Was there a worldwide flood? Genesis 6–9 and the geological record

The passages

And the waters prevailed exceedingly upon the earth; and all the high hills, that were under the whole heaven, were covered.

Genesis 7:19

And all flesh died that moved upon the earth, both of fowl, and of cattle, and of beast, and of every creeping thing that creepeth upon the earth, and every man.

Genesis 7:21

The problem

A flood that covered every mountain would leave a worldwide layer of sediment from a single year. The geological record shows no such layer. It shows many separate environments in many places and times: desert dunes under later rock, ancient coral reefs, layered lake beds with hundreds of thousands of annual layers, ice cores that run unbroken through the supposed flood date. The amount of water needed to cover Everest has no known source. The animals of Australia and the Americas would have had to return across oceans.

Outside the Bible, the Mesopotamian Atrahasis and Gilgamesh epics tell of a flood, a boat, a sending of birds and a sacrifice afterwards. Tablet XI of Gilgamesh in particular has details close to Genesis, and the manuscripts are older.

What believers and scholars say

Flood geology. Morris and Whitcomb in 1961, and organizations since, argue that the geological column was laid down largely by the Flood and its aftermath. Geologists, including many Christian geologists, have written detailed rebuttals on the grounds of sedimentology, heat and the order of the fossils.

A local flood. Many evangelical scholars, including Young and Stearley, accept the geology and read "all the earth" as meaning all the known world, a regional flood in Mesopotamia remembered as universal. Critics note that the Genesis language of covering the mountains and killing every man is hard to square with a local event.

A theological retelling. Wenham and others read Genesis as a Hebrew response to the older Mesopotamian flood myths, keeping the shape but changing the cause. In the older stories the gods flood the earth because humans are noisy. In Genesis it is because of violence, and the story ends in a covenant. On this reading, the text is not a geology report.

Where this leaves it

Few readers dispute that Genesis speaks of a universal flood. The questions are whether the earth shows that it happened, and whether the author meant to claim it. A believer can answer yes, no, or "not in that sense" and still be reading the story in good faith. The geology, as far as it can be read, supports only the second and third.