20120515-Crop harvest in Indonesia.jpg
Crop harvest in Indonesia
Indonesia is the largest archipelago in the world. Located north of Australia and south of the Philippines and Southeast Asia, it is also the largest archipelago nation in the world and the largest and most widely-spread country in Southeast Asia. Satellite imagery analysis done in the early 2000s, revealed that it had 18,108 islands, more than 1,000 islands than previously thought, at high tide. There are even more at low tide. [Sources: Library of Congress, CIA World Factbook]

In terms of area, Indonesia is the 15th largest country in the world. Straddling the equator and located where the Pacific and Indian Oceans meet, it covers an area of 1,904,569 square kilometers (about 741,000 square miles), which is roughly the size of Mexico or three times the area of Texas. Indonesia stretches 5,120 kilometers (3,575 miles) along the equator, across three times zones from Malaysia in the west to Papua New Guinea in the east, and 1,760 kilometers 1,100) miles from north to south, from northern Kalimantan in Borneo in the north to a small group of islands south of Timor in the south. The distance from its furthest western point in the Indian ocean to its furthest eastern point in the Pacific is the roughly equal to the distance between California and Bermuda or London and Baghdad.

Of Indonesia’s total area 1,811,569 square kilometers is land and 93,000 square kilometers is inlands seas (straits, bays, and other bodies of water). The additional surrounding sea areas bring Indonesia's generally recognized territory (land and sea) to about 5 million square kilometers. The government, however, also claims an exclusive economic zone, which brings the total to about 7.9 million square kilometers. The country has 54,716 kilometers of coastline and 2,958 kilometers of land boundaries with borders of 253 kilometers with East Timor, 1,881 kilometers with Malaysia and 824 kilometers with Papua New Guinea. Elevation extremes: lowest point: Indian Ocean 0 meters; highest point: Puncak Jaya 4,884 meters in Papua Province in New Guinea.

Most of Indonesia is coastal lowlands, with the larger islands having interior mountains .About 12.34 percent of the country is good for agriculture (compared to 21 percent in the U.S.) and most of this arable land is located on Java, Sumatra, Sulawesi and the islands of Nusa Tengarra. Land use: permanent crops: 10.5 percent; other: 77.16 percent (2011). Irrigated land: 67,220 square kilometers (2005). About 50 percent of Indonesia’s land is covered by rain forest (down from nearly 90 percent 60 years ago), most of it in Sumatra, Kalimantan, Papua and Sulawesi. Indonesia’s rainy, humid, tropical climate is ideal for rain forests but the amount of forest get smaller everyday as lumber companies, slash-and-burn farmers and palm oil and coffee plantation owners cut down these forests. The east coast of Sumatra, the southern coast of Kalimantan and Papua and much of the northern coast of Java is covered by marshes, swamps and mangrove forests.

The fact that there are so many islands and so much water and the islands are often mountainous and covered by dense forest has traditionally hindered transportation and communication and helps explain why Indonesia boast so many different ethnic groups. Indonesia's variations in culture have been shaped — although not specifically determined — by centuries of complex interactions with the physical environment. Although Indonesians are now less vulnerable to the vicissitudes of nature as a result of improved technology and social programs, to some extent their social diversity has emerged from traditionally different patterns of adjustment to their physical circumstances.[Source: Library of Congress]

Natural Disasters

Indonesia suffers from relatively frequent natural disasters, including occasional floods; severe droughts; tsunamis; earthquakes; volcanoes; forest fires.

Indonesia sits on the fault lines of the Pacific Ring of Fire, which sees frequent earthquakes and volcanic activity. The archipelago is home to some of the world’s most famous volcanic eruptions, including the Mount Toba super-eruption around 74,000 years ago in North Sumatra that created what is today the world’s largest volcanic lake, and the eruption of Mount Krakatau, which lies west of Java, in 1883.

Time Zones and Major Cities and Rivers in Indonesia

Major Cities: (estimated population in 2013 and 1991): Jakarta (the capital) 9,770,000 and 8,300,000; Surabaya (Java), 2,880,000 and 2,400,000; Bandung (Java), 2,430,000 and 2,000,000; and Medan, 2,120,000 and 1,700,000 (Sumatra); Semarang (2013), 1,570,000; Palembang 1,460,000; Ujuung Padang, 1,390,000; and Batam, 1,035,000

Principal Rivers: Indonesia’s waterways total 21,579 kilometers. The principal rivers are the Musi, Batanghari, Indragiri, and Kampar rivers on Sumatra; the Kapuas, Barito, and Mahakam rivers on Kalimantan; the Memberamo and Digul rivers on Papua; and the Bengawan Solo, Citarum, and Brantas rivers on Java, which are used primarily for irrigation. [Source: Library of Congress, 2011]

Located on the equator, the archipelago experiences relatively little change in the length of daylight hours from one season to the next; the difference between the longest day of the year and the shortest is only 48 minutes. Sunrises and sunsets occur quickly with relatively little twilight.

The archipelago stretches across three time zones: Western Indonesian Time—seven hours in advance of Greenwich Mean Time (GMT)—applies to Sumatra, Java, and west and central Kalimantan; Central Indonesian Time—eight hours ahead of GMT—is observed in Bali, Nusa Tenggara, south and east Kalimantan, and Sulawesi; clocks are set to Eastern Indonesian Time—nine hours ahead of GMT—in the Malukus and Papua. The boundary between the western and central time zones—established in 1988—is a line running north between Java and Bali through the center of Kalimantan. The border between the central and eastern time zones runs north from the eastern tip of Timor to the eastern tip of Sulawesi. Indonesia does not operate daylight- saving time in the summer.

Islands of Indonesia

Indonesia is the world’s largest group of islands and the world's largest country comprised solely of islands. It includes the world’s second-, third- and fifth-largest islands, New Guinea, Borneo and Sumatra. Around 6,000 islands are inhabited. Only 3,000 of the islands have significant populations. More than half the islands are uninhabited. Some islands have disappeared as a result of the export of sand to Singapore.

Indonesia is a huge archipelagic country extending 5,120 kilometers from east to west and 1,760 kilometers from north to south. According to the Indonesian Naval Hydro-Oceanographic Office, the country encompasses 17,508 islands (some sources say more than 18,000, see above; others say 13,667 islands). There are five main islands (Sumatra, Java, Kalimantan, Sulawesi, and Papua), two major archipelagos (Nusa Tenggara and the Maluku Islands), and sixty smaller archipelagos. Two of the islands are shared with other nations; Kalimantan (known in the colonial period as Borneo) is shared with Malaysia and Brunei, and Papua shares the island of New Guinea with Papua New Guinea.

The largest areas landwise are Sumatra (between Java and peninsular Malaysia. 473,605 square kilometers), Kalimantan (southern two thirds of Borneo, 539,000 square kilometers) and Papua and West Papua (western half of New Guinea, 421,981 square kilometers). These places have large areas of wilderness with marshy coastal plains and rainforest-covered mountains in the interior. They have also suffered from heavy deforestation.

The western archipelago embraces the largest islands of Indonesia. Sulawesi (Celebes, 202,000 square kilometers) is crab-shaped islands fringed by coral refs and covered by mountains that are more deforested than those on Borneo. The volcanic Malukas (Moluccas) were formerly known as the Spice Islands. Nusa Tenggara, a string of agricultural volcanic islands east of Bali, includes Komodo home of the Komodo dragon. The eastern archipelago is composed of many islands but they account for only 10 percent of the country’s land area. Many of the small islands are new and volcanic.

Mountains and Volcanoes of Indonesia

Except for coastal plains and river valleys most of Indonesia is mountainous. Mountains ranging between 3,000 and 3,800 meters above sea level can be found on the islands of Sumatra, Java, Bali, Lombok, Sulawesi, and Seram. The country's tallest mountains, which reach between 4,700 and 5,000 meters, are located in the Jayawijaya Mountains and the Sudirman Mountains in Papua. The highest peak, Puncak Jaya, which reaches 5,039 meters, is located in the Sudirman Mountains. On Papua there are mountains so high they covered with snow throughout the year.

Many of Indonesia’s islands are rugged remnants of extinct volcanoes. There are around 400 volcanoes in Indonesia, A string of volcanoes runs all the way from Sumatra to Flores with more in Sulawesi and The Moluccas. Of these 127 are active, about a third of all the world's active volcanoes. Indonesia is one of the most geologically active regions in the world. On average there are three earthquakes a day, measuring 5 or more on the Richter scale. There are about 10 times as many deaths from volcanic eruptions in Indonesia as in there are in any other country. On the positive side the volcanoes produce rich soil.

Between 1972 and 1991 alone, twenty-nine volcanic eruptions were recorded, mostly on Java. The most violent volcanic eruptions in modern times occurred in Indonesia. In 1815 a volcano at Gunung Tambora on the north coast of Sumbawa, Nusa Tenggara Barat Province, claimed 92,000 lives and created "the year without a summer" in various parts of the world. In 1883 Krakatau in the Sunda Strait, between Java and Sumatra, erupted and some 36,000 West Javans died from the resulting tsunamis. The sound of the explosion was reported as far away as Turkey and Japan. For almost a century following that eruption, Krakatau was quiet, until the late 1970s, when it erupted twice. [Source: Library of Congress]

Maritime Areas and Seas Around Indonesia

Indonesia has a strategic location astride or along major sea lanes from the Indian Ocean to Pacific Ocean between east Asia and west Asia, the Middle East, Africa and Europe. These include the Malacca Strait between Sumatra and Malaysia and the southern part of the South China Sea. Indonesia is surrounded by ocean currents that travel in al directions. Its islands provide a convenient stepping stones between Southeast Asia and Australia. Sea lanes around the islands provide a route through which oil passes from the Middle East to east Asia and goods from Asia are transported to Europe.

Indonesia embraces 93,000 square kilometers of inlands seas (straits, bays, and other bodies of water) and 54,716 kilometers of coastline. The sea areas surrounding Indonesia bring its generally recognized territory (land and sea) to about 5 million square kilometers (about half the size of the U.S.). The government, however, also claims an exclusive economic zone, which brings the total to about 7.9 million square kilometers—more than four times Indonesia’s total land area. Indonesians call their country Tanah Air Kita (“Our Earth and Water”).

Eastern Sumatra, northeastern Java and most of Borneo are located on an extension of the Asiatic continental shelf called the Sunda Platform. The seas over the platform are several shallow, warm and have a relatively low salt content because of the fresh water delivered to the area by rivers from mainland Southeast Asia. Similar conditions prevail on the Sahul shelf which extends from Australia to New Guinea. A deep trench runs along the southern coast of the Indonesian chain from northern Sumatra through Nusa Tengarra. The water here is deep, cold and salty.

Geographers have conventionally grouped Sumatra, Java (and Madura), Kalimantan (formerly Borneo), and Sulawesi (formerly Celebes) in the Greater Sunda Islands. These islands, except for Sulawesi, lie on the Sunda Shelf — an extension of the Malay Peninsula and the Southeast Asian mainland. Far to the east is Papua (formerly Irian Jaya, Irian Barat or West New Guinea), which takes up the western half of the world's second largest island — New Guinea — on the Sahul Shelf. Sea depths in the Sunda and Sahul shelves average 200 meters or less. Between these two shelves lie Sulawesi, Nusa Tenggara (also known as the Lesser Sunda Islands), and the Maluku Islands (or the Moluccas), which form a second island group where the surrounding seas in some places reach 4,500 meters in depth. The term Outer Islands is used inconsistently by various writers but it is usually taken to mean those islands other than Java and Madura.

Typhoons and other large storms pose little hazard to mariners in Indonesia’s waters; the primary danger comes from swift currents in channels such as the Lombok, Sape, and Sunda straits.

Maritime Claims: Indonesia claims a 12-nautical-mile territorial sea and a 200-nautical-mile exclusive economic zone, measured from claimed archipelagic straight baselines. The total area claimed by the Indonesian government, including Indonesia’s territorial sea and an exclusive economic zone, encompasses 7.9 million square kilometers. [Source: Library of Congress, 2011]

In 1982 during the UN Conference on the Law of the Sea, Indonesia sought to defend its March 1980 claim to a 200-nautical-mile exclusive economic zone. Based on the doctrine of the political and security unity of archipelagic land and sea space (wawasan nusantara), the government asserted its rights to marine and geological resources within this coastal zone. The Strait of Malacca — one of the most heavily traveled sea-lanes in the world — was considered by Indonesia and Malaysia to be their joint possession, and the two countries requested that other nations notify their governments before moving warships through these waters. The United States and several other nations rejected those claims, considering the strait an international waterway. [Library of Congress]

Geology of Indonesia

Indonesia lies in the Ring of Fire and is one the most volcanically active and earthquake prone areas on earth. The islands in Indonesia were created mostly by volcanic activity and ocean mountain-building activity created by the movement of tectonic plates in Asia, the Indian Ocean and the Pacific Ocean. In the area of Indonesia, two large plates—the Indian Ocean and western Pacific plates—slide under an even more massive plate—the Eurasian plate—and the Eurasian and Australian continental plates collide.

Tectonically, this region — especially Java — is highly unstable, and although the volcanic ash has resulted in fertile soils, it makes agricultural conditions unpredictable in some areas. The country has numerous mountains and some 400 volcanoes, of which approximately 100 are active. Indonesia was forced up from geological plates from Australia, Asia and the Pacific. A deep trench runs along the southern coast of the Indonesian chain.

The collision of the Eurasian and Australian continental plates form a subduction zone that produces numerous earthquakes and a chain of volcanoes that runs from Sumatra through Java to New Guinea with a a few side branches to Sulawesi and the Molluccas. At subduction zones two plates collide head on, with one plate going over the top, forcing the other one down. In some cases the motion produces a descending convection current that sucks down the ocean floor. In these places deep seas trenches form; mountain building activity and earthquakes occur; and millions of tons of rock sink into the crust everyday. Subduction faults are usually angled at about 10 to 15 percent and often located where major oceans and continents meet. Where ocean crust, pushed down by the weigh of ocean water, is shoved under the thick crust of continents, the rock is heated, causing water and gases to bubble out. As they rise they melt the rock above it, creating magma that can fuel volcanoes.

Geographers believe that the island of New Guinea, of which Papua is a part, may once have been part of the Australian continent. The breakup and tectonic action created both towering, snowcapped mountain peaks lining its central east-west spine and hot, humid alluvial plains along the coast of New Guinea. Papua's mountains range some 650 kilometers east to west, dividing the province between north and south. [Source: Library of Congress]

Geographic Regions of Indonesia

Indonesia is divided into about three dozen provinces, each with a distinctive character, culture and people. Most of the land and people are concentrated in a few islands. Java (132,107 square kilometers) and Bali are filled with people, volcanoes and rice terraces. Java alone is home to about 60 percent of Indonesia’s population and the nation’s capital, Jakarta. Java and nearby Bali and Madura make up on 7 percent of Indonesia’s land area but are home to two thirds of the population, Java and Bali contain the most intensive areas of rice production and are the center of the modern tourist industry.

Administrative Divisions: Thirty-three provincial-level units: 31 provinces (“propinsi), autonomous province (Aceh), one special region (“daerah istimewa; Yogyakarta), and one special capital city region (“daerah khusus; Jakarta). Provinces subdivided into districts, called municipalities (“kota) in urban areas and regencies (“kabupaten) in rural areas; below are subdistricts (“kecamatan), with village (“desa) at lowest tier. Indonesia in 2009 had 348 regencies, 91 municipalities, 5,263 subdistricts, and 66,979 villages. [Source: Library of Congress *]

Provinces: Bali, Banten, Bengkulu, Gorontalo, Jambi, Jawa Barat (West Java), Jawa Tengah (Central Java), Jawa Timur (East Java), Kalimantan Barat (West Kalimantan), Kalimantan Selatan (South Kalimantan), Kalimantan Utara (North Kalimantan), Kalimantan Tengah (Central Kalimantan), Kalimantan Timur (East Kalimantan), Kepulauan Bangka Belitung (Bangka Belitung Islands), Kepulauan Riau (Riau Islands), Lampung, Maluku, Maluku Utara (North Maluku), Nusa Tenggara Barat (West Nusa Tenggara), Nusa Tenggara Timur (East Nusa Tenggara), Papua, Papua Barat (West Papua), Riau, Sulawesi Barat (West Sulawesi), Sulawesi Selatan (South Sulawesi), Sulawesi Tengah (Central Sulawesi), Sulawesi Tenggara (Southeast Sulawesi), Sulawesi Utara (North Sulawesi), Sumatera Barat (West Sumatra), Sumatera Selatan (South Sumatra) and Sumatera Utara (North Sumatra). [Source: CIA World Factbook]

There are five main islands (Sumatra, Java, Kalimantan, Sulawesi, and Papua), two major archipelagos (Nusa Tenggara— also known as the Lesser Sunda Islands—and the Maluku Islands— also called the Moluccas), and 60 smaller archipelagos. Three of the islands are shared with other nations: Kalimantan, the world’s third-largest island—also known as Borneo—is shared with Malaysia and Brunei; Papua and Papua Barat provinces (two provinces carved from what was formerly called West New Guinea or, later, Irian Jaya) share the island of New Guinea with the nation of Papua New Guinea; and the island of Timor is divided between Timor-Leste (former East Timor) and Indonesia’s Nusa Tenggara Timur Province. *

Geographers have conventionally labeled Sumatra, Java (and Madura, a small island near Java’s northeast coast), Kalimantan, and Sulawesi collectively as the Greater Sunda Islands. These islands, except for Sulawesi, lie on the Sunda Shelf, an extension of the Malay Peninsula and the Southeast Asian mainland. Far to the east are Papua and Papua Barat provinces, which take up the western half of the world’s second-largest island, New Guinea, which lies on the Sahul Shelf. Sea depths on the Sunda and Sahul shelves average 200 meters or less. Between these two shelves lie Sulawesi, Nusa Tenggara, and the Maluku Islands, whose adjacent seas are 4,500 meters deep in some places. The term Outer Islands is used inconsistently by various writers but is usually taken to mean those islands other than Java, Bali, and Madura. *

Nusa Tenggara consists of two strings of islands stretching eastward from Bali toward Papua. The inner arc of Nusa Tenggara is a continuation of the chain of mountains and volcanoes extending from Sumatra through Java, Bali, and Flores, and trailing off in the Banda Islands. The outer arc of Nusa Tenggara is a geological extension of the chain of islands west of Sumatra that includes Nias, Mentawai, and Enggano. This chain resurfaces in Nusa Tenggara in the ruggedly mountainous islands of Sumba and Timor. *

The Maluku Islands (or Moluccas) are geologically among the most complex of the Indonesian islands. They are located in the northeast sector of the archipelago, bounded by the Philippines to the north, Papua to the east, and Nusa Tenggara to the south. The largest of these islands include Halmahera, Seram, and Buru, all of which rise steeply out of very deep seas. This abrupt relief pattern from sea to high mountains means that there are very few level coastal plains. *

Boundary and Territorial Issues Involving Indonesia

The legal rights to, and responsibility for, Indonesia’s territorial environment are a matter of controversy. Among the continuing concerns are the exact boundaries between Indonesia and Timor-Leste; another issue of concern between the two states is sovereignty over a tiny uninhabited island off the coast of Timor that is called Pulau Batek by Indonesia but known locally as Fatu Sinai. Differences over the precise maritime boundaries between Australia and Indonesia in the Timor Gap remain an area in need of reconciliation. [Source: Library of Congress *]

In another dispute, the International Court of Justice ruled in favor of Malaysia in 2002 regarding jurisdiction over the Sipadan and Ligitan islands (off northeastern Kalimantan). However, Indonesia continues to assert a claim to the outer islands of the Ligitan group and has established a presence on them. In 2005 tensions flared again between Indonesia and Malaysia concerning Ambalat Island, located in the Sulawesi Sea (Celebes Sea) on the boundary between the two states, off the northeast corner of Kalimantan Timur Province. *

Basing its claim on a doctrine of the political and security unity of archipelagic land and waters (wawasan nusantara), the Indonesian government has asserted its rights to marine and geologic resources within a coastal zone of 200 nautical miles. Indonesia, Malaysia, and Singapore each consider the Strait of Malacca (Selat Malaka in Bahasa Indonesia), one of the most heavily traveled sea-lanes in the world, to be their primary responsibility. At a conference in Singapore in 2004, the United States recognized the right of the three countries to organize security as they saw fit, while at the same time offering assistance for their efforts. *

Since the late 1990s, Indonesia has experienced major challenges to its territorial integrity. The most profound resulted from a United Nations (UN)–monitored referendum in August 1999 in East Timor on whether to accept special autonomy within Indonesia or to separate from Indonesia and declare independence. After 78.5 percent of East Timorese voted for independence, pro-Indonesia and pro-independence forces fought each other, and thousands died or fled to West Timor (Nusa Tenggara Timur Province) to avoid the fighting. The violence began shortly after President Bacharuddin J. (B. J.) Habibie announced the referendum and continued until well after the vote. On October 25, 1999, the UN Transitional Administration in East Timor (UNTAET) was established, and on May 20, 2002, East Timor, as the Democratic Republic of Timor- Leste, became fully independent of Indonesia. Most of the estimated 200,000 refugees who went to West Timor had returned by 2003.

Another dispute has involved Indonesia's conflict with Australia over rights to the continental shelf off the coast of Timor. This problem was resolved in 1991 by a bilateral agreement calling for joint economic exploitation of the disputed area in the so-called "Timor Gap." Still other controversies arose regarding overflight rights in Papua (disputed with Papua New Guinea) and conflicting claims to the Spratly Islands in the South China Sea by Brunei, China, Malaysia, the Philippines, Taiwan, and Vietnam. Indonesia played the role of mediator in the Spratly Islands controversy. [Library of Congress]

Aceh and Papua

Two other regional struggles in recent times were in the Special Region of Aceh, in northwestern Sumatra, and in Papua. In Aceh, the long-standing conflict between the Free Aceh Movement and the Indonesian military intensified into an open secessionist effort. The struggle escalated in 1998, but two years later secret negotiations held in Geneva led to a Cessation of Hostilities Agreement signed on December 9, 2002. The parties had agreed to a dialogue leading to democratic elections and a cessation of hostilities. Within six months, however, the agreement had broken down, and martial law was declared in the province until May 2004.

Following the December 2004 earthquake and tsunami, a much more comprehensive peace agreement, brokered by former Finnish president Martti Ahtisaari, was officially signed in Helsinki on August 15, 2005, by chief Indonesian negotiator Hamid Awaluddin and GAM leader Malik Mahmud. The Indonesian government agreed to facilitate the establishment of Aceh-based political parties and to allow 70 percent of the income from local natural resources to stay within Aceh. On December 27, 2005, GAM leaders announced that they had disbanded their military wing and GAM itself was dissolved the next month.

Another important challenge to Indonesia’s sovereignty comes from the Free Papua Organization (OPM). After years of sabotage, secret meetings, and public demonstrations, OPM gained considerable international attention in January 1996 when members of the group kidnapped 14 members of a multinational World Wildlife Fund for Nature scientific expedition. All except two hostages were freed following negotiations; later a rescue operation was conducted in which six OPM members and the two remaining Indonesian hostages were killed. Although in 2001 local leaders were granted more financial and political autonomy and had been permitted a year earlier to change the name of their province from Papua to the locally more acceptable Papua, tension persists. (In 2003 Papua was subdivided into Papua and Papua Barat provinces; the latter was renamed Papua Barat in 2007.)

Amnesty International reported grave concern about acts of torture and prisoner abuse in 2000 by the Indonesian military. Demonstrations for Papuan independence intensified in 2006 in the wake of revelations of pollution caused by the Grasberg mine, a source of copper, gold, and silver operated by Phoenix, Arizona–based Freeport-McMoRan Copper and Gold. In 2008 Indonesian police arrested separatist leader Buchtar Tabuni as he was about to attend a massive rally in Jayapura, the capital of Papua, to show support for an international legislative caucus for Papua Barat. [Library of Congress]

Image Sources:

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Lonely Planet Guides, Library of Congress, Compton’s Encyclopedia, The Guardian, National Geographic, Smithsonian magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Wall Street Journal, The Atlantic Monthly, The Economist, Global Viewpoint (Christian Science Monitor), Foreign Policy, Wikipedia, BBC, CNN, and various books, websites and other publications.

Last updated June 2015

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