GEOGRAPHY OF JAVA ISLAND

Most populated island of Indonesia, situated between Sumatra and Bali; area (with the island of Madura) 132,000 sq km/51,000 sq mi; population (with Madura; 2000 est) 118,230,300. The capital is Jakarta (which is also the capital of Indonesia). The island is divided into three provinces: Jawa Tengah, Jawa Timur, and Jawa Barat, together with Jakarta Raya (the Jakarta metropolitan district). About half the island is under cultivation, the rest being thickly forested. Mountains and sea breezes keep the temperature down, but humidity is high, with heavy rainfall from December to March. Ports include Surabaya and Semarang.

Java is crossed from east to west by a chain of mountains rising to 2,750 m/9,000 ft. Of these mountains, 112 are volcanic and 35 are active. Eruptions of Mount Merapi (2,911 m/9,551 ft) killed 1,300 people in 1930 and 64 people in 1994. The highest mountain, Semeru (3,676 m/12,060 ft), is in the east. The weathering of volcanic ash has given rise to fertile soils which has helped to produce a very productive agriculture. About 40% of the cultivated land consists of rice terraces, while major commercial crops include rubber, coffee, tea, sugar, quinine, tobacco, cacao, and timber. Mineral wealth includes petroleum, coal, tin, gold, and silver. Industries on the island at centres such as Jakarta, Bandung, and Surabaya are largely based on the processing of these agricultural and mineral products, with the addition of timber processing, chemicals, shipbuilding, and motor vehicle assembly. The population is predominantly Muslim, and includes people of Javanese, Sundanese, and Madurese origin, with differing languages.

Java, the most populous island of Indonesia. It is bordered on the north by the Java Sea and on the south by the Indian Ocean. Straits separate it from Madura to the northeast, Bali to the east, and Sumatra to the west. Java is about 650 miles (1,050 km) long (east-west) and up to 130 miles (210 km) wide. Its area is 48,842 square miles (126,500 km2).

A great mountain range with many active volcanoes runs along Java's length. Semeru, the highest peak, is 12,060 feet (3,676 m) above sea level. The weather is hot and damp in the lowlands, with no seasonal variation; the highlands are cooler. Java has several important seaports, and major cities are linked by road, rail, and air. Every piece of land fit for cultivation is intensively farmed; rice is grown on terraced hillsides. Other agricultural products are sugar, coffee, tea, rubber, cocoa, corn, cassava, soybeans, and yams. Teak is an important lumber product. Petroleum is the leading mineral resource.

The total population of Java and neighboring Madura in 2000 was 121,352,608. With a population density of nearly 2,485 persons per square mile (960 per km2), Java is perhaps the most crowded area of its size on earth.

Java's largest cities are Jakarta, the national capital (9,373,900); Surabaya (2,801,300); and Bandung (5,919,400).

Java Man, an early form of human, lived on Java more than 600,000 years ago. Hindu traders came to Java after the first century A.D.and established powerful kingdoms. By about 1500 the islanders had been converted to Islam. In 1619 the Dutch founded Batavia (now Jakarta) and gradually spread their rule over the island. The British ruled Java briefly, 1811–16. Following Japanese occupation in World War II, nationalist groups demanded independence from the Netherlands. In 1949 Java became part of the Indonesian Republic, reorganized as the Republic of Indonesia in 1950.

JAVA

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Java (Indonesian: Jawa) is an island of Indonesia and the site of its capital city, Jakarta. Once the centre of powerful Hindu kingdoms, Islamic Sultanates, and the core of the colonial Dutch East Indies, Java now plays a dominant role in the economic and political life of Indonesia. Housing a population of 130 million in 2006, it is the most populous island in the world, ahead of Honshu, the main island of Japan. Java is also one of the most densely populated regions on Earth.

Formed mostly as the result of volcanic events, Java is the 13th largest island in the world and the fifth largest island in Indonesia. A chain of volcanic mountains forms an east-west spine along the island. It has three main languages, and most residents are bilingual, with Indonesian as their second language. While the majority of Javanese are Muslim, Java has a diverse mixture of religious beliefs and cultures.

SUMATERA ISLAND

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

A 16th century map of Sumatra
By the late 13th century, the monarch of the Samudra kingdom had converted to Islam. Marco Polo visited the island in 1292 and Ibn Battuta visited twice during 1345-1346. 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 (1870-1905).
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. In addition to the subduction megatrust 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.

Administration
The administrative regions of Sumatra (or the smaller islands nearby) are:
Aceh - capital: Band Aceh
Bangka-Belitung - capital: Pangkalpinang
Bengkulu - capital: Bengkulu
Jambi - capital: Jambi
Lampung - capital: Bandar Lampung
Riau - capital: Pekanbaru
Riau Islands - capital: Tanjung Pinang
West Sumatra (Sumatera Barat) - capital: Padang
South Sumatra (Sumatera Selatan) - capital: Palembang
North Sumatra (Sumatera Utara) - capital: Medan

Geography
The longest axis of the island runs approximately 1,790 km (1,100 miles) northwest - southeast, crossing the equator near the center. At its widest point the island spans 435 km (270 miles). The interior of the island is dominated by two geographical regions: the Barisan Mountains in the west and swampy plains in the east.
To the southeast is Java, separated by the Sunda Strait. To the north is the Malay Peninsula, separated by the Straits of Malacca. To the east is Borneo, across the Karimata Strait. West of the island is the Indian Ocean.
The backbone of the island is the Barisan mountains chain, with the active volcano Mount Kerinci's 3,805 m (12,467 ft) the highest point, located at about the midpoint of the range. The volcanic activity of this region endowed the region with fertile land and beautiful sceneries, for instance around the Lake Toba. It also contains deposits of coal and gold.
To the east, big rivers carry silt from the mountain, 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 low lands. 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.
Most of Sumatra used to be covered by tropical rainforest, but economic development coupled with corruption and illegal logging has severely threatened its existence. Conservation areas have not been spared from destruction, either.
The island is the world's 5th highest island, although only the third highest in the Indonesian archipelago.

Flora and fauna
Rafflesia arnoldii
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: Sumatran Pine, Rafflesia arnoldii (world's largest individual flower), Titan arum (world's tallest and largest inflorescence flower).
The island is home to 201 mammal species and 580 bird species. There are 9 endemic mammal species on mainland Sumatra and 14 more endemic to the nearby Mentawai Islands. The species present include: Sumatran Tiger, Sumatran Orangutan, Sumatran Rhinoceros, Sumatran Elephant, Sumatran Striped Rabbit, Dhole, Dayak Fruit Bat, Malayan Tapir, Malayan Sun Bear and the Bornean Clouded Leopard.
The major threats to Sumatran forest are the pulp and paper industry and expansion of palm oil plantations.
The island includes more than 10 National Parks, including 3 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.

Demographics
Minangkabau women carrying platters of food to a ceremony
Sumatra is not very densely populated, about 96 people per km²—more than 45 million people in total. It is nonetheless the fifth most populous island in the world. The most populous regions include most of North Sumatra and central highlands in West Sumatra, while the major urban centers are Medan and Palembang.
The people composed of many different ethnic groups, speaking 52 different languages. Most of these groups, however, share many similar traditions and the different tongues are closely related. Malay-speaking people dominate the eastern coast, while people in the southern and central interior speak languages related to Malay, such as the Lampung and Minangkabau people. The highland of northern Sumatra is inhabited by the Bataks, while the northernmost coast is dominated by Acehs. Ethnic Chinese minorities are also present in urban centers.
A majority of people in Sumatra are Muslims (87%), while 10% are Christians, 2% are Buddhist and 1% Hindu. Most central Bataks are Protestant Christians—a religion introduced by Ludwig Ingwer Nommensen, a German.

From: Wikipedia

JAKARTA : THE CAPITAL CITY OF INDONESIA

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Jakarta is the capital of Indonesia and the largest citi of Indonesia. Jakarta has a greater population than any other city in Southeast Asia. Home to over 10 million people, Jakarta is always bustling, from the sound of the wheel of government turning to the sight of the economy churning. Skyscrapers, single story residential houses, modern apartment complexes, survivalists shanties - all coexist in this city.

Jakarta was formerly known as Sunda Kelapa (397-1527), Jayakarta (1527-1619), Batavia (1619-1942), and Djakarta (1942-1972). Located on the northwest coast of the Java Island, it has an area of 661.52 square kilometres (255.41 sq mi) and an official population of 8,389,443 (2000). Jakarta currently is the eleventh largest city in the world.

As the economic and political capital of Indonesia, Jakarta attracts many foreign as well as domestic immigrants. As a result, Jakarta has a decidedly cosmopolitan flavor and a diverse culture. Many of the immigrants are from the other parts of Java Island, bringing along a mixture of dialects of the Javanese and Sundanese languages, as well as their traditional foods and customs.

Jakarta is sometimes called "The Big Durian" by foreigners resident in the city. The durian is a tropical fruit with a distinctive odor and acquired taste. A bustling urban metropolis, Jakarta is known for its overcrowding, traffic congestion, and income disparity.

Jakarta has several performance centers, such as the Senayan center. Traditional music is often found at high-class hotels, including wayang and gamelan performances. As the nation's largest city and capital, Jakarta has lured much national and regional talent who hope to find a greater audience and more opportunities for success.

Jakarta Interesting Places

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There are a good number of recreation and sports activities available in Jakarta that will appeal to various members of the family. The American Embassy Recreation Association or AERA, usually called just the American Club, is very popular and centrally located in Kebayoran Baru. Membership is open to Americans and limited numbers of other nationalities. The facilities include an open-air restaurant and air-conditioned bar/restaurant, family recreation room, children's playroom, a very well equipped fitness center, large swimming pool and small pool and play area for young children, as well as basketball and tennis courts. AERA offers a wide variety of classes and activities and monthly celebrations of special events.

There are several water parks where children can enjoy swimming in various kinds of pools with water slides, etc. One is Pondok Indah Water Park adjacent to Pondok Indah Mall, and it's also worth going out to Lippo Cikarang in Bekasi, to spend a day at Water Boom, a beautifully landscaped park. Ancol Dreamland in North Jakarta also has the Gelanggang Renang "Water Park" featuring a large swimming pool with slides, wave pool, and children's pool.

To learn a little more about the cultures and ethnic groups across the Indonesian archipelago, it's well worth a visit to Taman Mini Indonesia Indah or the "Beautiful Indonesia in Miniature Park"; it's advisable to go on a weekday as Sundays in particular can be extremely crowded. The park features full size replicas of traditional houses from all the provinces of the Indonesian archipelago with displays of clothing, arts and handicrafts, numerous museums with different themes, an IMAX theater, bird aviary, orchid garden, a man-made lake with the islands of Indonesia, as well as a monorail and cable cars.

The Museum National is located on the side of Merdeka Square or Lapangan Merdeka and was built in 1862 at that time Dutch colonial administration realized about the great treasure of Indonesian cultural heritages and long history of Indonesia. The biggest surprised for the Western historians was the fact that historical record in Indonesia showing tremendous level of similarities with those in India.

At Taman Ismail Marzuki in Central Jakarta there is a planetarium with shows twice daily and a presentation in English can be arranged in advance. Taman Ismail Marzuki is Jakarta's showcase in cultural performances. As it is well known Java island including west Java which is called Sunda had strongly influenced by the Hindu tradition in the past. The Hindu tradition, especially initiated by the palaces, were various entertainments.

The Ragunan Zoo in South Jakarta, not far from popular expatriate residential areas ,is home to over 250 species from Indonesia and throughout the world and is set in over 135 hectares of parklands. This is a relatively green and shady place where you can enjoy walking or cycling and a picnic lunch. Once again it's best to avoid Sundays and public holidays as its very crowded.
Centrally located Taman Ria Senayan is an amusement park with ferris wheel, roller coaster, various other rides and pedal boats on a small lake, plus numerous restaurants and an excellent clothing factory outlet.

Taman Impian Jaya Ancol or Ancol Dreamland is a huge oceanfront recreational facility in North Jakarta featuring the water park mentioned above, a marina for boating, a golf course, as well as the following theme parks and attractions:
- Dunia Fantasi "Fantasy World" - rides include roller coasters, bumper cars, flume ride, carousel, and boat ride.
- Gelanggang Samudra "Oceanarium" - variety animal show, birds and orangutan show, sealion show, dolphin show, as well as a boat ride through tropical gardens.
- Sea World - large tanks with all sorts of sea creatures, touching pool with starfish, anemones, and walk through underwater tunnel where you are surrounded by sharks, turtles, manta rays and other marine life.
- Pasar Seni "Art Market" - art objects and handicrafts from thoughout the country, cultural events and performances.

Many shopping centers and malls have food courts, restaurants, indoor recreation facilities such as rides and arcade games, as well as multiplex cinemas. Many of the latest movies are screened in Jakarta not too long after their international release, with English soundtracks and Indonesian subtitles.

THE GEOGRAPHIC OF INDONESIA

Area total: 1,919,440 km², land: 1,826,440 km², water: 93,000 km².
Land boundaries total: 2,830 km, border countries: Malaysia 1,782 km, Papua New Guinea 820 km, East Timor 228 km, Other nearby countries: India NW of Acheh, Australia, Singapore, Philippines, Brunei.
Coastline 54,716 km.
Maritime claims measured from claimed archipelagic baselines exclusive economic zone: 200 nautical miles (370 km)territorial sea: 12 nautical miles (22 km).

Indonesia is an archipelagic country extending 5,120 kilometers from east to west and 1,760 kilometers from north to south. It encompasses and estimated 17,508 islands, only 6,000 of which are inhabited. It comprises five main islands; Sumatera, Java, Kalimantan (Borneo), Sulawesi, and New Guinea; two major archipelagos (Nusa Tenggara and the Maluku Islands); and sixty smaller archipelagos. Three of the islands are shared with other nations; Borneo is shared with Malaysia and Brunei, Timor is shared with East Timor, and the newly divided provinces of Papua and West Papua share the island of New Guinea with Papua New Guinea. Indonesia's total land area is 1,919,317 square kilometers. Included in Indonesia's total territory is another 93,000 square kilometers of inlands seas. 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.

Geographers have conventionally grouped Sumatra, Java (and Madura), Kalimantan (in Borneo island), and Sulawesi 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. At Indonesia's eastern extremity is Papua, 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 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.

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 150 are active. 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 tidal wave.

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 are located in the Jayawijaya Mountains and the Sudirman Mountains in Papua. The highest peak, Puncak Jaya, also known as Mount Carstenz, which reaches 4,884 meters, is located in the Sudirman Mountains.
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.
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 region between north and south.

The main variable of Indonesia's climate is not temperature or air pressure, but rainfall. The almost uniformly warm waters that make up 81 % of Indonesia's area ensure that temperatures on land remain fairly constant. Split by the equator, the archipelago is almost entirely tropical in climate, with the coastal plains averaging 28 °C, the inland and mountain areas averaging 26 °C, and the higher mountain regions, 23 °C. The area's relative humidity ranges between 70 and 90 %. Winds are moderate and generally predictable, with monsoons usually blowing in from the south and east in June through September and from the northwest in December through March. Typhoons and large scale storms pose little hazard to mariners in Indonesia waters; the major danger comes from swift currents in channels, such as the Lombok and Sape straits.

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 and the shortest day of the year is only forty-eight minutes. The archipelago stretches across three time zones: Western Indonesian Time--seven hours in advance of Greenwich Mean Time (GMT)--includes Sumatra, Java, and eastern Kalimantan; Central Indonesian Time--eight hours head of GMT--includes western Kalimantan, Nusa Tenggara, and Sulawesi; and Eastern Indonesian Time--nine hours ahead of GMT-- includes 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 central and eastern time zones runs north from the eastern tip of Timor to the eastern tip of Sulawesi.

For centuries, the geographical resources of the Indonesian archipelago have been exploited in ways that fall into consistent social and historical patterns. One cultural pattern consists of the formerly Indianized, rice-growing peasants in the valleys and plains of Sumatra, Java, and Bali; another cultural complex is composed of the largely Islamic coastal commercial sector; a third, more marginal sector consists of the upland forest farming communities which exist by means of subsistence swidden agriculture. To some degree, these patterns can be linked to the geographical resources themselves, with abundant shoreline, generally calm seas, and steady winds favoring the use of sailing vessels, and fertile valleys and plains--at least in the Greater Sunda Islands--permitting irrigated rice farming. The heavily forested, mountainous interior hinders overland communication by road or river, but fosters slash-and-burn agriculture.

Each of these patterns of ecological and economic adaptation experienced tremendous pressures during the 1970s and 1980s, with rising population density, soil erosion, river-bed siltation, and water pollution from agricultural pesticides and off-shore oil drilling. In the coastal commercial sector, for instance, the livelihood of fishing people and those engaged in allied activities--roughly 5.6 million people--began to be imperiled in the late 1970s by declining fish stocks brought about by the contamination of coastal waters. Fishermen in northern Java experienced marked declines in certain kinds of fish catches and by the mid-1980s saw the virtual disappearance of the terburuk fish in some areas. Effluent from fertilizer plants in Gresik in northern Java polluted ponds and killed milkfish fry and young shrimp. The pollution of the Strait of Malacca between Malaysia and Sumatra from oil leakage from the Japanese supertanker Showa Maru in January 1975 was a major environmental disaster for the fragile Sumatran coastline. The danger of supertanker accidents also increased in the heavily trafficked strait.

THE PETROLEUM GEOLOGY OF INDONESIA

Introduction
Indonesia is the largest archipleagic state in the world comprising five major islands and about 300 smaller island groups. Altogether there are 13,667 islands and islets of which about 6,000 inhabited. The archipelago is situated on a crossroad between two oceans, the Pacific and Indian oceans, and bridges two continents, the Asian and Australian. Indonesia has a total area of 9,8 million sq km, of which more than 7,9 million sq km under water. Physiographically, the islands of Sumatra, Java and Kalimantan are attached to the Sunda Shelf of the Asian continent. On this landmass the water depth does not exceed 200 meters. To the east, Irian Jaya and the Aru islands lie on the Sahul Shelf, which are parts of the Australian continent. Located between these two shelfal is the island grop of Nusa Tenggara, Sulawesi, Maluku and Halmahera. These islands are encircled by deep seas which in many places reach 5,000 meters. About 60 Tertiary sedimentary basins, spread out from Sumatra in the west to Irian Jaya in the east, are identified in Indonesia. So far only 38 basins have been explored and drilled for petroleum and 14 of the are now producing oil and gas. Seventy three percent of these basins are located offshore, about one third of them in the deeper sea, with water depth exceeding 200 m.
The basic premise to explore the petroleum is the existence of sedimentary basin. Sedimentary basin is a depression on the earth surface the can accummulated the sedimentation material through time. Since most of the sediment transporting agent are water, the sedimentary basin usually the place where the water finally accummulate. It can be in the form of sea, lake, delta, or river.
Indonesia is a large country with various type of sedimentary basins. Most of the sedimentary basin in the western Indonesia are already explored since the end of 19th century. The recent years also saws the exploration on the frontier basins, especially in the eastern Indonesia. Unfortunately, the interest of the major oil companies lost their appetite to conduct explorationa activities in Indonesia probably due to the unfavorable fiscal regime. As a result, the oil and gas production is keep declining in Indonesia without any substantial reserve replacement.
The sediment which comprise of clay, sand, boulder or carbonate are being deposited in the sedimentary basin over a geologic time (million years). Due to the weight of the sedimentary deposit, the sedimentary basin experience subsidence to allow more sedimentation. This sedimentary process may accummulate sediment with cumulative thickness of several thousand meters.

Structural Geology
The tectonics processes in Indonesia formed major structures in Indonesia. The most prominent fault in the west of Indonesia is the Semangko Fault, a dextral strike-slip fault along Sumatra Island. The formation of this fault zone is related to the subduction zone in the west of Sumatra.
Palu-Koro fault is another major structural feature formed in the central part of Indonesia. This fault has similar orientation as the Semangko fault, extend from Koro in central part of Sulawesi, to Palu in the west coast of Sulawesi and extend across the Makassar strait to East Kalimantan.

Stratigraphy
The stratigraphy of the western part of Indonesia is relatively young, ranged from Paleogene to Quarternary. The eastern Indonesia has older stratigraphy compare to the western part. The stratigraphy range from Triassic to Tertiary. Devonian limestone were found in Telen River, East Kalimantan, as fragments within Paleogene clastic sediments. Ichthyosaur fossils were found in the mud volcanoes in Kai Island, indicated Mesozoic deposit in the subsurface.

Characteristics
About 60 Tertiary sedimentary basins, spread out from Sumatra in the west to Irian Jaya in the east, are identified in Indonesia. So far only 38 basins have been explored and drilled for petroleum and 14 of the are now producing oil and gas. Seventy three percent of these basins are located offshore, about one third of them in the deeper sea, with water depth exceeding 200 m.

Back-arc Basin
The most prolific sedimentary basin in Indonesia are belong to back-arc basin, whichis located on the 'back' of the volcanic-arc. Most of the back-arc basin located in the northeastern coast of Sumatra, northern Java, and continue to northern Lesser Island. Almost all of the back-arc basin are currently producing oil and gas, therefore categorized as proven petroleum province.

Fore-arc Basin
The fore-arc basin located to the 'front' of the volcanic arc, which is located along southwestern coast of Sumatra, southern coast of Java and Lesser Island. The fore-arc basin is mainly considered as a frontier basin and no commercial hydrocarbon found yet. However, there is strong indication of working petroleum system in the fore-arc basin, such as gas discoveries in the Nias area. Oil shows also reported to be found in offshore Bengkulu (Southern Sumatra). On the interesting note, the fore-arc basin in the southern part of Papua New Guinea already found commercial gas accummulation in the Pandorra Gas Field.

Bali Island

Bali is one of Indonesian island, the westernmost of the Lesser Sunda Islands, lying between Java to the west and Lombok to the east. It is one of the country's 33 provinves with the provincial capital at Denpasar towards the south of the island.

With a population recorded as 3,151,000 in 2005, the island is home to the vast majority of Indonesia's small Hindu minority. 93.18% of Bali's population adheres to Balinese Hinduism, while most of the remainder follow Islam. It is also the largest tourist destination in the country and is renowned for its highly developed arts, including dance, sculpture, painting, leather, metalworking and music.

The island of Bali lies 3.2 km (2 mi) east of Java, and is approximately 8 degrees south of the equator. East to west, the island is approximately 153 km (95 mi) wide and is approximately 112 km (69 mi) north to south; it's land area is 5,632 km². The highest point is Mount Agung at 3,142 m (10,308 feet) high, an active volcano that last erupted in March 1963. Mountains cover centre to the eastern side, with Mount Agung the easternmost peak. Mount Batur (1,717 m) is also still active, an eruption 30,000 years was one of the largest known volcanic events on earth. In the south the land descends to form an alluvial plain, watered by shallow, north-south flowing rivers, drier in the dry season and overflowing during periods of heavy rain. The longest of these rivers, Sungai Ayung, is also the longest on the island (approx. 75 km).

The principal cities are the northern port of Singaraja, the former colonial capital of Bali, and the present provincial capital and largest city, Denpasar, near the southern coast. The town of Ubud (north of Denpasar), with its art market, museums and galleries, is arguably the cultural centre of Bali.
There are major coastal roads and those that cross the island mainly north-south. Due to the mountainous terrain in the island's center, the roads tend to follow the crests of the ridges across the mountains. There are no railway lines.
The island is surrounded by coral reefs. Beaches in the south tend to have white sand while those in the north and west have black sand. The beach town of Padangbai in the south east has both. The Ho River is navigable by small sampan boats. Black sand beaches between Pasut and Klatingdukuh are being developed for tourism, but apart from the seaside temple of Tanah Lot.

INDONESIA

The Republic of Indonesia (Indonesian: Republik Indonesia), is a country in Southeast Asia. Comprising 17,508 islands, it is the world's largest archipelagic state. With a population of 222 million people in 2006, it is the world's fourth most populous country and the most populous Muslim-majority nation, although officially it is not an Islamic state. Indonesia is a republic, with an elected parliament and president. The nation's capital city is Jakarta. The country shares land borders with Papua New Guinea, East Timor and Malaysia. Other neighboring countries include Singapore, Philippines, Australia, and the Indian territory of the Andaman and Nicobar Islands.
The Indonesian archipelago has been an important trade region since at least the seventh century, when the Srivijaya Kingdom formed trade links with China. Indonesian history has been influenced by foreign powers drawn to its natural resources. Under Indian influence, Hindu and Buddhist kingdoms flourished from the early centuries CE. Muslim traders brought Islam, and European powers fought one another to monopolize trade in the Spice Islands of Maluku during the Age of Discovery. Following three and a half centuries of Dutch colonialism, Indonesia secured its independence after World War II. Indonesia's history has since been turbulent, with challenges posed by natural disasters, corruption, separatism, a democratization process, and periods of rapid economic change.
Across its many islands, Indonesia consists of distinct ethnic, linguistic, and religious groups. The Javanese are the largest and most politically dominant ethnic group. As a unitary state and a nation, Indonesia has developed a shared identity defined by a national language, a majority Muslim population, and a history of colonialism and rebellion against it. Indonesia's national motto, "Bhinneka tunggal ika" ("Unity in Diversity" lit. "many, yet one"), articulates the diversity that shapes the country. However, sectarian tensions and separatism have led to violent confrontations that have undermined political and economic stability. Despite its large population and densely populated regions, Indonesia has vast areas of wilderness that support the world's second highest level of biodiversity. The country is richly endowed with natural resources, yet poverty is a defining feature of contemporary Indonesia.

The most populous of the Indonesian islands by far is Java, home to the sprawling capital city of Jakarta. Other notable islands include the exotic, popular resort island of Bali, Lombok, Catholic Flores, and Komodo, home of dragons.
Indonesia, The Land of Adventure! This country consist of more than 17,000 islands. Four-fifths of the area is occupied by the sea, with the major islands of : Sumatra, Java, Borneo, Sulawesi and Irian Jaya and ... Bali. Dotted with volcanoes, covered with thick tropical rainforest and bright green rice fields, and surrounded by coral reefs, make this archipelago is one of the world's most beautiful places. Unique cultures & tribes of Borneo, Irian Jaya, Nias/Mentawai and many more can be found. Indonesia amazingly rich in wildlife animal, plant life, and underwater marine species.