Indonesia - a large state in Southwest Asia - is not for nothing called the country of a thousand islands. It spreads over parts of New Guinea, the Moluks and Sunda Islands, the largest of which are Borneo, Sulawesi, Java, Sumatra, the islands of Timor, Flores, Sumbawa, Bali and others. The three islands of the Republic of Indonesia are among the six largest on the planet.
Tropical paradise
The islands of Indonesia are a colorful carpet of a mixture of peoples, cultures, diverse landscapes, climatic zones. One of the most amazing is Sumatra, which many call the continent in miniature. There are tropics and savannahs, lowland marshes and high mountains. The island is inhabited by rhinos and elephants, tigers and leopards, bears and buffaloes - a large fauna that is not characteristic of the islands.
Geographical position
Sumatra Island is one of the largest islands in the Malay Archipelago. It extends from the northwest to the southeast for 1800 km. The area of the island is 421,000 km 2 . It is formed by a system of mountain ranges extended far to the west. Their highest points are located at a distance of 30-50 km from the Indian Ocean. They have no names. The southern sections are known as the Barisan ridge; in the northern part of the island, the Batak plateau rises.
Around the "mother" of the island there are smaller land areas. Mountainous sparsely populated territories lined parallel to Sumatra from the Indian Ocean: Mentawai, Nias, Engano. Sinkep, Banka, Belitung are located along the eastern coast. Simalur (Simelue) - an Indonesian island west of Sumatra became notorious. In 2004, a giant tsunami hit its coast.
Very close, northeast, is the Malay Peninsula - part of the Asian continent. From Sumatra, the Strait of Malacca shares it. The most important shipping routes pass here: rich cargoes attract real pirates of the 21st century, robbing ships. To the east, 420 km, is the "elder brother" - the island of Borneo (Kalimantan). Between the "relatives" runs the Karimat Strait. The most densely populated Indonesian island of Java is separated from Sumatra by the 25 km wide Sunda Strait.
The question "where is Sumatra" can be answered simply: between Australia and Asia. And more precisely - in the extreme west of the Malay archipelago, in the triangle between Java, Kalimantan and the Malay Peninsula.
Geology
The Sumatra Mountains formed partly in the Hercynian, partly in the Mesozoic and later Paleogene folding, they also have young longitudinal faults. They are composed of quartzites, crystalline schists, and Paleozoic limestones; there are outcrops of granite intrusions. The average height of the mountains is from 1,500 to 3,000 m.
The Barisan ridge is divided by a longitudinal zone of faults and grabens into two parallel chains. The island is crowned with numerous cones of active and extinct volcanoes, among which the highest volcano on Sumatra is Kerinchi (Indrapura), 3800 m high, followed by Dempo (3159 m) and Marapi (2891 m). Only twelve operating giants.
Between Sumatra and neighboring Java, in the Sunda Strait, lies the stratovolcano Krakatau (813 m). His eruptions are rare, but they are catastrophic destruction. The last activity here was observed in 1999. In the years 1927-1929. as a result of an underwater explosion, the island of Anak-Krakatau was formed. And the eruption of 1883 actually destroyed the once-high island - a blast wave was felt on all continents, circling the Earth three times.
Relief
In contrast to the southwestern mountain range, in the east of Sumatra lies a large boggy alluvial lowland. A feature of the area is that its coastal part is flooded by sea tides. There are favorable conditions for extensive mangroves. Sumatra, the islands of the Bank and Belitung are rich in various types of minerals: oil, coal, gold, manganese, iron, nickel, tin.
Climate
The Malay Archipelago on the map is located in the equatorial belt, between Asia and Australia. The climate is humid. The amount of precipitation in Sumatra in places exceeds 3500-3800 mm (reaches 6000 mm), however, it falls unevenly. A large amount of rain is caused by a mountain barrier that extends along the entire island. The maximum moisture falls in October-November north of the equator, and in December-January - south of it. In the north, the season with less rainfall is more pronounced than in the south. The temperature is comfortable - 25-27 degrees almost throughout the whole year, however incredibly high humidity spoils the idyllic picture.
In the east of the island and in the Strait of Malacca , strong east winds often blow. They achieve the greatest strength during the action of the southwest monsoon. Basically, this hurricane wind, accompanied by a thunderstorm, is observed at night - obviously, this is facilitated by the Sumatra mountain range, which extends parallel to the Strait of Malacca.
Water land
The islands of Indonesia, due to heavy rainfall, have excess moisture. Due to this, in most regions numerous rivers flow. Sumatra is no exception: the river network is quite dense, water flows do not dry out during the year, washing away a lot of sediment from the mountains. The largest rivers of the island are Muse, Hari, Kampar, Rokan, Inderaghiri.
There are many lakes on the island. In the center of the tuff plateau Batak in the volcanic hollow lies the largest lake in Indonesia - Toba, with the island of Samosir in the middle. At one time, there was a separate Batak principality, the descendants of which, according to legend, settled throughout Sumatra. The lake is located at an altitude of 904 m above sea level. The area is more than 1000 km 2 and the maximum depth is 433 meters. It's cool here, especially at night. A 320,000 kW hydroelectric power station was built on the Asahan River flowing from a reservoir.
Soil cover
The most common soil types are podzolized laterites, which formed on the weathering crust. On the foothills and in the mountains, soils are represented by a variant lateritic mountain. In the east, alluvial and bog soils stretch in a wide strip, and mangrove in the narrow coastal strip.
Vegetation
The geographical position of Sumatra at the equator contributes to the growth of dense tropical forests, they occupy large spaces. Unfortunately, in the river valleys, on the plains and in mountain depressions, large areas of forest are cut down, and a variety of crops are grown in the developed territories. Rubber trees, rice, coconut, tobacco, tea, cotton, pepper are widely cultivated on the island.
The most typical forest species are:
- rasamal and ficus;
- several types of palm trees: sugar, palmyra, walnut, karyota, rattan; in the lower reaches of the rivers and in the swamps - nipa; coconut - in the coastal zone;
- peculiar tree-like ferns, huge bamboos (up to 30-40 m high), endemic amorphous falus and parasite rafflesia.
Mangroves prevail on the northeastern low coast. On the intermontane low areas, small areas are occupied by savannas. At heights of 1.5-3 km, forests with a predominance of evergreen trees (laurel, oak) are widespread, there are coniferous, broad-leaved deciduous (chestnut, maple) trees. Above 3000 m, forests are replaced by undersized thickets with falling leaves, shrubs and grasses.
Fauna
The island fauna is predominantly represented by forest species. The jungle of Sumatra has become a mecca of ecotourists who want to get acquainted with the life of one of the most interesting species of monkeys - orangutans.
Also typical mammals are primates (thick lori, siamang, pig tailed macaque, brownie macaque), woolly wings, lizards, squirrels, badgers, bats. Among the large inhabitants there are two-horned rhinoceros, Indian elephant, Sumatran tiger, black tapir, leopard, striped pig, island Wevera, Malay bear, wild dogs.
Of the birds, the most interesting are homray, argus, horned beak, several species of pigeons. From reptiles on the island are flying dragons, gavials (crocodiles), snakes. A legless worm stands out from amphibians. A lot of different insects, arachnids.
Dormant Super Volcano
Sumatra Island on the map is not much different from neighboring lands, but it was here that 73,000 years ago an epochal cataclysm occurred that changed the history of the Earth. The explosion of a supervolcano gave rise to the so-called volcanic winter, reminiscent of a nuclear one. In addition to 3000 km 3 of ash, a huge amount of anhydride was released into the atmosphere, which provoked the widespread precipitation of acid rain.
Unnaturally low temperature reigned for six years on the planet, acid rains destroyed vegetation. The next millennium is characterized by cooling and the onset of glaciers. As a result, only the most intelligent survived from the large human population - about 10,000 representatives of the species Homo sapiens in the heart of Africa. In fact, a natural disaster contributed to the "explosive" development of intelligence in our distant ancestors.
Toba Lake
Sumatra - islands with amazing nature. The most striking geological and cultural attraction is the largest lake on the planet of volcanic origin Toba, which filled a giant crater of the very supervolcano. Its dimensions (length - 100 km, width - 30 km, depth - 505 m) allowed the reservoir to become the largest in Indonesia and the second (after Lake Tonle Sap) in Southeast Asia.
On the lake Toba is located the picturesque island of Samosir. It is famous for its incredible landscapes, nature, authentic culture. Not only Muslims live here, but also a people called Batak. They are Christians, they have very peculiar folk traditions, art, and especially architecture. Samosir is quite small, the length of its coastline is 111 km. But in this small territory, developed tourist centers, the “untouched” natural landscape, and the everyday life of Sumatran peasants organically fit in organically.
Although the water in Toba is fresh, its transparency, azure, the surrounding landscapes and microclimate resemble the Mediterranean coast. The only violation of this association is the absence of large waves, which for many tourists is a great advantage.
Population
More than 300 peoples live in Indonesia, with linguists numbering 719 living languages and dialects. About 90% of citizens, including in Sumatra, are Muslims. Most of the islanders know the Indonesian language, which is only 50 years old. It unites different peoples and nationalities in the country, it is studied in schools, it dominates television and the press.
In the western region (Bank, Sumatra, Mentawai Island, Ling archipelago and others) there are more than 50 million people who speak 52 languages. In the north and east of Sumatra and on numerous islands, Malays dominate, in the south - Javanese. The Chinese and Tamils are concentrated in urban centers.
Less than a third of the population lives in cities. Largest megacities:
- Medan - 2.1 million people (2010).
- Palembang - 1.5 million (2010).
- Batam (Riau Islands) - 1.15 million (2012).
- Pekanbaru - 1.1 (2014).
In the central highlands and around Lake Toba, amazing people live - bataki. First of all, their fantastic architecture surprises: three-story houses resemble Noah's ark. Indigenous people explain that the first floor is for animals: earlier there were many wild animals in the forests, so the house was built on its feet (on stilts) for safety. Families live on the second floor, and perfumes in the attic. Although the Bataks are Christians, they very much believe in spirits, therefore the attics can even exceed the first two floors combined in size. In everyday life, Bataks (there are about 6 million of them on the island) speak their own language, but the majority speaks a national Indonesian. Many understand English.