![MOUNT PINATUBO, PHILIPPINS EXPLOSION
Mount Pinatubo (Sambali: Bakil nin Pinatubu; Kapampangan: Bunduk/Bulkan ning Pinatubu, Bunduk ning Apu
Malyari; Pangasinan: Palandey/Bulkan na Pinatubu; Ilocano: Bantay Pinatubo; Tagalog: Bundok/Bulkang Pinatubo)
is an activestratovolcanic caldera in the Zambales Mountains, located on the tripoint boundary of the Philippine
provinces of Zambales, Tarlac and Pampanga, all in Central Luzon on the northern island of Luzon.[3][4] Its eruptive
history was unknown to most before the pre-eruption volcanic activities of 1991, just before June. Pinatubo was
heavily eroded, inconspicuous and obscured from view. It was covered with dense forests which supported a
population of several thousand indigenous Aetas.
The volcano's Ultra Plinian eruption on June 15, 1991 produced the second-largest terrestrial eruption of the 20th
century after the 1912 eruption of Novarupta in the Alaska Peninsula.[5] Complicating the eruption was the arrival
of Typhoon Yunya (Diding), bringing a lethal messy mix of ash and rain to towns and cities surrounding the volcano.
Predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the
surrounding areas, saving many lives. Surrounding areas were severely damaged by pyroclastic surges, ash falls, and
subsequently, by the flooding lahars caused by rainwater re-mobilizing earlier volcanic deposits. This caused
extensive destruction to infrastructure and changed river systems for years after the eruption.[5][6]
The effects of the eruption were felt worldwide. It ejected roughly 10,000,000,000 tonnes (1.1×1010 short tons) or
10 km3(2.4 cu mi) of magma, and 20,000,000 tonnes (22,000,000 short tons) of SO
2, bringing vast quantities of minerals and toxic metals to the surface environment. It injected more particulate into
the stratosphere than any eruption since Krakatoa in 1883. Over the following months, the aerosols formed a global
layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C (0.9 °F) in the years 1991–
93,[7] and ozone depletion temporarily increased substantiall](https://image.slidesharecdn.com/volcanoandrelatedconcepts-190917161701/85/Volcano-and-related-concepts-46-320.jpg)
Volcano and related concepts
- 1. Presented by Uttiya Chattopadhyay Visva Bharati Geography Dept
- 2. DIIFERENT PARTS OF A VOLCANO
- 3. FAMOUS VOLCANOES OF THE WORLD
- 4. FEATURES OF A VOLCANO 1.Consolidation of magma. 2.Generally cone shaped. 3.With crater 4.Mostly found in the weak places of earth surface. 5.Slope generally within 20 – 30 degree
- 5. DIFFERENCE BETWEEN IGNEOUS INSTRUSION, VOLCANOCITY AND FISSURE ERUPTION IGNEOUS INTRUSION Magma enters in lithosphere, but does not come on the surface VOLCANOCITY When magma comes on the surface FISSURE ERUPTION Magma comes on the surface through a fault without any explosion. DECCAN TRAP OF INDIA, GAYANA PLATEAU OF BRAZIL Plateau or hilly plain made by fissure eruption called STEPTO in USA.
- 7. CONCEPT OF CRATER & CALDERA While studying vulcanology, students come across two terms caldera and crater that both refer to depressions made at the top of a volcano. What is the difference between Caldera and Crater? • A caldera looks like a volcanic crater, but it is actually formed when the overlying rocks collapse when a magma chamber is emptied creating vacuum below. • A volcanic crater is a bowl like structure at the top of a volcano that has the opening for the eruption of lava and the ashes. • Thus, a caldera is a special type of crater. • A crater is formed by sinking of the top of the volcano as lava weakens the rocks. On the other hand, a caldera is formed when the overlying rocks collapse to fill an emptied huge chamber of magma. • When a caldera gets filled with water after some time of its formation, it is called a crater lake such as the one in Oregon. CALDERA, A SPANISH WORD, MEANING ‘LARGE FRYING PAN OR CAULDRON. THE NAME DERIVED FROM ‘LA CALDERA LAKE’ OF CANARY ISLAND
- 8. CRATER A Greek word meaning ‘cup’. There are 4 types of crater, namely 1. Explosive crater : krakatoa, Indonesia 2. Ring crater : ubihir crater, California 3. Collapsed crater 4. Pit crater : Hawaii island the crater of aniachok, Alaska is 9.6 km in diameter
- 10. Classification of Volcanoes According to shape & structure According to nature According to emission of gas According to nature of explosion Active Dormant Dead Incessant or continuous intermittent Salfatra (sulfar) Matifis (CO2) Safioni (boric acid) Fumaroles (Amonium cloride) Hawaii type Stromboli type Vulcanian type Vesivius type Plinian type Pelean type CONE DOME COMPOSITE EXPLOSIVE CRATER CALDERA
- 11. A Hawaiian eruption is a type of volcanic eruption where lava flows from the vent in a relatively gentle, low level eruption; it is so named because it is characteristic of Hawaiian volcanoes. It is non-explosive in nature, found in Hawaii island, Iceland etc. HAWAII TYPE VOLCANO
- 12. STROMBOLI TYPE VOLCANO A pattern of eruption is maintained in which explosions occur at the summit craters, with mild to moderate eruptions of incandescent volcanic bombs, at intervals ranging from minutes to hours. This Strombolian eruption, as it is known, is also observed at other volcanoes worldwide. Eruptions from the summit craters typically result in a few short, mild, but energetic bursts, ranging up to a few hundred meters in height, containing ash, incandescent lava fragments and stone blocks.
- 13. The term Vulcanian was first used by Giuseppe Mercalli, witnessing the 1888-1890 eruptions on the island of Vulcano. His description of the eruption style is now used all over the world for eruptions characterized by a dense cloud of ash-laden gas exploding from the crater and rising high above the peak. Mercalli described vulcanian eruptions as "...Explosions like cannon fire at irregular intervals..." Their explosive nature is due to increased silica content of the magma. Found in Lipari island of Mediterranean sea. viscous lava Less spread of lava Explosive With cloud of gas and ashes VULCANIAN TYPE VOLCANO
- 14. VESUVIUS TYPE VOLCANO Vesuvius consists of a large cone partially encircled by the steep rim of a summit caldera caused by the collapse of an earlier and originally much higher structure. viscous lava Explosive Cone shaped body Emission of gas like Cauliflower Like Cauliflower
- 15. PLINIAN TYPE VOLCANO Plinian eruptions, also known as Extreme Vesuvian eruptions, are volcanic eruptions marked by their similarity to the eruption of Mount Vesuvius in AD 79. The eruption was described in a letter written by Pliny the Younger; it killed his uncle, Pliny the Elder. Plinian eruptions are marked by columns of gas and volcanic ash extending high into the stratosphere, a high layer of the atmosphere. The key characteristics are ejection of large amount of pumice and very powerful continuous gas blast eruptions.
- 16. PELEAN TYPE VOLCANO They can occur when viscous magma, typically of rhyolitic or andesitic type, is involved, and share some similarities with Vulcanian eruptions. The most important characteristics of a Peléan eruption is the presence of a glowing avalanche of hot volcanic ash, a pyroclastic flow. Formation of lava domes is another characteristically feature. ex- Caribbean islands
- 17. ACTIVE –mouna loa, hawaii island stromboli, itali st. helen, USA DORMANT – fujiama, japan pari kutil, mexico baron, india DEAD - popo, myanmar cotopaxi, mexico According to Selby, at least 2500 years of no eruption from a volcano can be called a dead volcano.
- 18. INTRUSIVE IGNEOUS FORMS 1. Dyke 2. Sill 3. Batholith 4. Phacolith 5. Laccolith 6. Lopolth 7. Conolith
- 20. A batholith (from Greek bathos, depth & lithos, rock) is a large emplacement of igneous intrusive (also called plutonic) rock that forms from cooled magma deep in the Earth's crust.
- 21. Like a sill but swelling out to form a lens- shaped mass, several laccoliths form a cedar tree like structure.
- 22. A large intrusion of igneous rock concordant with the strata, forming a saucer-shaped basin.
- 23. A lens-shaped intrusion of igneous rock occupying the saddle (crest) of an anticline or the keel (the trough) of syncline, differing from a laccolith in that it is shallower and the laccolith has a flat base.
- 24. This intrusion does not have definite form, found in Karo region of Africa
- 25. LAVA According to nature 1. Acidic lava ( Granite) 2. Basic lava (Basalt) According to Hawaiian language 1. Aa Aa lava 2. Pa Hoe Hoe lava
- 26. Aa Aa LAVA It is like rough, stony rough, rugged surface, having blocky surface. It contains high bubbles, less gas and it cannot spread to a large distance due to viscosity.
- 27. PA HOE HOE LAVA It is having a lava field having rope like or ropy surface, viscous, high gas content, with design and smooth. It is found in niamuragia volcano in N. Africa.
- 28. Negative Landform When the anticlines are suppressed due land slides or erosion , and is transformed into synclines, is termed as a Negative Landform. Ex- Caldera is an example of Negative landform.
- 29. FIRY RING OF PACIFIC Ring means a Belt around Pacific ocean. Here remains most of active volcanoes of the world. Starting from Horn cape of the south of south America spreads through Andes, Rocky, Kamchatka, Sakhalin, Japan, Philippines and Indonesia etc.
- 32. TUMULI The upper part of a volcano is hard, but due to the viscous part beneath or pressure of that viscous magma, a ridge shaped mount is formed just above the fault or fissure zone, that mount is called tumuli. Large shaped tumuli is called pressure-ridge . According to dictionary, a small mound or hummock of solid lava on a lava flow, in some cases up to 9 mt in height & 18 mt across the base, produced by the resistance of lava surface to the spreading of a more fluid lava below, thus resembling a laccolith in origin.
- 33. TUFF A rock formed from compacted or cemented pyroclastic materials ( fine volcanic dust, ash etc thrown out of a volcano in eruption) with particles smaller than 4 mm in diameter. Or a light, porous rock formed by consolidation of volcanic ash
- 34. MAGMA STEPPING When there is no vein or fissure, but magma makes its own path to come out on the earth surface, is called magma stepping. It happens due to compression and tension or collapse etc.
- 35. SCORIACIOUS When magma is turned into lava very fast , consolidating around the crater, a porous rock is formed. That is called scoriacious.
- 36. flank eruption is the release of lava and pyroclastic material from a source on the slopes of a volcano, away from its primary central vent or fissure-vent area. FLANK ERUPTION
- 38. Hornitos are formed in lava flows and are small openings that release small quantities of lava. Similar to spatter cones, Hornitos are rootless meaning they don't sit on top of the main vent like spatter cones. Instead they are usually created by the slow upwelling of lava through the roof of a lava tube. High pressure causes lava to ooze and spatter out. They are cone shaped. Hornito
- 39. a rounded umbrella-shaped mass of lava rising above the surface of a lava flow or crater floor THOLOID
- 40. A plug dome volcano is a rounded volcano containing very thick lava that congests or “plugs” easily. Plug dome volcanoes come in many different forms. However, they all possess viscous lava that cannot flow readily. These structures form through repeated outpourings of bulbous lava masses around the volcanoes’ vents. PLUGDOME
- 41. An ignimbrite is the deposit of a pyroclastic density current, or pyroclastic flow. It is a hot suspension of particles and gases flowing rapidly from a volcano driven by having a greater density than the surrounding atmosphere. New Zealand geologist Patrick Marshall derived the term 'ignimbrite' from ‘fiery rock dust cloud’ (from the Latin igni- (fire) and imbri- (rain)), formed as the result of immense explosions of pyroclastic ash, lapilli and blocks flowing down the sides of volcanoes. IGNIMBRITE
- 43. A lahar is a 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 extremely destructive: they can flow tens of metres per second, be 140 meters (460 ft) deep, and destroy any structures in their path. Notable lahars include those at Mount Pinatubo and Nevado del Ruiz, the latter of which killed thousands of people. LAHAR
- 44. CAULDRON Large size caldera are often called cauldron. It is about 25 to 70 mile in length and found in australia.
- 45. nuée ardente, ( French: “glowing cloud”) highly destructive, fast- moving, incandescent mass of gas-enveloped particles that is associated with certain types of volcanic eruptions. In 1902, nuee ardente of mount pelee devastated st piere city. NUÉE ARDENTE
- 46. MOUNT PINATUBO, PHILIPPINS EXPLOSION Mount Pinatubo (Sambali: Bakil nin Pinatubu; Kapampangan: Bunduk/Bulkan ning Pinatubu, Bunduk ning Apu Malyari; Pangasinan: Palandey/Bulkan na Pinatubu; Ilocano: Bantay Pinatubo; Tagalog: Bundok/Bulkang Pinatubo) is an activestratovolcanic caldera in the Zambales Mountains, located on the tripoint boundary of the Philippine provinces of Zambales, Tarlac and Pampanga, all in Central Luzon on the northern island of Luzon.[3][4] Its eruptive history was unknown to most before the pre-eruption volcanic activities of 1991, just before June. Pinatubo was heavily eroded, inconspicuous and obscured from view. It was covered with dense forests which supported a population of several thousand indigenous Aetas. The volcano's Ultra Plinian eruption on June 15, 1991 produced the second-largest terrestrial eruption of the 20th century after the 1912 eruption of Novarupta in the Alaska Peninsula.[5] Complicating the eruption was the arrival of Typhoon Yunya (Diding), bringing a lethal messy mix of ash and rain to towns and cities surrounding the volcano. Predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives. Surrounding areas were severely damaged by pyroclastic surges, ash falls, and subsequently, by the flooding lahars caused by rainwater re-mobilizing earlier volcanic deposits. This caused extensive destruction to infrastructure and changed river systems for years after the eruption.[5][6] The effects of the eruption were felt worldwide. It ejected roughly 10,000,000,000 tonnes (1.1×1010 short tons) or 10 km3(2.4 cu mi) of magma, and 20,000,000 tonnes (22,000,000 short tons) of SO 2, bringing vast quantities of minerals and toxic metals to the surface environment. It injected more particulate into the stratosphere than any eruption since Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C (0.9 °F) in the years 1991– 93,[7] and ozone depletion temporarily increased substantiall