A report on Volcano and Hotspot (geology)

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.

Diagram showing a cross section through the Earth's lithosphere (in yellow) with magma rising from the mantle (in red). Lower diagram illustrates a hotspot track caused by the lithosphere's movement.

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).

Schematic diagram showing the physical processes inside the Earth that lead to the generation of magma. Partial melting begins above the fusion point.

Sabancaya volcano erupting, Peru in 2017

Over millions of years, the Pacific Plate has moved over the Hawaii hotspot, creating a trail of underwater mountains that stretches across the Pacific

Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station, May 2006

Kilauea is the most active shield volcano in the world. The volcano erupted nonstop from 1983 to 2018 and it is part of the Hawaiian–Emperor seamount chain.

An eruption of Mount Pinatubo on June 12, 1991, three days before its climactic eruption

Mauna Loa is a large shield volcano. Its last eruption was in 1984 and it is part of the Hawaiian–Emperor seamount chain.

Fountain of lava erupting from a volcanic cone in Hawaii, 1983

Bowie Seamount is a dormant submarine volcano and it is part of the Kodiak-Bowie Seamount chain.

Aerial view of the Barren Island, Andaman Islands, India, during an eruption in 1995. It is the only active volcano in South Asia.

Axial Seamount is the youngest seamount of the Cobb–Eickelberg Seamount chain. Its last eruption was on 6 April 2011.

Map showing the divergent plate boundaries (oceanic spreading ridges) and recent sub-aerial volcanoes (mostly at convergent boundaries)

Mauna Kea is the tallest volcano in the Hawaiian–Emperor seamount chain. It is dormant and it has cinder cones growing on the volcano.

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.

Hualalai is a massive shield volcano in the Hawaiian–Emperor seamount chain. Its last eruption was in 1801.

Skjaldbreiður, a shield volcano whose name means "broad shield"

An example of mantle plume locations suggested by one recent group. Figure from Foulger (2010).

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".

Distribution of hotspots in the list to the left, with the numbers corresponding to those in the list. The Afar hotspot (29) is misplaced.

Cross-section through a stratovolcano (vertical scale is exaggerated):

Over millions of years, the Pacific Plate has moved over the Bowie hotspot, creating the Kodiak-Bowie Seamount chain in the Gulf of Alaska

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

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.

In geology, hotspots (or hot spots) are volcanic locales thought to be fed by underlying mantle that is anomalously hot compared with the surrounding mantle.

- Hotspot (geology)

This results in hotspot volcanism, of which the Hawaiian hotspot is an example.

- Volcano

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Simplified map of Earth's principal tectonic plates, which were mapped in the second half of the 20th century (red arrows indicate direction of movement at plate boundaries)

Plate tectonics

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Generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago.

Diagram of the internal layering of Earth showing the lithosphere above the asthenosphere (not to scale)

Plate motion based on Global Positioning System (GPS) satellite data from NASA JPL. Each red dot is a measuring point and vectors show direction and magnitude of motion.

Detailed map showing the tectonic plates with their movement vectors.

Alfred Wegener in Greenland in the winter of 1912–13.

Global earthquake epicenters, 1963–1998. Most earthquakes occur in narrow belts that correspond to the locations of lithospheric plate boundaries.

A demonstration of magnetic striping. (The darker the color is, the closer it is to normal polarity)

Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries (or faults).

The theories find resonance in the modern theories which envisage hot spots or mantle plumes which remain fixed and are overridden by oceanic and continental lithosphere plates over time and leave their traces in the geological record (though these phenomena are not invoked as real driving mechanisms, but rather as modulators).

Yellowstone hotspot

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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.

Magma

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Molten or semi-molten natural material from which all igneous rocks are formed.

Phase diagram for the diopside-anorthite system

$Schematic diagrams showing the principles behind fractional crystallisation in a magma. While cooling, the magma evolves in composition because different minerals crystallize from the melt. 1: olivine crystallizes; 2: olivine and pyroxene crystallize; 3: pyroxene and plagioclase crystallize; 4: plagioclase crystallizes. At the bottom of the magma reservoir, a cumulate rock forms.$

Two silica tetrahedra joined by a bridging oxygen ion (tinted pink)

Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots.

Following its ascent through the crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion, such as a dike, a sill, a laccolith, a pluton, or a batholith.

Yellowstone National Park

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American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho.

Ferdinand V. Hayden (1829–1887), American geologist who convinced Congress to make Yellowstone a national park in 1872

Ferdinand V. Hayden's map of Yellowstone National Park, 1871

Portrait of Nathaniel P. Langford (1870), the first superintendent of the park

Great Falls of the Yellowstone, U.S. Geological and Geographic Survey of the Territories (1874–1879), photographer William Henry Jackson

Fort Yellowstone (circa 1910), formerly a U.S. Army post, now serves as park headquarters.

Superintendent Horace M. Albright and black bears (1922). Tourists often fed black bears in the park's early years, with 527 injuries reported from 1931 to 1939.

The Roosevelt Arch in Gardiner, Montana, at the north entrance

Pictorial map by Heinrich C. Berann (1991); scale exaggerated

Official park map c. undefined 2006 (click on map to enlarge)

Satellite image of Yellowstone National Park in 2020

Columnar basalt near Tower Fall; large floods of basalt and other lava types preceded mega-eruptions of superheated ash and pumice.

Boardwalks allow visitors to safely approach the thermal features, such as Grand Prismatic Spring.

Infrastructure damage at Hebgen Lake due to the 7.2 magnitude earthquake of 1959

Yellowstone sand verbena are endemic to Yellowstone's lakeshores.

A reintroduced wolf in Yellowstone National Park

Pronghorn are commonly found on the grasslands in the park.

Wildfire in Yellowstone National Park produces a pyrocumulus cloud.

A crown fire approaches the Old Faithful complex on September 7, 1988.

Union Pacific Railroad brochure promoting travel to the park (1921)

Tourists watch Old Faithful erupt, 2019.

Vintage photo of human-habituated bears seeking food from visitors

Idaho portion of park highlighted in southwest corner (click to enlarge)

Official park map c. undefined 2020 (click on map to enlarge)

The caldera is considered a dormant volcano.

Yellowstone is thus the active part of a hotspot that has moved northeast over time.

Map showing the underwater topography (bathymetry) of the ocean floor. Like land terrain, the ocean floor has mountains including volcanoes, ridges, valleys, and plains.

Seabed

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Bottom of the ocean.

Total sediment thickness of the world's oceans and continental margins in meters.

Satellite image of wind-blown mineral dust over the Atlantic. Dust may become terrigenous sediment on the seabed.

Phytoplankton grow shells which later sink to the seabed to become biogenous sediments. For example, diatoms make silicate shells, which become siliceous ooze.

Hydrothermal vent fluids cause chemical reactions that precipitate out minerals that form sediments on the surrounding seafloor.

Sediment types from the Southern Ocean showing many different grain sizes: A) gravel and sand, B) gravel, C) bioturbated mud and sand, and D) laminated clays and silts.

Map of underwater topography (1995 NOAA)

Hotspot volcanic island ridges are created by volcanic activity, erupting periodically, as the tectonic plates pass over a hotspot.

The submerged surface has mountainous features, including a globe-spanning mid-ocean ridge system, as well as undersea volcanoes, oceanic trenches, submarine canyons, oceanic plateaus and abyssal plains.

Hawaii hotspot

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Map, color-coded from red to blue to indicate the age of crust built by seafloor spreading. 2 indicates the position of the bend in the hotspot trail, and 3 points to the present location of the Hawaii hotspot.

Cutaway diagram of Earth's internal structure

The Loa and Kea volcanic trends follow meandering parallel paths for thousands of miles.

A lava fountain at Pu'u 'O'o, a volcanic cone on the flank of Kilauea. Pu'u 'O'o is one of the most active volcanoes in the world, and erupted nearly continuously from 3 January 1983 to April 2018.

Bathymetry and topography of the southeastern Hawaiian Islands, with historic lava flows shown in red

An animated sequence showing the erosion and subsidence of a volcano, and the formation of a coral reef around it—eventually resulting in an atoll

The Hawai’i hotspot is a volcanic hotspot located near the namesake Hawaiian Islands, in the northern Pacific Ocean.

Four of these volcanoes are active, two are dormant; more than 123 are extinct, most now preserved as atolls or seamounts.

Hawaiian Islands

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Archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some 1500 mi from the island of Hawaii in the south to northernmost Kure Atoll.

3-D perspective view of the southeastern Hawaiian Islands, with the white summits of Mauna Loa (4170 m high) and Mauna Kea (4207.3 m high). The islands are the tops of massive volcanoes, the bulk of which lie below the sea surface. Ocean depths are colored from violet (5750 m deep northeast of Maui) and indigo to light gray (shallowest). Historical lava flows are shown in red, erupting from the summits and rift zones of Mauna Loa, Kilauea, and Hualalai volcanoes on Hawaii.

A composite satellite image from NASA of the Hawaiian Islands taken from outer space. Click on the image for a larger view that shows the main islands and the extended archipelago.

Eruptions from the Hawaii hotspot left a trail of underwater mountains across the Pacific over millions of years, called the Emperor Seamounts.

Aftermath of the 1960 Chilean tsunami in Hilo, Hawaii, where the tsunami left 61 people dead and 282 seriously injured. The waves reached 35 ft high.

The Hawaiian Islands are the exposed peaks of a great undersea mountain range known as the Hawaiian–Emperor seamount chain, formed by volcanic activity over a hotspot in the Earth's mantle.