Sumatra (also spelled Sumatera) is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia (two larger islands, Borneo and New Guinea, are partially in Indonesia), and the sixth largest island in the world (approximately 470,000 km²).

Etymology

Sumatra was known in ancient times by the Sanskrit names of Swarnadwīpa ("Island of Gold") and Swarnabhūmi ("Land of Gold"), due likely to the gold deposits of the island's highlands. Arab geographers referred to the island as Lamri (Lamuri, Lambri or Ramni) in the 10-13th centuries, in reference to a kingdom near modern day Banda Aceh which was the first landfall for traders. Late in the 14th century the name Sumatra became popular, in reference to the kingdom of Samudra which was a rising power. European writers in the 19th century found that the indigenous inhabitants did not have a name for the island.

History

People who spoke Austronesian languages first arrived in Sumatra around 500 BCE, as part of the Austronesian expansion from Taiwan to Southeast Asia. With its location in the India-China sea trade route, several trading towns flourished, especially in the eastern coast, and were influenced by Indian religions. One of the earliest known kingdoms was Kantoli, which flourished in the 5th century AD in southern Sumatra. Kantoli was replaced by the Empire of Srivijaya and then later by the Kingdom of Samudra. Srivijaya was a Buddhist monarchy centered in what is now Palembang. Dominating the region through trade and conquest throughout the 7th to 9th centuries, the Empire helped spread the Malay culture throughout Sumatra, Malay Peninsula, and western Borneo. The empire was a thalassocracy, or maritime power that extended its influence from island to island. Palembang was a center for scholarly learning, and it was there the Chinese Buddhist pilgrim I Ching studied Sanskrit in 671 CE before departing for India. On his journey to China he spent four years in Palembang translating Buddhist texts and writing two manuscripts.

Srivijayan influence waned in the 11th century after it was defeated by the Chola Empire of southern India. Sumatra was then subject to conquests from Javanese kingdoms, first Singhasari and subsequently Majapahit. At the same time Islam made its way to Sumatra, spreading through contacts with Arabs and Indian traders.

On December 26 2004, the western coast and islands of Sumatra, particularly Aceh province, were devastated by a nearly 15 meter high tsunami following the 9.2-magnitude Indian Ocean earthquake. The death toll surpassed 170,000 in Indonesia alone, primarily in Aceh.

In 2005 there was an 8.7 magnitude aftershock of the previous earthquake in December 2004. See 2005 Sumatran Earthquake. In addition to the subduction megathrust earthquake off the west coast, Sunda arc, the Great Sumatran Fault, a transform fault, runs the entire length of the island. The pressure on this fault increased dramatically after the December 2004 earthquake, and seismologists are afraid an earthquake is going to occur soon. The fault ends directly below the devastated city of Banda Aceh.