The Semeru ( jv, ꦱꦼꦩꦺꦫꦸ), or Mount Semeru ( jv, ꦒꦸꦤꦸꦁꦱꦼꦩꦺꦫꦸ (Pegon:, Gunung Semeru), is an active

volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are ...

located in

East Java East Java ( id, Jawa Timur) is a Provinces of Indonesia, province of Indonesia located in the easternmost hemisphere of Java island. It has a land border only with the province of Central Java to the west; the Java Sea and the Indian Ocean bord ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. It is located in a subduction zone, where 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 ...

subducts Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

under the

Eurasia 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 ...

. It is the highest

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited Summit (topography), summit area, and ...

on the island of

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...

. The name "Semeru" is derived from

Meru Meru may refer to: Geography Kenya * Meru, Kenya, a city in Meru County, Kenya ** Meru County, created by the merger of *** Meru Central District *** Meru North District *** Meru South District * Meru National Park, a Kenyan wildlife park Tanza ...

, the central world mountain in

Hinduism Hinduism () is an Indian religion or '' dharma'', a religious and universal order or way of life by which followers abide. As a religion, it is the world's third-largest, with over 1.2–1.35 billion followers, or 15–16% of the global p ...

, or Sumeru, the abode of gods. This

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

is also known as Mahameru, meaning "The Great Mountain" in

Sanskrit Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late ...

. It is one of the more popular hiking destinations in Indonesia.

Geology

Semeru rises steeply above the coastal plains of eastern Java.

Maar A maar is a broad, low-relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma). A maar characteristically fills with water to form a relatively shallow ...

s containing crater lakes have formed along a line through the summit of the

. It was formed south of the overlapping Ajek-ajek and Jambagan

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 ...

s. The eruptive products are andesitic. Semeru lies at the south end of the

Tengger Volcanic Complex The Bromo ( jv, ꦧꦿꦩ), or Mount Bromo ( jv, ꦒꦸꦤꦸꦁꦧꦿꦩ Pegon: , Gunung Bromo) is an active somma volcano and part of the Tengger mountains, in East Java, Indonesia. At it is not the highest peak of the massif, but th ...

Eruptive history

Semeru's eruptive history is extensive. Since 1818, at least 55 eruptions have been recorded (11 of which resulted in fatalities) consisting of both

lava flow Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or und ...

s and

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 bu ...

s. All historical eruptions have had a Volcanic Explosivity Index (VEI) of 2 or 3. Semeru has been in a state of near-constant eruption from 1967 to the present. Semeru is regularly climbed by tourists, usually starting from the village of Ranu Pane to the north, but though non-technical, it can be dangerous. Soe Hok Gie, an Indonesian political activist of the 1960s, died in 1969 from inhaling poisonous gases while hiking on Mount Semeru.

2021 eruption

On 4 December 2021, Semeru erupted for a second time in the year – the first having been on 16 January 2021. Semeru erupted a third time on 6 December 2021. At least 57 people died, 104 more were injured, while 23 are unaccounted for. Thousands were displaced.

2022 eruption

A fresh eruption started on 4 December 2022, as monsoon rains collapsed the mountain's lava dome, provoking evacuations. Hot gas clouds flowed up to from the crater. Evacuation of people was quickly undertaken.Indonesia raises volcano warning to highest level after Mount Semeru erupts
ABC News Online, 2022-12-04

Mythology

Semeru is named after Sumeru, the central world-mountain in

. As stated in legend, it was transplanted from

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

to create the island of Java; the tale is recorded in the 15th-century East Javanese work '' Tantu Pagelaran''. It was originally placed in the western part of the island, but that caused the island to tip, so the gods moved it eastward. On that journey, parts kept coming off the lower rim, forming the mountains

Lawu The Lawu ( jv, ꦭꦮꦸ), or Mount Lawu ( jv, ꦒꦸꦤꦸꦁꦭꦮꦸ, Gunung Lawu) is a massive compound stratovolcano straddling the border between East Java and Central Java, Indonesia. The north side is deeply eroded and the eastern ...

, Wilis, Kelud, Kawi, Arjuno and Welirang. The damage thus caused to the foot of the mountain caused it to shake, and the top came off and created Penanggungan as well. Indonesian Hindus also hold a belief that the mountain is the abode of

Shiva Shiva (; sa, शिव, lit=The Auspicious One, Śiva ), also known as Mahadeva (; ɐɦaːd̪eːʋɐ, or Hara, is one of the principal deities of Hinduism. He is the Supreme Being in Shaivism, one of the major traditions within Hindu ...

in Java.

Floral problems

Non-native invasive plants

25 non-native plants have been found in Mount Semeru National Park. The non-native plants, which threaten the

endemic 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 elsew ...

local plants, were imported by Dutch botanist Van Steenis, in the colonial era. They include ''

Foeniculum vulgare Fennel (''Foeniculum vulgare'') is a flowering plant species in the carrot family. It is a hardy, perennial herb with yellow flowers and feathery leaves. It is indigenous to the shores of the Mediterranean but has become widely naturalize ...

'', ''

Verbena brasiliensis ''Verbena brasiliensis'', the Brazilian verbena or Brazilian vervain, is a flowering plant species from the vervain family (Verbenaceae). It is native to parts of South America, namely Brazil, but has spread its range in recent times and has occa ...

'', ''

Chromolaena odorata ''Chromolaena odorata'' is a tropical and subtropical species of flowering shrub in the family Asteraceae. It is native to the Americas, from Florida and Texas in the United States south through Mexico and the Caribbean to South America. It ...

'', and '' Salvinia molesta''.

Vegetable plantations

Mud

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

from surrounding vegetable plantations is adding silt to Ranu Pani Lake, causing the lake to gradually shrink. Research has predicted that the lake will disappear by about 2025, unless the vegetable plantations on the hillsides are replaced with more ecologically sustainable perennials.

Citations

General sources

* * Holt, Claire. ''Art in Indonesia: Continuities and Change''. Ithaca:

Cornell University Press The Cornell University Press is the university press of Cornell University; currently housed in Sage House, the former residence of Henry William Sage. It was first established in 1869, making it the first university publishing enterprise in th ...

, 1967. Page 36 explains the mythological aspect of the mountain.

External links

Satellite picture by Google Maps Early December 2022 eruptions
at NASA Earth Observatory
Semeru Volcano by Drone
{{authority control Active volcanoes of Indonesia Maars of Indonesia Mountains of East Java Sacred mountains Stratovolcanoes of Indonesia VEI-3 volcanoes Volcanic crater lakes Volcanoes of East Java Holocene stratovolcanoes Volcanic eruptions in 2022