Arabian Sea

The Arabian Sea is the great northwestern arm of the Indian Ocean, a deep basin swept twice a year by the monsoon winds that have governed life and commerce around it for millennia. Bounded by the Arabian Peninsula, the Horn of Africa, Iran, Pakistan, and India, it has been the highway of dhow traders since antiquity, carrying frankincense, spices, horses, and ideas between three continents. Its rhythms still dictate the rains that water the farms of an entire subcontinent.

At about 3.86 million square kilometres and reaching depths beyond 4,600 metres, the Arabian Sea is fed chiefly by the Indus River and opens into the Persian Gulf through the Strait of Hormuz and into the Red Sea through the Gulf of Aden. The southwest monsoon drives powerful currents and intense upwelling along the Somali and Omani coasts, lifting cold, nutrient-rich water that fuels enormous plankton blooms — yet the sea also harbours one of the world's largest oxygen-minimum zones in its depths.

Long before European sailors arrived, mariners here mastered the monsoon to make round-trip voyages between Africa, Arabia, and India, building a trading world that linked the Swahili coast to the ports of Gujarat. Vasco da Gama crossed it in 1498 to reach India, opening the sea to Portuguese and later British empire. Today its lanes carry much of the oil leaving the Persian Gulf, and its piracy-prone approaches off Somalia and its warming, deoxygenating waters keep it under close international attention.

• Persian Gulf
  The shallow, oil-laden sea at the heart of the Middle East connects to
• Red Sea
  A young ocean in the making, splitting Africa from Arabia connects to
• Indian Ocean
  The world's third-largest and warmest ocean drains to
• Indus River
  Cradle of an ancient civilization, lifeline of Pakistan feeds from
• Asia
  Earth's largest and most populous continent located on