In Noah's Ark myth God sent 40 days of rain to flood the Earth. Are any such long periods of persistent rain recorded? What kind of disaster could happen to cover all continents with water?

  • 1
    Or at least one whole continent?
    – Egle
    Mar 24 '11 at 16:24
  • 3
    I suggest changing the title to "Could a Great Flood of happened?", flood myths are common among many religions. Mar 24 '11 at 16:27
  • 5
    @rjstelling: for example there is an earlier myth in the Saga of Gilgameš
    – Sklivvz
    Mar 24 '11 at 16:44
  • 3
    To be more precise, is this question trying to ask, "Supposing an actual supernatural Great Flood didn't occur, could a similar naturally occurring world-covering flood have occurred?" Otherwise, the question boils down to "Are miracles possible?" Apr 13 '14 at 22:17
  • 1
    I know this is old, but I'm voting to close as too broad. So called "Flood geology" is a vast swath of claims posing as science. "Did the Great Flood happen?" doesn't give an opportunity to actually prove or disprove anything that will convince anybody. But claims like " [there are] several oceans’ worth of water locked up in mantle rocks and minerals" (source) are quite answerable.
    – fredsbend
    Dec 28 '18 at 19:26

The talk.origins archive documents an extensive list of claims about the flood. It also includes sections discussing the Ark and the various problems that aspect of story has. There's also a separate article dedicated to the flood.

Are any such long periods of persistent rain recorded?

I don't know about persistent rain, but Seattle has had 30 days of measurable rainfall twice in the past 60 years. It isn't unreasonable to believe that other locations could have had a longer, more aggressive chain of storms, and it's also not unreasonable to expect that there'd be problems with local waterways flooding as a result.

What kind of disaster could happen to cover all continents with water?

There are a few frequently suggested sources of the water. They all fail simple tests. If there was supernatural involvement, we'd also expect to see global evidence of a great flood, but this is absent.

The most logical explanation given the lack of evidence is that the story is mythical.

As @Sklivvz posted in the comments the flood story probably originates from part of the Epic of Gilgamesh which follows the same general plot. The resident deity is upset with humanity and selects one righteous man to be saved. Instructions are given to build a large boat to save all of the animals and the man's family. It rained, though only for six days. Birds are sent out, one doesn't come back, a mountain is found, a sacrifice is made, the resident deity is pleased / remorseful and promises not to do that again.

The talk.origins site hasn't been updated in a while. There was some evidence uncovered somewhat recently that suggested that the myth may have originated when the Black Sea grew rapidly after an influx of water from the Mediterranean in ~5600 BCE. In 2009, National Geographic published a follow-up that suggested the growth in the Black Sea was not as catastrophic as first thought, and might not really be the origin of the myth.

  • 11
    The Gilgamesh myth is probably the most well known origin of the biblical myth. One "CYA" attempt by bible literalists is to point out that nearly all mythologies have a flood myth or story of one sort or another. The fact that most human cultures live near seas, rivers, and other bodies of water seems to escape them... Mar 25 '11 at 1:38
  • Yep. Arizona and Colorado flood a lot.
    – mmyers
    Mar 25 '11 at 13:32
  • 4
    I should have said "traditionally". And if you look at those two locations, there are actually quite a few flash floods. Having lived in both locations, those things are not to be laughed at. Mar 25 '11 at 14:13
  • 2
    Just a note: 40 days and 40 nights is an idiom. It means "a long time". Aug 10 '13 at 20:13
  • 3
    @Himarm Floods happen "all the time", and if your worldview tells you that all the places you've ever been are all there is to the world, then a local disastrous flood can seem tremendous. Check out what's happened in the past week in Texas and Oklahoma, for example. There are similar local flood stories in other cultures as well, including a bunch from China. None of these tales match up well enough with the Great Flood mythology or from the likely origin of it in Gilgamesh to act as supporting evidence.
    – Charles
    Jun 3 '15 at 21:25

Given the time this was written, how would anyone know that all the continents were flooded? Let's just assume that the World was flooded, and that the World was considerably smaller. Horizon-to-horizon flooding happens, and if that's all you can see, that means the whole World's flooded.

Although unrelated, the same applies to pairs of "every single animal". This could well be just goats, sheep, chickens and dogs.


A point often missed about the Noah myth is that it doesn't claim the flooding was all due to rain. It says "the fountains of the deep were opened". Still, this CYA attempt fails, because there isn't enough water on the planet to cover all the land. Even if all the ice on the South Pole melted it would only raise sea level about 60 meters (200 feet).

  • 8
    And for a people that survive by trade over seas, even a fraction of that 200 feet would mean the utter removal of their entire world. A reasonable thing for some lone primitive family that survived a truly great flood, would be to say it covered the world.
    – DampeS8N
    Mar 24 '11 at 17:54
  • 7
    "There isn't enough water on the planet to cover all the land" -- Sure there is. It only depends on how high the continents are at the time, and we already know that e.g. Mount Everest was once part of an ocean floor.
    – mmyers
    Mar 24 '11 at 19:11
  • 3
    @mmyers, the reason that the Himalayans were part of the ocean floor is because of plate tectonics. NOW there is no way that all the water on the planet could flood even a modest mountain. Mar 25 '11 at 14:14
  • 10
    The difference between today and the time the Noah myth supposedly happened is, in geological terms, negligible. So Noah still counts as "now".
    – clgood
    Mar 30 '11 at 22:34
  • 3
    @mmyers so you're saying that at some point in the past all the earth was flat land, with no geological features taller than maybe a decent sized molehill? And that that happened during a time when humans lived on the earth (and remember, biblical tradition has that time set as a few thousand years, not billions)?
    – jwenting
    Sep 14 '13 at 11:57

I observe 4 questions here:

  • Could a Great Flood have happened?
  • Are 40-day-periods of rain recorded?
  • What kind of disaster could happen to cover all continents with water?
  • Can the Noah's Ark myth be correct? (implicit)


  1. The smaller your universe is, the bigger a flood is. If you don't know that Africa, Europe, Asia, America and Antarctic exist, it's impossible to know that the whole earth is covered.
  2. I'm sure so; see Charles about Seattle. Investigate weather stations in regions of rain periods.
  3. To cover Himalaya, Alpen, Anden, Appalachen, Rocky Mountains and so on: Not enogh water. But from rain apart, tsunamis, smelting ice, river outbreaks (rain elsewhere) cause dramatique floods.
  4. If you know 500 species, most of them small, you can imagine them to fit into a big ship. Today, we know how many different animals there are, and that you need much bigger groups, to have enough genetic diversity to let one survive. But of cause predators need other animals as meal as well. To put all of them, and enough food on a ship, the ship would need to be multiple times the size of the Maracana stadium. So it's just a story.
  • 1 and 3 are kind of same thing. And I never asked 4. Used Noah's Ark just as example (and as answers show - not best one). Other than that - good answer :)
    – Egle
    Mar 25 '11 at 7:54
  • Shouldn't Great Flood, with capitals, be spelled great flood then? I'm sorry - while in many aspects my own English is pretty poor, I allow myself to give hints ... . Mar 25 '11 at 8:04
  • I noted the same thing: many questions, of which #2 seems quite unrelated to others IMO. Mar 25 '11 at 9:31
  • 3 is bogus, a tsunami moves water around, meaning somewhere else sea levels drop (and also, its effect is temporary, measured in minutes or at most hours. Noah's flood is supposed to have lasted a long time).
    – jwenting
    Sep 14 '13 at 11:54
  • 2
    So this question was marked as needing citation, but in an unspecific way. What information needs citation? The Mt. Everest is more than 8800 m high. That's common knowledge. That jewish people in the area of todays Israel where not well educated about the size of the earth and existing continents, does that need citation? Childish questions can't be answered with everyones knowledge? Be specific! And don't introduce such requirements over 3 years later. Feb 11 '17 at 18:38

It seems likely that there was a flooding event of some sort which contributed to this legend. Probably the best candidate is the "Black Sea deluge", an event that is believed to have occurred around 5600BC.

What supposedly happened is that the Mediterranean Sea broke through the Strait of Bosporus and flooded the Black Sea (which was, prior to this, much lower than it is now).

The sea, though low, was still quite large, and it's not implausible that there were farmers along its shore who had fairly large boats. Some of these could well have seen the waters rising and herded numbers of their livestock onto their boats to escape the flood.

Note, though, that this theory has numerous critics, and definitive proof is lacking.

  • Floods are the most common natural disaster, thus, "some non global flood created the myth" is a common skeptical reply. What's missing in this answer is that explanation. Without already knowing it, one might reply that this Black Sea flood was surely not global.
    – fredsbend
    Oct 1 '20 at 15:04
  • Certainly to nearby observers it would have seemed that the flooding "covered all the earth". And the water level would have remained high essentially forever, distinguishing this event from a simple rainfall flood event. Oct 1 '20 at 17:10
  • -1 because the OP doesn't ask for an explanation of the origin of the biblical story, but instead quite explicitly asks three different questions: (1) Are 40 days of rain plausible? (2) Can a flood cover continents? (3) Is an event like the biblical flood at least theoretically possible (this is asked in the title)? None of these questions are addressed here.
    – Schmuddi
    Oct 1 '20 at 19:43
  • @Schmuddi: If this question, asked in the first couple of months on the site, was asked again today, it would be closed because of the strawman (Believers: "God made it miraculously flood." Naturalists: "Models in Hydrology say that's not possible." Believers: "That's right. God miraculously did the impossible.") Answering it would not distinguish between either of the competing hypotheses.
    – Oddthinking
    Oct 2 '20 at 2:16
  • It is too few characters for a suggested edit, but you have misspelled Bosphorus.
    – phoog
    Oct 2 '20 at 3:42

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