Sumatra is one of the
Sunda Islands of western
Indonesia. It is the largest island that is fully within Indonesian territory, as well as the
sixth-largest island in the world at 473,481 km
2 (182,812 mi.
2), not including adjacent islands such as the
Simeulue,
Nias,
Mentawai,
Enggano,
Riau Islands,
Bangka Belitung and
Krakatoa archipelago.
Sumatra is an elongated landmass spanning a diagonal northwest–southeast axis. The
Indian Ocean borders the west, northwest, and southwest coasts of Sumatra, with the island chain of
Simeulue,
Nias,
Mentawai, and
Enggano off the western coast. In the northeast, the narrow
Strait of Malacca separates the island from the
Malay Peninsula, which is an extension of the Eurasian continent. In the southeast, the narrow
Sunda Strait, containing the
Krakatoa Archipelago, separates Sumatra from
Java. The northern tip of Sumatra borders the
Andaman Islands, while off the southeastern coast lie the islands of Bangka and Belitung,
Karimata Strait and the
Java Sea. The
Bukit Barisan mountains, which contain several active volcanoes, form the backbone of the island, while the northeastern area contains large plains and lowlands with swamps, mangrove forest and complex river systems. The
equator crosses the island at its centre in
West Sumatra and
Riau provinces. The climate of the island is
tropical, hot, and humid. Lush
tropical rain forest once dominated the landscape.
Sumatra has a wide range of plant and animal species but has lost almost 50% of its tropical rainforest in the last 35 years. Many species are now
critically endangered, such as the
Sumatran ground cuckoo, the
Sumatran tiger, the
Sumatran elephant, the
Sumatran rhinoceros, and the
Sumatran orangutan.
Deforestation on the island has also resulted in serious seasonal smoke haze over neighbouring countries, such as the
2013 Southeast Asian haze which caused considerable tensions between Indonesia and affected countries
Malaysia and
Singapore.
Etymology
Sumatra was known in ancient times by the
Sanskrit names of ''Suwarnadwīpa'' ("Island of Gold") and ''Suwarnabhūmi'' ("Land of Gold"), because of the gold deposits in the island's
highlands. The earliest known mention of the current form "Sumatra" was in 1017, when the
local king
Haji Sumatrabhumi ("King of the land of Sumatra") sent an envoy to
China.
Arab geographers referred to the island as ''Lamri'' (
Lamuri, Lambri or Ramni) in the tenth through thirteenth centuries, in reference to a kingdom near modern-day
Banda Aceh which was the first landfall for traders. The island has also been known by other names, including Andalas or Percha Island.
In the late 13th century,
Marco Polo referred to the kingdom as "Samara", while his contemporary fellow Italian traveller
Odoric of Pordenone used the form "Sumoltra". Later in the 14th century the local form "Sumatra" became popular abroad due to the rising power of the kingdom of
Samudera Pasai and the subsequent
Sultanate of Aceh.
From then on, subsequent European writers mostly used "Sumatra" or similar forms of the name for the entire island.
History

By the year
692, the
Melayu Kingdom was absorbed by
Srivijaya.
Srivijayan influence waned in the 11th century after it was defeated by the
Chola Empire of southern India. At the same time, Islam made its way to Sumatra through
Arabs and
Indian traders in the 6th and 7th centuries AD. By the late 13th century, the monarch of the
Samudra kingdom had converted to Islam.
Marco Polo visited the island in 1292, and his fellow Italian
Odoric of Pordenone in 1321.
Moroccan scholar
Ibn Battuta visited with the sultan for 15 days, noting the city of Samudra was "a fine, big city with wooden walls and towers", and another two months on his return journey.
Samudra was succeeded by the powerful
Aceh Sultanate, which survived to the 20th century. With the coming of the
Dutch, the many Sumatran princely states gradually fell under their control. Aceh, in the north, was the major obstacle, as the Dutch were involved in the long and costly
Aceh War (1873–1903).
The
Free Aceh Movement fought against Indonesian government forces in the
Aceh Insurgency from 1976 to 2005. Security crackdowns in 2001 and 2002 resulted in several thousand civilian deaths.
The island was heavily impacted by both the 1883
Krakatoa eruption and the 2004
Boxing Day Tsunami.
Demographics
Sumatra is not particularly densely populated, with 123.46 people per km
2 – about 58.5 million people in total (in mid 2019).
[Badan Pusat Statistik, Jakarta, 2019.] Because of its great extent, it is nonetheless the fifth
most populous island in the world.
File:Minangprocession.jpg|Minangkabau women carrying platters of food to a ceremony
File:House in Nias North Sumatra.jpg|Traditional house in Nias North Sumatra
Languages
There are over 52
languages spoken, all of which (except Chinese and Tamil) belong to the
Malayo-Polynesian branch of the
Austronesian language family. Within Malayo-Polynesian, they are divided into several sub-branches:
Chamic (which are represented by
Acehnese in which its closest relatives are languages spoken by
Ethnic Chams in Cambodia and Vietnam),
Malayic (
Malay,
Minangkabau and other closely related languages),
Northwest Sumatra–Barrier Islands (
Batak languages,
Gayo and others),
Lampungic (includes Proper Lampung and
Komering) and
Bornean (represented by
Rejang in which its closest linguistic relatives are
Bukar Sadong and
Land Dayak spoken in
West Kalimantan and
Sarawak (
Malaysia)). Northwest Sumatra–Barrier Islands and Lampungic branches are endemic to the island. Like all parts of Indonesia,
Indonesian (which was based on Riau Malay) is the official language and the main lingua franca. Although Sumatra has its own local lingua franca,
variants of Malay like Medan Malay and
Palembang Malay are popular in North and South Sumatra, especially in urban areas. Minangkabau (Padang dialect) is popular in West Sumatra, some parts of North Sumatra, Bengkulu, Jambi and Riau (especially in
Pekanbaru and areas bordered with
West Sumatra) while Acehnese is also used as an inter-ethnic means of communication in some parts of Aceh province.
Religion
The majority of people in Sumatra are Muslims (87.1%), while 10.7% are Christians, and less than 2% are Buddhists and Hindus.
Administration
Sumatra (including its adjacent islands) were one province between 1945 and 1948. It now covers ten of Indonesia's
34 provinces, which are set out below with their areas and populations.
Geography

The longest axis of the island runs approximately northwest–southeast, crossing the equator near the centre. At its widest point, the island spans . The interior of the island is dominated by two geographical regions: the
Barisan Mountains in the west and swampy plains in the east. Sumatra is the closest Indonesian island to mainland Asia.
To the southeast is
Java, separated by the
Sunda Strait. To the north is the
Malay Peninsula (located on the Asian mainland), separated by the
Strait of Malacca. To the east is
Borneo, across the
Karimata Strait. West of the island is the
Indian Ocean.
The
Great Sumatran fault (a
strike-slip fault), and the
Sunda megathrust (a
subduction zone), run the entire length of the island along its west coast. On 26 December 2004, the western coast and islands of Sumatra, particularly
Aceh province, were struck by a
tsunami following the
Indian Ocean earthquake. This was the longest earthquake recorded, lasting between 500 and 600 seconds. More than 170,000 Indonesians were killed, primarily in Aceh. Other recent earthquakes to strike Sumatra include the
2005 Nias–Simeulue earthquake and the
2010 Mentawai earthquake and tsunami.
Lake Toba is the site of a
supervolcanic eruption that occurred around 74,000 years ago, representing a climate-changing event.
To the east, big rivers carry silt from the mountains, forming the vast lowland interspersed by swamps. Even if mostly unsuitable for farming, the area is currently of great economic importance for Indonesia. It produces oil from both above and below the soil –
palm oil and
petroleum.
Sumatra is the largest producer of
Indonesian coffee. Small-holders grow Arabica coffee (''
Coffea arabica'') in the highlands, while Robusta (''
Coffea canephora'') is found in the lowlands. Arabica coffee from the regions of Gayo, Lintong and Sidikilang is typically processed using the
Giling Basah (wet hulling) technique, which gives it a heavy body and low acidity.
Sumatra is a highly seismic island, huge earthquakes have been recorded throughout history, in 1797 an 8.9 earthquake shook Western Sumatra, in 1833 a 9.2 earthquake shook Bengkulu and Western Sumatra both events caused large tsunamis. They are very common throughout the coastal area of the west and center of the island, tsunamis are common due to the high seismicity in the area.
Largest cities

By population, Medan is the largest city in Sumatra.
[Biro Pusat Statistik, Jakarta.] Medan is also the most visited and developed city in Sumatra.
Flora and fauna

Sumatra supports a wide range of vegetation types which are home to a rich variety of species, including 17 endemic genera of plants.
Unique species include the
Sumatran pine which dominates the
Sumatran tropical pine forests of the higher mountainsides in the north of the island and rainforest plants such as ''
Rafflesia arnoldii'' (the world's largest individual flower), and the
titan arum (the world's largest unbranched
inflorescence).
The island is home to 201 mammal species and 580 bird species, such as the
Sumatran ground cuckoo. There are nine endemic mammal species on mainland Sumatra and 14 more endemic to the nearby
Mentawai Islands.
There are about 300 freshwater fish species in Sumatra. There are 93
amphibian species in Sumatra, 21 of which are endemic to Sumatra.
The
Sumatran tiger,
Sumatran rhinoceros,
Sumatran elephant,
Sumatran ground cuckoo, and
Sumatran orangutan are all critically endangered, indicating the highest level of threat to their survival. In October 2008, the Indonesian government announced a plan to protect Sumatra's remaining forests.
The island includes more than 10 national parks, including three which are listed as the
Tropical Rainforest Heritage of Sumatra World Heritage Site –
Gunung Leuser National Park,
Kerinci Seblat National Park and
Bukit Barisan Selatan National Park. The
Berbak National Park is one of three national parks in Indonesia listed as a
wetland of international importance under the
Ramsar Convention.
Rail transport
Several unconnected railway networks built during
Netherlands East Indies exist in Sumatra, such as the ones connecting
Banda Aceh-
Lhokseumawe-
Besitang-
Medan-Tebingtinggi-
Pematang Siantar-Rantau Prapat in Northern Sumatra (the Banda Aceh-Besitang section was closed in 1971, but is currently being rebuilt).
Padang-
Solok-
Bukittinggi in
West Sumatra, and
Bandar Lampung-
Palembang-Lahat-Lubuk Linggau in Southern Sumatra.
See also
*
Architecture of Sumatra
*
Bukit Seguntang
*
Communism in Sumatra
*
Music of Sumatra
References
Further reading
*
* William Marsden
''The History of Sumatra'' (1783); 3rd ed. (1811) freely available online.
External links
*
{{Authority control
Category:Greater Sunda Islands
Category:Maritime Southeast Asia