Volcanic eruption


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Volcanic eruption

  2. 2.
  3. 3. What is a volcano? A volcano is a vent or 'chimney' that connects molten rock (magma) to the Earth's surface. It includes the surrounding cone of built-up material. Magma erupting from a volcano is called lava. Gases and pieces of rock erupt from volcanoes too. A volcano is active if it erupts lava, releases gas or shows seismic activity. It is dormant if it hasn't erupted for a long time but could again one day. An extinct volcano will never erupt again. The explosiveness of a volcanic eruption depends on how easily magma can flow and the amount of gas trapped in it. Large amounts of water and carbon dioxide are dissolved in magma. They behave like gas in fizzy drinks. After opening the bottle the gas expands, forming bubbles that escape. This also happens when magma rises quickly through the crust - gas bubbles form and expand up to 1000 times their original size.
  4. 4. WHAT IS VOLCANIC ERUPTION ? It is the sudden occurrence of a violent discharge of steam and volcanic material like volcanic bombs, lapilli, ash and lava are expelled violently in the land air and water surfaces
  5. 5. List of active volcanoes in the Philippines From Wikipedia, the free encyclopedia Jump to: navigation, search Active volcanoes in the Philippines, as categorized by the Philippine Institute of Volcanology and Seismology (PHIVOLCS), include volcanoes in the country having erupted within historical times (within the last 600 years), with accounts of these eruptions documented by man; or having erupted within the last 10,000 years (holocene) based on analyses of datable materials. However, there is no consensus among volcanologists on how to define an "active" volcano. As of 2012, PHIVOLCS lists 23 volcanoes as active in the Philippines, 21 of which have historical eruptions and two strongly fumarolic volcanoes - Cabalian and Leonard Kniaseff.[1][not in citation given]; the Smithsonian Institution's Global Volcanism Program categories 20 Philippine volcanoes as "historical" and 59 as "holocene".[2] The Smithsonian Institution's Global Volcanism Program (GVP) list volcanoes with historical, Holocene eruptions, or possibly older if strong signs of volcanism are still evident through thermal features like fumaroles, hot springs, mud pots, etc.[3] GVP currently lists 50 Philippines volcanoes.[2] The eruptions from the table below were based more on GVP which gives a more detailed eruption history for a particular mountain. The frequency of Historical Eruptions are based on definite historical eruptions and excludes questionable or Uncertain accounts based on the two sources mentioned. The list below shows 25 active volcanoes in the Philippines was based more on the PHIVOLCS list with some included from the GVP list. The number is not a definite number and could depend on someone's definition of "active" or historical
  6. 6. timeframe. Also, volcanoes listed as inactive or potentially active could renew activity after long periods of dormancy such as Mount Pinatubo in 1991
  7. 7. Active volcanoes in the Philippines Volcano Ambalatungan Group Babuyan Claro Coordinates 17.310982°N 121.103668°E 9.523°N 121.940°E Elevation (m) 2,329 metres (7,641 ft) 1,080 metres (3,540 ft) Province/s Kalinga Cagayan Historical Eruptions Eruption Description and Current Status 0 Explosions in 1952 is uncertain.[4] Fumarolic with solfataras and thermal springs. 3 Eruptions were recorded in 1831, 1860 and 1913. Askedna Hot Springs is located in the southern base of the volcano. Banahaw 14.07°N 121.48°E 2,158 metres (7,080 ft) Quezon 0 Eruptions were uncertain during the mudflows of 1730, 1743, 1843 and 1909.[5] Biliran 11.558°N 124.513°E 1,301 metres (4,268 ft) Biliran 1 Phreatic eruption in 1939. Fumarolic with thermal springs 17 Eruptions years are from 1886 to 2011. Permanently monitored 1 Eruption in 1860 and strong solfataric activity in 1907. Thermal areas are located near the summit and NW to NNE flanks. Bulusan Cagua 12.770°N 124.05°E 18.222°N 122.123°E 1,565 metres (5,135 ft) 1,133 metres (3,717 ft) Sorsogon Cagayan
  8. 8. Camiguin de Babuyanes Didicas Hibok-Hibok Iraya 18.83°N 121.860°E 19.077°N 122.202°E 9.203°N 124.673°E 20.469°N 122.010°E 712 metres (2,336 ft) 244 metres (801 ft) 1,552 metres (5,092 ft) 1,009 metres (3,310 ft) Cagayan Cagayan Camiguin Batanes 1 Its only recorded eruption was in 1857. Fumarolic with thermal springs 6 Eruptions in 1773, 1856, 1900, 1952, 1969 and 1978. A submarine volcano till 1952 when a permanent island was formed.[6] 5 Eruption in years 1827, 1862, 1871 and 1948–1952. Activity from 1897-1902 was only solfataric. Permanently monitored. 1 Last eruption was in 1454. Seismic swarm in 1998.
  9. 9. Iriga Jolo Group Kanlaon Leonard Kniaseff Makaturing 13.457°N 123.457°E 6.013°N 121.057°E 10.412°N 123.132°E 7.382°N 126.047°E 7.647°N 124.32°E 1,196 metres (3,924 ft) 811 metres (2,661 ft) 2,435 metres (7,989 ft) 1,190 metres (3,900 ft) 1,940 metres (6,360 ft) Camarines Sur Sulu Negros Occidental, Negros Oriental Davao del Norte Lanao del Sur 0 The eruption in 1628 was discredited.[7] 0 Uncertain submarine eruption in 1897. Listed as Bud Dajo, a cinder cone on Jolo Island, in the PHIVOLCS list. 26 Eruptions were recorded from 1886 to 2006. Permanently monitored. 0 Last eruption was dated as c.120 AD.[8] Strong thermal features. 2 Eruption recorded in 1865 and 1882. The 1856 and 1858 eruptions was credited to Ragang[9][10]
  10. 10. Matutum Mayon Musuan Parker Pinatubo 6.37°N 125.07°E 13.257°N 123.685°E 2,286 metres (7,500 ft) 2,462 metres (8,077 ft) 7.877°N 125.068°E 646 metres (2,119 ft) 6.113°N 124.892°E 1,824 metres (5,984 ft) 15.13°N 120.35°E 1,486 metres (4,875 ft) South Cotabato Albay Bukidnon South Cotabato Zambales, Tarlac, Pampanga 0 Mountain was fumarolic on March 7, 1911, but if an eruption occurred was uncertain. Thermal springs in Almoan and Linan.[11][12] 50 Eruptions were recorded from 1616 to 2013. Permanently monitored. 2 Eruptions in 1866 & 1867. Strong seismic swarm in 1976. 1 A caldera-forming eruption occurred on January 4, 1641. 3 Reawakened in 1991 producing the 2nd largest eruption in the 20th century. Followed by milder eruptions in 1992 and 1993.
  11. 11. Ragang San Pablo Volcanic Field 7.70°N 124.50°E 14.12°N 121.30°E 2,815 metres (9,236 ft) 1,090 metres (3,580 ft) Lanao del Sur, Cotabato Laguna, Batangas 7 Eruption years are from 1765 to 1873. Eruptions were uncertain in 1915 and 1916. 0 Last activity was the formation of Sampaloc Lake around 1350 AD +/- 100 years determined by anthropology[3][13] Smith 19.534°N 121.917°E 688 metres (2,257 ft) Cagayan 6 Taal 14.002°N 120.993°E 400 metres (1,300 ft) Batangas 33 −24 metres (−79 ft) Batanes 3 Unnamed 20.33°N 121.75°E volcano (Ibugos) Eruption years are from 1652 to 1924. Combined with Babuyan Claro on the GVP list. Eruption years is from 1572 to 1977. Showing signs of unrest since 1991 and permanently monitored. Submarine eruptions in 1773, 1850 and 1854.
  12. 12. When does the volcanic eruption happen? Volcanic eruptions happen when lava and gas are discharged from a volcanic vent. What is the cause of volcanic eruption? Volcanic eruptions are caused when magma from the magma chamber of the Earth rises up the pipe and out of the vent. Magma is continuously supplied from the mantle of the Earth. Shield volcanoes usually have a gentle eruption, as it contains basic lava. Acid-lava and composite volcanoes usually have a violent eruption as it contains acidic lava. The vent of the volcano might also be blocked, causing the magma to force its way out thus causing a huge explosion.
  13. 13. During a volcanic eruption, lava, tephra (ash, lapilli, volcanic bombs and blocks), and various gases are expelled from a volcanic vent or fissure. Several types of volcanic eruptions have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series. There are three different metatypes of eruptions. The most well-observed are magmatic eruptions, which involve the decompression of gas within magma that propels it forward. Phreatomagmatic eruptions are another type of volcanic eruption, driven by the compression of gas within magma, the direct opposite of the process powering magmatic activity. The last eruptive metatype is the phreatic eruption, which is driven by the superheating of steam via contact with magma; these eruptive types often exhibit no magmatic release, instead causing the granulation of existing rock. Within these wide-defining eruptive types are several subtypes. The weakest are Hawaiian and submarine, then Strombolian, followed by Vulcanian and Surtseyan. The stronger eruptive types are Pelean eruptions, followed by Plinian eruptions; the strongest eruptions are called "Ultra Plinian." Subglacial and phreatic eruptions are defined by their eruptive mechanism, and vary in strength. An important measure of eruptive strength is Volcanic Explosivity Index (VEI), a magnitudic scale ranging from 0 to 8 that often correlates to eruptive types.
  14. 14. Eruption mechanisms Volcanic eruptions arise through three main mechanisms: Gas release under decompression causing magmatic eruptions. Thermal contraction from chilling on contact with water causing phreatomagmatic eruptions. Ejection of entrained particles during steam eruptions causing phreatic eruptions.[1] There are two types of eruptions in terms of activity, explosive eruptions and effusive eruptions. Explosive eruptions are characterized by gas-driven explosions that propels magma and tephra.[1] Effusive eruptions, meanwhile, are characterized by the outpouring of lava without significant explosive eruption.[2] Volcanic eruptions vary widely in strength. On the one extreme there are effusive Hawaiian eruptions, which are characterized by lava fountains and fluid lava flows, which are typically not very dangerous. On the other extreme, Plinian eruptions are large, violent, and highly dangerous explosive events. Volcanoes are not bound to one eruptive style, and frequently display many different types, both passive and explosive, even the span of a single eruptive cycle.[3] Volcanoes do not always erupt vertically from a single crater near their peak, either. Some volcanoes exhibit lateral and fissure eruptions. Notably, many Hawaiian eruptions start from rift zones,[4] and some of the strongest Surtseyan eruptions develop along fracture zones.[5] Scientists believed that pulses of magma mixed together in the chamber before climbing upward -- a process estimated to take several thousands of years. But Columbia University volcanologists found that the eruption of Costa Rica‘s Irazú Volcano in 1963 was likely
  15. 15. 1.Magmatic eruptions a. Hawaiian b. Strombolian c. Vulcanian d. Peléan e. Plinian 2. Phreatomagmatic eruptions a. Surtseyan b. Submarine c. Subglacial
  16. 16. Magmatic eruptions Magmatic eruptions produce juvenile clasts during explosive decompression from gas release. They range in intensity from the relatively small lava fountains on Hawaii to catastrophic Ultra Plinian eruption columns more than 30 km (19 mi) high, bigger than the AD 79 eruption that buried Pompeii.[1] Phreatomagmatic eruptions Phreatomagmatic eruptions are eruptions that arise from interactions between water and magma. They are driven from thermal contraction (as opposed to magmatic eruptions, which are driven by thermal expansion) of magma when it comes in contact with water. This temperature difference between the two causes violent water-lava interactions that make up the eruption. The products of phreatomagmatic eruptions are believed to be more regular in shape and finer grained than the products of magmatic eruptions because of the differences in eruptive mechanisms.[1][34] There is debate about the exact nature of phreatomagmatic eruptions, and some scientists believe that fuel-coolant reactions may be more critical to the explosive nature than thermal contraction.[34] Fuel coolant reactions may fragment the volcanic material by propagating stress waves, widening cracks and increasing surface area that ultimetly
  17. 17. What Causes Volcanoes? To understand what causes volcanoes, you need to understand how the earth is made up. The earth has three main layers: the crust, the mantle and the core. The crust is made up of solid rock and varies in thickness. It is more than 60km thick under mountain chains like the Alps and Himalayas, but just 5km under the oceans. The mantle is a thick layer of molten rock (called magma), and the core is made up of an outer liquid layer and a solid centre. Temperatures inside the earth are very high – over 5000‘C in the core. This means that the planet on which we live is like a huge fiery ball of hot molten rock, surrounded by a few kilometers of relatively cool, hard rock – the crust. Because heat rises, the magma in the earth‘s mantle has to find a way to rise upwards though the crust above it, rather like the way that hot air rises. An erupting volcano A volcano erupts when magma escapes from inside the earth. As the magma is escaping from a confined space, a lot of energy is released with it, as happens with any other explosion. This is why many eruptions also produce huge quantities of gases and dust. Magma sometimes rises under enormous pressure, so it not only finds cracks in the earth‘s crust, it can also create them. When magma reaches the earth‘s surface it is called lava. Tectonic plates and volcanoes The earth‘s crust is its thinnest layer. It is broken up into large pieces, called tectonic plates. These plates lie above the hot, liquid mantle. Each plate contains some continental crust (land) and some oceanic crust (sea-bed). Huge currents of molten rock
  18. 18. This is no coincidence. Plate boundaries are among the most geologically active places on earth. Here, new rock is being both created and destroyed, so this is where most of the world‘s volcanic eruptions and earthquakes occur. The Pacific ‘Ring of Fire’ More than half of all the world‘s volcanoes are found in the Pacific ‗Ring of Fire‘. This area forms a circle stretching down the eastern side of the Pacific Ocean, from Alaska in the north, through the Rocky Mountains of Canada and the USA, to the Andes mountains of South America. It loops back around the western side of the Pacific, up through New Zealand, Indonesia and Japan. Many of the world‘s most famous volcanoes are found in this ‗Ring of Fire‘: Cotopaxi in Ecuador, which last erupted in 1928; Mount St Helens in the USA, which erupted spectacularly in 1980; and Krakatoa in Indonesia, which killed 36000 people when it erupted in 1883. Spreading centers Some plate boundaries follow the line of the land surface. For example, the eastern edge of the Pacific Plate seems to run down the coast of the American continent. Others are found at the bottom of the world‘s oceans. Here, hidden from view, lie extensive ranges of mountains, canyons and volcanoes. New rock is being created here by volcanoes spewing out lava underwater. Scientists estimate that between 2-5 cm of new crust is created each year by volcanoes along the Mid-Atlantic Ocean Ridge.
  19. 19. How do volcanoes effect the weather? The first is how the weather near an erupting volcano is being affected. The second is how large eruptions will affect the weather/climate around the world. I think more people are worried about the second issue than the first. As far as we know, the main effect on weather right near a volcano is that there is often a lot of rain, lightning, and thunder during an eruption. This is because all the ash particles that are thrown up into the atmosphere are good at attracting/collecting water droplets. Another problem in Hawaii is that involves the formation of volcanic fog. The ongoing eruption is very quiet, with lava flowing through lava tubes and then into the ocean. How do volcanoes effect people? Volcanoes affect people in many ways, some are good and some are not. Some of the bad ways are that houses, buildings, roads and fields can get covered with ash. As long as you can get the ash off (especially if it is wet), your house may not collapse, but often people leave because of the ash and are not around to continually clean off their roofs. If the ash fall is really heavy it can make it impossible to breathe. The good part of volcanoes The main good effect that volcanoes have on the environment is to provide nutrients to the surrounding soil. Volcanic ash often contains minerals that are beneficial to plants, and if it is very fine ash it is able to break down quickly and get mixed into the soil.
  20. 20. NO but we can prepare for it, How?
  21. 21. Key Facts About Preparing for a Volcanic Eruption You can do many things to protect yourself and your family from the dangers a volcanic eruption can cause. The best way to protect yourself and your family is to follow the advice of local officials. Local authorities will give you information on how to prepare for a volcanic eruption, and if necessary, on how to evacuate (leave the area) or take shelter where you are.
  22. 22. How to prepare Be prepared either to shelter or to evacuate. Develop an evacuation plan and a sheltering plan for yourself, your family, and others in your household. Review the plans and make sure that everyone understands them. If you haven‘t already done so, put together an emergency supply kit . Supplies should include the following: Flashlight and extra batteries First aid kit and manual Emergency food and water Manual (nonelectric) can opener Essential medicines Sturdy shoes Respiratory (breathing) protection Eye protection (goggles) Battery-powered radio Exposure to ash can harm your health, particularly the respiratory (breathing) tract. To protect yourself while you are outdoors or while you are cleaning up ash that has gotten indoors, use an N-95 disposable respirator (also known as an ―air purifying respirator‖). N-95 respirators can be purchased at businesses such as hardware stores. It is important to follow directions for proper use of this respirator. For more information, see NIOSH-Approved Disposable Particulate Respirators (Filtering Facepieces) . If you don‘t have an N-95 respirator, you can protect yourself by using a nuisance dust mask as a last resort, but you should stay outdoors for only short periods while dust is falling. Nuisance dust masks can provide comfort and relief from exposure to relatively non-hazardous contaminants such as pollen, but they do not offer as much protection as an N-95 respirator. Cleanup or emergency workers may need a different type of breathing protection.
  23. 23. If you are told to evacuate Follow authorities‘ instructions if they tell you to leave the area. Though it may seem safe to stay at home and wait out an eruption, doing so could be very dangerous. Volcanoes spew hot, dangerous gases, ash, lava, and rock that are powerfully destructive.
  24. 24. Preparing to evacuate • Tune in the radio or television for volcano updates. • Listen for disaster sirens and warning signals. • Review your emergency plan and gather your emergency supplies. Be sure to pack at least a 1-week supply of prescription medications. • Prepare an emergency kit for your vehicle with food, flares, booster cables, maps, tools, a first aid kit, a fire extinguisher, sleeping bags, a flashlight, batteries, etc. • Fill your vehicle‘s gas tank. • If no vehicle is available, make arrangements with friends or family for transportation, or follow authorities‘ instructions on where to obtain transportation. • Place vehicles under cover, if at all possible. • Put livestock in an enclosed area. Plan ahead to take pets with you, but be aware that many emergency shelters cannot accept animals. • Fill your clean water containers. • Fill sinks and bathtubs with water as an extra supply for washing. • Adjust the thermostat on refrigerators and freezers to the coolest possible temperature. If the power goes out, food will stay cooler longer. As you evacuate • Take only essential items with you, including at least a 1-week supply of prescription medications. • If you have time, turn off the gas, electricity, and water. • Disconnect appliances to reduce the likelihood of electrical shock when power is restored. • Make sure your automobile‘s emergency kit is ready. • Follow designated evacuation routes—others may be blocked—and expect heavy traffic and delays.
  25. 25. If you are told to take shelter where you are  Keep listening to your radio or television until you are told all is safe or you are told to evacuate. Local authorities may evacuate specific areas at greatest risk in your community.  Close and lock all windows and outside doors.  Turn off all heating and air conditioning systems and fans.  Close the fireplace damper.  Organize your emergency supplies and make sure household members know where the supplies are.  Make sure the radio is working.  Go to an interior room without windows that is above ground level.  Bring your pets with you, and be sure to bring additional food and water supplies for them.  It is ideal to have a hard-wired (non-portable) telephone in the room you select. Call your emergency contact—a friend or family member who does not live near the volcano—and have the phone available if you need to report a life-threatening condition. Remember that telephone equipment may be overwhelmed or damaged during an emergency.
  28. 28. Submitted to: Mrs. Orpha Fajardo Mangulabnan