Lake Toba ( id, Danau Toba) (
Toba Batak: ᯖᯀᯬ ᯖᯬᯅ;
romanized: ''Tao Toba'') is a large natural
lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
in
North Sumatra, Indonesia, occupying the
caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...
of a
supervolcano. The lake is located in the middle of the northern part of the
island
An island (or isle) is an isolated piece of habitat that is surrounded by a dramatically different habitat, such as water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island ...
of Sumatra, with a surface elevation of about , the lake stretches from to . The lake is about long, wide, and up to deep. It is the largest
lake in Indonesia and the largest
volcanic lake
A volcanogenic lake is a lake formed as a result of volcanic activity. They are generally a body of water inside an inactive volcanic crater (crater lakes) but can also be large volumes of molten lava within an active volcanic crater ( lava lakes) ...
in the world.
Toba Caldera is one of twenty
Geopark
A geopark is a protected area with internationally significant geology within which sustainable development is sought and which includes tourism, conservation, education and research concerning not just geology but other relevant sciences.
In 2 ...
s in Indonesia, and was recognised in July 2020 as one of the
UNESCO Global Geoparks
UNESCO Global Geoparks (UGGp) are geoparks certified by the UNESCO Global Geoparks Council as meeting all the requirements for belonging to the Global Geoparks Network (GGN). The GGN is both a network of geoparks and the agency of the United Nati ...
.
Lake Toba is the site of a
supervolcanic eruption estimated at
VEI 8 that occurred 69,000 to 77,000 years ago,
representing a climate-changing event. Recent advances in dating methods suggest a more accurate identification of 74,000 years ago as the date. It is the largest-known explosive eruption on
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
in the last 25 million years. According to the
Toba catastrophe theory
The Youngest Toba eruption was a supervolcano eruption that occurred around 74,000 years ago at the site of present-day Lake Toba in Sumatra, Indonesia. It is one of the Earth's largest known explosive eruptions. The Toba catastrophe theory ho ...
, it had global consequences for human populations; it killed most humans living at that time and is believed to have created a
population bottleneck in central east Africa and India, which affects the genetic make-up of the human worldwide population to the present. More recent studies have cast doubt on this theory and found no evidence of substantial changes in global population.
It has been accepted that the eruption of the Toba Caldera led to a
volcanic winter
A volcanic winter is a reduction in global temperatures caused by volcanic ash and droplets of sulfuric acid and water obscuring the Sun and raising Earth's albedo (increasing the reflection of solar radiation) after a large, particularly explosiv ...
with a worldwide decrease in temperature between , and up to in higher latitudes. Additional studies in
Lake Malawi
Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is an African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania.
It is the fifth largest fr ...
in East Africa show significant amounts of ash being deposited from the Toba Caldera eruptions, even at that great distance, but little indication of a significant climatic effect in East Africa.
Geology
The Toba
Caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...
in
North Sumatra comprises four overlapping volcanic craters that adjoin the Sumatran "volcanic front". At it is the world's largest
Quaternary caldera, and the fourth and youngest caldera. It intersects the three older calderas. An estimated of
dense-rock equivalent
Dense-rock equivalent (DRE) is a volcanologic calculation used to estimate volcanic eruption volume. One of the widely accepted measures of the size of a historic or prehistoric eruption is the volume of magma ejected as pumice and volcanic ash, k ...
pyroclastic material, known as the youngest Toba
tuff
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock ...
, was released during one of the largest explosive volcanic eruptions in recent geological history. Following this eruption, a resurgent dome formed within the new caldera, joining two half-domes separated by a longitudinal
graben.
At least four cones, four
stratovolcanoes, and three craters are visible in the lake. The Tandukbenua cone on the northwestern edge of the caldera has only sparse vegetation, suggesting a young age of several hundred years. Also, the Pusubukit (Hill Center) volcano ( above sea level) on the south edge of the caldera is
solfatarically active.
Major eruption
The ''Toba eruption'' (the ''Toba event'') occurred at what is now Lake Toba about 73,700±300 years ago. It was the last in a series of at least four
caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...
-forming eruptions at this location, with the earlier known caldera having formed around 1.2 million years ago.
[ This last eruption had an estimated VEI=8, making it the largest-known explosive ]volcanic eruption
Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are oft ...
in the Quaternary.
Bill Rose and Craig Chesner of Michigan Technological University have estimated that the total amount of material released in the eruption was at least —about of ignimbrite
Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surro ...
that flowed over the ground, and approximately that fell as ash mostly to the west. However, as more outcrops become available, Toba possibly erupted of ignimbrite and co-ignimbrite. The pyroclastic flow
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of b ...
s of the eruption destroyed an area of least , with ash deposits as thick as by the main vent.[ The eruption was large enough to have deposited an ash layer approximately thick over all of ]South Asia
South Asia is the southern subregion of Asia, which is defined in both geographical
Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth descr ...
; at one site in central India, the Toba ash layer today is up to thick and parts of Malaysia
Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...
were covered with of ash fall.
The subsequent collapse formed a caldera that filled with water, creating Lake Toba. The island in the center of the lake is formed by a resurgent dome.
The exact year of the eruption is unknown, but the pattern of ash deposits suggests that it occurred during the northern summer because only the summer monsoon
A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscill ...
could have deposited Toba ashfall in the South China Sea. The eruption lasted perhaps two weeks, and the ensuing volcanic winter resulted in a decrease in average global temperatures by for several years. Ice cores from Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland i ...
record a pulse of starkly reduced levels of organic carbon sequestration
Carbon sequestration is the process of storing carbon in a carbon pool. Carbon dioxide () is naturally captured from the atmosphere through biological, chemical, and physical processes. These changes can be accelerated through changes in lan ...
. Very few plants or animals in southeast Asia would have survived, and it is possible that the eruption caused a planet-wide die-off. However, the global cooling has been discussed by Rampino and Self. Their conclusion is that the cooling had already started before Toba's eruption. This conclusion was supported by Lane and Zielinski who studied the lake-core from Africa and GISP2
The Greenland Ice Sheet Project (GISP) was a decade-long project to drill ice cores in Greenland that involved scientists and funding agencies from Denmark, Switzerland and the United States. Besides the U.S. National Science Foundation (NSF), f ...
. They concluded that there was no volcanic winter after the Toba eruption and that high H2SO4 deposits do not cause long-term effects. Furthermore, due to the low solubility of sulfur in the magma, the emission of volatiles and climate impacts are likely limited.
Evidence from studies of mitochondrial DNA suggests that humans may have passed through a genetic bottleneck
A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts; or human activities such as specicide, widespread violen ...
around this time that reduced genetic diversity below what would be expected given the age of the species. According to the Toba catastrophe theory, proposed by Stanley H. Ambrose of the University of Illinois at Urbana–Champaign
The University of Illinois Urbana-Champaign (U of I, Illinois, University of Illinois, or UIUC) is a public land-grant research university in Illinois in the twin cities of Champaign and Urbana. It is the flagship institution of the Univer ...
in 1998, the effects of the Toba eruption may have decreased the size of human populations to only a few tens of thousands of individuals. However, this hypothesis is not widely accepted because similar effects on other animal species have not been observed, and paleoanthropology suggests there was no population bottleneck.[Gathorne-Hardy, F. J., and Harcourt-Smith, W. E. H.]
"The super-eruption of Toba, did it cause a human bottleneck?"
, Journal of Human Evolution 45 (2003) 227–230. The genetic bottleneck is now recognized to be the Out-of-Africa founder effect, rather than an actual reduction in population.
More recent activity
Since the major eruption ~70,000 years ago, eruptions of smaller magnitude have also occurred at Toba. The small cone of Pusukbukit formed on the southwestern margin of the caldera and lava domes. The most recent eruption may have been at Tandukbenua on the northwestern caldera edge, suggested by a lack of vegetation that could be due to an eruption within the last few hundred years.
Some parts of the caldera have shown uplift due to partial refilling of the magma chamber
A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it up ...
, for example, pushing Samosir Island
Samosir, or Samosir Island, is a large volcanic island in Lake Toba, located in the north of the island of Sumatra in Indonesia. Administratively, Samosir Island is governed as six of the nine districts within Samosir Regency. The lake and i ...
and the Uluan Peninsula Uluan Peninsula extends into Lake Toba on the eastern side toward Medan, in Simalungun Regency and Toba Samosir Regency of North Sumatra province. It has experienced a large amount of uplift because of a series of massive volcanic eruptions that beg ...
above the surface of the lake. The lake sediments on Samosir Island show that it has risen by at least [ since the cataclysmic eruption. Such uplifts are common in very large calderas, apparently due to the upward pressure of below-ground ]magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...
. Toba is probably the largest resurgent caldera on Earth. Large earthquake
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...
s have recently occurred in the vicinity of the volcano, notably in 1987 along the southern shore of the lake at a depth of . Such earthquakes have also been recorded in 1892, 1916, and 1920–1922.[Stratigraphy of the Toba Tuffs and the evolution of the Toba Caldera Complex, Sumatra, Indonesia](_blank)
/ref>
In 2016, a study revealed that the Toba Supervolcano has a magma chamber containing of eruptible magma, about underground. This makes the supervolcano's magma chamber more than four times larger than the volume of Lake Superior
Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh wa ...
in North America, and also larger than the magma chamber underneath Yellowstone
Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowston ...
.
Lake Toba lies near the Great Sumatran fault
The Indonesian island of Sumatra is located in a highly seismic area of the world. In addition to the subduction zone off the west coast of the island, Sumatra also has a large strike-slip fault, the Great Sumatran Fault also known as Semangko ...
, which runs along the centre of Sumatra in the Sumatra Fracture Zone.[ The volcanoes of Sumatra and Java are part of the Sunda Arc, a result of the northeasterly movement of the ]Indo-Australian Plate
The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and the surrounding ocean and extends northwest to include the Indian subcontinent and the adjacent waters. It was formed by the fusion of the Indian an ...
, which is sliding under the eastward-moving Eurasian Plate
The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...
. The subduction zone in this area is very active: the seabed near the west coast of Sumatra has had several major earthquakes since 1995, including the 9.1 2004 Indian Ocean earthquake and the 8.7 2005 Nias–Simeulue earthquake, the epicenters of which were around from Toba.
People
Most of the people who live around Lake Toba are ethnically Bataks
Batak is a collective term used to identify a number of closely related Austronesian ethnic groups predominantly found in North Sumatra, Indonesia, who speak Batak languages. The term is used to include the Karo, Pakpak, Simalungun, Toba, ...
. Traditional Batak houses are noted for their distinctive roofs (which curve upwards at each end, as a boat's hull does) and their colorful decor.
Transportation
Parapat
Parapat, also known as the City of Parapat, is a small town in North Sumatra province on the edge of Lake Toba, on the Uluan Peninsula where it forms the narrowest eastern link to Samosir Island. It is the primary transit point by ferry for v ...
is located on the edge of the lake, which is the transit point to travel the lake and Samosir Island
Samosir, or Samosir Island, is a large volcanic island in Lake Toba, located in the north of the island of Sumatra in Indonesia. Administratively, Samosir Island is governed as six of the nine districts within Samosir Regency. The lake and i ...
. Medan
Medan (; English: ) is the capital and largest city of the Indonesian province of North Sumatra, as well as a regional hub and financial centre of Sumatra. According to the National Development Planning Agency, Medan is one of the four mai ...
is about 173 km by road from the town and is connected via the Trans-Sumatran Highway
The Trans-Sumatra Highway (Indonesian: ''Jalan Raya Trans-Sumatra'') is a primary north–south road in the Indonesian island of Sumatra, 2,508.5 km in length, and connecting the northern island at Banda Aceh to Bandar Lampung in the south ...
to Pematang Siantar
Pematangsiantar (sometimes written as Pematang Siantar, acronym PS or ''P. Siantar'', colloquially just Siantar), is an independent city in North Sumatra, Indonesia, surrounded by, but not part of, the Simalungun Regency, making Pematangsiantar a ...
by a 48 km road. Sisingamangaraja XII International Airport
Sisingamangaraja XII International Airport ( id, Bandar Udara Internasional Sisingamangaraja XII) is an international airport located in Silangit, North Tapanuli, North Sumatra, Indonesia. is located about 47 mi (76 km) from Parapat.
Flora and fauna
The flora
Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' ...
of the lake includes various types of phytoplankton, emerged macrophytes, floating macrophytes, and submerged macrophytes, while the surrounding countryside is rainforest including areas of Sumatran tropical pine forests on the higher mountainsides.
The fauna
Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is ''flora'', and for fungi, it is ''funga''. Flora, fauna, funga and other forms of life are collectively referred to as ''Biota (ecology ...
includes several species of zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...
and benthic animals. Since the lake is oligotrophic (nutrient-poor), the native fish fauna is relatively scarce, and the only endemics
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...
are '' Rasbora tobana'' (strictly speaking near-endemic, since also found in some tributary rivers that run into the lake) and '' Neolissochilus thienemanni'', locally known as the Batak fish. The latter species is threatened by deforestation (causing siltation
Siltation, is water pollution caused by particulate Terrestrial ecoregion, terrestrial Clastic rock, clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the ...
), pollution, changes in water level and the numerous fish species that have been introduced to the lake.[ Other native fishes include species such as '']Aplocheilus panchax
The blue panchax or whitespot (''Aplocheilus panchax'') is a common freshwater fish found in a large variety of habitats due to its high adaptability. This species is native to southern Asia from Pakistan to Indonesia. It has been discovered in t ...
'', '' Nemacheilus pfeifferae'', '' Homaloptera gymnogaster'', '' Channa gachua'', ''Channa striata
''Channa striata'', the striped snakehead, is a species of snakehead fish. It is also known as the common snakehead, chevron snakehead, or snakehead murrel and generally referred simply as mudfish. It is native to South and Southeast Asia, and h ...
'', ''Clarias batrachus
The walking catfish (''Clarias batrachus'') is a species of freshwater airbreathing catfish native to Southeast Asia. It is named for its ability to "walk" and wiggle across dry land, to find food or suitable environments. While it does not trul ...
'', '' Barbonymus gonionotus'', '' Barbonymus schwanenfeldii'', '' Danio albolineatus'', '' Osteochilus vittatus'', '' Puntius binotatus'', '' Rasbora jacobsoni'', ''Tor tambra
''Tor tambra'', the Javan mahseer, is a species of mahseer native to Southeast Asia.
Taxonomy
Tor tambra is a typical mahseer, with Cyprinidae features, large scales and a large head comparative to body depth. It is usually longer and slimmer b ...
'', '' Betta imbellis'', '' Betta taeniata'' and ''Monopterus albus
The Asian swamp eel (''Monopterus albus''), also known as rice eel, ricefield eel, or rice paddy eel, is a commercially important, air-breathing species of fish in the family Synbranchidae. It occurs in East and Southeast Asia, where it is a ve ...
''.[ FishBase (2012). ]
Species in Toba.
' Accessed 25 January 2012 Among the many introduced species are ''Anabas testudineus
The climbing perch (''Anabas testudineus'') is a species of amphibious freshwater fish in the family Anabantidae (the climbing gouramis). A labyrinth fish native to Far Eastern Asia, the fish inhabits freshwater systems from Pakistan, India ...
'', ''Oreochromis mossambicus
''Oreochromis'' is a large genus of oreochromine cichlids, fishes endemic to Africa and the Middle East. A few species from this genus have been introduced far outside their native range and are important in aquaculture. Many others have ver ...
'', '' Oreochromis niloticus'', ''Ctenopharyngodon idella
The grass carp (''Ctenopharyngodon idella'') is a species of large herbivorous freshwater fish in the family Cyprinidae, native to the Pacific Far East, with a native range stretching from northern Vietnam to the Amur River on the Sino-Russian ...
'', ''Cyprinus carpio
The Eurasian carp or European carp (''Cyprinus carpio''), widely known as the common carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia.Fishbase''Cyprinus carpio'' Linnaeus, 1758/ref>Arkive The ...
'', '' Osphronemus goramy'', '' Trichogaster pectoralis'', '' Trichopodus trichopterus'', ''Poecilia reticulata
''Poecilia'' is a genus of fishes in the family Poeciliidae of the order Cyprinodontiformes. These livebearers are native to fresh, brackish and salt water in the Americas, and some species in the genus are euryhaline. A few have adapted to livin ...
'' and '' Xiphophorus hellerii''.[
]
Sinking of MV Sinar Bangun
On 18 June 2018, Lake Toba was the scene of a ferry disaster, in which over 190 people drowned. MV Sinar Bangun was an irregular operating vessel on the lake which capsized with many passengers on board. The incident caused the death of 190 people and injuries to a number of others. Preliminary reports found the vessel was in operation with irregularities. Ignoring overloading on the vessel and operating in rough weather conditions were concluded as the main reasons leading to the disaster.
In popular culture
''The Origin of Lake Toba'' is a folk story about the lake, in which once upon a time, there was a fisherman who caught a golden fish. Samosir Island is believed to be the golden fish's son.
Gallery
File:Lake Toba Aerial View.JPG, Lake Toba Aerial View
File:LakeTobaSEShore.jpg, Aerial view of the southern shore with Sibandang Island visible in the background
File:AmbaritaView.jpg, View of the lake with an example of Batak architecture in the foreground
File:Tradbatakhouse.jpg, Traditional Batak house at Ambarita, Lake Toba
File:Air terjun sipiso-piso.jpg, Sipiso-Piso Waterfall
File:DanauToba20110608-1.jpg, Lake Toba from Tongging Village, near Sipiso-Piso Waterfall
File:Indonesia 1992 1000r o.jpg, Lake Toba featured in 1,000-rupiah banknote
File:COLLECTIE TROPENMUSEUM Houtsnijwerk op de voorsteven van een Toba Batak prauw Tobameer TMnr 10017614.jpg, Details of carvings on the prow of a Toba Batak canoe
File:Toba zoom.jpg, The caldera of Lake Toba, with a resurgent dome, forming Samosir Island
File:A partial view of Toba Lake.jpg, alt=A panoramic partial view of Toba Lake, as seen from the west side to the southeast, A panoramic partial view of Toba Lake, as seen from the west side to the southeast
See also
* List of lakes of Indonesia
This is a list of the notable lakes of Indonesia. Indonesia has 521 natural lakes and over 100 reservoirs, covering approximately 21,000 km². The total volume of water held is approximately 500 km³. The largest lake, by both area an ...
* List of volcanoes in Indonesia
The geography of Indonesia is dominated by volcanoes that are formed due to subduction zones between the Eurasian plate and the Indo-Australian plate. Some of the volcanoes are notable for their eruptions, for instance, Krakatoa for its globa ...
* Mount Sinabung
Mount Sinabung ( Indonesian: ''Gunung Sinabung'', Karo: ''Deleng Sinabung'') is a Pleistocene-to-Holocene stratovolcano of andesite and dacite in the Karo plateau of Karo Regency, North Sumatra, Indonesia, from the Lake Toba supervolcano. M ...
* Lake Taupo
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...
* Yellowstone Caldera
The Yellowstone Caldera, sometimes referred to as the Yellowstone Supervolcano, is a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States. The caldera and most of the park are located in the northwest corn ...
* La Garita Caldera
La Garita Caldera is a large caldera in the San Juan volcanic field in the San Juan Mountains near the town of Creede in southwestern Colorado, United States.
It is west of La Garita, Colorado. The eruption that created the La Garita Calde ...
References
Further reading
*
*
*
External links
Toba, Sumatra, Indonesia – Volcano.oregonstate.edu
Accessed 11 December 2005
Stanley H. Ambrose, ''Volcanic Winter, and Differentiation of Modern Humans''
Accessed 11 December 2005
Accessed 11 December 2005
(Lake Toba Ecosystem Management Plan) From laketoba.org
*
{{DEFAULTSORT:Toba, Lake
Batak
Volcanic crater lakes
Lakes of Sumatra
Tourist attractions in Indonesia
Tourist attractions in North Sumatra
Subduction volcanoes
Supervolcanoes
VEI-8 volcanoes
Calderas of Indonesia
Volcanoes of Sumatra
Landforms of North Sumatra
Pleistocene calderas