Q: If climbers need oxygen tanks to climb Mount Everest, how was Noah able to breathe if his ark floated above the highest mountains?
A: There are a number of aspects that need to be considered. First, at the time of the Flood, mountains like Mount Everest were not necessarily the height they are now. In fact, the earth’s highest mountains, have fossils of sea creatures at their tops, showing they were once under the sea. Either the sea rose to cover the mountains, or the mountains were once under the sea and have risen out of the sea – or both things occurred.
Second, measurements indicate that Mount Everest is currently rising at six inches per year. This movement was probably much greater in the past – particularly at the end of the flood.
Third, as the water rose during the Flood, the atmosphere would have risen as well. The difference in pressure for Noah’s family would have been equivalent to standing on top of a 100 foot-high building.
Skeptics try to discredit Noah’s Flood, So, it’s important to know how to defend its record in Genesis. —Answers Update
Glad Tidings of Good Things, Vol. 14, Mar. 20, 2008, page 3