You had more then this and I had to cut some to shorten my post.
You have done your homework.
In their catastrophic plate tectonics model for the Flood, Austin et al. have proposed that at the onset of the Flood, the ocean floor rapidly lifted up to 2,000 metres (6,500 feet) due to an increase in temperature as horizontal movement of the tectonic plates accelerated. This would spill the seawater onto the land and cause massive floodingperhaps what is aptly described as the breaking up of the fountains of the great deep.
I can give my opinion instead of a theory in that I have no calculations to give on this subject.
I agree with most of what you have said except the fountains were lava volcanoes.
The tendency is to assume the water level must rise as in your reference to Austin. This is based on an incorrect assumption that the continents and the ocean floor are fixed which is not the case. If water was added the continents would float like an ice cube in a glass. There is no amount of water you could add to make the ice cube sink.
The question that you need to ask is what is the buoyancy of a vertical column through a continent and what is the buoyancy of a vertical column through the ocean? Both columns include a portion of the mantel layer in which they float.
The two columns contain a weight which is almost equal when the entire columns are considered even though the tip of the continent which is above seal level seems large to us. If for some reason the column through a continent became heaver then a column through the ocean the continents would sink until submerged. Water need not be added to make this occur.
The ocean bottom is now broken allowing an average thickness of 400 foot of lava to be ejected into seawater. This kind of event causes Pumice which is lava which has cooled quickly after a reduction in pressure. Gases expand in the lava which cause bubbles in the rock formed. Before the bubbles can escape the rock hardens containing the gas bubbles. The rocks have a specific gravity of about 0.6 which means they float having a lower specific gravity then water. One cubic foot of lava will cause five cubic foot of Pumice because Pumice is mostly hollow.
When the Pumice forms it will float to the oceans surface unless there are strong vertical upwards and downward currents or it is attached to the ocean floor.
When the Pumice reaches the surface wave motion will quickly grind the Pumice against itself into a fine silt which will fall to the ocean floor.
Huge pumice 'island' floating in Pacific - Technology & science - Science - LiveScience | NBC News
Note that the ocean floor has not been elevated.
Our 400 of lava has caused a 2,000 elevation in sea level but all of the water column will not remain over the ocean but will flood the continental areas.
Now we will consider the buoyancy of the continent and the ocean columns.
While this event is occurring the ocean is a mixture of Pumice and water which has a decreased density. The ocean column has also lost the weight of hundreds of foot of water.
The continent has taken on the additional weight of a water column above most of the continental areas, rain will only increase the weight of the continents as any dip in the landscape will collect water and saturate ground areas however I do not think this is a major contributor to the buoyancy shift.
In short the continents have become heaver and the oceans have become lighter. When the continents begin to sink magma is forced ejected from the ocean floor causing more Pumice. Eventually the decrease in the mantle portion of the continent column will cause a new balance point because the mantle is composed of very dense material. Once the ocean floor is sealed Pumice will float to the surface, grind itself into a powder and settle to the bottom of the ocean. Which is what we find today however some areas are thick and others are not indicating the condition was uneven over the ocean floors.
ocean basin (Earth feature) : Deep-sea sediments -- Britannica Online Encyclopedia
The ocean water has now returned to its original density which means the continents have a lighter buoyancy column then the ocean does. The continents must rise from the ocean. This process may take some time however. The continents will have many inland lakes captured during the rise of the continents and the soils are saturated. Plate tectonics will have formed much higher mountains then would have been formed on land due to the added buoyancy provide by submersion in the ocean water. There must be time for water runoff and evaporate from the continents. Glaciers will also affect the new continent elevation equilibrium point.
Genesis 7:12 says that it rained for 40 days and 40 nights
continuously.
There is no indication of the volume of water from the Bible text. That is why the initial calculation was performed.
Genesis 2:5 tells us that there was no rain before man was created. Some have suggested that there was no rainfall anywhere on the Earth until the time of the Flood. However, the Bible does not actually say this, so we should not be dogmatic.
You are correct we do not know if rain occurred from the time Adam left the garden until the flood.
Some have argued that Gods use of the rainbow as the sign of His covenant with Noah (Gen. 9:1217) suggests that there were no rainbows, and therefore no clouds or rain, before the Flood. However, if rainbows (and clouds) existed before the Flood, this would not be the only time God used an existing thing as a special new sign of a covenant (e.g., bread and wine in the Lords Supper).
You need two things to make a rainbow. Rain droplets and direct sunlight are required. I do not think there was direct sunlight before the flood so it would have been impossible to have a rainbow until after the flood regardless of the existence of rain or not. Again my opinion only.
It is difficult to envisage a pre-Flood water cycle without clouds and rain, as the suns heat, even in that era, must have evaporated large volumes of surface waters which would have to have eventually condensed back into liquid water. And droplets of liquid water form clouds from which we get rain.
The pre-flood condition was very different. The landscape was watered by springs. There would be no thunder, lighting or hurricanes. There are a lot of possibilities to ponder but the text is not that specific so we would be guessing.
The expression windows of heaven is used twice in reference to the Flood (Gen. 7:11, 8:2). It is used only three times elsewhere in the Old Testament: in 2 Kings 7:2,19 and in Malachi 3:10. In all three cases, it refers to God intervening in an extraordinary way to pour out blessings on his people. Windows of heaven is not a term applied to ordinary events. Clearly, in Genesis the expression suggests the extraordinary nature of the rainfall attending the Flood. It is not a term applied to ordinary rainfall.
Yes but if they never had it before it would be extraordinary regardless of the amount.
We are told in Genesis 1:68 that on the second day of creation God divided the waters that were on the Earth from the waters that He placed above the Earth when He made a firmament (Hebrew, raqiya, meaning expanse) between those waters. Many have concluded that this expanse was the atmosphere, because God placed the birds in the expanse, suggesting that the expanse includes the atmosphere where the birds fly.This would put these waters above the atmosphere.
Dr Russell Humphreys has argued that since Genesis 1:17 tells us that God put the sun, moon and stars also in the expanse of the heaven then the expanse must at least include interstellar space, and thus the waters above the expanse of Genesis 1:7 would be beyond the stars at the edge of the universe.
You are confused because you are missing the whole point of the creation story.
Notice that the cosmos is called heaven and also call he sky heaven?
Adam is created in the image of God.
So we have a little god and a big God.
We have a little heaven and a big heaven.
We have a little creation ( animals ) and a big creation (angles)
Do you know what a parable is?
Duordi
