Lesser Sunda Islands

1.3 Lesser Sunda Islands

Lesser Sunda Islands
Geography


Location South East Asia

Coordinates 9°00′S 120°00′E9°S 120°E

Archipelago Sunda Islands

Country
Indonesia
Provinces Bali,
West Nusa Tenggara,
East Nusa Tenggara

East Timor


Map of Lesser Sunda Islands


Satellite picture of the Lesser Sunda Islands
The Nusa Tenggara (lit. Southeast Islands), or Lesser Sunda Islands, are a group of islands in the middle-south part of Maritime Southeast Asia. Together with the Greater Sunda Islands to the west they make up the Sunda Islands. The islands are part of a volcanic arc, the Sunda Arc, formed by subduction along the Java Trench.
Contents
1 Partial list
2 Administration
3 Geology
4 Ecology
5 References
6 Notes
7 See also
8 External links

Partial list
Adonara
Alor
Bali
Flores
Komodo
Lombok
Nusa Ceningan
Nusa Lembongan
Nusa Penida
Palu'e
Pantar
Rote
Solor
Sangeang
Savu
Sumba
Sumbawa
Timor




Administration
They are split into the independent state of East Timor (Timor-Leste) and the Indonesian provinces of Bali, West Nusa Tenggara (Nusa Tenggara Barat) and East Nusa Tenggara (Nusa Tenggara Timur).
Geology
The Lesser Sunda Islands consist of two geologically distinct archipelagos.[1] The northern archipelago, which includies Bali, Lombok, Sumbawa, Flores and Wetar, is volcanic in origin. It began to be formed during the Pliocene, about 15 million years ago, as a result of the collision between the Australian and the Asian plates.[1] The islands of the southern archipelago, including Sumba, Timor and Babar, are non-volcanic and appear to belong to the Australian plate.[2] The geology and ecology of the northern archipelago share a similar history, characteristics and processes with the southern Maluku Islands, which continue the same island arc to the east.
There is a long history of geological study of these regions since Indonesian colonial times; however, the geological formation and progression is not fully understood, and theories of the geological evolution of the islands changed extensively during the last decades of the 20th century.[3]
Lying at the collision of two tectonic plates, the Lesser Sunda Islands comprise some of the most geologically complex and active regions in the world.[3] Biodiversity and distribution is affected by various tectonic activities. The islands of the northern archipelago are geologically young being from 1 to 15 million years old, and have never been attached to a larger land mass. Only Bali was part of the Ice Age continent of Sundaland, separated by the Lombok Strait from a 400-mile-long island including present-day Lombok, Sumbawa, Komodo, Flores, Solor, Adonara, and Lembata. Pantar and Alor formed a small island just to the east, while Sumba and Timor remained separate islands to the south.
Ecology
The Lesser Sunda Islands differ from the large islands of Java or Sumatra containing many small islands as well as deep oceanic trenches. Flora and fauna immigration between islands is restricted, leading to the evolution of a high rate of localized species.[3] The Wallace Line passes through the islands between Bali and Lombok, along the deep waters of the Lombok Strait which formed a water barrier even when lower sea levels linked the now-separated islands and landmasses on either side. Alfred Wallace's famous book, The Malay Archipelago was the first significant recording of this natural history, and remains one of the most important sources on Indonesian natural history.[4]
While many ecological problems affect both small islands and large landmasses, small islands suffer their particular problems and are highly exposed to external forces. Development pressures on small islands are increasing, although their effects are not always anticipated. Although Indonesia is richly endowed with natural resources, the resources of the small islands of Nusa Tenggara are limited and specialised; furthermore human resources in particular are limited.[5]
General observations[6] about small islands that can be applied to Nusa Tenggara include:[5]
a higher proportion of the landmass will be affected by volcanic activity, earthquakes, landslips, and cyclone damage;
Climates are more likely to be maritime influenced;
Catchment areas are smaller and degree of erosion higher;
A higher proportion of the landmass is made up of coastal areas;
A higher degree of environmental specialisation, including a higher proportion of endemic species in an overall depauperate community;
Societies may retain a strong sense of culture having developed in relative isolation;
Small island populations are more likely to be affected by economic migration.