The Indian Ocean is the third largest of the world's oceanic divisions, covering about 20% of the Earth's water surface. It is bounded on the north by Asia on the west by Africa; on the east by Australia; and on the south by the Southern Ocean. One component of the all-encompassing World Ocean, the Indian Ocean is delineated from the Atlantic Ocean by the 20° east meridian running south from the Pacific by the 147° east meridian. The northernmost extent of the Indian Ocean is approximately 30° north latitude in the Persian Gulf and, thus, has asymmetric ocean circulation. This ocean is nearly 10,000 kilometers (6,200 mi) wide at the southern tips of Africa and Australia; its area is 73,556,000 square kilometers (28,400,000 mi²).