To be fair, in pretty much every religion and even in history, there are stories about a “great flood.” The stories might differ a bit, where some claim the whole world flooded while others claim a specific region did. It is really all in what you want to believe. But let’s go with the Christian version, involving Noah, his great ark, and the flood of 40 days and 40 nights. If this happened, some great event would need to cause it as this is a flood of the entire world. Let’s say two large meteors broke through and landed in the ocean, coming with their own water. They also land in both artic areas and melt all the ice.
This would likely result in flooding, but it would first start tidal waves that will drastically hurt cities near shores worldwide. They’d completely flood and we’d likely see all land underwater for a short time. Water would go down a bit, but we could assume in the U.S. that both the East and West coasts would be completely underwater. The water might begin to freeze up again one day, allowing these shoreline cities and states to rise back up. But not for a while. Major electrical grids, oil lines, and much more would be hit hard. Many plants and animals would be hit hard and we’d be in an extinction-level event.
Funny enough, asteroids have hit the Earth before and did nothing worth note. But much larger ones caused mass extinctions in world history. Such as the one that caused the Ice Age to take place. This asteroid was quite large, but an asteroid does not necessarily need to be massive to cause damage. If an asteroid the size of the average New York apartment hits the Earth, it could level a small city. That is because it would likely hit with a great deal of speed. If it landed in the middle of a city, this speed would cause an impact that would increase its damage potential. Let’s look at it in terms of a quarter.
The coin falls and hits the Earth, it would likely be felt but not much. Damage potential would maybe be about 5 to 10 feet max. Now let’s combine two quarters, the damage potential would be 20 to 40 feet. Keep combining and you’ll see a huge issue. The size combines with speed to create damage potential even greater than the size. Extinction level asteroids hit and blocked out sunlight for quite some time, due to dust and smoke rising. This caused global temperatures to drop, because sunlight could not pierce through. We now have some protectors from these asteroids but none of them are guaranteed to work.
Where do we find this stuff? Here are our sources: