# How heavy would it have to rain to flood the Earth in 40 days? **URL:** \ **Category:** Factual Questions\ **Created:** [May 25, 2019, 6:24am UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494 "2019-05-25T06:24:19Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 26, 2019, 6:17pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/61 "2019-05-26T18:17:10Z")
> [@kaylasdad99](#): > > o\_o > > \>\_\< > > o\_O > > Oh dear. [How soon you forget](https://boards.straightdope.com/sdmb/showthread.php?t=844998)… ---
**Author:** ![Biffster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/biffster/32/339_2.png) [@Biffster](https://boards.straightdope.com/u/Biffster)\ **Post date:** [May 26, 2019, 6:32pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/62 "2019-05-26T18:32:15Z")
And in related news, is it likely anyone with an ark might have been prepared for that much rain? [![](https://uploads.tapatalk-cdn.com/20190526/23eee8e03c6617118755023847fb4418.jpg) ](https://uploads.tapatalk-cdn.com/20190526/23eee8e03c6617118755023847fb4418.jpg) [Noah’s Ark theme park damaged by heavy rain ... and the lawyers come two-by-two | The Province](https://theprovince.com/news/world/noahs-ark-theme-park-damaged-by-heavy-rain-and-the-lawyers-come-two-by-two/wcm/4004233e-41bd-489e-b9ed-213dad54c136) ---
**Author:** ![Folacin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/folacin/32/3195_2.png) [@Folacin](https://boards.straightdope.com/u/Folacin)\ **Post date:** [May 27, 2019, 5:32pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/63 "2019-05-27T17:32:57Z")
> [@TokyoBayer](#): > > Mt. Everest is 29,029 ft. Divide that by 40 days, 24 hours per day and 60 minute per hour. I get 6” of rain per minute. > > A quick google search shows the record rainfall in one minute is 1.22”. Assuming it is all water from above (none of Kanicbird’s Biblical fountains) - could a wooden boat survive 40 days of that pounding? Heck, could a steel boat? I think I’d want a submarine. ---
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [May 27, 2019, 6:21pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/64 "2019-05-27T18:21:12Z")
> [@Riemann](#): > > Of course, volumes may have been measured in square inches at the time the earth actually flooded. There’s just no way to know. If we’re measuring depths in cubits, I don’t see why we can’t measure volumes in squarits. ---
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [May 27, 2019, 6:31pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/65 "2019-05-27T18:31:05Z")
> [@Czarcasm](#): > > Is there space between the raindrops at that rate? If there weren’t, the Earth would be flooded instantly. Rain with no space between the drops is called an ocean. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [May 27, 2019, 6:45pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/66 "2019-05-27T18:45:05Z")
So yeah, the op is being a bit coy. Obviously he is trying to prove the Biblical flood could not have happened. However, he is quite wrong. Let’s look at it from two ways- the mythical and the rational; Mythical. If we postulate a Supernatural or super-scientific being capable of creating a whole planet in a couple of days, said being would have no problem with creating enough water to flood the earth. And of course the water came up, as well as down, the the rain might not even be that heavy. Rational: What is a “world”? We say today “rock my world” “He meant the world to me” and other such phrases when you mean less the the entirety of the planet Earth. The Tigris Euphrates plain had several great floods in Biblical times, floods so great they flooded those peoples entire known world\*. Not to mention, there has been theorized a vast flood in the Black Sea area [Evidence Noah's Biblical Flood Happened, Says Robert Ballard - ABC News](https://abcnews.go.com/Technology/evidence-suggests-biblical-great-flood-noahs-time-happened/story?id=17884533) where the locals certainly would have thought their whole world had flooded. Of course it’s just not the Bible that contains the flood myth, the Epic of Gilgamesh also contains a similar tale, and there are others. So, yes, the Genesis flood is a\* myth\* built upon a _legend_ of a vast flood, a flood so big that it became a myth or legend in several narratives. - [https://ncse.com/library-resource/yes-noahs-flood-may-have-happened-not-over-whole-earth](https://ncse.com/library-resource/yes-noahs-flood-may-have-happened-not-over-whole-earth) _Conclusions If the 3.4-meter–thick layer of flood deposits in southeastern Mesopotamia (MacDonald 1988) represents a huge flood of ancient times, and if it is the remnants of the one described in the early Babylonian epics, then the authors of these epics were likely survivors who lived in a village on natural levees on the lower parts of either the Euphrates or Tigris Rivers where the flood waters covered their village, natural levees, and adjacent flood plains for distances of 160 to 320 kilometers so that no land could be seen, and their “whole world” would have been under water._ ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [May 27, 2019, 10:12pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/67 "2019-05-27T22:12:51Z")
Suppose “somehow” all the water in the ocean basins- Pacific, Atlantic, Indian, Arctic, etc.- was splashed up onto the continents. I presume the total volume of water would be sufficient to inundate them, and the rain could simply be ocean water coming down after being hurled into the atmosphere. How long would it take to flow back into the ocean basins? (Although in that case I doubt there’d be any continents left, given that the mere drainage of [Glacial Lake Missoula - Wikipedia](https://en.wikipedia.org/wiki/Lake_Missoula) created the [Channeled Scablands - Wikipedia](https://en.wikipedia.org/wiki/Channeled_Scablands)) P.S. ask a biblical literalist if the Flood erased the Garden of Eden or not. 😃 ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [May 27, 2019, 10:16pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/68 "2019-05-27T22:16:52Z")
> [@DrDeth](#): > > Obviously he is trying to prove the Biblical flood could not have happened. > > However, he is quite wrong… > > So, yes, the Genesis flood is a\* myth\* built upon a _legend_ of a vast flood, a flood so big that it became a myth or legend in several narratives. You say it’s a myth - that some substantial regional event may have occurred, but not literally as the biblical account describes. Then how is the OP “quite wrong” to have said exactly the same thing? All I can make of this it that you’re suggesting that OP is attacking a straw man, that nobody takes the biblical account seriously, that _obviously_ it’s a myth rather than a truth claim? ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [May 27, 2019, 10:38pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/69 "2019-05-27T22:38:55Z")
> [@kaylasdad99](#): > > o\_o > > \>\_\< > > o\_O > > Oh dear. > [@Darren\_Garrison](#): > > [How soon you forget](https://boards.straightdope.com/sdmb/showthread.php?t=844998)… On the one hand, your point is well-taken. OTOH, a year and a half (give or take) doesn’t strike me as all that soon. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [May 27, 2019, 11:17pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/70 "2019-05-27T23:17:35Z")
> [@Riemann](#): > > You say it’s a myth - that some substantial regional event may have occurred, but not literally as the biblical account describes. Then how is the OP “quite wrong” to have said exactly the same thing? > > All I can make of this it that you’re suggesting that OP is attacking a straw man, that nobody takes the biblical account seriously, that _obviously_ it’s a myth rather than a truth claim? He didnt say anything of the sort. he was “just asking questions”:rolleyes: Yes, that is exactly it. ---
**Author:** ![MarvinKitFox](https://avatars.discourse-cdn.com/v4/letter/m/7ba0ec/32.png) [@MarvinKitFox](https://boards.straightdope.com/u/MarvinKitFox)\ **Post date:** [May 28, 2019, 6:49am UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/71 "2019-05-28T06:49:04Z")
> [@panache45](#): > > And what the hell kind of clouds could supply the planet with that much rain? You mean, What the HEAVEN kind of clouds… The source of the rain was explicitly stated, you know. As for OP’s question about boiling temperatures: No. With the global sealevel raised 29000 feet, the atmosphere is just “shoved” up by the same amount. Air pressure would be very very very nearly the same. The changes in earth mass, sealevel distance from center of mass, scale height of atmosphere, volume of atmosphere would all change, but by **so** small fractions that the difference slip between the cracks in this, admittedly, very cracked scenario. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 28, 2019, 12:59pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/72 "2019-05-28T12:59:56Z")
Air pressure after the rain, once everything has had a chance to get back into equilibrium, will be very very very nearly the same. But air pressure _during_ the rain will be higher. ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [May 28, 2019, 1:06pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/73 "2019-05-28T13:06:00Z")
[\*\*A Great Article on the Subject \*\*](https://medium.com/@AndrewLSeidel/how-much-water-would-be-needed-for-noahs-flood-ef3145ae1945) > [@](#): > > The volume of a sphere is easy to calculate: V = 4/3πr³ > > The earth has a radius of 3959 miles. Now we need to know the radius of the flood. That’s the earth radius, plus the height of Everest, plus 15 cubits (22ft). So 3959 miles + 29,028 ft +22 feet = 3959 miles + 29050 feet = 3959 miles + 5.5018939 miles = 3964.5018939 miles > > If we plug those two radii in to our volume formula, we get the volumes: > > 259,923,241,564 miles³ for the volume of the earth. > > 261,008,408,332 miles³ for the volume of the earth at flood. > > So, if we subtract the earth volume from the flood volume, we’ll get the volume of water required to fill that space. That’s how much it would need to rain. That turns out to be 1,085,166,768 miles³of rain. I think we’re talking inches per second here. :eek: ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [May 28, 2019, 1:08pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/74 "2019-05-28T13:08:55Z")
> [@panache45](#): > > And what the hell kind of clouds could supply the planet with that much rain? Never been to Wales, have you? ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [May 28, 2019, 2:39pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/75 "2019-05-28T14:39:24Z")
> [@Jasmine](#): > > [\*\*A Great Article on the Subject \*\*](https://medium.com/@AndrewLSeidel/how-much-water-would-be-needed-for-noahs-flood-ef3145ae1945) > > I think we’re talking inches per second here. :eek: No, that’s a terrible article. Try reading this thread. It’s a hallmark of bad estimation to use a wildly inappropriate number of significant figures to make a calculation seem impressive (Mr Spock, I’m looking at you). In fact, as noted by TokyoBayer at post #6, it’s a trivial matter to calculate the required rainfall rate without volume calculations. It is **6" per minute**. The writer of that article pulls a figure of 25% out of his backside to adjust for the volume of land. This is wrong by an order of magnitude. See post #42 - a quick estimate using an average elevation figure that took me just a couple of minutes to find on Wikipedia shows that the volume of land requires an adjustment of only ~3%. ---
**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\ **Post date:** [May 28, 2019, 3:42pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/76 "2019-05-28T15:42:50Z")
As far as using sea level as a starting point for calculations, what about the grand canyon? Is that below sea level? If so, it’ll need to be filled, too. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [May 28, 2019, 3:45pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/77 "2019-05-28T15:45:44Z")
> [@bobot](#): > > As far as using sea level as a starting point for calculations, what about the grand canyon? Is that below sea level? If so, it’ll need to be filled, too. The bottom of the Grand Canyon is above sea level (it has the Colorado River in it, which flows downhill to the sea - or nearly to the sea, these days). There are quite a few areas of land that are below sea level around the world, but none of them are especially big or all that deep, so they won’t make too much difference to the calculations. (And in fact they are presumably taken into account in the figures for average land elevation already.) ---
**Author:** ![Cheesesteak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cheesesteak/32/3694_2.png) [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)\ **Post date:** [May 28, 2019, 3:47pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/78 "2019-05-28T15:47:27Z")
> [@TokyoBayer](#): > > I get 6” of rain per minute. I’d keep playing. I don’t think the heavy stuff will come down for quite a while. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [May 28, 2019, 4:05pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/79 "2019-05-28T16:05:57Z")
> [@bobot](#): > > As far as using sea level as a starting point for calculations, what about the grand canyon? Is that below sea level? If so, it’ll need to be filled, too. Well you’d have to fill it up whatever the elevation, right? But the order of magnitude of the size of the Grand Canyon is 10 miles wide, a mile deep, 100 miles long, so ~10^3 cubic miles. Whereas the area of earth is ~200 million square miles, and Everest is ~5 miles high, so we’re considering filling a volume of ~10^9 cubic miles, or a million Grand Canyons. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [May 28, 2019, 5:10pm UTC](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494/80 "2019-05-28T17:10:32Z")
One thing to note is that the Earth is smoother than a billiard ball. Minor variations like most mountain ranges, Death Valley, the Dead Sea, etc. are low order noise in the calculation. (And ~3/4 of the Earth is about sea level anyway.) The only point that matters is the top of Everest (plus 15 cubits). Claiming that Everest wasn’t nearly as tall then as now requires an explanation for all the energy required to raise it to it’s current height within a _very_ short period of time, geologically speaking. The heat produced would have been amazing. All this flood stuff requires a huge amount of water magically coming from someplace, magically going to someplace and all magically not killing off either all the salt water fish or all the fresh water fish. And several zillion other magically’s. [Previous page](https://boards.straightdope.com/t/how-heavy-would-it-have-to-rain-to-flood-the-earth-in-40-days/834494.md?page=3)