It wasn’t just rain. Underground water was released as well:
“all the springs of the great deep burst forth”
In other words, a lot of water previously contained beneath the ground and/or the sea was released. I wonder if the world wasn’t a lot flatter prior to The Flood? Perhaps the bursting open of underground springs resulted in shifting land masses on a massive scale. The top of Mt. Everest is marine limestone. Something to think about.
You are mostly correct. A lot of people (those who believe in Noah's flood) believe that it was just 40 days and 40 nights of rain that flooded the Earth. As a meteorologist (and a preacher), I feel very certain that is not the case. Even in the moistest of climates, the precipitable water of an environment would not be enough to give you more than 150 feet of rain over a very localized area...much less over the entire globe. If the entire atmosphere was saturated and the precipitable water was off the chart...I doubt you could get 2 feet of total rain over the entire globe.
BUT...the key lies in the "springs of the deep were BROKEN up." This word doesn't necessitate a spring as we think of it...it can mean just a source of water. So, here is what I think happened:
One of the flaws in the thinking is that the antediluvian world looked like the world does now. We are under this misguided notion that Mt Everest as 29,000 feet high. That the Mt’s of Ararat were 17K feet high. I propose they were not…and we know this because of Peleg: “In HIS days the Earth was divided.” This is how God separated mankind…and the continents. The Bible teaches that the Earth used to be all one landmass and in the life of Peleg, He divided it (Gen 10:25; 1 Chron 1:19).
When the Japanese tsunami happened, I just happened to be reading through Psalms. I heard on the news how the tsunami covered parts of Japan and breached their protective walls…even though they were high enough. They breached them because the EARTH lowered. Then I read Pslams 104. So I started to wonder: What if the “fountains of the deep being broken up” was actually some sort of tsunami action caused by the land beneath the sea heaving upwards and the dry ground subsiding all at once? Combine that with the rain…and you have a world wide flood. Add to that the splitting of the earth and the separation of continents in Peleg’s life, and you have fish fossils in Wyoming.
Psalms 104:6 – “Thou coveredst it with the deep as with a garment: the waters stood above the mountains.” – God could have brought up water from the deep…as in the sea…and covered the mountains with tectonic action. We saw just a hint of it last March.