Artificial islands in the South China Sea

The South China Sea is located in the Western Pacific Ocean and covers aproximately 3,500,000 km². This marginal sea is surrounded by China, Taiwan, Philippines, Malaysia, Brunei, Thailand, Cambodia and Vietnam and includes several archipelagos which consist of small islands, cays, shoals, reefs, atolls and seamounts.
The significance of the region lays in the maritime shipping, fisheries, oil & gas, among other things. According to the United Nations Conference on Trade and Development (UNCTAD), 33% of the maritime shipping passes through the South China Sea (source ChinaPower making reference to UNCTAD report). Concerning oil & gas reserves, the U.S. Energy Information Administration (EIA) "estimates the South China Sea contains approximately 11 billion barrels of oil and 190 trillion cubic feet of natural gas in proved and probable reserves" (source EIA).

The depth of a large part of the South China Sea is less than 300m but can reach more than 5000m by location. Paracel Islands, Macclesfield Bank, Scarborough Shoal and Spratly Islands are located in the deepest part of the South China Sea.

Due to the geostrategic importance of the region, several sovereign states dispute maritime boundaries and islands (source Voice of America). "In 2013, the PRC began island building in the Spratly Islands and the Paracel Islands region. According to Reuters, island building in the South China Sea primarily by Vietnam and the Philippines has been going on for decades; while China has come late to the island building game, its efforts have been on an unprecedented scale as it had from 2014 to 2016 constructed more new island surface than all other nations have constructed throughout history and as of 2016 placed military equipment on one of its artificial islands unlike the other claimants. A 2019 article in Voice of America that compared China and Vietnam's island building campaign in the South China Sea similarly noted that the reason why Vietnam in contradistinction to China has been subject to little international criticism and even support was because of the slower speed and widely perceived defensive nature of its island-building project." (source Wikipedia).

"The reef was occupied by China (PRC) in early 1988, despite immediate opposition from Vietnam, which led to armed conflict at Johnson Reef South in March of that year. In 2014, the PRC commenced reclamation activity in the area, and it has been converted into an artificial island of 274 hectares (677 acres). There were around 200 Chinese troops on the reef in late 2014, though this number was likely to have increased significantly in 2015 with the addition of support personnel for the new airbase, including a 3,125-meter-long (1.9 mi) runway and associated early warning radar site." (source Wikipedia).

"During 2014, the PRC started reclaiming land at Subi Reef, and by the end of 2015 had developed it into an island of 3.95 square kilometres (1.53 sq mi), with a military base, a large harbor, and an airstrip of about 3,000 metres (9,800 ft). In November 2015, two U.S. B-52 strategic bombers flew in airspace near the area. They were contacted by Chinese ground control, but were allowed to continue their mission undeterred.In April 2016 a new lighthouse 55 meters (180') high commenced operations. A civilian test flight to the new airport was conducted by a passenger jet of Hainan Airlines on July 13, 2016." (source Wikipedia).

"In 2014, land reclamation started inside the rims. The Philippines filed a diplomatic protest against China after the discovery of their reclamation activities. By January 2016, work was well advanced on developing a military base with a large harbour and a 2,644 metres (8,675 ft) runway, with the reclaimed land covering 558 hectares (1,380 acres). A civilian test flight to the runway was conducted by a China Southern Airlines passenger jet on 13 July 2016." (source Wikipedia).