The Tongue of the Sinai Peninsula

How did they do that? The Sinai Peninsula is described as a tongue in the Book of Jubilees. They couldn't have known that when the Book of Jubilees was written. Is this evidence of angelic mapping?

"And his portion reaches unto the great sea (Mediterranean Sea), and reaches straight until it approaches the west of the tongue which looks toward the south; for the sea is called the tongue of the Egyptian Sea (Red Sea)." Jubilees 8:12.