the numerous, customary regions, the distinctive properties and vegetation found in the various lands and zones, and the different kinds of minerals and commercial goods produced in each quarter.

They said: The earth is covered by the great ocean save for roughly one quarter of its surface—about ninety degrees—and divine providence decreed that the waters withdraw from exactly this amount so that living creatures might inhabit it and crops and fruits might grow there, as the Exalted says:

“He spread out the earth for all creatures;
in it are fruits, and the date-palms with sheathed clusters,
and grain with husk, and fragrant herbs.
So which of your Lord’s favors will you both deny?”
(Q 55:10-13).

They also said: Of the part now submerged, a little more than two-thirds—ninety-five degrees—remains beneath the waters.

They continued: The western encircling ocean, called Oceanus, borders the lands of the Maghrib. Within it are the so-called Fortunate Isles, lying about ten degrees—approximately a month’s journey—from the mainland. This sea cannot be navigated or sailed because of its violent turbulence, its churning waves, and the ever-shifting winds. It yields no fish, nothing is extracted from it, and no voyages are undertaken upon it for trade or any other purpose.

It runs southward until it aligns with the Mountains of the Moon—said to be the range from which the principal source of the Nile of Egypt springs—and it passes beyond the equator. Thence it extends eastward, becoming the southern sea of the earth. There lie the Islands of the Blacks, and along its shores much territory lies in ruins. It then stretches east and north until it meets the Sea of China and the Sea of India, after which it continues eastward to the furthest exposed eastern limit of the earth, where the land of China is found.

From the eastern side of China it bends northward, passes beyond Chinese territory, and runs parallel to the barrier of Gog and Magog. It then turns and circles lands whose conditions are unknown, pushes westward across the earth’s northern reaches, passes the land of the Rus, then curves west and south, encircling the earth once more. From the western side of Arabia it pours into the narrow strait whose far end reaches the western outskirts of Greater Syria, after which it enters the lands of Byzantium and reaches Constantinople and other territories under their rule.

From the eastern encircling ocean branch other seas dotted with countless islands. It is even said that the Indian Ocean alone contains two thousand seven hundred islands, with inhabited cities and settlements besides deserted towns. This ocean is called the Green Sea: its eastern expanse is the Sea of China, its western expanse the Sea of Yemen, its northern expanse the Sea of India, and its southern limits are unknown.