Other than saying "Huh"! it is hard to do with someone who bases their knowledge of the universe on a required literal reading of a cobbled together book from several thousand years ago.
there is no evidence of a world wide flood just a few thousand years ago. The evidence simply does not comport with a literal reading of Genesis for the history of the earth.
Contra, Jonah, it is all over the place. We are probably having some confusion of definition. The ancient world, including some New Testament writers referring back to it called it the 'cataclysm' which is ancient Greek spelled the same (ks for the cs). This was not a high water mark of a predictable 1000 year possibility; it was the complete change of the surface and atmosphere as we know it. We are not talking about 'rain' as we know it.
If it resembles anything today, it would be
like the ongoing eruption cycle of Iceland. Or
like the breaking out of Lake Missoula. Yosemite would have formed in mere hours. It would be vertical tectonic changes as well as some horizontal. It would be the end of one atmosphere and the beginning of another. It would be a period of unsettled weather for several years, including such bizarre events as the 'loess' (blowing sand and snow) that trapped the thousands of Siberian mammoths, all oriented in the same direction, often found standing, eating, etc.
European sediment is found in the New England area, New England sediment is found in the Grand Canyon, and the 'Centralia theory' of Australia says that the entire center deposit happened rapidly and bent the chunk of layer known as Ayers Rock, forcing up the exposure we see today, the closeup view of which reveals that it is not ancient. What kind of hydrology does that?
As for ancient accounts, Hyppolytus wrote that the cataclysm (the same term shared by the New Testament) was a volatile volcanic disruption of the surface with water gushing from
below the surface. Nearly exactly how Genesis actually describes it. We now know, fyi, that there is still an entire ocean of saltwater under China. There are some 500 indigenous accounts, many with 'unnecessary' details, like that of CoxCox among the Mayans. Btw, they have rather exact dates for the period from creation to the cataclysm. In S. Africa, the highest known vertical 'slip' is some 10,000 feet and nearby are chunks of layered rock on their sides, intact. Several hundred yards in dimensions. It happened quickly and recently. Things that have been there millions of years do not look that way.
What does modern science ask us to do? To believe that the hundreds of yards of piled dinosaurs in Alberta happened because one tripped and drowned, the next tripped on him etc., like Laurel and Hardy. It says so on the reader board at the site. Nevermind that as soon as one beast goes down, there are 10 who want dinner nearby, and there is no sign of such dismemberment, just opisthotonics.
