A report on Volcano

Bromo volcano in Indonesia. This country has more than 130 active volcanoes, one of which is a supervolcano, making Indonesia the country with the most active volcanoes in the world.
Cordillera de Apaneca volcanic range in El Salvador. The country is home to 170 volcanoes, 23 which are active, including two calderas, one being a supervolcano. El Salvador has earned the epithets endearment La Tierra de Soberbios Volcanes, (The Land of Magnificent Volcanoes).
Sabancaya volcano erupting, Peru in 2017
Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station, May 2006
An eruption of Mount Pinatubo on June 12, 1991, three days before its climactic eruption
Fountain of lava erupting from a volcanic cone in Hawaii, 1983
Aerial view of the Barren Island, Andaman Islands, India, during an eruption in 1995. It is the only active volcano in South Asia.
Map showing the divergent plate boundaries (oceanic spreading ridges) and recent sub-aerial volcanoes (mostly at convergent boundaries)
Lakagigar fissure vent in Iceland, the source of the major world climate alteration of 1783–84, has a chain of volcanic cones along its length.
Skjaldbreiður, a shield volcano whose name means "broad shield"
Izalco volcano, the youngest volcano in El Salvador. Izalco erupted almost continuously from 1770 (when it formed) to 1958, earning it the nickname of "Lighthouse of the Pacific".
Cross-section through a stratovolcano (vertical scale is exaggerated):
Satellite images of the 15 January 2022 eruption of Hunga Tonga-Hunga Haʻapai
Pāhoehoe lava flow on Hawaii. The picture shows overflows of a main lava channel.
The Stromboli stratovolcano off the coast of Sicily has erupted continuously for thousands of years, giving rise to its nickname "Lighthouse of the Mediterranean"
Columnar-jointed basalt lava erupted from a volcano, South Penghu Marine National Park in Taiwan
Light-microscope image of tuff as seen in thin section (long dimension is several mm): The curved shapes of altered glass shards (ash fragments) are well preserved, although the glass is partly altered. The shapes were formed around bubbles of expanding, water-rich gas.
Fresco with Mount Vesuvius behind Bacchus and Agathodaemon, as seen in Pompeii's House of the Centenary
Narcondam Island, India, is classified as a dormant volcano by the Geological Survey of India
Fourpeaked volcano, Alaska, in September 2006 after being thought extinct for over 10,000 years
Mount Rinjani eruption in 1994, in Lombok, Indonesia
Shiprock in New Mexico, US
Capulin Volcano National Monument in New Mexico, US
Koryaksky volcano towering over Petropavlovsk-Kamchatsky on Kamchatka Peninsula, Far Eastern Russia
Schematic of volcano injection of aerosols and gases
Solar radiation graph 1958–2008, showing how the radiation is reduced after major volcanic eruptions
Sulfur dioxide concentration over the Sierra Negra Volcano, Galapagos Islands, during an eruption in October 2005
Comparison of major United States supereruptions (VEI 7 and 8) with major historical volcanic eruptions in the 19th and 20th century. From left to right: Yellowstone 2.1 Ma, Yellowstone 1.3 Ma, Long Valley 6.26 Ma, Yellowstone 0.64 Ma . 19th century eruptions: Tambora 1815, Krakatoa 1883. 20th century eruptions: Novarupta 1912, St. Helens 1980, Pinatubo 1991.
The Tvashtar volcano erupts a plume 330 km (205 mi) above the surface of Jupiter's moon Io.
Olympus Mons (Latin, "Mount Olympus"), located on the planet Mars, is the tallest known mountain in the Solar System.

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.

- Volcano
Bromo volcano in Indonesia. This country has more than 130 active volcanoes, one of which is a supervolcano, making Indonesia the country with the most active volcanoes in the world.

121 related topics with Alpha

Overall
The supervolcano caldera Lake Toba

Volcanic winter

4 links

The supervolcano caldera Lake Toba

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 explosive volcanic eruption.

Yellowstone sits on top of four overlapping calderas. (US NPS)

Yellowstone Caldera

4 links

Yellowstone sits on top of four overlapping calderas. (US NPS)
Incidence of earthquakes in Yellowstone National Park region (1973–2014)
Diagram of the Yellowstone Caldera
Path of the Yellowstone hotspot over the past 16 million years

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.

In this phase diagram, the green dotted line illustrates the anomalous behavior of water. The dotted green line marks the melting point and the blue line the boiling point, showing how they vary with pressure; the solid green line shows the typical melting point behavior for other substances.

Hydrothermal vent

3 links

Fissure on the seafloor from which geothermally heated water discharges.

Fissure on the seafloor from which geothermally heated water discharges.

In this phase diagram, the green dotted line illustrates the anomalous behavior of water. The dotted green line marks the melting point and the blue line the boiling point, showing how they vary with pressure; the solid green line shows the typical melting point behavior for other substances.
Deep-sea vent biogeochemical cycle diagram
Black smokers were first discovered in 1979 on the East Pacific Rise at 21° north latitude
A dense fauna (Kiwa anomurans and Vulcanolepas-like stalked barnacles) near East Scotia Ridge vents
Giant tube worms (Riftia pachyptila) cluster around vents in the Galapagos Rift
A cross-section of a typical volcanogenic massive sulfide (VMS) ore deposit as seen in the sedimentary record
Distribution of hydrothermal vents. This map was created by making use of the InterRidge ver.3.3 database.

They are commonly found near volcanically active places, areas where tectonic plates are moving apart at spreading centers, ocean basins, and hotspots.

Mount St. Helens from Monitor Ridge, this image shows the cone of devastation, the huge crater open to the north, the posteruption lava dome inside, and Crater Glacier surrounding the lava dome. The small photo on the left was taken from Spirit Lake before the eruption and the small photo on the right was taken after the eruption from roughly the same place. Spirit Lake can also be seen in the larger image, as well as two other Cascade volcanoes.

1980 eruption of Mount St. Helens

5 links

On March 27, 1980, a series of volcanic explosions and pyroclastic flows began at Mount St. Helens in Skamania County, Washington, United States.

On March 27, 1980, a series of volcanic explosions and pyroclastic flows began at Mount St. Helens in Skamania County, Washington, United States.

Mount St. Helens from Monitor Ridge, this image shows the cone of devastation, the huge crater open to the north, the posteruption lava dome inside, and Crater Glacier surrounding the lava dome. The small photo on the left was taken from Spirit Lake before the eruption and the small photo on the right was taken after the eruption from roughly the same place. Spirit Lake can also be seen in the larger image, as well as two other Cascade volcanoes.
USGS photo showing a pre-avalanche eruption on April 10
Photo showing the cryptodome on April 27
Sequence of events on May 18
Lakes nearest to Mount St. Helens have been partly covered with felled trees for more than 40 years. This photograph was taken in 2012.
North Fork Toutle River valley filled with landslide deposits
Computer graphics showing the May 18 landslide (green) being overtaken by the initial pyroclastic flow (red)
Photographer Reid Blackburn's Volvo after the eruption
Many trees in the direct blast zone were snapped off at their bases and the earth was stripped and scorched.
Volcanologist David A. Johnston (photographed on April 4, 1980) was among the approximately 57 people killed in the eruption.
The ash cloud produced by the eruption, as seen from the village of Toledo, Washington, 35 miles (56 km) to the northwest of Mount St. Helens: The cloud was roughly 40 mi wide and 15 mi high.
Ash cloud from Mt. St. Helens as captured by the GOES 3 weather satellite at 15:45 UTC.
Residual lateral blast effects in the channelized blast zone, some 30 years after the eruption: Damage ranged from scorched earth, through tree trunks snapped at various heights, to more superficial effects.
Mudline next to Muddy River from the 1980 lahars
Mount St. Helens one day before the eruption, photographed from the Johnston ridge
Mount St. Helens four months after the eruption, photographed from roughly the same location as was the earlier picture: Note the barrenness of the terrain as compared to the image above.
Map of ash distribution over the United States
One of the 200 houses destroyed by the eruption
Eruption on July 22, 1980
The growing third dome on October 24, 1980
Plume of volcanic ash and steam in the October 2004 eruption
Satellite image of Mount St. Helens crater (22 July 1982)
Satellite image of Mount St. Helens crater 30 June 1980 (color infrared)
Satellite image of Mount St. Helens before eruption (23 July 1975)
Digital elevation model (DEM) of Mount St. Helens (1982)
DEM of Mount St. Helens (2003)
DEM of Mount St. Helens (2017)
Lava domes growth and landscape change of Mount St. Helens 2002-2017
Lava domes growth and landscape change of Mount St. Helens 1982-2003
Lava domes growth and landscape change of Mount St. Helens 1982-2017

Several small earthquakes, beginning on March 15, indicated that magma might have begun moving below the volcano.

Volcanic arc formation along a subducting plate

Volcanic arc

3 links

Volcanic arc formation along a subducting plate
Cascade Volcanic Arc, a continental volcanic arc
The Aleutian Arc, with both oceanic and continental parts.

A volcanic arc is a chain of volcanoes formed above a subducting plate,

Diagram of the geological process of subduction

Subduction

6 links

Geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries.

Geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries.

Diagram of the geological process of subduction
The Juan de Fuca plate sinks below the North America plate at the Cascadia subduction zone
Oceanic plates are subducted creating oceanic trenches.
350 px

Volcanoes that occur above subduction zones, such as Mount St. Helens, Mount Etna, and Mount Fuji, lie approximately one hundred kilometers from the trench in arcuate chains called volcanic arcs.

Yellowstone hotspot

3 links

Yellowstone Caldera map
Number of earthquakes in Yellowstone National Park region (1973–2014)
Map of recent Yellowstone eruption fields, in comparison with a recent Long Valley Caldera eruption and Mount St. Helens.

The Yellowstone hotspot is a volcanic hotspot in the United States responsible for large scale volcanism in Idaho, Montana, Nevada, Oregon, and Wyoming, formed as the North American tectonic plate moved over it.

A lahar travels down a river valley in Guatemala near the Santa Maria volcano, 1989

Lahar

4 links

Violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water.

Violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water.

A lahar travels down a river valley in Guatemala near the Santa Maria volcano, 1989
Excavated 9th century Sambisari Hindu temple near Yogyakarta in Java, Indonesia. The temple was buried 6.5 metres under the lahar volcanic debris accumulated from centuries of Mount Merapi eruptions.
Mudline left behind on trees on the banks of the Muddy River after the 1980 eruption of Mount St. Helens showing the height of the lahar
The aftermath of a lahar from the 1982 eruption of Galunggung, Indonesia
The lahar from the 1985 eruption of Nevado del Ruiz that wiped out the town of Armero in Colombia
A before-and-after photograph of a river valley filled in by lahars from Mount Pinatubo

The material flows down from a volcano, typically along a river valley.

Aerial view of Mount Lassen with snow, early May 2018

Lassen Peak

3 links

Aerial view of Mount Lassen with snow, early May 2018
Lassen Peak's northeastern face
Dacitic volcanic rock on Lassen Peak's summit
The Chaos Crags and Lassen Peak, as seen from Manzanita Lake
The Lassen Peak National Monument, later expanded into Lassen Volcanic National Park, was established by United States President Theodore Roosevelt (pictured) in 1907.
Lassen Peak Before 1914
The "Great Explosion" eruption column of May 22, 1915, was seen as far as 150 mi away. In the foreground is the Loomis Hot Rock, one of the many large boulders dislodged in the eruption that were too hot to touch for days after. (Photograph by B. F. Loomis; [[:File:Loomis Hot Rock-750px.JPG|modern photo]])
Lassen Volcanic National Park has an extensive hydrothermal system that includes fumaroles, hot springs, and mudpots.
A volcanic hazard map for Lassen Peak made by the United States Geological Survey. For basaltic volcanism, blue dots indicate vents, yellow space indicates lava flow zones, and orange space indicates ash fall hazard zones. For dacitic volcanism, triangles mark vents, dark pink dashed lines mark pyroclastic flow hazard zones, light pink spaces indicate mudflow zones, blue dashed lines indicate heavy ashfall zones, blue dotted lines mark moderate ash fall zones, and green spaces mark flood zones. Any red space indicates combined hazard zones (including lahars, pyroclastic flows, avalanches, and ash).
Snow covered summit of Lassen Peak

Lassen Peak, commonly referred to as Mount Lassen, is the southernmost active volcano in the Cascade Range of the Western United States.

Carbonatite from Jacupiranga, Brazil. This rock is a mixture of calcite, magnetite, and olivine.

Carbonatite

3 links

Type of intrusive or extrusive igneous rock defined by mineralogic composition consisting of greater than 50% carbonate minerals.

Type of intrusive or extrusive igneous rock defined by mineralogic composition consisting of greater than 50% carbonate minerals.

Carbonatite from Jacupiranga, Brazil. This rock is a mixture of calcite, magnetite, and olivine.
Carbonatite lava at Ol Doinyo Lengai volcano, Tanzania
Magnesiocarbonatite, from Verity-Paradise Carbonatite Complex of British Columbia. Specimen is 75 mm wide.
Okaite, an ultramafic rock found near the carbonatite of the Oka Carbonatite Complex, Oka, Quebec
Thin section of apatite-rich carbonatite in cross polarised transmitted light. The sample is from Siilinjärvi apatite mine.

Only one carbonatite volcano is known to have erupted in historical time, the active Ol Doinyo Lengai volcano in Tanzania.