Spratly Islands

The Spratly Islands are a large, disputed archipelago located in the South China Sea.

This group of landforms sits near the coasts of the Philippines, Malaysia, and southern Vietnam. It is composed of many different features, including islands, islets, cays, and more than 100 reefs. Many of these are grouped into submerged old atolls. An atoll is a ring-shaped coral reef that surrounds a lagoon.

The archipelago is a major part of Southeast Asia. Its location in strategic shipping lanes makes it a very important area for global trade.

Most of the islands in this group are cays. A cay is a small, low-lying island formed on top of old, degraded, or submerged coral reefs. The islands are mostly made of biogenic carbonate. This is material created by living organisms, such as coral. These carbonate accumulations sit upon the high crests of submarine ridges. Geologists call these raised blocks of the Earth's crust horsts. These horsts are part of a complex system of half-grabens and rotated fault-blocks. These geological structures lie parallel to magnetic anomalies in the nearby oceanic crust.

The formation of these islands happened in two distinct tectonic periods. First, tectonic stretching occurred during the Late Cretaceous and Early Oligocene. This happened during the rifting and sea-floor spreading that created the South China Sea. Later, during the Late Oligocene and Early Miocene, additional stretching and faulting occurred. This activity happened within the Spratly Islands and the nearby Dangerous Ground. During this time, corals and other marine life colonized the crests of the horsts. Over time, the remains of these organisms built up to create the modern reefs and cays.

The geography of the region can be quite difficult to navigate. The northeast section is known as the Dangerous Ground. This area is characterized by many low islands and sunken reefs. Some reefs rise abruptly from ocean depths greater than 1,000 meters.

This makes the area very hazardous for ships. The islands themselves offer almost no arable land for farming. Most islands also lack a permanent supply of drinkable water. Even the groundwater on some islands fluctuates with the rhythm of the tides.

The history of the islands is tied to exploration and many different claims. The archipelago was named after Richard Spratly, a British whaling captain. He sighted Spratly Island in 1843. In 1939, the area consisted mostly of coral islets inhabited by seabirds. Today, the islands are highly contested by several nations. China, Taiwan, the Philippines, Vietnam, and Malaysia all occupy different islands or reefs with military forces.

Brunei also claims an exclusive economic zone in the southeastern part of the islands.

There are significant economic resources in and around the Spratly Islands. The area contains rich fishing grounds and may hold large oil and natural gas reserves. Some islands have been used for guano mining, which is the collection of bird droppings used for fertilizer.

However, a 2013 US EIA report questioned if many of these reserves are actually viable to use. The islands vary in size. For example, Itu Aba Island is the largest at 46 hectares. Thitu Island is the second largest at 37.20 hectares. Some islands, like West London Reef, are much smaller, measuring only 1.10 hectares.

The ecology of the Spratly Sea is incredibly diverse and complex. Scientists have recorded 2,927 different marine species in the area. This includes 382 species of hard coral and 524 species of marine fish. The islands provide vital habitats for seabirds and sea turtles. The green turtle and the hawksbill turtle both use these islands.

However, human activities like heavy commercial fishing and tourism can cause environmental pollution. Some scientists have proposed turning parts of the islands into marine parks to help protect these ecosystems.