SettingsVolcanology
Aden Lava Flow Wilderness Study Area
Aden Lava Flow Wilderness Study Area is one of many Wilderness Study Areas (WSAs) operated by the Bureau of Land Management (BLM) in New Mexico.
Aden Lava Flow Wilderness Study Area is one of many Wilderness Study Areas (WSAs) operated by the Bureau of Land Management (BLM) in New Mexico.
Agglomerate
Agglomerates (from the Latin 'agglomerare' meaning 'to form into a ball') are coarse accumulations of large blocks of volcanic material that contain at least 75% bombs.
Agglomerates (from the Latin 'agglomerare' meaning 'to form into a ball') are coarse accumulations of large blocks of volcanic material that contain at least 75% bombs.
Amygdule
Amygdules or amygdales form when the gas bubbles or vesicles in volcanic lava are infilled with a secondary mineral such as calcite, quartz, chlorite or one of the zeolites.
Amygdules or amygdales form when the gas bubbles or vesicles in volcanic lava are infilled with a secondary mineral such as calcite, quartz, chlorite or one of the zeolites.
Andesite
Andesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture.
Andesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture.
Andesite line
The andesite line is the most significant regional geologic distinction in the Pacific Ocean basin.
The andesite line is the most significant regional geologic distinction in the Pacific Ocean basin.
Apache tears
Apache tears are rounded nodules of obsidian (volcanic black glass) with diameter from about 0.5 to 5 cm.
Apache tears are rounded nodules of obsidian (volcanic black glass) with diameter from about 0.5 to 5 cm.
Ashstone
Ashstone is a kind of volcanic rock formed from fine volcanic ash.
Ashstone is a kind of volcanic rock formed from fine volcanic ash.
Batholith
A batholith (from Greek bathos, depth + lithos, rock) is a large emplacement of igneous intrusive (also called plutonic) rock that forms from cooled magma deep in the Earth's crust.
A batholith (from Greek bathos, depth + lithos, rock) is a large emplacement of igneous intrusive (also called plutonic) rock that forms from cooled magma deep in the Earth's crust.
Bowen's reaction series
Within the field of geology, Bowen's reaction series is the work of the petrologist, Norman L. Bowen who was able to explain why certain types of minerals tend to be found together while others ...
Within the field of geology, Bowen's reaction series is the work of the petrologist, Norman L. Bowen who was able to explain why certain types of minerals tend to be found together while others ...
Bradyseism
Bradyseism is the gradual uplift or descent of part of the Earth's surface caused by the filling or emptying of an underground magma chamber and/or hydrothermal activity, particularly in volcani...
Bradyseism is the gradual uplift or descent of part of the Earth's surface caused by the filling or emptying of an underground magma chamber and/or hydrothermal activity, particularly in volcani...
Bridge River Ash
The Bridge River Ash is a large geologically recent volcanic ash deposit that spans from southwestern British Columbia to central Alberta, Canada.
The Bridge River Ash is a large geologically recent volcanic ash deposit that spans from southwestern British Columbia to central Alberta, Canada.
British Tertiary Volcanic Province
The British Tertiary Volcanic Province was created 60-50 million years ago during the formation of the North Atlantic.
The British Tertiary Volcanic Province was created 60-50 million years ago during the formation of the North Atlantic.
Brito-Arctic province
The Brito-Arctic province (also known as the North Atlantic Tertiary Volcanic Province) is a major flood basalt province of the North Atlantic Ocean.
The Brito-Arctic province (also known as the North Atlantic Tertiary Volcanic Province) is a major flood basalt province of the North Atlantic Ocean.
Caldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption.
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption.
Carbonatite
Carbonatites are intrusive or extrusive igneous rocks defined by mineralogic composition consisting of greater than 50 percent carbonate minerals.
Carbonatites are intrusive or extrusive igneous rocks defined by mineralogic composition consisting of greater than 50 percent carbonate minerals.
Caribbean large igneous province
The Caribbean large igneous province consists of a major flood basalt, which created this large igneous province.
The Caribbean large igneous province consists of a major flood basalt, which created this large igneous province.
Cryovolcano
A cryovolcano (colloquially known as an ice volcano) is a volcano that erupts volatiles such as water, ammonia or methane, instead of molten rock.
A cryovolcano (colloquially known as an ice volcano) is a volcano that erupts volatiles such as water, ammonia or methane, instead of molten rock.
Dense-rock equivalent
Dense-rock equivalent is a volcanologic calculation used to estimate volcanic eruption volume.
Dense-rock equivalent is a volcanologic calculation used to estimate volcanic eruption volume.
Diatreme
A diatreme is a breccia-filled volcanic pipe that was formed by a gaseous explosion.
A diatreme is a breccia-filled volcanic pipe that was formed by a gaseous explosion.
Dike swarm
A dike swarm or dyke swarm is a large geological structure consisting of a major group of parallel, linear, or radially oriented dikes intruded within continental crust.
A dike swarm or dyke swarm is a large geological structure consisting of a major group of parallel, linear, or radially oriented dikes intruded within continental crust.
East Australia hotspot
The East Australia hotspot is a volcanic hotspot that forces magma up at weak spots in the Indo-Australian Plate to form volcanoes of Eastern Australia.
The East Australia hotspot is a volcanic hotspot that forces magma up at weak spots in the Indo-Australian Plate to form volcanoes of Eastern Australia.
Extrusive
Extrusive refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere t...
Extrusive refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere t...
Finlay tephras
The Finlay tephras is the term for two tephra deposits in northern British Columbia, Canada.
The Finlay tephras is the term for two tephra deposits in northern British Columbia, Canada.
Fissure vent
A fissure vent, also known as a volcanic fissure or simply fissure, is a linear volcanic vent through which lava erupts, usually without any explosive activity.
A fissure vent, also known as a volcanic fissure or simply fissure, is a linear volcanic vent through which lava erupts, usually without any explosive activity.
Flow banding
Flow banding is a geological term to describe bands or layers that can sometimes be seen in rock that formed from the substance molten rock or magma.
Flow banding is a geological term to describe bands or layers that can sometimes be seen in rock that formed from the substance molten rock or magma.
Gas slug
A gas slug is a conglomerate of high pressure gas bubbles that forms within certain volcanoes, the agittation of which is a key driving factor in Strombolian eruptions.
A gas slug is a conglomerate of high pressure gas bubbles that forms within certain volcanoes, the agittation of which is a key driving factor in Strombolian eruptions.
Glacial lake outburst flood
A glacial lake outburst flood (GLOF) is a type of outburst flood that occurs when the dam containing a glacial lake fails.
A glacial lake outburst flood (GLOF) is a type of outburst flood that occurs when the dam containing a glacial lake fails.
Glaciovolcanism
Glaciovolcanism is a term used to describe volcanism and related phenomena associated with glacial ice.
Glaciovolcanism is a term used to describe volcanism and related phenomena associated with glacial ice.
Global Volcanism Program
The Smithsonian Institution's Global Volcanism Program (GVP) documents Earth's volcanoes and their eruptive history over the past 10,000 years.
The Smithsonian Institution's Global Volcanism Program (GVP) documents Earth's volcanoes and their eruptive history over the past 10,000 years.
Granophyre
Granophyre (, from granite and porphyry) is a subvolcanic rock that contains quartz and alkali feldspar in characteristic angular intergrowths such as those in the accompanying image.
Granophyre (, from granite and porphyry) is a subvolcanic rock that contains quartz and alkali feldspar in characteristic angular intergrowths such as those in the accompanying image.
Great Meteor hotspot track
The Great Meteor hotspot track, also referred to as the New England hotspot track, is a vast trail of hotspot magmatism in the Northern Hemisphere, stretching over from Nunavut in Norther...
The Great Meteor hotspot track, also referred to as the New England hotspot track, is a vast trail of hotspot magmatism in the Northern Hemisphere, stretching over from Nunavut in Norther...
Gregoryite
Gregoryite is an anhydrous carbonate that is rich in potasium and sodium (examples of geochemical composition: (Na,Ca)2CO3
Na0.78K0.05Ca0.17CO3).
Gregoryite is an anhydrous carbonate that is rich in potasium and sodium (examples of geochemical composition: (Na,Ca)2CO3
Na0.78K0.05Ca0.17CO3).
Harmonic tremor
Harmonic tremor describes a long-duration release of seismic energy, with distinct spectral lines, that often precedes or accompanies a volcanic eruption.
Harmonic tremor describes a long-duration release of seismic energy, with distinct spectral lines, that often precedes or accompanies a volcanic eruption.
Hot blob
A hot blob is a body of magma which rises by convection to the surface of the mantle.
A hot blob is a body of magma which rises by convection to the surface of the mantle.
Hotspot (geology)
The places known as hotspots or hot spots in geology are volcanic regions thought to be fed by underlying mantle that is anomalously hot compared with the mantle elsewhere.
The places known as hotspots or hot spots in geology are volcanic regions thought to be fed by underlying mantle that is anomalously hot compared with the mantle elsewhere.
Huckleberry Ridge Tuff
The Huckleberry Ridge Tuff is a tuff formation created by the Huckleberry Ridge eruption that formed the Island Park Caldera that lies partially in Yellowstone Park, Wyoming and stretches westwa...
The Huckleberry Ridge Tuff is a tuff formation created by the Huckleberry Ridge eruption that formed the Island Park Caldera that lies partially in Yellowstone Park, Wyoming and stretches westwa...
Hyaloclastite
Hyaloclastite is a hydrated tuff-like breccia rich in black volcanic glass, formed during volcanic eruptions under water, under ice or where subaerial flows reach the sea or other bodies of water.
Hyaloclastite is a hydrated tuff-like breccia rich in black volcanic glass, formed during volcanic eruptions under water, under ice or where subaerial flows reach the sea or other bodies of water.
Ice-marginal lava flow
An ice–marginal lava flow is a lava flow that has impounded against a glacier, ice sheet, ice field or any other body of glacial ice.
An ice–marginal lava flow is a lava flow that has impounded against a glacier, ice sheet, ice field or any other body of glacial ice.
Ice–marginal lava flow
An ice–marginal lava flow is a lava flow that has impounded against a glacier, ice sheet, ice field or any other body of glacial ice.
An ice–marginal lava flow is a lava flow that has impounded against a glacier, ice sheet, ice field or any other body of glacial ice.
Igneous rock
Igneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock.
Igneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock.
Instituto Nacional de Sismología, Vulcanología, Meteorología e Hidrología
The National Institute for Seismology, Vulcanology, Meteorology and Hydrology of Guatemala (in Spanish: Instituto Nacional de Sismología, Vulcanología, Meteorología e Hidrología (INSIVUMEH)) is ...
The National Institute for Seismology, Vulcanology, Meteorology and Hydrology of Guatemala (in Spanish: Instituto Nacional de Sismología, Vulcanología, Meteorología e Hidrología (INSIVUMEH)) is ...
Interagency Volcanic Event Notification Plan
The Interagency Volcanic Event Notification Plan (IVENP) is a program in Canada established to outline the notification procedure of some of the main agencies that would be involved in response ...
The Interagency Volcanic Event Notification Plan (IVENP) is a program in Canada established to outline the notification procedure of some of the main agencies that would be involved in response ...
International Association of Volcanology and Chemistry of the Earth's Interior
The International Association of Volcanology and Chemistry of the Earth's Interior, or IAVCEI, is an association that represents the primary international focus for research in volcanology...
The International Association of Volcanology and Chemistry of the Earth's Interior, or IAVCEI, is an association that represents the primary international focus for research in volcanology...
International Volcanic Ashfall Impacts Working Group
The International Volcanic Ashfall Impacts Working Group was established in 2010 to investigate volcanic ashfall impacts following volcanic eruptions.
The International Volcanic Ashfall Impacts Working Group was established in 2010 to investigate volcanic ashfall impacts following volcanic eruptions.
International Volcanic Health Hazard Network
The International Volcanic Health Hazard Network is an organization the provides research and information on volcanic health hazards.
The International Volcanic Health Hazard Network is an organization the provides research and information on volcanic health hazards.
Io as an X-ray source
The discoveries of Jupiter's moon Io as an X-ray source and X-rays from the region of the Io plasma torus are by the Chandra X-ray Observatory while observing the Jovian system on November 25-6,...
The discoveries of Jupiter's moon Io as an X-ray source and X-rays from the region of the Io plasma torus are by the Chandra X-ray Observatory while observing the Jovian system on November 25-6,...
Journal of Volcanology and Geothermal Research
Journal of Volcanology and Geothermal Research is a scientific journal that publishes recent research on the fields of volcanology and geothermal activity.
Journal of Volcanology and Geothermal Research is a scientific journal that publishes recent research on the fields of volcanology and geothermal activity.
Komatii Formation
The Komatii Formation is a 3.475 billion year old rock formation, named after the nearby Komati River in South Africa.
The Komatii Formation is a 3.475 billion year old rock formation, named after the nearby Komati River in South Africa.
Lahar
A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water.
A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water.
Lamproite
Lamproites are ultrapotassic mantle-derived volcanic and subvolcanic rocks.
Lamproites are ultrapotassic mantle-derived volcanic and subvolcanic rocks.
Large igneous province
A large igneous province is an extremely large accumulation of igneous rocks—intrusive, extrusive, or both—in the earth's crust.
A large igneous province is an extremely large accumulation of igneous rocks—intrusive, extrusive, or both—in the earth's crust.
Latite
Latite is an igneous, volcanic (extrusive) rock, with aphanitic-aphyric to aphyric-porphyritic texture.
Latite is an igneous, volcanic (extrusive) rock, with aphanitic-aphyric to aphyric-porphyritic texture.
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling.
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling.
Lava bench
A lava bench is a volcanic landform with a horizontal surface raised above the level of the surrounding area.
A lava bench is a volcanic landform with a horizontal surface raised above the level of the surrounding area.
Lava channel
A lava channel is a stream of fluid lava contained within marginal zones of static (i.e., solid and stationary) lava or levees.
A lava channel is a stream of fluid lava contained within marginal zones of static (i.e., solid and stationary) lava or levees.
Lava coil
A lava coil is a spiral or scroll-shaped lava formation occurring when relatively low viscosity lava such as Pahoehoe solidifies along a slow-moving shear zone in the flow.
A lava coil is a spiral or scroll-shaped lava formation occurring when relatively low viscosity lava such as Pahoehoe solidifies along a slow-moving shear zone in the flow.
Lava Creek Tuff
Lava Creek Tuff is a tuff formation, in Wyoming, created when the Yellowstone Caldera erupted about 640,000 years ago.
Lava Creek Tuff is a tuff formation, in Wyoming, created when the Yellowstone Caldera erupted about 640,000 years ago.
Lava fountain
A lava fountain is a volcanic phenomenon in which lava is forcefully but non-explosively ejected from a crater, vent, or fissure.
A lava fountain is a volcanic phenomenon in which lava is forcefully but non-explosively ejected from a crater, vent, or fissure.
Lava tube
Lava tubes are natural conduits through which lava travels beneath the surface of a lava flow, expelled by a volcano during an eruption.
Lava tubes are natural conduits through which lava travels beneath the surface of a lava flow, expelled by a volcano during an eruption.
Lavacicle
Lavacicles are geological formations resembling small round-tipped stalactites that are found in lava tubes, the name comes from their resemblance to icicles.
Lavacicles are geological formations resembling small round-tipped stalactites that are found in lava tubes, the name comes from their resemblance to icicles.
Limu o Pele
Limu o Pele or Pele's seaweed is a geological term for thin sheets and subsequently shattered flakes of brownish-green to near-colourless volcanic glass lava spatter that commonly resemble...
Limu o Pele or Pele's seaweed is a geological term for thin sheets and subsequently shattered flakes of brownish-green to near-colourless volcanic glass lava spatter that commonly resemble...
Macellum of Pozzuoli
The Macellum of Pozzuoli was the macellum or market building of the Roman town of Puteoli, now known as Pozzuoli.
The Macellum of Pozzuoli was the macellum or market building of the Roman town of Puteoli, now known as Pozzuoli.
Magma
Magma is a mixture of molten or semi molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets.
Magma is a mixture of molten or semi molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets.
Magma chamber
A magma chamber is a large underground pool of liquid rock found beneath the surface of the Earth.
A magma chamber is a large underground pool of liquid rock found beneath the surface of the Earth.
Maritime impacts of volcanic eruptions
Less commonly publicized than the effects on aviation—and with less potential for catastrophe—maritime Impacts of volcanic eruptions are also dangerous.
Less commonly publicized than the effects on aviation—and with less potential for catastrophe—maritime Impacts of volcanic eruptions are also dangerous.
Mesa Falls Tuff
The Mesa Falls Tuff is a tuff formation created by the Mesa Falls eruption that formed the Henry's Fork Caldera that is located in Idaho west of Yellowstone Park.
The Mesa Falls Tuff is a tuff formation created by the Mesa Falls eruption that formed the Henry's Fork Caldera that is located in Idaho west of Yellowstone Park.
Mofetta
Mofetta (Italian from Latin mephitis, a pestilential exhalation), is a name applied to a volcanic discharge consisting chiefly of carbon dioxide, often associated with other vapours, representin...
Mofetta (Italian from Latin mephitis, a pestilential exhalation), is a name applied to a volcanic discharge consisting chiefly of carbon dioxide, often associated with other vapours, representin...
Monogenetic volcanic field
A monogenetic volcanic field is a volcanic field of small, scattered volcanic vents.
A monogenetic volcanic field is a volcanic field of small, scattered volcanic vents.
Mount Chimaera
Mount Chimaera was a place or places in ancient Lycia, notable for volcanic phenomena and said by some ancient sources to be the origin of the myth of the Chimera.
Mount Chimaera was a place or places in ancient Lycia, notable for volcanic phenomena and said by some ancient sources to be the origin of the myth of the Chimera.
Mud volcano
The term mud volcano or mud dome are used to refer to formations created by geo-excreted liquids and gases, although there are several different processes which may cause such activity.
The term mud volcano or mud dome are used to refer to formations created by geo-excreted liquids and gases, although there are several different processes which may cause such activity.
Natrocarbonatite
Natrocarbonatite is a rare carbonatite lava which erupts from the Ol Doinyo Lengai volcano in Tanzania within the Great Rift Valley of eastern Africa.
Natrocarbonatite is a rare carbonatite lava which erupts from the Ol Doinyo Lengai volcano in Tanzania within the Great Rift Valley of eastern Africa.
Negative Volcano
A negative volcano is a Caldera volcano that is a lake filled with hot springs.
A negative volcano is a Caldera volcano that is a lake filled with hot springs.
New islands
New islands are islands which have been created recently, whether by means of vulcanism, erosion, glacial retreat, or other mechanisms.
New islands are islands which have been created recently, whether by means of vulcanism, erosion, glacial retreat, or other mechanisms.
Northern Cordilleran Volcanic Province
The Northern Cordilleran Volcanic Province (NCVP), formerly known as the Stikine Volcanic Belt, is a geologic province defined by the occurrence of Miocene to Holocene volcanoes in the Pac...
The Northern Cordilleran Volcanic Province (NCVP), formerly known as the Stikine Volcanic Belt, is a geologic province defined by the occurrence of Miocene to Holocene volcanoes in the Pac...
Nova Iguaçu Volcano
The Nova Iguaçu Volcano is located in the state of Rio de Janeiro, Brazil, in an area of volcanic rocks at the north-eastern border of the Mendanha massif.
The Nova Iguaçu Volcano is located in the state of Rio de Janeiro, Brazil, in an area of volcanic rocks at the north-eastern border of the Mendanha massif.
Oslo Graben
The Oslo Graben or Oslo Rift is a graben formed during a geologic rifting event in Permian time, the last phase of the Variscan orogeny.
The Oslo Graben or Oslo Rift is a graben formed during a geologic rifting event in Permian time, the last phase of the Variscan orogeny.
Pacific Ring of Fire
The Pacific Ring of Fire is an area where a large number of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean.
The Pacific Ring of Fire is an area where a large number of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean.
Palagonite
Palagonite is an alteration product from the interaction of water with volcanic glass of chemical composition similar to basalt.
Palagonite is an alteration product from the interaction of water with volcanic glass of chemical composition similar to basalt.
Parasitic cone
A parasitic cone (or satellite cone) is the cone-shaped accumulation of volcanic material created by eruptions from fractures other than the central vent of a volcano.
A parasitic cone (or satellite cone) is the cone-shaped accumulation of volcanic material created by eruptions from fractures other than the central vent of a volcano.
Pebble Creek Formation
Pebble Creek Formation is a volcanic formation in the Garibaldi Volcanic Belt created when Mount Meager erupted about 2,350 years ago and by two rock avalanche deposits.
Pebble Creek Formation is a volcanic formation in the Garibaldi Volcanic Belt created when Mount Meager erupted about 2,350 years ago and by two rock avalanche deposits.
Pele's hair
Pele's hair is a geological term for volcanic glass threads or fibers formed when small particles of molten material are thrown into the air and spun out by the wind into long hair-like strands.
Pele's hair is a geological term for volcanic glass threads or fibers formed when small particles of molten material are thrown into the air and spun out by the wind into long hair-like strands.
Pele's tears
Pele’s tears is a geological term for small pieces of solidified lava drops formed when airborne particles of molten material fuse into tearlike drops of volcanic glass.
Pele’s tears is a geological term for small pieces of solidified lava drops formed when airborne particles of molten material fuse into tearlike drops of volcanic glass.
Peperino
Peperino is an Italian name applied to a brown or grey volcanic tuff, containing fragments of basalt and limestone, with disseminated crystals of augite, mica, magnetite, leucite, and other s...
Peperino is an Italian name applied to a brown or grey volcanic tuff, containing fragments of basalt and limestone, with disseminated crystals of augite, mica, magnetite, leucite, and other s...
Peralkaline
Peralkaline is a term used to describe igneous rocks that have a deficiency of aluminium such that sodium and potassium are in excess of that needed for feldspar.
Peralkaline is a term used to describe igneous rocks that have a deficiency of aluminium such that sodium and potassium are in excess of that needed for feldspar.
Peralkaline rock
Peralkaline rocks include those igneous rocks which have a deficiency of aluminium such that sodium and potassium are in excess of that needed for feldspar.
Peralkaline rocks include those igneous rocks which have a deficiency of aluminium such that sodium and potassium are in excess of that needed for feldspar.
Phreatomagmatic eruption
Phreatomagmatic eruptions are defined as juvenile forming eruptions as a result of interaction between water and magma.
Phreatomagmatic eruptions are defined as juvenile forming eruptions as a result of interaction between water and magma.
Picrite basalt
Picrite basalt, picrobasalt or oceanite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine.
Picrite basalt, picrobasalt or oceanite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine.
Pillow lava
Pillow lavas are lavas that contain characteristic pillow-shaped structures that are attributed to the extrusion of the lava under water, or subaqueous extrusion.
Pillow lavas are lavas that contain characteristic pillow-shaped structures that are attributed to the extrusion of the lava under water, or subaqueous extrusion.
Pit crater
A pit crater is a depression formed by a sinking of the ground surface lying above a void or empty chamber, rather than by the eruption of a volcano or lava vent.
A pit crater is a depression formed by a sinking of the ground surface lying above a void or empty chamber, rather than by the eruption of a volcano or lava vent.
Pitchstone
Pitchstone is a dull black glassy volcanic rock formed when viscous lava or magma cools swiftly.
Pitchstone is a dull black glassy volcanic rock formed when viscous lava or magma cools swiftly.
Polygenetic volcanic field
A polygenetic volcanic field is a volcanic field of scattered volcanic vents.
A polygenetic volcanic field is a volcanic field of scattered volcanic vents.
Post shield stage
Post-Shield Stage refers to a stage of growth in the life of a volcano, referring to a late period in the life of a shield volcano.
Post-Shield Stage refers to a stage of growth in the life of a volcano, referring to a late period in the life of a shield volcano.
Pozzolana
Pozzolana, also known as pozzolanic ash (pulvis puteolanus in Latin), is a fine, sandy volcanic ash.
Pozzolana, also known as pozzolanic ash (pulvis puteolanus in Latin), is a fine, sandy volcanic ash.
Prediction of volcanic activity
Prediction of volcanic eruption (also: volcanic eruption forecasting) is an interdisciplinary scientific and engineering approach to natural catastrophic event forecasting.
Prediction of volcanic eruption (also: volcanic eruption forecasting) is an interdisciplinary scientific and engineering approach to natural catastrophic event forecasting.
Pressure ridge (lava)
A pressure ridge (sometimes referred to as a tumulus or tumuli in plural form) is created in an active lava flow.
A pressure ridge (sometimes referred to as a tumulus or tumuli in plural form) is created in an active lava flow.
Pseudocrater
A pseudocrater is a volcanic landform which resembles a true volcanic crater, but differs in that it is not an actual vent from which lava has erupted.
A pseudocrater is a volcanic landform which resembles a true volcanic crater, but differs in that it is not an actual vent from which lava has erupted.
Pumice raft
A pumice raft is a floating raft of pumice occasionally created by ocean-based volcanic activity.
A pumice raft is a floating raft of pumice occasionally created by ocean-based volcanic activity.
Pyroclastic fall
A pyroclastic fall is a uniform deposit of material which has been ejected from a volcanic eruption or plume such as an ash fall or tuff.
A pyroclastic fall is a uniform deposit of material which has been ejected from a volcanic eruption or plume such as an ash fall or tuff.
Pyroclastic flow
A pyroclastic flow (also known scientifically as a pyroclastic density current) is a fast-moving current of superheated gas (which can reach temperatures of about ) and rock (collectively ...
A pyroclastic flow (also known scientifically as a pyroclastic density current) is a fast-moving current of superheated gas (which can reach temperatures of about ) and rock (collectively ...
Pyroclastic rock
Pyroclastic rocks or pyroclastics are clastic rocks composed solely or primarily of volcanic materials.
Pyroclastic rocks or pyroclastics are clastic rocks composed solely or primarily of volcanic materials.
Pyroclastic shield
In volcanology, a pyroclastic shield or terrestrial ignimbrite shield is an uncommon type of shield volcano.
In volcanology, a pyroclastic shield or terrestrial ignimbrite shield is an uncommon type of shield volcano.
Pyroclastic surge
A pyroclastic surge is a fluidized mass of turbulent gas and rock fragments which is ejected during some volcanic eruptions.
A pyroclastic surge is a fluidized mass of turbulent gas and rock fragments which is ejected during some volcanic eruptions.
Resurgent dome
In geology, a resurgent dome is a dome formed by swelling or rising of a caldera floor due to movement in the magma chamber beneath it.
In geology, a resurgent dome is a dome formed by swelling or rising of a caldera floor due to movement in the magma chamber beneath it.
Rhyodacite
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite.
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite.
Rift zone
A rift zone is a feature of some volcanoes, especially the shield volcanoes of Hawaii, in which a linear series of fissures in the volcanic edifice allows lava to be erupted from the volcano's f...
A rift zone is a feature of some volcanoes, especially the shield volcanoes of Hawaii, in which a linear series of fissures in the volcanic edifice allows lava to be erupted from the volcano's f...
Sheep Track Pumice
Sheep Track Pumice or Sheep Track Member by Canadian volcanologist Jack Souther, is the name for a pumice deposit in northern British Columbia, Canada.
Sheep Track Pumice or Sheep Track Member by Canadian volcanologist Jack Souther, is the name for a pumice deposit in northern British Columbia, Canada.
Sheepeater Cliff
The Sheepeater Cliffs are a series of exposed cliffs made up of columnar basalt in Yellowstone National Park in the United States.
The Sheepeater Cliffs are a series of exposed cliffs made up of columnar basalt in Yellowstone National Park in the United States.
Sheet intrusion
A sheet intrusion is a type of intrusion where a mass of molten or solidified igneous rock that takes advantage of a pre-existing linear feature in a host rock, such as a long rupture or fault.
A sheet intrusion is a type of intrusion where a mass of molten or solidified igneous rock that takes advantage of a pre-existing linear feature in a host rock, such as a long rupture or fault.
Sill (geology)
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or even along the direction of foliation in metamorph...
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or even along the direction of foliation in metamorph...
Sill swarm
A sill swarm in geology is a major group of sills intruded within continental crust.
A sill swarm in geology is a major group of sills intruded within continental crust.
Society hotspot
The Society hotspot is a volcanic hotspot located in the Pacific Ocean, and is responsible for the creation of the Society Islands.
The Society hotspot is a volcanic hotspot located in the Pacific Ocean, and is responsible for the creation of the Society Islands.
Soffioni
Soffioni (sometimes spelt suffioni), a name applied in Italy to certain volcanic vents which emit jets of steam, generally associated with hydrogen sulfide and carbon dioxide, sometimes also...
Soffioni (sometimes spelt suffioni), a name applied in Italy to certain volcanic vents which emit jets of steam, generally associated with hydrogen sulfide and carbon dioxide, sometimes also...
Somma volcano
A somma volcano (also known simply as a somma) is a volcanic caldera that has been partially filled by a new central cone.
A somma volcano (also known simply as a somma) is a volcanic caldera that has been partially filled by a new central cone.
Stock (geology)
In geology, a stock is a discordant igneous intrusion having a surface exposure of less than, differing from batholiths only in being smaller.
In geology, a stock is a discordant igneous intrusion having a surface exposure of less than, differing from batholiths only in being smaller.
Subaqueous volcano
A subaqueous volcano is a volcano formed beneath water (similar to submarine volcanoes) and never builds above lake level.
A subaqueous volcano is a volcano formed beneath water (similar to submarine volcanoes) and never builds above lake level.
Subvolcanic rock
A subvolcanic rock, also known as a hypabyssal rock, is an igneous rock that originates at medium to shallow depths within the crust and contain intermediate grain size and often porphyrit...
A subvolcanic rock, also known as a hypabyssal rock, is an igneous rock that originates at medium to shallow depths within the crust and contain intermediate grain size and often porphyrit...
Supervolcano
A supervolcano is a volcano capable of producing a volcanic eruption with an ejecta volume greater than 1,000 cubic kilometers.
A supervolcano is a volcano capable of producing a volcanic eruption with an ejecta volume greater than 1,000 cubic kilometers.
Tephra layer
A tephra layer which bears its own unique chemistry and character may be used as a temporal marker horizon in archaeological and geological sites.
A tephra layer which bears its own unique chemistry and character may be used as a temporal marker horizon in archaeological and geological sites.
Tephrite
Tephrite is an igneous, volcanic (extrusive) rock, with aphanitic to porphyritic texture.
Tephrite is an igneous, volcanic (extrusive) rock, with aphanitic to porphyritic texture.
Tezontle
Tezontle (tezontle) is a porous, extrusive, igneous, volcanic rock used extensively in construction in Mexico.
Tezontle (tezontle) is a porous, extrusive, igneous, volcanic rock used extensively in construction in Mexico.
Thorarinsson Medal
The Thorarinsson Medal is awarded by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) for outstanding contributions to the general field of volcanolog...
The Thorarinsson Medal is awarded by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) for outstanding contributions to the general field of volcanolog...
Tiltmeter
A tiltmeter is an instrument designed to measure very small changes from the horizontal level, either on the ground or in structures.
A tiltmeter is an instrument designed to measure very small changes from the horizontal level, either on the ground or in structures.
Tornillo event
A tornillo event is a low-frequency seismic event associated with volcanoes.
A tornillo event is a low-frequency seismic event associated with volcanoes.
Traprock mountains
The term traprock (or basalt) mountains, ridges, (or just traps) is used to describe elevated landscape features made of the rock known as basalt and its close relatives.
The term traprock (or basalt) mountains, ridges, (or just traps) is used to describe elevated landscape features made of the rock known as basalt and its close relatives.
Tuya
A tuya is a type of distinctive, flat-topped, steep-sided volcano formed when lava erupts through a thick glacier or ice sheet.
A tuya is a type of distinctive, flat-topped, steep-sided volcano formed when lava erupts through a thick glacier or ice sheet.
Types of volcanic eruptions
During a volcanic eruption, lava, tephra, and various gases are expelled from a volcanic vent or fissure.
During a volcanic eruption, lava, tephra, and various gases are expelled from a volcanic vent or fissure.
Ubehebe Crater
Ubehebe Crater is a large volcanic crater of the Ubehebe Craters volcanic field in the northern half of Death Valley, in Death Valley National Park, California.
Ubehebe Crater is a large volcanic crater of the Ubehebe Craters volcanic field in the northern half of Death Valley, in Death Valley National Park, California.
Verneshot
A verneshot is a hypothetical volcanic eruption event caused by the buildup of gas deep underneath a craton.
A verneshot is a hypothetical volcanic eruption event caused by the buildup of gas deep underneath a craton.
Vesicular texture
Vesicular texture is a volcanic rock texture characterized by a rock being pitted with many cavities at its surface and inside.
Vesicular texture is a volcanic rock texture characterized by a rock being pitted with many cavities at its surface and inside.
Vog
Vog is a form of air pollution that results when sulfur dioxide and other gases and particles emitted by an erupting volcano react with oxygen and moisture in the presence of sunlight.
Vog is a form of air pollution that results when sulfur dioxide and other gases and particles emitted by an erupting volcano react with oxygen and moisture in the presence of sunlight.
Volatiles
In planetary science, volatiles are that group of chemical elements and chemical compounds with low boiling points that are associated with a planet's or moon's crust and/or atmosphere.
In planetary science, volatiles are that group of chemical elements and chemical compounds with low boiling points that are associated with a planet's or moon's crust and/or atmosphere.
Volcanic Ash Advisory Center
A Volcanic Ash Advisory Center (VAAC) is a group of experts responsible for coordinating and disseminating information on atmospheric volcanic ash clouds that may endanger aviation.
A Volcanic Ash Advisory Center (VAAC) is a group of experts responsible for coordinating and disseminating information on atmospheric volcanic ash clouds that may endanger aviation.
Volcanic block
A volcanic block is a fragment of rock that measures more than in diameter and is erupted in a solid condition.
A volcanic block is a fragment of rock that measures more than in diameter and is erupted in a solid condition.
Volcanic Explosivity Index
The Volcanic Explosivity Index was devised by Chris Newhall of the U.S. Geological Survey and Stephen Self at the University of Hawaii in 1982 to provide a relative measure of the explosiveness ...
The Volcanic Explosivity Index was devised by Chris Newhall of the U.S. Geological Survey and Stephen Self at the University of Hawaii in 1982 to provide a relative measure of the explosiveness ...
Volcanic hazards
Volcanic hazards are threats to life and/or infrastructure due to volcanic activity.
Volcanic hazards are threats to life and/or infrastructure due to volcanic activity.
Volcanic passive margin
Volcanic passive margins (VPM) and non-volcanic passive margins are the two forms of transitional crust that lie beneath passive continental margins that occur on Earth as the result of the form...
Volcanic passive margins (VPM) and non-volcanic passive margins are the two forms of transitional crust that lie beneath passive continental margins that occur on Earth as the result of the form...
Volcanic pipe
Volcanic pipes are subterranean geological structures formed by the violent, supersonic eruption of deep-origin volcanoes.
Volcanic pipes are subterranean geological structures formed by the violent, supersonic eruption of deep-origin volcanoes.
Volcanic winter
A volcanic winter is the reduction in temperature caused by volcanic ash and droplets of sulfuric acid obscuring the sun and raising Earth's albedo after a large particularly explosive type of v...
A volcanic winter is the reduction in temperature caused by volcanic ash and droplets of sulfuric acid obscuring the sun and raising Earth's albedo after a large particularly explosive type of v...
Volcano
A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, volcanic ash and gases to escape from below the surface.
A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, volcanic ash and gases to escape from below the surface.
Volcano Disaster Assistance Program
Volcano Disaster Assistance Program was developed by the U.S. Geological Survey and U.S. Office of Foreign Disaster Assistance after the eruption of Nevado del Ruiz in 1985 that killed 23,000 people.
Volcano Disaster Assistance Program was developed by the U.S. Geological Survey and U.S. Office of Foreign Disaster Assistance after the eruption of Nevado del Ruiz in 1985 that killed 23,000 people.
Volcano Hazards Program
The Volcano Hazards Program is a program directed by the USGS that monitors the activity of volcanoes and the public awareness of eruptions.
The Volcano Hazards Program is a program directed by the USGS that monitors the activity of volcanoes and the public awareness of eruptions.
Volcano Number
The Volcano Number (also: Volcano Reference File Number, Volcano Numbering System, or VNUM) is a hierarchical geographical systematic system to uniquely identify and tag volcanoes an...
The Volcano Number (also: Volcano Reference File Number, Volcano Numbering System, or VNUM) is a hierarchical geographical systematic system to uniquely identify and tag volcanoes an...
Volcano observatory
A volcano observatory is an institution that conducts research and monitoring of a volcano.
A volcano observatory is an institution that conducts research and monitoring of a volcano.
Volcano tectonic earthquake
A volcano tectonic earthquake is an earthquake induced by the movement of magma.
A volcano tectonic earthquake is an earthquake induced by the movement of magma.
Volcanological Survey of Indonesia
Volcanological Survey of Indonesia is the official Indonesian government body responsible for investigating, recording, and warning about volcanos within the Indonesian region of responsibility.
Volcanological Survey of Indonesia is the official Indonesian government body responsible for investigating, recording, and warning about volcanos within the Indonesian region of responsibility.
Volcanology
Volcanology (also spelled vulcanology) is the study of volcanoes, lava, magma, and related geological, geophysical and geochemical phenomena.
Volcanology (also spelled vulcanology) is the study of volcanoes, lava, magma, and related geological, geophysical and geochemical phenomena.
Vulcania
Vulcania, the "European Park of Volcanism", is a park with a Volcano theme situated in Saint-Ours-les-Roches, Auvergne, France.
Vulcania, the "European Park of Volcanism", is a park with a Volcano theme situated in Saint-Ours-les-Roches, Auvergne, France.
Wadati-Benioff zone
A Wadati–Benioff zone (also Benioff–Wadati zone or Benioff zone or Benioff seismic zone) is a deep active seismic area in a subduction zone.
A Wadati–Benioff zone (also Benioff–Wadati zone or Benioff zone or Benioff seismic zone) is a deep active seismic area in a subduction zone.
Yanartaş
Yanartaş, proposed as the ancient Mount Chimaera, is the name of a geographical feature near Olympos valley and national park in Antalya Province in southwestern Turkey, at a distance of about e...
Yanartaş, proposed as the ancient Mount Chimaera, is the name of a geographical feature near Olympos valley and national park in Antalya Province in southwestern Turkey, at a distance of about e...