INDONESIA, the largest archipelago in the world to form a single state, consists of five main islands and some 30 smaller archipelagoes, totaling about 18,110 islands and islets of which about 6,000 are inhabited.

The name “INDONESIA” is composed of the two Greek words: “Indos” meaning India and “Nesos” meaning islands. The Indonesian archipelago forms a crossroad between two oceans, the Pacific and Indian oceans and a bridge between two continents, Asia and Australia. Because of its strategic position, therefore, Indonesia’s cultural, social, political and economic patterns have always been conditioned by its geographical position.

Geographical Features

The territory of the Republic of Indonesia stretches from 6°8′ north latitude to 11°15′ south latitude and from 94°45′ to 141°65′ east longitude. Its estimated total area is 9.8 million sq km (including Exclusive Economic Zone -EEZ), which consists of a land territory of 1.9 million sq km and a sea territory of 7.9 million sq km.

Indonesia’s five main islands are: Sumatra is about 473,606 sq km in size, Java -the most fertile and densely populated island- 132, 187 sq km, Kalimantan or two-thirds of the island of Borneo measuring 539,460 sq km, Sulawesi 189,216 sq km and Papua 421,981 sq km which forms part of the world’s second biggest island of New Guinea. The other islands are smaller in size.

The Indonesian archipelago is divided into three groups. The island of Java, Sumatra and Kalimantan, together with the small islands in between, lie on the Sunda Shelf which begin on the coasts of Malaysia and Indo China, where the sea depth does not exceed 700 feet. Papua which is part of the island of New Guinea, and the Aru Islands lie on the Sahul Shelf, which stretches northwards from the Australian coast. Here the sea depth is similar to that of the Sunda Shelf. Located between two shelves is the island group of Nusa Tenggara, Maluku and Sulawesi, where the sea depth reaches 15,000 feet.

The Country’s land area is generally covered by thick tropical rain forests where fertile soils are continuously replenished by volcanic eruptions like that on the island of Java. The island of Java has 112 volcanic centers of which 15 are active. The lava ejected has a high degree of fertility.

An additional advantage of the island of Java is that its coastal plains are neither edged by wide swamps as in the case of Sumatra, Kalimantan and Papua, nor bordered by coral reefs as in the case of the island of Sulawesi. On the island of Sumatra there is plenty of evidence of past volcanic activities, although the ejected material contained acid which is of less fertility compared with Java.

Climate and Weather

Indonesia‘s climate and weather is characterized by an equatorial double rainy season. Its variation is caused by the equatorial circulation (Walker circulation) and the meridian circulation (Hardley circulation). The displacement of the latter circulation is closely related to the North-South movement of the sun and its position at a certain period with regard to the earth and the continents of Asia and Australia. These factors contribute to the displacement and intensity of the Inter-Tropical Convergence Zone (ITCZ) being an equatorial through of low pressure. This characterizes the weather of Indonesia, while the prevalence of the West monsoon and the East monsoon (the rainy and dry seasons) are characterizing Indonesia’s climate.

Indonesia‘s monsoon-type climate changes approximately every six months although in recent years weather patterns have been somewhat disrupted as part of global changes in weather. Humidity and temperatures are varying according to the season but temperatures are affected additionally by rime of day, height above sea level and proximity to the sea and exception. The dry season is from June to September and the rainy season from December to March. Intervening periods are transition months in which the weather will be mixed.

Average temperatures are classified as follows: Coastal plains: 28°C; inland and mountain areas: 26°C; higher mountain areas: 23°C, varying with the altitude. Indonesia has an average relative humidity between 70 percent and 90 percent, with a minimum of 73 percent and a maximum of 87 percent.

Indonesia Standard Time

Indonesia‘s three time zones are as below:

1. Western Indonesia Standard Time equals GMT plus 7 hours (meridian 105 ‘0 E), covering all provinces in Sumatra and Java, and the provinces of West and Central Kalimantan.

2. Central Indonesia Standard Time equals GMT plus 8 hours (meridian120’0 E), covering the provinces of East and South Kalimantan, all provinces in Sulawesi, and the provinces of Bali, West and East Nusatenggara.

3. Eastern Indonesia Standard Time equals GMT plus 9 hours (meridian 135°E), covering the provinces of Maluku and Papua.