Arabian Sea

The Arabian Sea is a section of the northern Indian Ocean. It is bordered to the west by the Arabian Peninsula, the Gulf of Aden, and the Guardafui Channel; to the northwest by the Gulf of Oman and Iran; to the north by Pakistan; to the east by India; to the southeast by the Laccadive Sea and the Maldives; and to the southwest by Somalia. Covering roughly 3,862,000 square kilometers, its deepest point reaches 5,395 meters. The Gulf of Aden links it to the Red Sea via the Bab-el-Mandeb strait, while the Gulf of Oman connects it to the Persian Gulf. Much of its southern and central expanse is taken up by the Arabian Basin, a broad, mostly flat seabed that in places drops below 4,500 meters. Most of the sea’s islands and seamounts lie near the coasts of major landmasses.

Since the 3rd millennium BC, the straits of Hormuz and Bab-el-Mandeb have served as crucial passageways between the Eastern and Western Old World. This created a network of interdependent trade nodes, linking merchants from the Mediterranean to the Near East, Persia, East Africa, India, Southern Africa, Southeast Asia, East Asia, and the Malay Archipelago. Over millennia, this activity spread ideas, peoples, philosophies, technologies, religions, currency, and domesticated crops and livestock across the Old World, especially within the Indian Ocean and Near Eastern spheres.

Monsoon winds and the currents they generate with the Indian Ocean Warm Pool historically shaped trade. In midsummer, strong winds push warm, moist air northeast from Africa and the Indian Ocean, bringing heavy rain to the northeastern Arabian basin while leaving the Horn of Africa and Arabian Peninsula dry—though recent years have seen more intense rainfall in both areas. During winter and spring, cold, shallow, dry southwesterly winds from the Karakoram and Himalayas dominate.

The Arabian Sea forms the core of the Arabian Sea large marine ecosystem, which stretches from the Laccadive Sea to the Red Sea and Persian Gulf. It is considered one of the most biologically productive marine regions on Earth. Its southern boundary is the Carlsberg Ridge. In recent decades, overfishing, bycatch, industrial and residential development, pollution, global heating, and coastal eutrophication have placed it under severe strain, leading to many endangered and critically endangered marine and terrestrial species.

Modern major seaports include Jawaharlal Nehru and Mormugao in India; Karachi, Qasim, and Gwadar in Pakistan; Chabahar in Iran; and Salalah in Oman. The largest islands are Socotra (Yemen), Masirah (Oman), and Astola (Pakistan). Countries with Arabian Sea coastlines are Yemen, Oman, Pakistan, Iran, India, and the westernmost islands of the Maldives and Laccadive archipelagos.

The sea covers about 3,862,000 square kilometers, with a maximum width of roughly 2,400 kilometers and a maximum depth of 5,395 meters. The Indus is its largest inflowing river. Its two main arms are the Gulf of Aden (southwest, connecting to the Red Sea via Bab-el-Mandeb) and the Gulf of Oman (northwest, connecting to the Persian Gulf). It also borders the Gulfs of Khambhat and Kutch along India’s coast, and the Laccadive Sea off southern India.

The only difference between NOAA and IHO demarcations of the Arabian Sea concerns its eastern border with India—specifically whether the limit lies at Devgad Island or Sadashivgad Village in Karnataka. NOAA defines the boundaries as follows: north and east from Cape Jiwani in Pakistan, eastward and southward along the coasts of Pakistan and India to Devgad Island, then southwest to Cora Divh, then south along the western side of the Lakshadweep and Maldives to the southern tip of Addu Atoll; south from Addu Atoll northwest to Cape Hafun in Somalia; west from Cape Hafun north along Somalia’s coast to Cape Asir (Guardafui), then northeast to Cape Fartak in southern Yemen, then northeast along the coasts of southern Yemen and Oman to Cape Al Hadd, then northeast to Cape Jiwani in Pakistan.