71-542: Mount Taranaki ( Māori : Taranaki Maunga , also known as Mount Egmont ) is a dormant stratovolcano in the Taranaki region on the west coast of New Zealand's North Island . At 2,518 metres (8,261 ft), it is the second highest mountain in the North Island, after Mount Ruapehu . It has a secondary cone, Fanthams Peak ( Māori : Panitahi ), 1,966 metres (6,450 ft), on its south side. The name Taranaki
142-747: A 4-inch thick ash layer can weigh 120-200 pounds and can get twice as heavy when wet. Wet ash also poses a risk to electronics due to its conductive nature. Dense clouds of hot volcanic ash can be expelled due to the collapse of an eruptive column , or laterally due to the partial collapse of a volcanic edifice or lava dome during explosive eruptions . These clouds are known as pyroclastic surges and in addition to ash , they contain hot lava , pumice , rock , and volcanic gas . Pyroclastic surges flow at speeds over 50 mph and are at temperatures between 200 °C – 700 °C. These surges can cause major damage to property and people in their path. Lava flows from stratovolcanoes are generally not
213-479: A fast moving mudflow . Lahars are typically about 60% sediment and 40% water. Depending on the abundance of volcanic debris the lahar can be fluid or thick like concrete. Lahars have the strength and speed to flatten structures and cause great bodily harm, gaining speeds up to dozens of kilometers per hour. In the 1985 eruption of Nevado del Ruiz in Colombia , Pyroclastic surges melted snow and ice atop
284-515: A final intermediate composition . When the magma nears the top surface, it pools in a magma chamber within the crust below the stratovolcano. The processes that trigger the final eruption remain a question for further research. Possible mechanisms include: These internal triggers may be modified by external triggers such as sector collapse , earthquakes , or interactions with groundwater . Some of these triggers operate only under limited conditions. For example, sector collapse (where part of
355-558: A former First Lord of the Admiralty who had supported the concept of an oceanic search for Terra Australis Incognita . Cook described it as "of a prodigious height and its top cover'd with everlasting snow," surrounded by a "flat country ... which afforded a very good aspect, being clothed with wood and verdure ". When the French explorer Marc-Joseph Marion du Fresne saw the mountain on 25 March 1772 he named it Pic Mascarin . He
426-485: A group of tribes in the region, the mountain will be officially named Taranaki Maunga , and will be the first natural geographic feature with an official name in Māori, rather than English. The settlement was initialled on 31 March 2023, and has been ratified by the iwi of Taranaki. Some iwi in the region had referred to the mountain as Taranaki Mounga rather than Taranaki Maunga , per the local Māori dialect. Mount Taranaki
497-491: A large eruption is "overdue". Research from Massey University indicates that significant seismic activity from the local faults is likely again in the next 50 years and such might be permissive to an eruption. What ever in the next 50 years, the probability of at least one eruption is between 33% and 42%. Prevailing winds would probably blow ash east, covering much of the North Island, and disrupting air routes, power transmission lines and local water supplies. Mount Taranaki
568-415: A moderate ash eruption occurred about 1755, of the size of Ruapehu 's activity in 1995/1996. The last major eruption occurred around 1655. Recent research has shown that over the last 9,000 years minor eruptions have occurred roughly every 90 years on average, with major eruptions every 500 years. Some of these eruptions may have occurred with very brief warning, of only days or less. Taranaki
639-711: A potential path of more than 300 kilometres (190 mi). Lahars from the 1985 Nevado del Ruiz eruption in Colombia caused the Armero tragedy , burying the city of Armero under 5 metres (16 ft) of mud and debris and killing an estimated 23,000 people. A lahar caused New Zealand's Tangiwai disaster , where 151 people died after a Christmas Eve express train fell into the Whangaehu River in 1953. Lahars have caused 17% of volcano-related deaths between 1783 and 1997. Lahars have several possible causes: In particular, although lahars are typically associated with
710-769: A result of intraplate volcanism on oceanic islands far from plate boundaries. Examples are Teide in the Canary Islands , and Pico do Fogo in Cape Verde . Stratovolcanoes in the East African Rift include Ol Doinyo Lengai in Tanzania, and Longonot in Kenya. Subduction zone volcanoes form when hydrous minerals are pulled down into the mantle on the slab. These hydrous minerals, such as chlorite and serpentine , release their water into
781-461: A significant threat to humans or animals because the highly viscous lava moves slowly enough for everyone to evacuate. Most deaths attributed to lava are due to related causes such as explosions and asphyxiation from toxic gas . Lava flows can bury homes and farms in thick volcanic rock which greatly reduces property value. However, not all stratovolcanoes erupt viscous and sticky lava . Nyiragongo , near Lake Kivu in central Africa ,
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#1732791718661852-531: A summit crater and explosive eruptions. Some have collapsed summit craters called calderas . The lava flowing from stratovolcanoes typically cools and solidifies before spreading far, due to high viscosity . The magma forming this lava is often felsic , having high to intermediate levels of silica (as in rhyolite , dacite , or andesite ), with lesser amounts of less viscous mafic magma . Extensive felsic lava flows are uncommon, but can travel as far as 8 km (5 mi). The term composite volcano
923-557: A wall of mud 140 metres (460 ft) deep in the White River canyon and covered an area of over 330 square kilometres (130 sq mi), for a total volume of 2.3 cubic kilometres ( 1 ⁄ 2 cu mi). A debris-flow lahar can erase virtually any structure in its path, while a hyperconcentrated-flow lahar is capable of carving its own pathway, destroying buildings by undermining their foundations. A hyperconcentrated-flow lahar can leave even frail huts standing, while at
994-520: A warning to Taranaki not to return. The mountain was tapu in Māori culture and at the time of European settlement not climbed by them. In 1839 the mountain was climbed by James Heberley, a whaler who reached the summit first and the Swiss trained doctor and naturalist Ernst Dieffenbach . During his initial ascent, he identified the fast-flowing streams as being well suited to water driven mills. Dieffenbach
1065-531: Is a passive release of gas during periods of dormancy. As per the above examples, while eruptions like Mount Unzen have caused deaths and local damage, the impact of the June 1991 eruption of Mount Pinatubo was seen globally. The eruptive columns reached heights of 40 km and dumped 17 megatons of SO 2 into the lower stratosphere . The aerosols that formed from the sulfur dioxide (SO 2 ), carbon dioxide (CO 2 ), and other gases dispersed around
1136-470: Is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano , typically along a river valley . Lahars are often extremely destructive and deadly; they can flow tens of metres per second, they have been known to be up to 140 metres (460 ft) deep, and large flows tend to destroy any structures in their path. Notable lahars include those at Mount Pinatubo in
1207-564: Is from the Māori language . The mountain was named after Rua Taranaki, the first ancestor of the iwi (tribe) called Taranaki , one of several iwi in the region. The Māori word tara means mountain peak, and naki may come from ngaki , meaning "clear of vegetation." It was also named Pukehaupapa ("ice mountain") and Pukeonaki ("hill of Naki") by iwi who lived in the region in "ancient times". Captain Cook named it Mount Egmont on 11 January 1770 after John Perceval, 2nd Earl of Egmont ,
1278-522: Is located near Fanthams Peak. It is maintained by the Department of Conservation and is available to trampers on a first come first served basis. For the average person, Taranaki would be considered a moderate mountain to climb. It takes a person with good fitness level a day to make the up-and-back climb. Weather on the mountain can change rapidly, which has caught inexperienced trampers and climbers unawares. As of 27 June 2017, 84 people have died on
1349-576: Is one of four closely associated Quaternary volcanoes in Taranaki province that have erupted from andesite magmas that have not extensively assimilated enriched crust unlike the cone volcanos of the North Island Volcanic Plateau . It sits on the remains of three older volcanic complexes that lie to the northwest. The Indo-Australian Plate is slowly moving relative to the magma source that feeds these volcanoes. This trend
1420-545: Is reflected in Fanthams Peak, the newer secondary cone on the southeast side of Taranaki and named after Fanny Fantham who was the first European woman to climb the peak in 1887. The oldest volcanic remnants consist of a series of lava plugs: Paritutu Rock (156 metres), which forms part of New Plymouth 's harbour, and the Sugar Loaf Islands close offshore. These have been dated at 1.75 million years. On
1491-630: Is situated in the sedimentary Taranaki Basin and is part of the Taranaki Volcanic Lineament which has had a 3 cm/year (1.2 in/year) north to south migration over the last 1.75 million years. A Wadati–Benioff zone exists at about 200 km (120 mi) depth and the volcano's magma has the geochemical features of an arc volcano . Under the volcano itself there is high heat flow with only about 10 km (6.2 mi) crustal thickness although this rapidly normalises for continental crust to 35 km (22 mi) east of
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#17327917186611562-451: Is the most famous example of a hazardous stratovolcano eruption. It completely smothered the nearby ancient cities of Pompeii and Herculaneum with thick deposits of pyroclastic surges and pumice ranging from 6–7 meters deep. Pompeii had 10,000-20,000 inhabitants at the time of eruption. Mount Vesuvius is recognized as one of the most dangerous of the world's volcanoes, due to its capacity for powerful explosive eruptions coupled with
1633-450: Is typically between 700 and 1,200 °C (1,300-2,200 °F). Volcanic bombs are masses of unconsolidated rock and lava that are ejected during an eruption. Volcanic bombs are classified as larger than 64mm (2.5 inches). Anything below 64mm is classified as a volcanic block . When erupted Bombs are still molten and partially cool and solidify on their descent. They can form ribbon or oval shapes that can also flatten on impact with
1704-579: Is unusual in that it has experienced at least five of its major eruptions by the method of cone collapse. Few volcanoes have undergone more than one cone collapse. The vast volume of material involved in these collapses is reflected in the extensive ring plain surrounding the volcano. There is also evidence of lahars being a common result of eruption. The major collapse cycles have a potential maximum size of collapse of 7.9 km (1.9 cu mi) every 30,000 to 35,000 years. Such collapse debris fields have been found up to 5–6 km (3.1–3.7 mi) beyound
1775-1014: Is used because the strata are usually mixed and uneven instead of neat layers. They are among the most common types of volcanoes; more than 700 stratovolcanoes have erupted lava during the Holocene Epoch (the last 11,700 years), and many older, now extinct, stratovolcanoes erupted lava as far back as Archean times. Stratovolcanoes are typically found in subduction zones but they also occur in other geological settings. Two examples of stratovolcanoes famous for catastrophic eruptions are Krakatoa in Indonesia (which erupted in 1883 claiming 36,000 lives) and Mount Vesuvius in Italy (which erupted in 79 A.D killing an estimated 2,000 people). In modern times, Mount St. Helens (1980) in Washington State , US, and Mount Pinatubo (1991) in
1846-403: Is very dangerous because its magma has an unusually low silica content , making it much less viscous than other stratovolcanoes. Low viscosity lava can generate massive lava fountains , while lava of thicker viscosity can solidify within the vent, creating a volcanic plug . Volcanic plugs can trap gas and create pressure in the magma chamber, resulting in violent eruptions. Lava
1917-581: The Philippine government were not adequate to stop over 6 m (20 ft) of mud from flooding many villages around Mount Pinatubo from 1992 through 1998. Scientists and governments try to identify areas with a high risk of lahars based on historical events and computer models . Volcano scientists play a critical role in effective hazard education by informing officials and the public about realistic hazard probabilities and scenarios (including potential magnitude, timing, and impacts); by helping evaluate
1988-579: The Philippines have erupted catastrophically, but with fewer deaths. Stratovolcanoes are common at subduction zones , forming chains and clusters along plate tectonic boundaries where an oceanic crust plate is drawn under a continental crust plate (continental arc volcanism, e.g. Cascade Range , Andes , Campania ) or another oceanic crust plate ( island arc volcanism, e.g. Japan , Philippines , Aleutian Islands ). Stratovolcanoes also occur in some other geological settings, for example as
2059-891: The magma is too viscous to allow easy escape of volcanic gases . As a consequence, the tremendous internal pressures of the trapped volcanic gases remain and intermingle in the pasty magma . Following the breaching of the vent and the opening of the crater, the magma degasses explosively. The magma and gases blast out with high speed and full force. Since 1600 CE , nearly 300,000 people have been killed by volcanic eruptions . Most deaths were caused by pyroclastic flows and lahars , deadly hazards that often accompany explosive eruptions of subduction-zone stratovolcanoes. Pyroclastic flows are swift, avalanche-like, ground-sweeping, incandescent mixtures of hot volcanic debris, fine ash , fragmented lava , and superheated gases that can travel at speeds over 150 km/h (90 mph). Around 30,000 people were killed by pyroclastic flows during
2130-443: The mantle which decreases its melting point by 60 to 100 °C. The release of water from hydrated minerals is termed " dewatering ", and occurs at specific pressures and temperatures for each mineral, as the plate descends to greater depths. This allows the mantle to partially melt and generate magma . This is called flux melting . The magma then rises through the crust , incorporating silica-rich crustal rock, leading to
2201-616: The 1902 eruption of Mount Pelée on the island of Martinique in the Caribbean . During March and April 1982, El Chichón in the State of Chiapas in southeastern Mexico , erupted 3 times, causing the worst volcanic disaster in that country's history and killied more than 2,000 people in pyroclastic flows . Two Decade Volcanoes that erupted in 1991 provide examples of stratovolcano hazards. On 15 June, Mount Pinatubo erupted and caused an ash cloud to shoot 40 km (25 mi) into
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2272-485: The 1982 eruption of Galunggung in Java , British Airways Flight 9 flew into the ash cloud, causing it to sustain temporary engine failure and structural damage. Although no crashes have happened due to ash, more than 60, mostly commercial aircraft , have been damaged. Some of these incidents resulted in emergency landings. Ashfalls are a threat to health when inhaled and are also a threat to property. A square yard of
2343-585: The 5,321 m (17,457 ft) high Andean volcano. The ensuing lahar killed 25,000 people and flooded the city of Armero and nearby settlements. As a volcano forms, several different gases mix with magma in the volcanic chamber. During an eruption the gases are then released into the atmosphere which can lead to toxic human exposure. The most abundant of these gases is H 2 O ( water ) followed by CO 2 ( carbon dioxide ), SO 2 ( sulfur dioxide ), H 2 S ( hydrogen sulfide ), and HF ( hydrogen fluoride ). If at concentrations of more than 3% in
2414-536: The East Egmont plateau, with a viewing platform and parking facilities for the skifield. It lies at the transition between subalpine scrub and alpine herbfields . There are park visitor centres at North Egmont and at the waterfall Te Rere o Kapuni on the southeast side. The eastern side from Stratford leads to the Stratford Mountain House, and the ski field. There is poor road access on
2485-746: The Philippines and Nevado del Ruiz in Colombia, the latter of which killed more than 20,000 people in the Armero tragedy . The word lahar is of Javanese origin. Berend George Escher introduced it as a geological term in 1922. The word lahar is a general term for a flowing mixture of water and pyroclastic debris. It does not refer to a particular rheology or sediment concentration. Lahars can occur as normal stream flows (sediment concentration of less than 30%), hyper-concentrated stream flows (sediment concentration between 30 and 60%), or debris flows (sediment concentration exceeding 60%). Indeed,
2556-819: The air, when breathed in CO 2 can cause dizziness and difficulty breathing. At more than 15% concentration CO 2 causes death. CO 2 can settle into depressions in the land, leading to deadly, odorless pockets of gas. SO 2 classified as a respiratory, skin, and eye irritant if come into contact with. It is known for its pungent egg smell and role in ozone depletion and has the potential to cause acid rain downwind of an eruption. H 2 S has an even stronger odor than SO 2 as well as being even more toxic. Exposure for less than an hour at concentrations of over 500 ppm causes death. HF and similar species can coat ash particles and once deposited can poison soil and water. Gases are also emitted during volcanic degassing, which
2627-748: The air. It produced large pyroclastic surges and lahar floods that caused a lot of damage to the surrounding area. Pinatubo , located in Central Luzon just 90 km (56 mi) west-northwest of Manila , had been dormant for six centuries before the 1991 eruption. This eruption was one of the 2nd largest in the 20th century. It produced a large volcanic ash cloud that affected global temperatures, lowering them in areas as much as .5 °C. The volcanic ash cloud consisted of 22 million tons of SO 2 which combined with water droplets to create sulfuric acid . In 1991 Japan's Unzen Volcano also erupted, after 200 years of inactivity. It's located on
2698-471: The backdrop for the 2003 film The Last Samurai . In 2017, a record of understanding was signed between Taranaki iwi and the New Zealand government that will see the mountain become a legal personality. It is the third geographic feature in the country to be granted a legal personality, after Te Urewera and Whanganui River . On 2 December 2019, an agreement between the crown and Ngā Iwi o Taranaki
2769-595: The coast, 15 kilometres southwest of New Plymouth is the Kaitake Range (682 metres), last active over 500,000 years ago. Nearest to Taranaki is the Pouakai Range . Pouakai may have originated around the same time as Kaitake but remained active until about 210,000 years ago. Much of Pouakai's large ring plain was obliterated by the Egmont Volcano, the hills near Eltham being the only remnant to
2840-506: The coast. Another major edifice collapse is expected to occur within 16,200 years. Much of the region is at risk from lahars, which have reached the eastern coast. A volcanic event is not necessary for a lahar: even earthquakes combined with heavy rain or snow could dislodge vast quantities of unstable layers resting on steep slopes. Many farmers live in the paths of such possible destructive events. Although volcanic eruptions are notoriously chaotic in their frequency, some scientists warn that
2911-663: The deep gorges of the Whanganui River , paused for a while, creating the depression that formed the Te Ngaere swamp, then heading north. Further progress was blocked by the Pouakai Ranges , and as the sun came up Taranaki became petrified in his current location. When Taranaki conceals himself with rainclouds, he is said to be crying for his lost love, and during spectacular sunsets, he is said to be displaying himself to her. In turn, Tongariro's eruptions are said to be
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2982-489: The eastern slope. Equipment access to the skifield is by flying fox across the Manganui Gorge. The Taranaki Alpine Club maintains Tahurangi Lodge on the north slope of the mountain, next to the television tower. The lodge is frequently used as the base for public climbs to the summit held in the summer months. The various climbing and tramping clubs organize these public events and provide informal guides. Syme Hut
3053-557: The effectiveness of proposed risk-reduction strategies; by helping promote acceptance of (and confidence in) hazards information through participatory engagement with officials and vulnerable communities as partners in risk reduction efforts; and by communicating with emergency managers during extreme events. An example of such a model is TITAN2D . These models are directed towards future planning: identifying low-risk regions to place community buildings, discovering how to mitigate lahars with dams, and constructing evacuation plans. In 1985,
3124-552: The effects of volcanic activity, lahars can occur even without any current volcanic activity, as long as the conditions are right to cause the collapse and movement of mud originating from existing volcanic ash deposits. Several mountains in the world – including Mount Rainier in the United States, Mount Ruapehu in New Zealand, and Merapi and Galunggung in Indonesia – are considered particularly dangerous due to
3195-894: The event of a Mount Rainier eruption. A lahar warning system has been set up at Mount Ruapehu by the New Zealand Department of Conservation and hailed as a success after it successfully alerted officials to an impending lahar on 18 March 2007. Since mid-June 1991, when violent eruptions triggered Mount Pinatubo 's first lahars in 500 years, a system to monitor and warn of lahars has been in operation. Radio-telemetered rain gauges provide data on rainfall in lahar source regions, acoustic flow monitors on stream banks detect ground vibration as lahars pass, and staffed watchpoints further confirm that lahars are rushing down Pinatubo's slopes. This system has enabled warnings to be sounded for most but not all major lahars at Pinatubo, saving hundreds of lives. Physical preventative measures by
3266-447: The evidence that the hapū agreed to this arrangement. Many who made submissions to us were adamant that most knew nothing of it." It cited a submission that suggested the political climate of 1975 was such that the board felt it was necessary to perform a gesture of goodwill designed to create a more favourable environment within which a monetary settlement could be negotiated. Because of its resemblance to Mount Fuji , Taranaki provided
3337-540: The flank of a volcano collapses in a massive landslide) can only trigger the eruption of a very shallow magma chamber . Magma differentiation and thermal expansion also are ineffective as triggers for eruptions from deep magma chambers . In recorded history , explosive eruptions at subduction zone ( convergent-boundary ) volcanoes have posed the greatest hazard to civilizations. Subduction-zone stratovolcanoes, such as Mount St. Helens , Mount Etna and Mount Pinatubo , typically erupt with explosive force because
3408-478: The ground. Volcanic Bombs are associated with Strombolian and Vulcanian eruptions and basaltic lava . Ejection velocities ranging from 200 to 400 m/s have been recorded causing volcanic bombs to be destructive. Lahars (from a Javanese term for volcanic mudflows) are a mixture of volcanic debris and water. Lahars can result from heavy rainfall during or before the eruption or interaction with ice and snow. Meltwater mixes with volcanic debris causing
3479-696: The heart of the city and surrounding areas. Over 6 metres (20 ft) of mud inundated and damaged the towns of Castillejos , San Marcelino and Botolan in Zambales , Porac and Mabalacat in Pampanga , Tarlac City , Capas , Concepcion and Bamban in Tarlac . The Bamban Bridge on the MacArthur Highway, a major north–south transportation route, was destroyed, and temporary bridges erected in its place were inundated by subsequent lahars. On
3550-458: The high population density of the surrounding Metropolitan Naples area (totaling about 3.6 million inhabitants). In addition to potentially affecting the climate, volcanic ash clouds from explosive eruptions pose a serious hazard to aviation . Volcanic ash clouds consist of ash which is made of silt or sand sized pieces of rock, mineral, volcanic glass . Ash grains are jagged, abrasive, and don't dissolve in water. For example, during
3621-504: The island of Kyushu about 40 km (25 mi) east of Nagasaki . Beginning in June, a newly formed lava dome repeatedly collapsed. This generated a pyroclastic flow that flowed down the mountain's slopes at speeds as high as 200 km/h (120 mph). The 1991 eruption of Mount Unzen was one of the worst volcanic disasters in Japan's history, once killing more than 15,000 people in 1792. The eruption of Mount Vesuvius in 79 AD
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#17327917186613692-480: The lahars killed more than 1500. The eye of Typhoon Yunya passed over the volcano during its eruption on 15 June 1991, and the resulting rain triggered the flow of volcanic ash , boulders, and water down rivers surrounding the volcano. Angeles City in Pampanga and neighbouring cities and towns were damaged by lahars when Sapang Balen Creek and the Abacan River became channels for mudflows and carried them to
3763-652: The land of Māori "in rebellion" and providing it as farmland for military settlers. The mountain was returned to the people of Taranaki in 1978 by means of the Mount Egmont Vesting Act 1978, which vested it to the Taranaki Maori Trust Board. By means of the same Act, it was immediately passed back to the Government as a gift to the nation. The Waitangi Tribunal , in its 1996 report, Kaupapa Tuatahi, observed: "We are unaware of
3834-676: The morning of 1 October 1995, pyroclastic material which clung to the slopes of Pinatubo and surrounding mountains rushed down because of heavy rain, and turned into an 8-metre (25 ft) lahar. This mudflow killed at least 100 people in Barangay Cabalantian in Bacolor . The Philippine government under President Fidel V. Ramos ordered the construction of the FVR Mega Dike in an attempt to protect people from further mudflows. Typhoon Reming triggered additional lahars in
3905-418: The mountain since records began in 1891, many having been caught by a sudden change in the weather. In terms of fatalities this mountain is the second most dangerous mountain in New Zealand after Aoraki / Mount Cook . There are three roads on the mountain's eastern slopes that lead part-way up the mountain with many more around the foot of the mountain that access walking tracks. The highest access road reaches
3976-529: The overall death toll to over 25,000. Footage and photographs of Omayra Sánchez , a young victim of the tragedy , were published around the world. Other photographs of the lahars and the impact of the disaster captured attention worldwide and led to controversy over the degree to which the Colombian government was responsible for the disaster. Lahars caused most of the deaths of the 1991 eruption of Mount Pinatubo . The initial eruption killed six people, but
4047-524: The reserve and in 1900 all this land was designated as Egmont National Park, the second national park in New Zealand. There are parts of the national park where old-growth forests are found. With intensively-farmed dairy pasture right up to the park boundary, the change in vegetation is sharply delineated as a circular shape in satellite images. The Stratford Mountain Club operates the Manganui skifield on
4118-640: The rheology and subsequent behaviour of a lahar may vary in place and time within a single event, owing to changes in sediment supply and water supply. Lahars are described as 'primary' or 'syn-eruptive' if they occur simultaneously with or are triggered by primary volcanic activity. 'Secondary' or 'post-eruptive' lahars occur in the absence of primary volcanic activity, e.g. as a result of rainfall during pauses in activity or during dormancy. In addition to their variable rheology, lahars vary considerably in magnitude. The Osceola Lahar produced by Mount Rainier in modern-day Washington some 5600 years ago resulted in
4189-706: The risk of lahars. Several towns in the Puyallup River valley in Washington state, including Orting , are built on top of lahar deposits that are only about 500 years old. Lahars are predicted to flow through the valley every 500 to 1,000 years, so Orting, Sumner , Puyallup , Fife , and the Port of Tacoma face considerable risk. The USGS has set up lahar warning sirens in Pierce County, Washington , so that people can flee an approaching debris flow in
4260-691: The same time burying them in mud, which can harden to near-concrete hardness. A lahar's viscosity decreases the longer it flows and can be further thinned by rain, producing a quicksand -like mixture that can remain fluidized for weeks and complicate search and rescue. Lahars vary in speed. Small lahars less than a few metres wide and several centimetres deep may flow a few metres per second. Large lahars hundreds of metres wide and tens of metres deep can flow several tens of metres per second (22 mph or more), much too fast for people to outrun. On steep slopes, lahar speeds can exceed 200 kilometres per hour (120 mph). A lahar can cause catastrophic destruction along
4331-511: The site was commissioned by the New Zealand Broadcasting Corporation (NZBC) in 1966 to relay Wellington's WNTV1 channel (now part of TVNZ 1 ). Stratovolcano A stratovolcano , also known as a composite volcano , is a conical volcano built up by many alternating layers ( strata ) of hardened lava and tephra . Unlike shield volcanoes , stratovolcanoes are characterized by a steep profile with
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#17327917186614402-464: The size of Mount Pinatubo affected the weather for a few years; with warmer winters and cooler summers observed. A similar phenomenon occurred in the April 1815, the eruption of Mount Tambora on Sumbawa island in Indonesia . The Mount Tambora eruption is recognized as the most powerful eruption in recorded history. Its eruption cloud lowered global temperatures as much as 0.4 to 0.7 °C. In
4473-491: The south. According to Māori mythology, Taranaki once resided in the middle of the North Island, with all the other New Zealand volcanoes. The beautiful Pihanga was coveted by all the mountains, and a great battle broke out between them. Tongariro eventually won the day, inflicted great wounds on the side of Taranaki, and causing him to flee. Taranaki headed westwards, following Te Toka a Rahotu (the Rock of Rahotu ) and forming
4544-517: The volcano Nevado del Ruiz erupted in central Colombia. As pyroclastic flows erupted from the volcano's crater , they melted the mountain's glaciers, sending four enormous lahars down its slopes at 60 kilometers per hour (37 miles per hour). The lahars picked up speed in gullies and coursed into the six major rivers at the base of the volcano; they engulfed the town of Armero , killing more than 20,000 of its almost 29,000 inhabitants. Casualties in other towns, particularly Chinchiná , brought
4615-405: The volcano and 25 km (16 mi) to the west. Taranaki is geologically young, having commenced activity approximately 135,000 years ago. The most recent volcanic activity was the production of a lava dome in the crater and its collapse down the side of the mountain in the 1850s or 1860s. Between 1755 and 1800, an eruption sent a pyroclastic flow down the mountain's northeast flanks, and
4686-438: The western side beyond the bush line. However, a road winds for 10 km through native bush over the saddle between Pouakai and Kaitake. Near the top of this road is the renowned Pukeiti Trust rhododendron garden. The Mount Taranaki transmitter is the main television and FM radio transmitter for the Taranaki region. It is located on the north-eastern slope of the mountain adjacent to Tahurangi Lodge. The first transmitter at
4757-412: The world. The SO 2 in this cloud combined with water (both of volcanic and atmospheric origin) and formed sulfuric acid , blocking a portion of the sunlight from reaching the troposphere . This caused the global temperature to decrease by about 0.4 °C (0.72 °F) from 1992 to 1993. These aerosols caused the ozone layer to reach the lowest concentrations recorded at that time. An eruption
4828-488: The year following the eruption, most of the Northern Hemisphere experienced cooler temperatures during the summer. In the northern hemisphere , 1816 was known as the " Year Without a Summer ". The eruption caused crop failures, food shortages, and floods that killed over 100,000 people across Europe , Asia , and North America . Lahar A lahar ( / ˈ l ɑː h ɑːr / , from Javanese : ꦮ꧀ꦭꦲꦂ )
4899-538: Was announced that the mountain was to only be referred to as Taranaki Maunga. The national park will be renamed from Egmont National Park to Te Papakura o Taranaki. The name change has not yet been ratified by the New Zealand Geographic Board. In 1881, a circular area with a radius of six miles (9.6 km) from the summit was protected as a forest reserve. Areas encompassing the older volcanic remnants of Pouakai and Kaitake were later added to
4970-722: Was employed by the New Zealand Company to advise on the potential of land he explored in the North Island in 1839–40. In 1865 the mountain was confiscated from Māori by the New Zealand Government under the powers of the New Zealand Settlements Act 1863 , ostensibly as a means of establishing and maintaining peace amid the Second Taranaki War . The legislation was framed with the intention of seizing and dividing up
5041-541: Was unaware of Cook's earlier visit. It appeared as Mount Egmont on maps until 29 May 1986, when the name officially became "Mount Taranaki or Mount Egmont" following a decision by the Minister of Lands , Koro Wētere . The Egmont name still applies to the national park that surrounds the peak and geologists still refer to the peak as the Egmont Volcano. As part of the Treaty of Waitangi settlement with Ngā Iwi o Taranaki,
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