Indonesia, a large state in Southwest Asia, is not for nothing called the Land of a Thousand Islands. It is spread over parts of New Guinea, the Moluccas 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 motley carpet of a mixture of peoples, cultures, diverse landscapes, natural and climatic zones. One of the most amazing is Sumatra, which many call a continent in miniature. There are tropics and savannahs, lowland swamps and high mountains. Rhinos and elephants, tigers and leopards, bears and buffaloes live on the island - a large fauna not typical of the islands.
Geographic location
Sumatra is one of the largest islands in the Malay Archipelago. It stretches from northwest to southeast for 1800 km. Island area - 421,000km2. 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 don't have names. The southern sections are known as the Barisan Range, while the Batak Plateau rises in the northern part of the island.
There are smaller land areas around the "mother" island. From the side of the Indian Ocean, mountainous sparsely populated territories lined up parallel to Sumatra: Mentawai, Nias, Engano. Along the eastern shore are Sinkep, Banka, Belitung. Notorious became Simalur (Simelue) - an Indonesian island to the west of the island of Sumatra. In 2004, a giant tsunami hit its coast.
Very close, to the northeast, is the Malay Peninsula - part of the Asian continent. It is separated from Sumatra by the Strait of Malacca. The most important shipping routes pass here: rich cargo attracts real pirates of the 21st century who rob ships. To the east, 420 km, is the "big brother" - the island of Borneo (Kalimantan). Between the "relatives" lies the Karimata Strait. Indonesia's most populous island, 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. More precisely, in the extreme west of the Malay Archipelago, in the triangle between Java, Kalimantan and the Malay Peninsula.
Geology
The mountains of Sumatra were formed partly in the Hercynian, partly in the Mesozoic and later Paleogene folding, onthey also contain young longitudinal faults. They are composed of quartzites, crystalline schists, Paleozoic limestones, there are outcrops of granite intrusions. The average height of the mountains is from 1500 to 3000 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 in Sumatra - Kerinchi (Indrapura), 3800 m high, is clearly distinguished. It is followed by Dempo (3159 m) and Marapi (2891 m). Only twelve active giants.
Between Sumatra and neighboring Java, in the Sunda Strait, the stratovolcano Krakatau (813 m) lurks. Its eruptions are rare, but catastrophic. The last activity here was observed in 1999. In 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 - the 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 swampy alluvial lowland. A feature of the area is that its coastal part is flooded by sea tides. Here are fertile conditions for extensive mangrove forests. Sumatra, Banka and Belitung Islands 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 here is humid. The amount of precipitation in Sumatra in some places exceeds 3500-3800 mm (up to 6000 mm), but they fall unevenly. A large amount of rain is due to a mountain barrier that stretches along the entire island. The maximum moisture falls in October-November to the north of the equator, and in December-January - to the 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 year, but the incredibly high humidity spoils the idyllic picture.
In the east of the island and in the Strait of Malacca, strong easterly winds often blow. They reach their greatest strength during the action of the southwest monsoon. Most of this hurricane wind, accompanied by thunderstorms, is observed at night - apparently, this is facilitated by the Sumatra mountain range, which runs parallel to the Strait of Malacca.
Waterlands
The islands of Indonesia, due to heavy rainfall, have excess humidity. Due to this, numerous rivers flow in most regions. Sumatra is no exception: the river network is quite dense, water flows do not dry up during the year, washing away a lot of sedimentary material from the mountains. The largest rivers of the island are Muse, Khari, Kampar, Rokan, Inderagiri.
There are many lakes on the island. In the center of the Batak tuff plateau in a volcanic depression lies the largest lake in Indonesia - Toba, with the island of Samosir in the middle. At one time, there was a separate Batak principality here, whose descendants, according to legend, settled inthroughout Sumatra. The lake is located at an altitude of 904 m above sea level. The area is more than 1000 km2, and the maximum depth is 433 meters. It's cold here, especially at night. A 320,000 kW hydroelectric power plant was built on the Asahan River, flowing from a reservoir.
Land cover
The most common soil types are podzolized laterites that have formed on weathered crust. On the foothills and in the mountains, soils are represented by a variant of mountain lateritic soils. In the east, alluvial and marsh soils stretch in a wide strip, and mangrove soils in a narrow coastal strip.
Vegetation
The geographical position of Sumatra near the equator contributes to the growth of dense tropical forests, they occupy large areas. Unfortunately, in the river valleys, on the plains and in the mountain basins, large areas of forests have been cut down, and a variety of agricultural crops are grown in the developed territories. Rubber trees, rice, coconut palm, tobacco, tea, cotton, pepper are widely cultivated on the island.
The most typical forest species are:
- rasamals and ficuses;
- several types of palms: sugar, palmyra, walnut, cariota, rattan; in the lower reaches of the rivers and in the swamps - nipa; coconut - in the seaside zone;
- peculiar tree ferns, huge bamboos (up to 30-40 m in height), endemic amorpha-falus and rafflesia parasite.
The northeast low-lying coast is dominated by mangroves. In intermountain low areas, small areas are occupied by savannahs. At altitudes of 1.5-3 km, forests are widespread with a predominance of evergreen trees (laurel, oak), there are also coniferous, broad-leaved deciduous (chestnut, maple) trees. Above 3000 m, the forests give way to stunted thickets with falling leaves, shrubs and grasses.
Fauna
The island fauna is mainly represented by forest species. The jungles of Sumatra have become a Mecca for ecotourists who want to get acquainted with the life of one of the most interesting species of monkeys - orangutans.
Also typical mammals are primates (fat loris, siamang, pig-tailed macaques, brownie macaques), woolly wings, pangolins, squirrels, badgers, bats. Among the large inhabitants, the two-horned rhinoceros, the Indian elephant, the Sumatran tiger, the black-backed tapir, the leopard, the striped pig, the island Weaver, the Malayan bear, and wild dogs stand out.
Of the birds, the most interesting are gomrai, argus, hornbeak, and several species of pigeons. Of the reptiles on the island, flying dragons, gharials (crocodiles), snakes are found. Of the amphibians, the legless worm stands out. A lot of different insects, arachnids.
Sleep Supervolcano
The island of Sumatra on the map is not much different from neighboring lands, but it was here that an epoch-making cataclysm occurred 73,000 years ago that changed the history of the Earth. The explosion of a supervolcano gave rise to the emergence of the so-called volcanic winter, reminiscent of a nuclear one. In addition to 3000 km3 ash, a huge amount of anhydride entered the atmosphere, which provoked widespread acid rain.
Six years of unnaturally low temperatures reigned 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 a large population of people - about 10,000 representatives of the Homo sapiens species in the heart of Africa. In fact, a natural disaster contributed to the "explosive" development of intelligence in our distant ancestors.
Lake Toba
Sumatra - islands with amazing nature. The most striking geological and cultural attraction is the largest lake of volcanic origin on the planet, Toba, which filled the giant crater of that 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 Tonle Sap Lake) in Southeast Asia.
The picturesque island of Samosir is located on Lake Toba. 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 area, developed tourist centers, and the "untouched" natural landscape, and the daily life of Sumatran peasants fit organically.
Although the water in Toba is fresh, its transparency, azure, surrounding landscapes and microclimate are reminiscent of the Mediterranean coast. Breaks this association onlythe absence of big waves, which is a big advantage for many tourists.
Population
In Indonesia, more than 300 peoples live, while linguists have 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 on television and in the press.
The western region (Banka, Sumatra, the Mentawai Islands, the Linga Archipelago and others) is home to 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. Chinese and Tamils are concentrated in urban centers.
Less than a third of the population lives in cities. Largest metropolitan areas:
- 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, an amazing people live - the Batak. First of all, their fantastic architecture surprises: three-story houses resemble Noah's Ark. The 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 legs” (on stilts) for safety. Families live on the second floor, and spirits live in the attic. Although the Bataks are Christians, they really believe in spirits, so attics can even exceed the first two in size.floors combined. In everyday life, the Bataks (there are about 6 million of them on the island) speak their own language, but most speak the national Indonesian. Many understand English.
