South China Sea

Verified Timeline

Lore & Background

The South China Sea opened around 45 million years ago when the 'Dangerous Ground' rifted away from southern China. Extension culminated in seafloor spreading around 30 million years ago, a process that propagated to the southwest, resulting in the V-shaped basin we see today. Extension ceased around 17 million years ago. Arguments have continued about the role of tectonic extrusion in forming the basin. Paul Tapponnier and colleagues have argued that as India collides with Asia, it pushes Indochina to the southeast, causing the South China Sea to open. Marine geophysical studies in the Gulf of Tonkin by Peter Clift have shown that the Red River Fault was active and causing basin formation at least by 37 million years ago in the northwest South China Sea, consistent with extrusion playing a part. During recent ice ages, global sea level was hundreds of metres lower, and Borneo was part of the Asian mainland. The IHO in its Limits of Oceans and Seas, 3rd edition (1953), defines the limits of the South China Sea, but a revised draft edition (1986) recognized the Natuna Sea, revising the southern limit from the Bangka Belitung Islands to the Natuna Islands.

Reader's Guide

The South China Sea is subject to competing claims of sovereignty by several countries. These claims are reflected in the variety of names used for the islands and the sea. In China, it is referred to as the South Sea (南海; Nánhǎi), and in Vietnam the East Sea (Biển Đông). In Malaysia, Indonesia, and the Philippines, it was long known as the South China Sea. Following an escalation of the Spratly Islands dispute in 2011, various Philippine government agencies started using the name West Philippine Sea. In September 2012, Philippine President Benigno Aquino III signed Administrative Order No. 29, mandating that all government agencies use the name West Philippine Sea to refer to the parts of South China Sea within the Philippines exclusive economic zone. In July 2017, to assert its sovereignty, Indonesia renamed the northern reaches of its exclusive economic zone in the South China Sea as the North Natuna Sea. There has been no agreement between China and Indonesia regarding the Natuna waters dispute, with China remaining ambiguous about the southern limit of its area of interest. The South China Sea Islands, collectively comprising several archipelago clusters of mostly small uninhabited islands, islets (cays and shoals), reefs/atolls, and seamounts numbering in the hundreds, are subject to competing claims of sovereignty by several countries.

Did You Know?

• The South China Sea communicates with the East China Sea via the Taiwan Strait, the Philippine Sea via the Luzon Strait, the Sulu Sea via the straits around Palawan, and the Java Sea via the Karimata and Bangka Straits.
• The Yi Zhou Shu, a chronicle of the Western Zhou dynasty (1046–771 BCE), gives the first Chinese name for the South China Sea as Nanfang Hai, meaning 'Southern Sea'.
• In Southeast Asia, it was once called the Champa Sea or Sea of Cham, after the maritime kingdom of Champa (nowadays Central Vietnam), which flourished there before the 16th century.
• The South China Sea has an average depth of 1,212 m (3,976 ft), and the deepest recorded point is either 5,559 m (18,238 ft) or 5,567 m (18,264 ft).
• Major rivers that flow into the South China Sea include the Pearl, Min, Jiulong, Red, Mekong, Menam, Rajang, Baram, Kapuas, Batang Hari, Musi, Kampar, Indragiri, Pahang, Agno, Pampanga, and Pasig Rivers.