Why don’t we have “megafloods” today?
global warming...
Most of the world’s large rivers have dams limiting flow into stages. They will slow down the release following a huge storm moving through.
No melting ice sheets to create massive ice dams holding back massive lakes.
Wait until after the next ice age, when the ice dams start to melt and then break, releasing the huge amount of water they held back. While you’re waiting, check your homeowner’s insurance for appropriate megaflood coverage.
Oh... and according to some geologists, you might want to check your home coverage for supervolcanos, like the one under Yellowstone National Park, which is due to blow in the next few millennia, taking out most of the U.S. Of course, being under a kilometer or so of solidified lava might affect your resale value.
“Why don’t we have megafloods today?”
Answer: For events occurring on geologic timescales (i.e. in every hundred thousand years or more) we have not experienced it yet in recorded history (which is only ~ 5-7,000 years) but we have proof that these things happen.
That does NOT mean it can’t / won’t happen.
How then did a global flood occur (which would be much bigger?)
A popular postulate is that in the ancient times, the earth’s barometric pressure was 2, or 3 times what we have today. As many people know, when our barometric pressure drops a few inches we get heavy rainstorms as H20 is forced out of suspension in the atmosphere. Imagine that time 1,000. And earthquakes breaking open underground rivers. That’s what the biblical account says occurred.
There is tremendous evidence for a world-wide flood, as improbable as it sounds. BTW, with higher barometric pressure, the ancient huge flying dinosaurs that are too heavy to fly today could easily get enough lift....
As I understand it, their origin was water building up under the ice sheets during the Ice Ages.
I saw a documentary that theorised that a huge glacial ice dam busted and created the Grand Canyon.