able to let out the animals and restart farming.

       The ark was needed to save not only Noah and his family but also the animals. They represented the most valuable products of that civilization, which had grown large and prosperous because the people had learned to farm crops and livestock. It took many generations to breed docile cattle from huge and dangerous wild bovines such as aurochs. We take farm animals for granted, but none of them were found in the wild – they all had to be bred by early farmers. The land also needed other animals and birds to provide a fully functioning ecology. Some of these wild species might have recolonized from surrounding areas, but the natural barriers of desert and mountains would have made this a slow process, so Noah was told to take some of these species too. But he only needed the local species – not everything in the whole world. And he didn’t need to take fish, which would come back into the area via the rivers when the flood ended.

       This is the story we find by a literal reading of the Genesis narrative. It describes an extraordinary event: Noah would have needed miraculous help from God to know that he should build an ark, and perhaps to get the wild animals into the ark. But the account in the Bible text itself doesn’t tell us that the water covered the whole planet, so there is no major conflict with what we have learned from science.


• The Hebrew is ambiguous about whether the flood covered every “mountain”/“hill” in the “earth”/“land” from “under all heaven”/“horizon to horizon.”
• The phrase “there was water over all the surface of the earth/land” was still true forty days after the “tops of the mountains became visible” (Gen 8:5-9).
• Details of the story concerning the birds and the olive leaf do not make sense if the flood was global.
• Archaeology shows evidence of a flood that covered the whole country of Mesopotamia.
• Proposal: The flood drowned the civilization occupying the 140,000-square-mile Mesopotamian plain. Noah’s ark was blown toward the Ararat mountains.

1^ See defenses of the global flood position at Answers in Genesis, “Noah’s Ark” (here) and “Chalk and ‘Upper Cretaceous’ Deposits Are Part of the Noachian Flood” (here). And see the practical problems with this listed by Mark Isaak, “Problems with a Global Flood,” The Talk Origins Archive ( Also see chap. 9, “Everyone Believes in Evolution.”
2^ See Wikipedia, “Horizon” (
3^ See “Tigris and Euphrates Floods,” Global Security (
4^ See Wikipedia, “Mount Ararat” (here) and “Little Ararat” (
5^ See Wikipedia, “Homing Pigeon” (
6^ See Mariela Torres et al., “Olive Cultivation in the Southern Hemisphere,” Frontiers in Plant Science 8 (October 2017) (
7^ See Genesis Rabbah 33:5-6 at Visual Midrash, “Noah and the Flood” (

This was previously published in a similar form in Christianity magazine

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