The Destruction of Jericho The Bible describes the Exodus as a period of 40 years that began with plagues in Egypt and ended with the destruction of Jericho. Archeologists seeking to establish the exact dates of these events have proposed that the plagues coincided with a huge eruption of the volcano Thera in the Aegean Sea Radiocarbon dating of blackened grains from the site of ancient Jericho provides a date of 1315 BC +/- 13 years for the fall of the city. What is the relative amount of 14C in the old grain vs. the new grain in 2007 AD (At/Ao)2007 AD =?