The Pacific Ring of Fire, with trenches marked with blue linesGlobal earthquakes (1900–2013) : Earthquakes of magnitude ≥ 7.0 (depth 0–69 km (0–43 mi)) : Active volcanoesGlobal map of subduction zones, with subducted slabs contoured by depthDiagram of the geological process of subduction
TheRing of Fire (also known as thePacific Ring of Fire, theRim of Fire, theGirdle of Fire or theCircum-Pacific belt)[note 1] is atectonic belt ofvolcanoes andearthquakes.
It is about 40,000 km (25,000 mi) long[1] and up to about 500 km (310 mi) wide,[2] and surrounds most of thePacific Ocean.
The Ring of Fire contains between 750 and 915 active or dormant volcanoes, around two-thirds of the world total.[3][4] The exact number of volcanoes within the Ring of Fire depends on which regions are included.
About 90% of the world's earthquakes,[5] including most of its largest,[6][7] occur within the belt.
The Ring of Fire has existed for more than 35 million years[9] but subduction has existed for much longer in some parts of the Ring;[10] many olderextinct volcanoes are located within the Ring.[3] More than 350 of the Ring of Fire's volcanoes have been active inhistorical times,[11][note 2] while the fourlargest volcanic eruptions on Earth in the Holocene epoch all occurred at volcanoes in the Ring of Fire.[13]
From Ancient Greek and Roman times until the late 18th century, volcanoes were associated with fire, based on the ancient belief that volcanoes were caused by firesburning within the Earth.[15] This historical link between volcanoes and fire is preserved in the name of the Ring of Fire, despite the fact that volcanoes donot burn the Earth with fire.
The existence of anorogenic belt of volcanic activity around the Pacific Ocean was known in the early 19th century; for example, in 1825 the pioneering volcanologistG. P. Scrope described the chains of volcanoes around the Pacific Ocean's rim in his bookConsiderations on Volcanos [sic].[16] Three decades later, a book about thePerry Expedition to Japan commented on the Ring of Fire volcanoes as follows: "They [the Japanese Islands] are in the line of that immense circle of volcanic development which surrounds the shores of the Pacific fromTierra del Fuego around to theMoluccas." (Narrative of the Expedition of an American Squadron to the China Seas and Japan, 1852–54.[17]) An article appeared inScientific American in 1878 with the title "The Ring of Fire, and the Volcanic Peaks of the West Coast of the United States", which outlined the phenomenon of volcanic activity around the boundaries of the Pacific.[18] Early explicit references to volcanoes forming a "ring of fire" around the Pacific Ocean also include Alexander P. Livingstone's book"Complete Story of San Francisco's Terrible Calamity of Earthquake and Fire", published in 1906, in which he describes "... the great ring of fire which circles round the whole surface of the Pacific Ocean.".[19]
In 1912, geologistPatrick Marshall introduced the term "Andesite Line" to mark a boundary between islands in the southwest Pacific, which differ in volcano structure and lava types. The concept was later extended to other parts of the Pacific Ocean.[20] The Andesite Line and the Ring of Fire closely match in terms of location.[21]
The development of the theory ofplate tectonics since the early 1960s has provided the current understanding and explanation of the global distribution of volcanoes and earthquakes, including those in the Ring of Fire.[22][23]
Geographic boundaries
There is consensus among geologists about most of the regions which are included in the Ring of Fire. There are, however, a few regions on which there is no universal agreement. (See:§ Distribution of volcanoes).Indonesia lies at the intersection of the Ring of Fire and theAlpide belt (which is the Earth's other very long subduction-related volcanic and earthquake zone, also known as the Mediterranean–Indonesian volcanic belt, running east–west through southern Asia and southern Europe).[24][25][26] Some geologists include all of Indonesia in the Ring of Fire;[27] many geologists exclude Indonesia's western islands (which they include in the Alpide belt).[28][25][29][30][31]
Some geologists include the Antarctic Peninsula and the South Shetland Islands in the Ring of Fire,[29][30] other geologists exclude these areas.[27] The rest of Antarctica is excluded because thevolcanism there is not related to subduction.[32][31]
The Ring of Fire does not extend across the southern Pacific Ocean from New Zealand to the Antarctic Peninsula or from New Zealand to the southern tip of South America[33] because the submarine plate boundaries in this part of the Pacific Ocean (thePacific–Antarctic Ridge, theEast Pacific Rise and theChile Ridge) aredivergent instead of convergent. Although some volcanism occurs in this region, it is not related to subduction.
Volcanoes in the central parts of the Pacific Basin, for example theHawaiian Islands, are very far from subduction zones[36] and they are not part of the Ring of Fire.[37]
Tectonic plate configurations
The Ring of Fire has existed for more than 35 million years.[9] In some parts of the Ring of Fire, subduction has been occurring for much longer.[38]
The current configuration of the Pacific Ring of Fire has been created by the development of the present-day subduction zones, initially (by about 115 million years ago) in South America, North America and Asia. As plate configurations gradually changed, the current subduction zones of Indonesia and New Guinea were created (about 70 million years ago), followed finally by the New Zealand subduction zone (about 35 million years ago).[39][9]
Past plate configurations
The tectonic plates of the Pacific Ocean in the Early Jurassic (180 Ma)
Along the coast of east Asia, during theLate Triassic about 210 million years ago, subduction of theIzanagi plate (the Paleo-Pacific plate) was occurring,[39] and this continued in theJurassic, producing volcanic belts, for example, in what is now eastern China.[40]
ThePacific plate came into existence in theEarly Jurassic about 190 million years ago,[41] far from the margins of the then Paleo-Pacific Ocean. Until the Pacific plate grew large enough to reach the margins of the ocean basin, other older plates were subducted ahead of it at the ocean basin margins. For example, subduction has been occurring at the coast of South America since theJurassic Period more than 145 million years ago, and remnants of Jurassic andCretaceous volcanic arcs are preserved there.[42]
At about 120 to 115 million years ago, theFarallon plate was subducting under South America, North America and north-east Asia while the Izanagi plate was subducting under east Asia. By 85 to 70 million years ago, the Izanagi plate had moved north-eastwards and was subducting under east Asia and North America, while the Farallon plate was subducting under South America and the Pacific plate was subducting under east Asia. About 70 to 65 million years ago, the Farallon plate was subducting under South America, theKula plate was subducting under North America and north-east Asia, and the Pacific plate was subducting under east Asia and Papua New Guinea. About 35 million years ago, the Kula and Farallon plates had been subducted and the Pacific plate was subducting around its rim in a configuration closely resembling the outline of the present-day Ring of Fire.[39][43][44]
Present-day plate configuration
Present-day principal tectonic plates of the Earth
The eastern parts of the Ring of Fire result from the collision of a few relatively large plates. The western parts of the Ring are more complex, with a number of large and small tectonic plates in collision.[45]
In South America, the Ring of Fire is the result of theAntarctic plate, theNazca plate and theCocos plate beingsubducted beneath theSouth American plate. InCentral America, the Cocos plate is being subducted beneath theCaribbean plate. A portion of thePacific plate and the smallJuan de Fuca plate are being subducted beneath theNorth American plate. Along the northern portion, the northwestward-moving Pacific plate is being subducted beneath theAleutian Islands arc. Farther west, the Pacific plate is being subducted at theKamchatka Peninsula andKuril arcs. Farther south, at Japan, Taiwan and the Philippines, the Philippine Plate is being subducted beneath the Eurasian plate. The southwest section of the Ring of Fire is more complex, with a number of smaller tectonic plates in collision with the Pacific plate at theMariana Islands, thePhilippines, easternIndonesia,Papua New Guinea,Tonga, and New Zealand; this part of the Ring excludesAustralia, because that landmass lies in the center of its tectonic plate far from subduction zones.[45]
Subduction zones and oceanic trenches
Chilean-type and Mariana-type subduction zones
If a tectonic plate's oceanic lithosphere is subducted beneath oceanic lithosphere of another plate, a volcanic island arc is created at the subduction zone. An example in the Ring of Fire is the Mariana Arc in the western Pacific Ocean. If, however, oceanic lithosphere is subducted under continental lithosphere, then a volcanic continental arc forms; a Ring of Fire example is the coast of Chile.[2]
The steepness of the descending plate at a subduction zone depends on the age of the oceanic lithosphere that is being subducted. The older the oceanic lithosphere being subducted, the steeper the angle of descent of the subducted slab. As the Pacific'smid-ocean ridges, which are the source of its oceanic lithosphere, are not actually in the middle of the ocean but located much closer to South America than to Asia, the oceanic lithosphere consumed at the South American subduction zones is younger and therefore subduction occurs at the South American coast at a relatively shallow angle. Older oceanic lithosphere is subducted in the western Pacific, with steeper angles of slab descent. This variation affects, for example, the location of volcanoes relative to the ocean trench, lava composition, type and severity of earthquakes,sediment accretion, and the amount of compression or tension. A spectrum of subduction zones exists between the Chilean and Mariana end members.[46][2]
Oceanic trenches
Map of earthquakeepicenters at the Kuril–Kamchatka trench and subduction zone
Oceanic trenches are the topographic expression of subduction zones on the floor of the oceans. Oceanic trenches associated with the Ring of Fire's subduction zones are:
Subduction zones around the Pacific Ocean do not form a complete ring. Where subduction zones are absent, there are corresponding gaps in subduction-related volcanic belts in the Ring of Fire. In some gaps there is no volcanic activity; in other gaps, volcanic activity does occur but it is caused by processes not related to subduction.
There are gaps in the Ring of Fire at some parts of the Pacific coast of the Americas. In some places, the gaps are thought to be caused byflat slab subduction; examples are the three gaps between the four sections of theAndean Volcanic Belt in South America.[47] In North America, there is a gap in subduction-related volcanic activity in northern Mexico and southern California, due partly to a divergent boundary in the Gulf of California and due partly to theSan Andreas Fault (a non-volcanictransform boundary). Another North American gap in subduction-related volcanic activity occurs in northern British Columbia, Yukon and south-east Alaska, where volcanism is caused byintraplate continentalrifting.[22]
Distribution of volcanoes
Distribution of Ring of Fire volcanoes active in the Holocene Epoch (last 11,700 years)[3][48]
excluding the Kermadec Islands; including 8 submarine volcanoes
Yes
Total
913
59
Very large events
Volcanic eruptions
The four largest volcanic eruptions on Earth in theHolocene Epoch (the last 11,700 years) occurred at volcanoes in the Ring of Fire. They are the eruptions atFisher Caldera (Alaska, 8700BC),Kurile Lake (Kamchatka, 6450 BC),Kikai Caldera (Japan, 5480 BC) andMount Mazama (Oregon, 5677 BC).[13] More broadly, twenty[note 3] of the twenty-five largest volcanic eruptions on Earth in this time interval occurred at Ring of Fire volcanoes.[13]
Earthquakes
About 90%[5] of the world's earthquakes and most of the world's largest earthquakes occur along the Ring of Fire.[note 4] The next most seismically active region (5–6% of earthquakes and some of the world's largest earthquakes) is the Alpide belt, which extends from central Indonesia to the northern Atlantic Ocean via theHimalayas and southern Europe.[6][7]
From 1900 to the end of 2020, most earthquakes of magnitudeMw≥ 8.0 occurred in the Ring of Fire.[54][note 5] They are presumed to have beenmegathrust earthquakes at subduction zones,[54] including four of the most powerful earthquakes on Earth sincemodern seismological measuring equipment and magnitude measurement scales were introduced in the 1930s:
Some geologists include the volcanoes of theSouth Shetland Islands, off the northern tip of the Antarctic Peninsula, as part of the Ring of Fire. These volcanoes, e.g.Deception Island, are due to rifting in theBransfield back-arc basin close to the South Shetland subduction zone.[56] The Antarctic Peninsula (Graham Land) is also sometimes included in the Ring.[57] Volcanoes south of theAntarctic Circle (e.g. the volcanoes ofVictoria Land includingMount Erebus, and the volcanoes ofMary Byrd Land) are not related to subduction; therefore, they are not part of the Ring of Fire.[31]
TheBalleny Islands, located between Antarctica and New Zealand, are volcanic but their volcanism is not related to subduction;[58] therefore, they are not part of the Ring of Fire.
The world's highest active volcano isOjos del Salado (6,893 m or 22,615 ft), which is in the Andes Mountains section of the Ring of Fire. It forms part of the border between Argentina and Chile and it last erupted inAD 750.[59] Another Ring of Fire Andean volcano on the Argentina-Chile border isLlullaillaco (6,739 m or 22,110 ft), which is the world's highest historically active volcano, last erupting in 1877.[60]
Chile has experienced numerous volcanic eruptions from about 90 volcanoes during the Holocene Epoch.[3]
Villarrica is one of Chile's most active volcanoes, rising above thelake andtown of the same name. It is the westernmost of three large stratovolcanoes that trend perpendicular to the Andes along theGastre Fault. Villarrica, along withQuetrupillán and the Chilean part ofLanín, are protected withinVillarrica National Park.
Villarrica, with its lava of basaltic-andesitic composition, is one of only five volcanoes worldwide known to have an activelava lake within its crater. The volcano usually generatesstrombolian eruptions, with ejection ofincandescent pyroclasts and lava flows. Melting of snow andglacier ice, as well as rainfall, often causeslahars, such as during the eruptions of 1964 and 1971.[61]
A two-kilometre-wide (1+1⁄4 mi) postglacial caldera is located at the base of the presently active dominantly basaltic-to-andesitic cone at the northwest margin of thePleistocene caldera. About 25 scoria cones dot Villarica's flanks.Plinian eruptions andpyroclastic flows have been produced during theHolocene from this dominantly basaltic volcano, but historical eruptions have consisted of largely mild-to-moderate explosive activity with occasional lava effusion. Lahars from the glacier-covered volcanoes have damaged towns on its flanks.
The Llaima Volcano is one of the largest and most active volcanoes in Chile. It is situated 82 km (51 mi) northeast ofTemuco and 663 km (412 mi) southeast ofSantiago, within the borders ofConguillío National Park. Llaima's activity has been documented since the 17th century, and consists of several separate episodes of moderate explosive eruptions with occasional lava flows.
Lascar erupting in 2006
Lascar is a stratovolcano and the most active volcano of the northern Chilean Andes. The largest eruption of Lascar took place about 26,500 years ago, and following the eruption of the Tumbres scoria flow about 9,000 years ago, activity shifted back to the eastern edifice, where three overlapping craters were formed. Frequent small-to-moderate explosive eruptions have been recorded from Lascar in historical time since the mid-19th century, along with periodic larger eruptions that produced ash andtephra fall up to hundreds of kilometers away from the volcano. The largest eruption of Lascar in recent history took place in 1993, producing pyroclastic flows as far as 8.5 km (5 mi) northwest of the summit and ash fall inBuenos Aires, Argentina, more than 1,600 km (1,000 mi) to the southeast.
Chiliques is a stratovolcano located in theAntofagasta Region of Chile, immediately north ofCerro Miscanti.Laguna Lejía lies to the north of the volcano and has been dormant for at least 10,000 years, but is now showing signs of life. A January 6, 2002, nighttime thermal infrared image fromASTER revealed a hot spot in the summit crater, as well as several others along the upper flanks of the volcano's edifice, indicating new volcanic activity. Examination of an earlier nighttime thermal infrared image from May 24, 2000, showed no such hot spots.[62]
Calbuco is a stratovolcano in southern Chile, located southeast ofLlanquihue Lake and northwest ofChapo Lake, inLos Lagos Region. The volcano and the surrounding area are protected withinLlanquihue National Reserve. It is a very explosiveandesite volcano that underwent edifice collapse in the latePleistocene, producing a volcanicdebris avalanche that reached the lake. At least nine eruptions occurred since 1837, with the latest one in 1972. One of the largest historical eruptions in southern Chile took place there in 1893–1894. Violent eruptions ejected 30 cm (12 in) bombs to distances of 8 km (5.0 mi) from the crater, accompanied by voluminous hot lahars. Strong explosions occurred in April 1917, and alava dome formed in the crater accompanied by hot lahars. Another short explosive eruption in January 1929 also included an apparent pyroclastic flow and a lava flow. The last major eruption of Calbuco, in 1961, sentash columns 12–15 km (7.5–9.3 mi) high and producedplumes that dispersed mainly to the southeast and two lava flows were also emitted. A minor, four-hour eruption happened on August 26, 1972. Strong fumarolic emission from the main crater was observed on August 12, 1996.
Lonquimay is a stratovolocano of late-Pleistocene to dominantly Holocene age, with the shape of a truncated cone. The cone is largely andesitic, thoughbasaltic anddacitic rocks are present. It is located inLa Araucanía Region ofChile, immediately southeast ofTolhuaca volcano.Sierra Nevada and Llaima are their neighbors to the south. The snow-capped volcano lies within the protected areaMalalcahuello-Nalcas. The volcano last erupted in 1988, ending in 1990. TheVEI was 3. The eruption was from a flank vent and involved lava flows and explosive eruptions. Some fatalities occurred.[63]
Bolivia hosts active and extinct volcanoes across its territory. The active volcanoes are located in western Bolivia where they make up theCordillera Occidental, the western limit of theAltiplano plateau. Some of the active volcanoes are international mountains shared withChile. AllCenozoic volcanoes of Bolivia are part of theCentral Volcanic Zone (CVZ) of theAndean Volcanic Belt that results due to processes involved in thesubduction of theNazca plate under theSouth American plate. The Central Volcanic Zone is a major lateCenozoic volcanic province.[67]
Sabancaya is an active 5,976-metre (19,606 ft) stratovolcano in the Andes of southernPeru, about 100 km (60 mi) northwest ofArequipa. It is the most active volcano in Peru, with an ongoing eruption that started in 2016.
Ubinas is another active volcano of 5,672-metre (18,609 ft) in southern Peru; its most recent eruption occurred in 2019.[68]
Volcanoes in Peru are monitored by the Peruvian Geophysical Institute.[69]
Cotopaxi is a stratovolcano in the Andes, located about 50 km (30 mi) south ofQuito,Ecuador, South America.[70] It is the second-highest summit in the country, reaching a height of 5,897 m (19,347 ft). Since 1738, Cotopaxi has erupted more than 50 times, resulting in the creation of numerous valleys formed by mudflows around the volcano.
In October 1999, Pichincha Volcano erupted in Quito and covered the city with several inches ofash. Prior to that, the last major eruptions were in 1553[71] and in 1660, when about 30 cm of ash fell on the city.[72]
At 5,286 m (17,343 ft),Sangay Volcano is an active stratovolcano in central Ecuador, one of the highest active volcanoes in the world and is one of Ecuador's most active volcanoes. It exhibits mostlystrombolian activity; An eruption, which started in 1934, ended in 2011.[73] More recent eruptions have occurred. Geologically, Sangay marks the southern bound of theNorthern Volcanic Zone, and its position straddling two major pieces ofcrust accounts for its high level of activity. Sangay's roughly 500,000-year history is one of instability; two previous versions of the mountain were destroyed in massive flank collapses, evidence of which still litters its surroundings today. Sangay is one of two active volcanoes located within the namesakeSangay National Park, the other beingTungurahua to the north. As such, it has been listed as aUNESCOWorld Heritage Site since 1983.
Reventador is an active stratovolcano that lies in the eastern Andes of Ecuador. Since 1541, it has erupted over 25 times, with its most recent eruption starting in 2008 and, as of 2020[update], still ongoing,[74] but the largest historical eruption occurred in 2002. During that eruption, the plume from the volcano reached a height of17 km (10+1⁄2 mi), and pyroclastic flows reached 7 km (4.3 mi) from the cone. On March 30, 2007, the volcano erupted ash again, which reached a height of about 3 km (2 mi).
Poás Volcano is an active 2,708-metre (8,885 ft) stratovolcano located in centralCosta Rica; it has erupted 39 times since 1828.
The Volcanological and Seismological Observatory of Costa Rica (OVSICORI,Observatorio Vulcanológico y Sismológico de Costa Rica) at theNational University of Costa Rica[75] has a dedicated team in charge of researching and monitoring the volcanoes, earthquakes, and other tectonic processes in theCentral America Volcanic Arc.
In 1902, theSanta Maria Volcano erupted violently inGuatemala, with the largest explosions occurring over two days, ejecting an estimated5.5 km3 (1+3⁄8 cu mi) of magma. The eruption was one of the largest of the 20th century, only slightly less in magnitude to that of Mount Pinatubo in 1991. The eruption had avolcanic explosivity index of 6. Today, Santiaguito is one of the world's most active volcanoes.[citation needed]
Volcanoes of Mexico related to subduction of theCocos andRivera plates occur in theTrans-Mexican Volcanic Belt, which extends 900 km (560 mi) from west to east across central-southern Mexico.Popocatépetl, lying in the eastern half of the Trans-Mexican Volcanic Belt, is the second-highest peak in Mexico after thePico de Orizaba. It is one of the most active volcanoes in Mexico, having had more than 20 major eruptions since the arrival of the Spanish in 1519. The 1982 eruption ofEl Chichón, which killed about 2,000 people who lived near the volcano, created a 1-km-wide caldera that filled with an acidic crater lake. Before 1982, this relatively unknown volcano was heavily forested and of no greater height than adjacent nonvolcanic peaks.[76]
TheCascade Volcanic Arc lies in the western United States. This arc includes nearly 20 major volcanoes, among a total of over 4,000 separate volcanic vents including numerous stratovolcanoes, shield volcanoes, lava domes, and cinder cones, along with a few isolated examples of rarer volcanic forms such astuyas. Volcanism in the arc began about 37 million years ago, but most of the present-day Cascade volcanoes are less than 2 million years old, and the highest peaks are less than 100,000 years old. The arc is formed by the subduction of theGorda andJuan de Fuca plates at theCascadia subduction zone. This is a 1,090-kilometre-long (680 mi)fault, running 80 km (50 mi) off the coast of thePacific Northwest from northern California toVancouver Island, British Columbia. The plates move at a relative rate of over 10 mm (0.4 in) per year at anoblique angle to the subduction zone.
Because of the very large fault area, the Cascadia subduction zone can produce very large earthquakes, magnitude 9.0 or greater, if rupture occurred over its whole area. When the "locked" zone stores energy for an earthquake, the "transition" zone, although somewhat plastic, can rupture. Thermal and deformation studies indicate that the locked zone is fully locked for 60 km (37 mi) down-dip from the deformation front. Further down-dip, a transition from fully locked toaseismic sliding occurs.
AmericanCascade Range volcano eruptions in the last 4000 years
Unlike most subduction zones worldwide, nooceanic trench is present along thecontinental margin inCascadia. Instead,terranes and theaccretionary wedge have been lifted up to form a series of coast ranges and exotic mountains. A high rate of sedimentation from the outflow of the three major rivers (Fraser River,Columbia River, andKlamath River) which cross the Cascade Range contributes to further obscuring the presence of a trench. However, in common with most other subduction zones, the outer margin is slowly being compressed, similar to a giantspring. When the stored energy is suddenly released by slippage across the fault at irregular intervals, the Cascadia subduction zone can create very large earthquakes such as the magnitude-9Cascadia earthquake of 1700. Geological evidence indicates that great earthquakes may have occurred at least seven times in the last 3,500 years, suggesting a return time of 400 to 600 years. Also, evidence of accompanying tsunamis with every earthquake is seen, as the prime reason these earthquakes are known is through "scars" the tsunamis left on the coast, and through Japanese records (tsunami waves can travel across the Pacific).
The1980 eruption of Mount St. Helens was the most significant to occur in the contiguous 48 U.S. states in recorded history (VEI = 5, 1.3 km3 (0.3 cu mi) of material erupted), exceeding the destructive power and volume of material released by the 1915 eruption of California'sLassen Peak. The eruption was preceded by a two-month series of earthquakes and steam-venting episodes caused by an injection ofmagma at shallow depth below the mountain that created a huge bulge and a fracture system onMount St. Helens' north slope. An earthquake at 8:32 am on May 18, 1980, caused the entire weakened north face to slide away, suddenly exposing the partly molten, gas-rich rock in the volcano to lower pressure. The rock responded by exploding into a very hot mix of pulverized lava and older rock that sped towardSpirit Lake so fast that it quickly passed the avalanching north face.
Alaska is known for its seismic and volcanic activity, holding the record for the second-largest earthquake in the world, theGood Friday earthquake, and having more than 50 volcanoes which have erupted since about 1760.[77] Volcanoes are found not only in the mainland, but also in theAleutian Islands.
British Columbia andYukon are home to a region of volcanoes and volcanic activity in the Pacific Ring of Fire. More than 20 volcanoes have erupted in the western Canada during the Holocene Epoch but only 6 are directly related to subduction:Bridge River Cones,Mount Cayley,Mount Garibaldi,Garibaldi Lake,Silverthrone Caldera, andMount Meager massif.[3] Several mountains in populated areas of British Columbia aredormant volcanoes. Most of these were active during the Pleistocene and Holocene epochs. Although none of Canada's volcanoes are currently erupting, several volcanoes, volcanic fields, and volcanic centers are considered potentially active.[78] There arehot springs at some volcanoes. Since 1975, seismic activity appears to have been associated with some volcanoes in British Columbia including the six subduction-related volcanoes as well as intraplate volcanoes such asWells Gray-Clearwater volcanic field.[78] The volcanoes are grouped into five volcanic belts with different tectonic settings.
TheGaribaldi Volcanic Belt in southwestern British Columbia is the northern extension of the Cascade Volcanic Arc in the United States (which includesMount Baker and Mount St. Helens) and contains the most explosive young volcanoes in Canada.[80] It formed as a result of subduction of the Juan de Fuca plate (a remnant of the much largerFarallon plate) under the North American plate along the Cascadia subduction zone.[80] The Garibaldi Volcanic Belt includes the Bridge River Cones, Mount Cayley,Mount Fee, Mount Garibaldi,Mount Price, Mount Meager massif, the Squamish Volcanic Field, and more smaller volcanoes. The eruption styles in the belt range from effusive to explosive, with compositions from basalt torhyolite. Morphologically, centers include calderas, cinder cones, stratovolcanoes and small isolated lava masses. Due to repeated continental and alpine glaciations, many of the volcanic deposits in the belt reflect complex interactions between magma composition, topography, and changing ice configurations. The most recent major catastrophic eruption in the Garibaldi Volcanic Belt was an explosive eruption of the Mount Meager massif about 2,350 years ago. It was similar to the 1980 eruption of Mount St. Helens,[80] sending anash column about 20 km into thestratosphere.[81]
TheChilcotin Group is a north–south range of volcanoes in southern British Columbia running parallel to the Garibaldi Volcanic Belt. The majority of the eruptions in this belt happened either 6–10 million years ago (Miocene) or 2–3 million years ago (Pliocene), although with some slightly more recent eruptions (in thePleistocene).[82] It is thought to have formed as a result ofback-arc extension behind the Cascadia subduction zone.[82] Volcanoes in this belt includeMount Noel, theClisbako Caldera Complex,Lightning Peak,Black Dome Mountain, and many lava flows.
Eruptions of basaltic to rhyolitic volcanoes andhypabyssal rocks of theAlert Bay Volcanic Belt in northern Vancouver Island are probably linked with the subducted margin flanked by theExplorer and Juan de Fuca plates at the Cascadia subduction zone. It appears to have been active during the Pliocene and Pleistocene. However, no Holocene eruptions are known, and volcanic activity in the belt has likely ceased.
The activeQueen Charlotte Fault on the west coast of theHaida Gwaii,British Columbia, has generated three large earthquakes during the 20th century: amagnitude 7 event in 1929; a magnitude 8.1 in 1949 (Canada's largest recorded earthquake); and a magnitude 7.4 in 1970.[83]
The Public Safety Geo-science Program at theNatural Resources Canada undertakes research to support risk reduction from the effects of space weather, earthquakes, tsunamis, volcanoes, and landslides.[84]
Kambalny, an active volcano in the Kamchatka Peninsula
TheKamchatka Peninsula in theRussian Far East is one of the most active volcanic areas in the world, with 20 historically active volcanoes.[85] It lies between the Pacific Ocean to the east and theOkhotsk Sea to the west. Immediately offshore along the Pacific coast of the peninsula runs the 10,500-metre-deep (34,400 ft) Kuril–Kamchatka Trench, where subduction of the Pacific plate fuels the volcanism. Several types of volcanic activity are present, including stratovolcanoes, shield volcanoes, Hawaiian-style fissure eruptions and geysers.
Active,dormant andextinct volcanoes of Kamchatka are in two major volcanic belts. The most recent activity takes place in the eastern belt, starting in the north at theShiveluch volcanic complex, which lies at the junction of theAleutian and Kamchatka volcanic arcs. Just to the south is the Klyuchi volcanic group, comprising the twin volcanic cones ofKliuchevskoi andKamen, the volcanic complexes ofTolbachik andUshkovsky, and a number of other large stratovolcanoes.Ichinsky, the only active volcano in the central belt, is located farther to the west. Farther south, the eastern belt of stratovolcanoes continues to the southern tip of Kamchatka, continuing onto theKuril Islands, with their 32 historically active volcanoes.[85][86]
About 10% of the world's active volcanoes are found in Japan, which lies in a zone of extreme crustal instability. They are formed by subduction of the Pacific plate and thePhilippine Sea plate. As many as 1,500 earthquakes are recorded yearly, and magnitudes of 4 to 6 are not uncommon. Minor tremors occur almost daily in one part of the country or another, causing some slight shaking of buildings. Major earthquakes occur infrequently; the most famous in the 20th century were: the1923 Great Kantō earthquake, in which 130,000 people died; and theGreat Hanshin earthquake of January 17, 1995, in which 6,434 people died. On March 11, 2011a magnitude 9.0 earthquake hit Japan, the country's biggest ever and the fifth largest on record, according to US Geological Survey data.[87] Undersea earthquakes also expose the Japanese coastline to danger fromtsunamis.
Mount Bandai, one of Japan's most noted volcanoes, rises above the north shore ofLake Inawashiro. Mount Bandai is formed of several overlapping stratovolcanoes, the largest of which is O-Bandai, constructed within a horseshoe-shapedcaldera that formed about 40,000 years ago when an earlier volcano collapsed, forming the Okinajimadebris avalanche, which traveled to the southwest and was accompanied by aplinian eruption. Four majorphreatic eruptions have occurred during the past 5,000 years, two of them in historical time, in 806 and 1888. Seen from the south, Bandai presents a conical profile, but much of the north side of the volcano is missing as a result of the collapse of Ko-Bandai volcano during the 1888 eruption, in which a debris avalanche buried several villages and formed several large lakes. In July 1888, the north flank of Mount Bandai collapsed during an eruption quite similar to the May 18, 1980, eruption of Mount St. Helens. After a week of seismic activity, a large earthquake on July 15, 1888, was followed by a tremendous noise and a large explosion. Eyewitnesses heard about 15 to 20 additional explosions and observed that the last one was projected almost horizontally to the north.
Mount Fuji is Japan's highest and most noted volcano, featuring heavily in Japanese culture and serving as one of the country's most popular landmarks. The modern postglacial stratovolcano is constructed above a group of overlapping volcanoes, remnants of which form irregularities on Fuji's profile. Growth of the younger Mount Fuji began with a period of voluminous lava flows from 11,000 to 8,000 years ago, accounting for four-fifths of the volume of the younger Mount Fuji. Minor explosive eruptions dominated activity from 8,000 to 4,500 years ago, with another period of major lava flows occurring from 4,500 to 3,000 years ago. Subsequently, intermittent major explosive eruptions occurred, with subordinate lava flows and small pyroclastic flows. Summit eruptions dominated from 3,000 to 2,000 years ago, after which flank vents were active. The extensive basaltic lava flows from the summit and some of the more than 100 flank cones and vents blocked drainage against theTertiary Misaka Mountains on the north side of the volcano, forming theFuji Five Lakes. The last eruption of this dominantly basaltic volcano in 1707 ejected andesiticpumice and formed a large new crater on the east flank. Some minor volcanic activity may occur in the next few years.
The1991 eruption of Mount Pinatubo is the world's second-largest eruption of the 20th century. Successful predictions of the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives, but as the surrounding areas were severely damaged by pyroclastic flows, ash deposits, and later, lahars caused by rainwater remobilising earlier volcanic deposits, thousands of houses were destroyed.
Mayon Volcano overlooks a pastoral scene about five months before the volcano's violent eruption in September 1984.
Mayon Volcano is the Philippines' most active volcano. It has steep upper slopes that average 35–40° and is capped by a small summit crater. The historical eruptions of this basaltic-andesitic volcano date back to 1616 and range fromStrombolian to basalticPlinian eruptions. Eruptions occur predominately from the central conduit and have also produced lava flows that travel far down the flanks. Pyroclastic flows and mudflows have commonly swept down many of the roughly 40 ravines that radiate from the summit and have often devastated populated lowland areas.
Taal Volcano has had 33 recorded eruptions since 1572. A devastating eruption occurred in 1911, which claimed more than a thousand lives. The deposits of that eruption consist of a yellowish, fairly decomposed (nonjuvenile)tephra with a high sulfur content. The most recent period of activity lasted from 1965 to 1977, and was characterized by the interaction of magma with the lake water, which produced violent phreatic and phreatomagmatic eruptions. The volcano was dormant from 1977 then showed signs of unrest since 1991 with strong seismic activity and ground-fracturing events, as well as the formation of small mud geysers on parts of the island. An eruption occurred in January 2020.
Kanlaon Volcano, the most active volcano in the central Philippines, has erupted 25 times since 1866. Eruptions are typically phreatic explosions of small-to-moderate size that produce minor ash falls near the volcano. On August 10, 1996, Kanlaon erupted without warning, killing 3 persons who were among 24 mountain climbers trapped near the summit. On June 3, 2024, Mt. Kanlaon erupted, displacing more than 1,000 people.
Indonesia is located where the Ring of Fire around the Pacific Ocean meets the Alpide belt (which runs from Southeast Asia to Southwest Europe).
The eastern islands of Indonesia (Sulawesi, the Lesser Sunda Islands (excluding Bali, Lombok, Sumbawa and Sangeang), Halmahera, the Banda Islands and the Sangihe Islands) are geologically associated with subduction of the Pacific plate or its related minor plates and, therefore, the eastern islands are often regarded as part of the Ring of Fire.
The western islands of Indonesia (the Sunda Arc of Sumatra, Krakatoa, Java, Bali, Lombok, Sumbawa and Sangeang) are located north of a subduction zone in the Indian Ocean. Although news media, popular science publications and some geologists include the western islands (and their notable volcanoes such asKrakatoa,Merapi,Tambora andToba) in the Ring of Fire, geologists often exclude the western islands from the Ring; instead the western islands are often included in the Alpide belt.[88]
Mount Ruapehu, at the southern end of the Taupō Volcanic Zone, is one of the most active volcanoes in New Zealand.[91] It began erupting at least 250,000 years ago. In recorded history, major eruptions have been about 50 years apart,[91] in 1895, 1945, and 1995–1996. Minor eruptions are frequent, with at least 60 since 1945. Some of the minor eruptions in the 1970s generated small ash falls and lahars that damaged ski fields.[92] Between major eruptions, a warm acidic crater lake forms, fed by melting snow. Major eruptions may completely expel the lake water. Where a major eruption has deposited a tephra dam across the lake's outlet, the dam may collapse after the lake has refilled and risen above the level of its normal outlet, the outrush of water causing a large lahar. The most notable lahar caused theTangiwai disaster on December 24, 1953, when 151 people aboard a Wellington to Auckland express train were killed after the lahar destroyed the Tangiwai rail bridge just moments before the train was due. In 2000, theERLAWS system was installed on the mountain to detect such a collapse and alert the relevant authorities.
TheAuckland volcanic field on the North Island of New Zealand has produced a diverse array of explosive craters, scoria cones, and lava flows. Currentlydormant, the field is likely to erupt again within the next "hundreds to thousands of years", a very short timeframe in geologic terms.[93] The field contains at least 40 volcanoes, most recently active about 600 years ago atRangitoto Island, erupting 2.3 km3 (0.55 cu mi) of lava.
Soil
The soils of the Pacific Ring of Fire includeandosols, also known asandisols; they have formed by theweathering ofvolcanic ash. Andosols contain large proportions ofvolcanic glass.[94] The Ring of Fire is the world's main location for this soil type, which typically has good levels offertility.[95]
Pacific Rim – Land area comprising the rim of the Pacific Ocean
Notes
^Spanish:cinturón de fuego del Pacífico, anillo de fuego del Pacífico;Malay:Lingkaran api Pasifik;Indonesian:Cincin Api Pasifik;Filipino:Singsing ng Apoy ng Pasipiko;Chinese:环太平洋火山带Huán Taìpíngyáng Huǒshān Daì;Russian:Тихоокеанское вулканическое огненное кольцо,romanized: Tikhookeanskoye vulkanicheskoye ognennoye kol'tso;Japanese:環太平洋火山帯,romanized: Kantaiheiyō kazan-tai or 環太平洋造山帯Kantaiheiyō zōzantai.
^Macdonald (1972) listed 361 historically active volcanoes in the Ring of Fire (or 398 historically active volcanoes if the western islands of Indonesia are included).[12]
^Twenty-two if the western islands of Indonesia are included.
^if Antarctica and the western islands of Indonesia are excluded[26]
^79 of 95 earthquakes (if the western islands of Indonesia are excluded).[55]
^Wright, John; Rothery, David A. (1998). "The Shape of Ocean Basins".The Ocean Basins: Their Structure and Evolution (2nd ed.).The Open University. pp. 26–53.ISBN978-0-08-053793-1.
^Sigurdsson, H. (2015). "The History of Volcanology". In Sigurdsson, H. (ed.).Encyclopedia of Volcanoes (2nd ed.). Amsterdam: Elsevier. pp. 17–18.ISBN978-0-12-385938-9.
^Hawkes, F. L. (1856).Narrative of the Expedition of an American Squadron to the China Seas and Japan, performed in the years 1852, 1853, and 1854, under the command of Commodore M. C. Perry, United States Navy. New York: D. Appleton and Company. p. 7.
^Livingstone, Alexander P. (1906).Complete Story of San Francisco's Terrible Calamity of Earthquake and Fire, the Most Appalling Disaster of Modern Times. p. 324.
^Watters, W.A. (1996)."Marshall, Patrick".Dictionary of New Zealand Biography. TeAra – The Encyclopedia of New Zealand. Retrieved18 December 2020.
^Macdonald, G.A. (1972).Volcanoes. Englewood Cliffs, New Jersey: Prentice-Hall. pp. 344–345.ISBN978-0-13-942219-5.
^abFrancis, P.; Oppenheimer, C. (2004).Volcanoes (2nd ed.). Oxford: Oxford University Press. pp. 18–22.ISBN0-19-925469-9.
^abHickson, C J; Edwards, B R (2001). "Volcanoes and volcanic hazards". In Brooks, G R (ed.).A synthesis of geological hazards in Canada. Geological Survey of Canada, Bulletin 548. Natural Resources Canada. pp. 145–181.doi:10.4095/212217.ISBN978-0-660-18316-9.OCLC1032874834.
^abcFrancis, Peter (1993).Volcanoes: A Planetary Perspective. Clarendon Press. pp. 18–22.ISBN978-0-19-854452-4.
^Lockwood, John P.; Hazlett, Richard W. (2010).Volcanoes: Global Perspectives. Chichester, John Wiley & Sons. p. 53.ISBN978-1-4051-6250-0.
^abcLi, Sanzhong; Suo, Yanhui; Li, Xiyao; Zhou, Jie; Santosh, M.; Wang, Pengcheng; Wang, Guangzeng; Guo, Lingli; Yu, Shengyao; Lan, Haoyuan; Dai, Liming; Zhou, Zaizhen; Cao, Xianzhi; Zhu, Junjiang; Liu, Bo; Jiang, Suhua; Wang, Gang; Zhang, Guowei (May 2019). "Mesozoic tectono-magmatic response in the East Asian ocean-continent connection zone to subduction of the Paleo-Pacific Plate".Earth-Science Reviews.192:91–137.Bibcode:2019ESRv..192...91L.doi:10.1016/j.earscirev.2019.03.003.S2CID134370032.
^Cao, Mingxuan; Zhao, Xilin; Xing, Guangfu; Fan, Feipeng; Yu, Minggang; Duan, Zheng; Chu, Pingli; Chen, Rong (24 November 2020). "Tectonic transition from subduction to retreat of the palaeo-Pacific plate: new geochemical constraints from the late Mesozoic volcanic sequence in eastern Fujian Province, SE China".Geological Magazine.158 (6):1074–1108.doi:10.1017/S0016756820001156.S2CID229477784.
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