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A lahar is a mudflow that forms from water mixing with volcanic material, primarily ash. A nuee ardente, more commonly known as a pyroclastic flow, is a superheated, fast-moving body of ash, rock, and gas that moves down the sides of a volcano as a direct result of an explosive eruption.
A lahar is a fast-moving mudflow caused by volcanic activity, while a nuee ardente is a fast-moving cloud of hot gas, ash, and other volcanic debris. Lahars typically contain water and mud, while nuee ardentes are composed of volcanic gases and ash. Both can be extremely destructive and hazardous.
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How to say 'bonne nuit' in french?
It is pronounced "bunn nuee" It means "good night"
What is the name for a superheated incandescent cloud of gas and volcanic ash that travels swiftly down a volcanic slope as an avalanche?
nuee ardente
Why are nuee ardentes so dangerous for human beings?
Nuee ardentes, or pyroclastic flows, are extremely dangerous for human beings because they move at high speeds (up to 450 mph) and can reach temperatures of 1,472°F (800°C). These deadly volcanic phenomena can incinerate everything in their path, releasing toxic gases and ash that can suffocate and burn individuals caught in their destructive path. The sheer force and speed of nuee ardentes make them nearly impossible to outrun, making them one of the deadliest volcanic hazards.
When did the first pyroclastic flow erupt in Pompeii?
The first pyroclastic flow that hit Pompeii during the eruption of Mount Vesuvius in 79 AD occurred early in the morning of August 24. This pyroclastic flow was followed by several others throughout the day, burying the city in ash and pumice.
What are the 3 main things that come out of a volcano?
Gases- Volcanoes eject different types of gases, the main ones being water vapor, carbon dioxide, nitrogen, sulfur, and other less abundant gases.Lava flows- are produced by the magma which reaches the earth's surface. This lava then begins to flow down the side of the mountain. One type of a lava flow is a Pahoehoe flow which has a smooth surface with wrinkles in it, which create a silky-apearance.Pyroclastic material is characterized by the rapid expansion of lava, rocks, and glass fragments which blow out in many pieces varying greatly in size. Many times bombs and blocks are ejected from the volcano, but normally they fall close to the cone, AND Nuee-ardente is an extremely fast-moving body of lava and gas. The lava actually floats on top of the gas which causes little friction, and thus the two travel down the mountain at speeds well over 60 miles-per-hour. The nuee-ardente is most commonly associated with the strato-volcano, and can be very devastating due to the rapid movement. Source:http://facstaff.gpc.edu/~pgore/students/w97/brian/#NUE
What was the cause of the eruption of Vesuvius in 79 AD?
the Truth is a 6 mile chamber of magma underneath the volcano had pressure built and blew the top extrusive igneous rock of and not only produced a nuee ardente cloud (a fast moving cloud filled with magma and ash) but also a pyroclastic flow. that is what destroyed pompeii Actually it was a sequence of previous earthquakes that occurred 17 years before.
What is a nuees ardantes?
A nuee ardente is a type of volcanic phenomena characterized by glowing avalanches of hot gas, ash, and volcanic rocks that flow rapidly down the slopes of a volcano during an eruption. These pyroclastic flows can be extremely dangerous and destructive due to their high temperatures and speed.
What has the author Jacques Brengues written?
Jacques Bens has written: 'Le Retour au pays (fragments)' 'Boris Vian' -- subject(s): Criticism and interpretation 'Pagnol' -- subject(s): Criticism and interpretation 'Queneau' 'Lente sortie de l'ombre' 'Gaspard de Besse' -- subject(s): Fiction, History
What type of lava flow was mount st Helens?
Dacite, a volcanic rock with about 65% silica. This amount of silica in dacite is a lot higher than the basalts of Hawaii which have less than 50% silica. The high silica content makes the magma "sticky" and can cause more pressure to build up. With so much pressure, eruptions from Mount St. Helens can be very violent like the famous 1980 eruption.
How many volcanoes are in the Philippines?
(by feet ang height. . .) 1. Mt Apo 9689ft.2. Mt Dulang-Dulang 9637 Mindanao3. Mt Pulog 9610 Luzon4. Mt Kitanglad 9509 Mindanao5. Mt Tabayac 9322 Luzon6. Mt Piapayungan 9233 Mindanao7. Mt Maagnaw 8994 Mindanao8. Mt Singakalca 8915 Luzon9. Mt Amuyao 8863 Luzon10. Mt Kapiligan 8758 Luzon11. Mt Cawit 8754 Luzon12. Mt Abao 8731 Luzon13. Mt Osdung 8584 Luzon14. Mt Lumuluyaw 8567 Luzon15. Mt Halcon 8482 Mindoro16. Mt Alchanon 8449 Luzon17. Mt Cauitan 8426 Luzon18. Mt Baco 8161 Mindoro19. Mt Kanla-on 8085 Negros20. Mt Bangbanglang 8082 Luzon21. Mt Pawoi 8056 Luzon22. Mt Sapacoy 8056 Luzon==nega_posi200@yahoo.com==Mayon VolcanoMayon Volcano lies in the eastern portion of the province of Albay and is about 300 km. southeast of Manila. Well known for its beauty and near perfect cone, this active volcano is one of the tourist attractions of the country.Mayon reaches up to around 2,462 m. above sea level and covers an area of 250 sq. km. Its base circumference is 62.8 km. encompassing the towns of Camalig, Malilipot and Sto. Domingo.Mayon is classified as a stratovolcano or composite cone. It consists of deposits formed basically by four major types of volcanic activity: airfall deposition, pyroclastic flows, rain triggered debris flows and lava flows. Airfalls and pyroclastic flow deposits are composed of unconsolidated materials, varying in size from ash to ssmall boulders. These deposits result from the eruption of fragmented rocks from the crater and are transported downslope under the influence of gravity, explosion blast and the prevailing wind.Considered as the most active volcano in the Philippines, Mayon Volcano has had at least 43 eruptions since 1616. Its most violent and devastating outburst occurred on February 1, 1814. Nearby towns of Camalig, Cagsawa and Budiao were severely damaged, half of Guinobatan was ruined and at least 1,200 people perished in this eruption.The eruptions of Mayon are usually "Vulcanian" or explosive in nature. They are characterized by the emission of fine ash and ash-laden gases forming huge "cauliflower" clouds. The symmetry of the volcano indicates that the eruptions have always occured at the central vent and that these have never been violent enough to destroy Mayon's form.Mayon, though sometimes destructive, is also productive. Its fertile slopes and surrounding plains, coupled by abundant rainfall through the year, have made Albay a rich agricultural region with the bulk of its population found in towns bordering the volcano such as Camalig, Guinobatan, Daraga, Legaspi, Sto. Domingo, Ligao and Malilipot. The region is suited for growing abaca and coconut, two of Bicol's major crops, as well as palay and vegetables.Taal VolcanoTaal Volcano, one of the world's lowest volcanoes, is an island located near the center of Taal Lake in Batangas Province. Its highest point, 311m . Above sea level, is on the eastern rim of the main crater.Covering an area of 23 sq. km., the Volcano Island is surrounded by a fresh body of water, about two meters above sea level and 127 sq. km. in area. Taal Lake is known to have originated from the collapse of pre-historic volcanic centers. The underwater topography suggests the presence of about 35 different submerged volcanic landforms.Taal Volcano is a tuff cone. The rock formation consists of moderately consolidated ash beds with varying amounts of coarser fragments. Composed of at least 35 cones coalesced by several eruptions, Taal has about 47 craters or depressions formed either by direct explosive eruptions or by collapse or ground subsience.The 35 identified cones were formed by different type of volcanic processes: base surges (rapidly moving mixtures of volcanic debris and steam), airfalls and effusion of lava. Twenty-six of these cones are tuff cones, five are cinder cones and four are maars (shallow to deep circular depressions of volcanic origin).The Main Crater occupies the central portion of the Volcano Island. Twelve of Taal Volcano's eruptions occured at this crater from 1749 to 1911. There are five other major eruption centers, namely: Binintiang Malaki, Binintiang Munti, Pira-0piraso, Calauit and Mt. Tabaro Eruption Site.To date, Taal Volcano, has had 33 recorded eruption since its first known outburst in 1572. Its most catastrophic eruptions occured in 1754 and 1911. In 1754, the towns of Sala, Lipa, Tanauan, and Taal, then on the borders of Lake Taal, were destroyed and were subsequently relocated to their present sites. The 1911 eruption completely devastated the whole Volcano Island and claimed a toll of 1,034 lives. Ashes spewed out by the volcano reached as far as Manila and covered an area of 2,000 sq. km.Based on Taal Volcano's morphological features, it can be deduced that most of its eruptions were either Phreatic or Phreatomagmatic. Ground water and mobile magma may have either separately or jointly played the pricipal role in determining the nature of Taal eruptions. The 1968 and 1969 activities were, however, characterized as Strombolian with lava fountaining from several active vents and the effussion of molten rocks at the base of crater.Despite the hazards posed by the volcano, Taal Volcano Island has been attracting migrants because of its fertile soil and rich fishing grounds. Lake Taal is known for several varieties of milkfish, carps, maliputo and tawilis.The island had a population of more than 5,000 in 1990.Butusan VolcanoButusan Volcano is located at the south central part of Sorsogon Province. It covers a surface area roughly 400 sq. km. and towers to about 1559 m. above sea level. The volcano forms part of the Bicol Volcanic Chain which stretches from Camarines Norte in the north to Sorsogon in the south. The chain, sometimes called volcanic belt, is composed of active and geologically young volcanoes most probably related to the Philippine Trench.Bulusan is clasified as a composite volcano and is made up of lava flows and domes. It is flanked by several cones namely: Mt. Homahan, Mt. Binactan, Mt. Batuan, Mt. Juban, Mt. Calaunan, Mt. Tabon-Tabon, Mt. Calungalan and Mt. Jormajan. Beside the active volcano is an old ridge called Sharp Peak which is 1215 m. high and 1.8 km. to the northeast. Between Bulusan and Jormajan is theNatakop lava dome.The earliest recorded eruption of Bulusan Volcano occured in 1852. This was followed by periods of eruptive activity in 1886, then 1892, and in 1894. Another 22 years elapsed before Bulusan showed signs of restiveness. On January 16, 1916, the volcano ejected mud and ash for five days, thereby triggering landslides. The volcano's eruptive activity from Oct. 1918 to March 1919 was characterized by dust emissions and lava outpourings.Bulusan's series of 17 eruptions during May 1919 to May 1922 were of short duration ranging from 15 to 30 minutes each. Other eruptions were recorded in June 1928 and Dec. 25, 1933 and then the volcano rested for 45 years. On June 28, 1978, it suddenly ejected ashladen steam clouds which formed in a dark column of smoke 1500 m. high. Andesitic baalt ash was ejected and blown by winds to as far as Barcelona in the northeast about 15 km. from the volcano.The eruptions which followed in 1979, 1980, 1981 and 1983 were all pheatric and as mild as the previous ones.A total of 60 barangays within the territorial jurisdiction of six municipalities (Barcelona, Bulusan, Casiguran, Gubat, Irosin and Juban) are covered by the Bulusan Volcano hazard zones established by PHIVOLCS. These barangays lie within 4-10 km. from the summit of Bulusan Volcano.Canlaon VolcanoCanlaon Volcano, a large stratovolcano, is located in the north central portion of Negros Island. It forms a natural boundary between the provinces of Negros Occidental and Negros Oriental.Canlaon has a maximum elevation of 2435 m and a basal diameter of 30 km. It is a part of the volcanic arc related to subduction along the Negros Trench, which includes Mt. Silay in the north, Mt. Mandalagon and Mt. Cuernos de Negros in the south.Canlaon consists of a multitude of craters and parasitic cones aligned linearly, with an older caldera in its central portion. Most of the older cratershave formed lakes or lagoons. The volcanic edifice has been built by airfall deposits, lava agglutinates and lava flows, pyroclastic flows and lahar.The earliest record of Canlaon's eruption dates back to 1866. Since then, it has had at least 15 eruption periods, the latest occurring this year (1988).Recorded eruptions have so far been mild, consisting of ash and steam explosion sometimes coupled with lava flows and pyroclastics. Occurrence of older deposits, however, suggests that pre-historic eruptions have been more violent.Though a large segment of the volcano is considered a forest reservation, settlers have already encroached on the area. Several sugarcane haciendas are located on Canlaon's slopes. Vegetable and rice form secondary agricultural products. JOLO ISLANDLOCATION:Southwestern Mindanao/Sulu ArchipelagoLatitude:5 degrees 57.57' NLongitude:121 degrees 10.44' EHEIGHT FROM SL:811 m. maximumTYPE OF VOLCANO:Compound, mostly cinder cones and maarsKNOWN ERUPTIONS:Mt. Dakula - 1641Lake Seit - 1897TYPE OF ACTIVITY:MAIN ROCK TYPE:BasaltNumerous cinder cones, tuff cones and maars make up the island province of Jolo. In 1641, Magisa reported that on Jan. 4, a small island "opposite the bar of the main river of Jolo" erupted and sent a shower of ash to as far as Zamboanga. However, a survey of Jolo and adjoining islands indicated that Mt. Dakula near Lake Panamo appears to be the most recent of all the cones in the province.A submarine volcanic activity was also reported on September 21, 1897. The presence of a still active solfatara at Lake Seit, makes this maar the probable center of this activity. MOUNT MATUTUMLOCATION:Southern Mindanao/CotabatoLatitude:6 degrees 21' NLongitude:125 degrees 06.5' EHEIGHT FROM SL:2293 m.TYPE OF VOLCANO:Strato-volcanoKNOWN ERUPTIONS:1911TYPE OF ACTIVITY:MAIN ROCK TYPES:AndesiteAbout 70 km. south-southwest of Mt. Apo is a well preserved 2,293 m high cone named Matutum (which in the local dialect means "has fired or burnt out"). At the top is a 120-m deep and 320-m wide crater, breached by three gorges and covered with dense growth.An unconfirmed report states that Matutum was smoking on March 7 , 1911. However, several authors believe that the volcano is dormant. Mount Musuan of CalayoLocation:BukidnonLatitude:7 52'NLongitude:125 04'EHeight from S.L.:646Type of Volcano:Essentially a tuff coneKnown Eruptions:1886 or 1887Type of Activity:Main Rock Type:Musuan or Calayao volcano is an isolated tuff cone amidst a relatively flat, agriculturally rich terrain. It is vegetated from foot to summit with cogon grasses. Some trees thrive sparingly in its northeastern side. Its peak is flat and nearly circular with a diameter of 10-15 m.Jesuit Father, Eusebio Barado who traveled across the island of Mindanao from Misamis to Cotobato in 1891, reported Calayo's eruption some four years ago, and its emission of sulfurous vapors which burned everything around it.Musuan Volcano came into limelight when a swarm of fairly strong earthquakes rocked Valencia, Bukidnon, a municipality 4.5 km north of the volcano, from November 13 to 16, 1976. The event followed three major earthquakes that hit the Mindanao region (Cotobato Earthquakes of August 16 and 17, Magnitude 7, 9 and 6,8 respectively, and Surigao Earthquake of November 7, Magnitude 6,8), giving the impression that the swarm resulted from crustal or magmatic movement in the volcano, following what could be considered as part of the crustal readjustment process in the region.In the investigation conducted on November 21-30, 19 local tremors of varying magnitudes were recorded (A temporary seismograph was installed 4.5 km from the volcano during the period). Of these, 4 were perceptible. All the tremors resembled deep volcanic earthquakes with S-P measured at about 1.0 sec. MOUNT RAGANGLocation:Northern Mindanao/Lanao and CotobatoLatitude:7 41.2'NLongtitude:124" 31.8'EHeight from S.L.:2815 mType of Volcano:Strato-volcanoKnown Eruption:1756, 1834, 1840, 1856, 1858,1865, 1871, 1873, 1915, 1916Type of Activity:Explosive with lava flowMain Rock Type:This volcano occupies the northeast end of a series of relatively young volcanic cones in the boundary of the provinces of Lanao and Cotobato. The eruptive vent is rimmed by three peaks with a deep hollow at the center. From the southeast of this crater, a flow of jagged lava radiates to about one km. All around the cones and craters, product of past eruptions are scattered in the order of their size: boulder near the cones and the cinders, lapilli, and ashes farther away. The numerous jets of sulfurous vapors from vents in the crater and along one of the cones serve as evidence of the volcano's past activity. A thick column of steam rising from the fissure was reported in 1916 by Capt. G.O. Fort, P.C. The scorched and burnt trees at the southeastern sector seem to indicate a strong blast of hot gases in the quite recent past, probably that of the 1915 eruption.Other eruptions of Ragang took place in 1834, on January 20-April 5, 1840, on November 1, 1856, on February 18, 1858, in 1865, shortly before December 8, 1871 and on January 16-April 1873.Showers from the volcano, particularly during the 1840 eruption,were reported to have reached as far as 95 km west and 480 km northwest of Mindanao. MOUNT HIBOK-HIBOKLOCATION:Northern Mindanao/CamiguinLatitude:9 12'NLongtitude:124 40.5'EHEIGHT FROM S.L.:Hibok-Hibok-1330 m; Vulcan -TYPE OF VOLCANO:Compound volcano appropriately a dome.KNOWN ERUPTIONS:Hibok-Hibok - 1827, 1862, 1897,1902, 1948-1953Vulcan - 1871, 1874TYPE OF ACTIVITY:Pelean, Dome building with nuee ardente.MAIN ROCK TYPE:Olivine-bearing andesite & daciteHibok-Hibok volcano, also called Catarman, has a summit formed of loose ejectamenta. It has several craterlets at or near its crest, some representing shallow lakes. The present crateral area at the northeast slope facing Mambajao was mined for sulfur before the volcano's activity in 1948. Rock is normal andesite with augite, little hypersthene and olivine. Plagioclase is oligoclase with little labradorite. Some lavas contain horn blende.The first recorded eruption of Hibok-Hibok ocurred in 1827. This was followed by similar activity in 1862. Both eruptions caused destruction to arable lands.In January 1871, earthquakes and subterranean rumbling sounds disturbed the north end of Camiguin island. Landslides and fissuring destroyed trees and plantations. When the swarm of earthquake ceased in April of the same year, an explosion followed accompanied by a shower of rocks, dust, and ashes. Destruction was complete within a radius of 3 km from the new vent. The eruption continued for a week, and a volcanic dome called Vulcan began to form 3.5 km from the general area of Hibok-Hibok. After four years of activity, the adventive lava dome reached a height of 457 m with a base nearly 1.5 km in diameter.Vulcan is quiet at present and appears to have been unaffected by the activity of the adjacent Hibok-Hibok. Vulcan's activity has been limited to emission of small amounts of steam from crevices at the top of the dome.In 1897, the area occupied by the present dome of Hibok-Hibok emitted white sulfurous vapors which ruined agricultural lands. Solfataric activity continued up to 1902 when a thunder storm occurred around the volcano and a new solfataric vent formed opposite the crest. Frequent subterranean sounds were noted during the activity which lasted for 8 to 10 days.The last activity of Hibok-Hibok started in August 1948, with a series of earth tremors. The landslides and earthquakes were climaxed by the crateral outburst in September 1953, Hibok-Hibok has been in more or less continuous activity punctuated by eruptive phases.In every few years of activity, Hibok-Hibok seems to follow a cycle of behavior consisting of :A short period of smoke emission from the crater and avalanche of volcanic materials with or without accompanying tremors;Explosions or steam blasts with emission of heavy clouds of steam, ashes and other fragmentary volcanic materialsDisorging of incandescent materials and emission of ash and smoke in large quantities; andDecrease in amount of smoke and other ejecta from the crater.The whole cycle covers a period of 9 to 14 months. Cold and hot mud flows, or lahars, had developed, especially after heavy rains, so that now they pose another hazard to inhabitants living near the drainage channels of the volcano.
