Sunda Arc
Encyclopedia
The Sunda Arc is a volcanic arc
that has produced the islands of Sumatra
and Java, the Sunda Strait
and the Lesser Sunda Islands
. A chain of volcano
es forms the topographic spine of these islands. The arc marks an active convergent boundary
between the East Eurasian plates that underlie Indonesia
, especially the Sunda Plate
and the Burma Plate
, with the India
and Australian Plates that form the seabed of the Indian Ocean
and the Bay of Bengal
. The Sunda Arc is a classic example of a volcanic island arc
, in which all the elements of such geodynamic features can be identified.
The India and Australian Plates are subducting
beneath the Sunda and Burma plates along the Sunda Arc. The tectonic deformation along this subduction zone in the Java Trench
(also known as the Sunda Trench) caused the 2004 Indian Ocean earthquake
of December 26, 2004.
The Sunda Arc is home to some of the world's most dangerous and explosive volcanoes. The eruption of Mount Tambora
on Sumbawa Island, in 1815, is thought to be the most massive in recorded history. Also this subduction zone has created arguably the world's largest active volcano Lake Toba
which produced the largest volcanic eruption in human history erupting just over 2,800 km³ of magma, a VEI of 8. The loudest noise in recorded history
occurred during the 1883 eruption of Krakatoa
and was heard 5000 km (3,106.9 mi) away. Hundreds of thousands of people have been killed by these eruptions and by episodes of activity at other volcanoes, including Papandayan, Galunggung
, and Kelut
.
Volcanic arc
A volcanic arc is a chain of volcanoes positioned in an arc shape as seen from above. Offshore volcanoes form islands, resulting in a volcanic island arc. Generally they result from the subduction of an oceanic tectonic plate under another tectonic plate, and often parallel an oceanic trench...
that has produced the islands of Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
and Java, the Sunda Strait
Sunda Strait
The Sunda Strait is the strait between the Indonesian islands of Java and Sumatra. It connects the Java Sea to the Indian Ocean...
and the Lesser Sunda Islands
Lesser Sunda Islands
The Lesser Sunda Islands or Nusa Tenggara are a group of islands in the southern Maritime Southeast Asia, north of Australia. Together with the Greater Sunda Islands to the west they make up the Sunda Islands...
. A chain of volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
es forms the topographic spine of these islands. The arc marks an active convergent boundary
Convergent boundary
In plate tectonics, a convergent boundary, also known as a destructive plate boundary , is an actively deforming region where two tectonic plates or fragments of lithosphere move toward one another and collide...
between the East Eurasian plates that underlie Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, especially the Sunda Plate
Sunda Plate
The Sunda Plate is the tectonic plate on which the majority of Southeast Asia is located. It was formerly considered a part of the Eurasian Plate, but GPS measurements have confirmed its independent movement at 10 mm/yr eastward relative to Eurasia...
and the Burma Plate
Burma Plate
The Burma Plate is a small tectonic plate or microplate located in Southeast Asia, often considered a part of the larger Eurasian Plate. The Andaman Islands, Nicobar Islands, and northwestern Sumatra are located on the plate...
, with the India
India Plate
The India Plate or Indian Plate is a tectonic plate that was originally a part of the ancient continent of Gondwanaland from which it split off, eventually becoming a major plate. About 50 to 55 million years ago , it fused with the adjacent Australian Plate...
and Australian Plates that form the seabed of the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
and the Bay of Bengal
Bay of Bengal
The Bay of Bengal , the largest bay in the world, forms the northeastern part of the Indian Ocean. It resembles a triangle in shape, and is bordered mostly by the Eastern Coast of India, southern coast of Bangladesh and Sri Lanka to the west and Burma and the Andaman and Nicobar Islands to the...
. The Sunda Arc is a classic example of a volcanic island arc
Island arc
An island arc is a type of archipelago composed of a chain of volcanoes which alignment is arc-shaped, and which are situated parallel and close to a boundary between two converging tectonic plates....
, in which all the elements of such geodynamic features can be identified.
The India and Australian Plates are subducting
Subduction
In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. These 3D regions of mantle downwellings are known as "Subduction Zones"...
beneath the Sunda and Burma plates along the Sunda Arc. The tectonic deformation along this subduction zone in the Java Trench
Java Trench
The Sunda Trench, earlier known as, and sometimes still indicated as the Java Trench, located in the northeastern Indian Ocean, with a length of and a maximum depth of , is the second-deepest point in the Indian Ocean after Diamantina Trench, which is 8,047 metres deep...
(also known as the Sunda Trench) caused the 2004 Indian Ocean earthquake
2004 Indian Ocean earthquake
The 2004 Indian Ocean earthquake was an undersea megathrust earthquake that occurred at 00:58:53 UTC on Sunday, December 26, 2004, with an epicentre off the west coast of Sumatra, Indonesia. The quake itself is known by the scientific community as the Sumatra-Andaman earthquake...
of December 26, 2004.
The Sunda Arc is home to some of the world's most dangerous and explosive volcanoes. The eruption of Mount Tambora
Mount Tambora
Mount Tambora is an active stratovolcano, also known as a composite volcano, on the island of Sumbawa, Indonesia. Sumbawa is flanked both to the north and south by oceanic crust, and Tambora was formed by the active subduction zone beneath it. This raised Mount Tambora as high as , making it...
on Sumbawa Island, in 1815, is thought to be the most massive in recorded history. Also this subduction zone has created arguably the world's largest active volcano Lake Toba
Lake Toba
Lake Toba is a lake and supervolcano. The lake is 100 kilometres long and 30 kilometres wide, and 505 metres at its deepest point. Located in the middle of the northern part of the Indonesian island of Sumatra with a surface elevation of about , the lake stretches from to...
which produced the largest volcanic eruption in human history erupting just over 2,800 km³ of magma, a VEI of 8. The loudest noise in recorded history
Recorded history
Recorded history is the period in history of the world after prehistory. It has been written down using language, or recorded using other means of communication. It starts around the 4th millennium BC, with the invention of writing.-Historical accounts:...
occurred during the 1883 eruption of Krakatoa
1883 eruption of Krakatoa
The 1883 eruption of Krakatoa began in May 1883 and culminated with the destruction of Krakatoa on 27 August 1883. Minor seismic activity continued to be reported until February 1884, though reports after October 1883 were later dismissed by Rogier Verbeek's investigation.-Early phase:In the years...
and was heard 5000 km (3,106.9 mi) away. Hundreds of thousands of people have been killed by these eruptions and by episodes of activity at other volcanoes, including Papandayan, Galunggung
Galunggung
Mount Galunggung is an active stratovolcano in West Java, Indonesia, around 80 km southeast of the West Java provincial capital, Bandung...
, and Kelut
Kelut
Kelud is a volcano located in East Java on Java in Indonesia. Like many Indonesian volcanoes and others on the Pacific Ring of Fire, Kelud is known for large explosive eruptions throughout its history...
.
Further reading
- Newcomb KR & McCann WR. (1987). Seismic history and seismotectonics of the Sunda Arc. Journal of Geophysical Research; 92:421–439.