Lake Toba (, Toba Batak: ᯖᯀᯬ ᯖᯬᯅ;

romanized In linguistics, romanization is the conversion of text from a different writing system to the Roman (Latin) script, or a system for doing so. Methods of romanization include transliteration, for representing written text, and transcription, ...

: ''Tao Toba'') is a large natural

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

North Sumatra North Sumatra () is a Provinces of Indonesia, province of Indonesia located in the northern part of the island of Sumatra. Its capital and largest city is Medan on the east coast of the island. It borders Aceh to the northwest, Riau to the sou ...

, Indonesia, occupying the

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the str ...

of the Toba supervolcano. The lake is located in the middle of the northern part of the

island An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been ...

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 (Volcanic crater lake, crater lakes) but can also be large volumes of molten lava within an active volcan ...

in the world. Toba Caldera is one of twenty

geopark A geopark is a protected area with internationally significant geology within which Sustainability, sustainable development is sought and which includes tourism, conservation, education and research concerning not just geology but other relevant s ...

s in Indonesia, and was recognised in July 2020 as one of the UNESCO Global Geoparks. 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 eruption date of 74,000 years ago. It is the largest-known explosive eruption on

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

in the last 25 million years. According to the

Toba catastrophe theory The Toba eruption (also called the Toba supereruption and the Youngest Toba eruption) was a supervolcanic eruption that occurred around 74,000 years ago, during the Late Pleistocene, at the site of present-day Lake Toba, in Sumatra, Indonesia. ...

, the eruption had global consequences for human populations as it killed most humans living at that time and is believed to have created a

population 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 genocide, speciocide, wid ...

in central east Africa and India, which affects the genetic make-up of the human worldwide population to the present. A recent study has cast doubt on this theory and found no evidence of substantial changes in global population. It was also suggested that the eruption of the Toba Caldera led to a

volcanic winter A volcanic winter is a reduction in global temperatures caused by droplets of sulfuric acid obscuring the Sun and raising Earth's albedo (increasing the reflection of solar radiation) after a large, sulfur-rich, particularly explosive volcanic eru ...

with a worldwide decrease in temperature between , and up to at 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 Lakes, African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania. It is ...

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 volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the str ...

comprises four overlapping volcanic craters that adjoin the Sumatran "volcanic front". At it is the world's largest

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

caldera, and the fourth and youngest caldera. It intersects the three older calderas. An estimated of dense-rock equivalent 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 co ...

, 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 In geology, a graben () is a depression (geology), depressed block of the Crust (geology), crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German language, German, meaning 'ditch' or 't ...

. At least four cones, four

stratovolcano A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with ...

es, 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

-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 of 8, making it the largest-known explosive

volcanic eruption A volcanic eruption occurs when material is expelled from a volcanic vent or fissure. Several types of volcanic eruptions have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior h ...

in the Quaternary. Bill Rose and Craig Chesner of

Michigan Technological University Michigan Technological University (Michigan Tech, MTU, or simply Tech) is a public research university in Houghton, Michigan, United States. It was founded in 1885 as the Michigan Mining School, the first post-secondary institution in the Uppe ...

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 surrou ...

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#Asia, subregion of Asia that is defined in both geographical and Ethnicity, ethnic-Culture, cultural terms. South Asia, with a population of 2.04 billion, contains a quarter (25%) of the world's populatio ...

; 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. Featuring the Tanjung Piai, southernmost point of continental Eurasia, it is a federation, federal constitutional monarchy consisting of States and federal territories of Malaysia, 13 states and thre ...

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. Toba overview

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 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 An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains i ...

from

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

record a pulse of starkly reduced levels of organic

carbon sequestration Carbon sequestration is the process of storing carbon in a carbon pool. It plays a crucial role in Climate change mitigation, limiting climate change by reducing the amount of Carbon dioxide in Earth's atmosphere, carbon dioxide in the atmosphe ...

. 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. 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 Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondrion, mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the D ...

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 genocide, speciocide, wid ...

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 (UIUC, U of I, Illinois, or University of Illinois) is a public land-grant research university in the Champaign–Urbana metropolitan area, Illinois, United States. Established in 1867, it is the f ...

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 Paleoanthropology or paleo-anthropology is a branch of paleontology and anthropology which seeks to understand the early development of anatomically modern humans, a process known as hominization, through the reconstruction of evolutionary kinsh ...

suggests there was no

.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 In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, us ...

, 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 u ...

, for example, pushing Samosir Island and the Uluan Peninsula 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 (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...

. Toba is probably the largest resurgent caldera on Earth. Large

earthquake An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...

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
/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 is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. Lake Michigan–Huron has a larger combined surface area than Superior, but is normally considered tw ...

in North America, and also larger than the magma chamber underneath

Yellowstone Yellowstone National Park is a List of national parks of the United States, national park of the United States located in the northwest corner of Wyoming, with small portions extending into Montana and Idaho. It was established by the 42nd U ...

. Lake Toba lies near the

Great Sumatran fault The Great Sumatran fault, also known as Semangko fault, is a large strike-slip fault running the entire length of the island of Sumatra. This Indonesian island is located in a highly seismic area of the world, including a subduction zone off th ...

, 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, which is sliding under the eastward-moving Eurasian plate. The

subduction Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second p ...

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 On 26 December 2004, at 07:58:53 local time (UTC+07:00, UTC+7), a major earthquake with a magnitude of 9.2–9.3 struck with an epicenter, epicentre off the west coast of Aceh in northern Sumatra, Indonesia. The Submarine earthquake, undersea ...

and the 8.7

2005 Nias–Simeulue earthquake The 2005 Nias–Simeulue earthquake occurred on 28 March off the west coast of northern Sumatra, Indonesia in the subduction zone of the Sunda megathrust. At least 915 people were killed, mostly on the island of Nias. It was among the top 10 mos ...

, the epicenters of which were around from Toba.

People

COLLECTIE TROPENMUSEUM Batak prauwen bij Haranggaol aan het Tobameer TMnr 60043981

Most of the people who live around Lake Toba are ethnically Bataks. 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 is located on the edge of the lake, which is the transit point to travel the lake and Samosir Island.

Medan Medan ( , ) is the capital city, capital and largest city of the Indonesian Provinces of Indonesia, province of North Sumatra. The nearby Strait of Malacca, Port of Belawan, and Kualanamu International Airport make Medan a regional hub and multi ...

is about 173 km by road from the town and is connected via the Trans-Sumatran Highway to Pematang Siantar by a 48 km road. Sisingamangaraja XII International Airport is located about 76 km from Parapat.

Flora and fauna

The

flora Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...

of the lake includes various types of

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...

, emerged

macrophyte Aquatic plants, also referred to as hydrophytes, are vascular plants and non-vascular plants that have adapted to live in aquatic environments ( saltwater or freshwater). In lakes, rivers and wetlands, aquatic vegetations provide cover for aquat ...

s, 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 (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...

includes several species of

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

and

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

animals. Since the lake is

oligotrophic An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments. Oligotrophs are characterized by slow growth, low rates o ...

(nutrient-poor), the native fish fauna is relatively scarce, and the only endemics 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 clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary o ...

), 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'', '' Nemacheilus pfeifferae'', '' Homaloptera gymnogaster'', '' Channa gachua'', '' Channa striata'', '' Clarias batrachus'', ''

Barbonymus gonionotus The Java barb (''Barbonymus gonionotus''; ''Ta-phian''; Lao language, Lao: ''Pa keng''; ''Trey Chpin''; ; Vietnamese language, Vietnamese: ''Mè Vinh''), more commonly known as silver barb in aquaculture, is a species of ray-finned fish in th ...

'', '' Barbonymus schwanenfeldii'', '' Danio albolineatus'', '' Osteochilus vittatus'', '' Puntius binotatus'', '' Rasbora jacobsoni'', '' Tor tambra'', '' Betta imbellis'', '' Betta taeniata'' and '' Monopterus albus''.

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

(2012).
Species in Toba.
' Accessed 25 January 2012 Among the many introduced species are '' Anabas testudineus'', '' Oreochromis mossambicus'', '' Oreochromis niloticus'', '' Ctenopharyngodon idella'', '' Cyprinus carpio'', '' Osphronemus goramy'', '' Trichogaster pectoralis'', '' Trichopodus trichopterus'', ''

Poecilia reticulata The Greater Underwater Propulsion Power Program (GUPPY) was initiated by the United States Navy after World War II to improve the submerged speed, maneuverability, and endurance of its submarines. (The "Y" in the acronym was added for pronouncea ...

'' and '' Xiphophorus hellerii''.

Sinking of MV ''Sinar Bangun''

On 18 June 2018, Lake Toba was the scene of a ferry disaster, in which over 160 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 167 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 to be 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

References

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 Geoparks 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 Asahan Toba basin