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From: Josh (draft # 2)
Date: 10/13/02
Time: 1:05:12 PM
Remote Name: 152.163.189.136
I fixed a few things in this draft, take a look and see what you think. If you have any more causal chains or the sources for any just let me know.
thanks, josh The Event Study of Volcanoes and Spheres
Information on Specific Spheres and Event:
Atmosphere:
The atmosphere is the gaseous area surrounding the Earth, divided into 5 areas: troposphere, stratosphere, mesosphere, thermosphere, and exosphere. The Troposphere is the atomospheric layer closest to Earth and contains the largest percentage of the mass of total atmosphere. The troposphere contains 99% of the water vapor in the atmosphere. All weather phenomena occur within the troposphere, but some turbulence may extend into the stratosphere, the next layer in the atmosphere. Approximately 90% of the ozone in the atmosphere resides in the stratosphere. The ozone( a particularly reactive form of oxygen which is formed when oxygen is produced: Http://csep10.phys.utk.edu/astr161/lect/earth/atmosphere.html) absorbs the bulk of the solar ultraviolet radiation in the atmosphere due to it’s closeness to the Sun (http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/ATM_CHEM/atmospheric_structure.html) The troposphere and stratosphere are the two layers that we will concentrate our sphere study on.
Lithosphere:
The Earth is divided into three different chemical layers: the core, mantle, and crust. The core, composed mostly of iron and nickel, remains very hot after 4.5 billion years of cooling. The mantle (middle layer) is rich in the elements iron, magnesium, silicon, and oxygen. The crust is rich in the elements oxygen and silicon with lesser amounts of aluminum, iron, magnesium, calcium, potassium, and sodium. There are two types of crust: dense oceanic crust made of basalt and continental crust made of lower density rock such as andosite and granite. The outermost layers of Earth can be divided by their physical properties into the lithosphere and atmosphere. The lithosphere is the rigid outer layer made of crust and uppermost mantle. It is the “plate” in the plate tectonic theory. Asthenosphere is the part of mantle flows, that is: exhibits “plastic behavior” much like toothpaste in a tube. The flow of the asthenosphere is part of mantle convection, which plays a major part in moving lithosphere plates. ( “http://volcano.und.nodak.edu/vwdocs/vwlessons/plate_tectonics/pla...”)
The lithosphere is the rigid inorganic portion of the Earth which contains the crust and between 80 to 100 km of the mantle. Thickness of the lithosphere averages about 100km; however, the lithosphere can be just a few miles under the oceans and up to 300km beneath the continents. Comprising the lithosphere are rocks, minerals, and elements. The tree types of rocks are igneous, sedimentary, and metamorphic. Scientists have found within these rocks over 2,000 types of minerals and have also identified or created from these rocks over 112 elements, which are found on the periodic table. Rested on and supported by the semi-fluid asthenosphere, the lithosphere is broken into several sections termed ‘tectonic plates’. These plates, because of the viscosity asthenosphere, cause movement of the lithosphere. Plate movements can be a few inches per year and in different directions. When plates collide with one another or slide over or under one another these meetings have been identified as Earthquakes. Sometimes these meetings occur over weak or thin portions of the lithosphere that have a large amount of magma. When this occurs , volcanoes can form. (Http://visearth.ucsd.edu/) (Wood,J.(1991 Volcanoes: Fires from Below. Milwaukee, WI: Gareth Stevens Children’s Book) The lithosphere includes all the geologic forms on the Earth’s surface: sea floors, trenches, islands, plains, plateaus and mesas, valleys and basins, hills, mountains, and volcanoes, and all their parts.
Hydrosphere:
The hydrosphere is made up of the entire planet’s water. Water is the most widespread substance found in the environment. Water exists in three states: liquid, solid, and invisible vapor. It forms the oceans, seas, rivers, and lakes. This also includes the underground waters found in the top layers of the Earth’s crust and soil cover. (http://www.dc.peachnet.edu/~pgore/geology/geo101/hydro.2html) It is hard to assess the total water storage on the Earth. Water is in permanent, it is constantly changing from liquid to solid, to a gaseous state and back again. It is estimated that 97.5% of the total water is salt water. 68.9% is made up of glaciers and permanent snow and 29.9% is fresh ground water. (http://webworld.unesco.org/water/ihp/publications/waterway/webpc./definition.html)
Biosphere:
The biosphere is made up of every living thing found on Earth. All living organisms, including animals, plants, and microorganisms, make up this sphere. Parts of the biosphere can be included in other spheres. For example: fish and aquatic plants can be found in our lakes, rivers, streams, and oceans. The biosphere is also known as the Earth’s thin zone of air, soil, and water. It is capable supporting life. It ranges from about 6 miles into the atmosphere to the deepest ocean floor. Life that is in this zone depends on the sun’s energy and on the heat and essential nutrients circulating about the Earth. (http://encarta.msn.com)
Volcanoes:
A volcano is a result of a mountain or hill being created from eruptions through one or more openings in the earth. As magma, or molten rock below the Earth’s surface is formed, it begins to rise toward lower pressure regions. Before erupting, it tends to accumulate in magma reservoirs, or underground storage regions. Materials such as lava, tephra, or rock fragments, and gases are released from a volcanic eruptions. Each eruption adds layers to the volcano. As this accumulation occurs, a topographic feature, such as mountains, hill, plateau, or crater is formed. Earth’s volcanoes are mostly formed beneath the oceans. (http://encarta.msn.com/encnet/refpages/refarticle.aspc?refid=7615)
Volcanoes are cones which form above and around a vent (an opening at the Earth’s surface through which volcanic materials are released) by accumulations of erupted volcanic materials like ash(volcanic rock that has exploded from a vent in fragments less than 2mm in size. It may be solid or molten when first erupted) pumice:( is cinder that is so bubbly it floats in water)and lava flows:( magma or molten rock which is outpoured in a flow on the land from a vent or fissure) (http://library.thinkquest.org/17457/glossary/glossary.html) There are also volcanic gases that are spewed out of a volcano, during and eruption. These gases include water vapor, sulfur dioxide, carbon dioxide, and traces of chlorine and fluorine gases. Volcanoes cause much widespread destruction and there are possible after effects of chain reactions that can last from a short time (days to weeks) to even up to 2 years after the event takes place.
Volcanoes have several different types of eruptions: Hawaiian, Basaltic Flood, Strombolian, Vulcanian, Peleean, Plinian, Rhyolitic Flood, Ultravulcanian, Gas Eruptions, and Furm
Volcano experts have classified volcanoes into groups based on their shape, the materials of which they are composed, and the way they erupt. (Http://www2.sunysuffolk.edu ) (http://volcanoe.und.edu) .
Mt. Pinatubo (Volcano)
Mt. Pinatubo is a volcano located on the Philippine Island of Luzon, north of Manila. Mt. Pinatubo erupted on June 15, 1991. The eruption of Mt. Pinatubo was one of the largest and it strongly affected some aspects of our climate. This eruption helped to produce the largest sulfur oxide cloud this century. There was an estimated 20 million tons of sulfur dioxide and ash particles blasted more than 12 miles into the atmosphere. (http://earthobservatory.nasa.gov/study/volcano) Part of this aerosol plume that Mt. Pinatubo left diffused around the globe in a matter of months. The data collected after this eruption showed that the mean world temperatures decreased by about 1 degree Centigrade over the subsequent two years. ( http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html) This caused a cooling effect of the Earth and it was welcomed by many scientists who saw it as a counter-balance to global warming. Although Mt. Pinatubo lay dormant for more than 500 years, geologists recognized some signs a few months before the eruptions. The full blow of Mount Pinatubo was quite unexpected. Over 50,000 people were forced to evacuate and two major military bases were closed. Several hundred lives were lost as a result of the Mount Pinatubo eruption. (http://earthobservatory.nasa.gov/Study/AstronautPinatubo)
EVENT TO SPHERE REACTIONS:
E>A The volcanic eruption of Mt. Pinatubo caused a dense thick “fog” or layer of gas in the atmosphere which caused low or no visibility in the surrounding areas of the eruption. The volcano erupted with such an intensely combustible force that volcanic ash, lava, and volcanic gases, {such as sulfur dioxide}, were spewed up and out for miles and miles into the atmosphere and onto the Earth making visibility very low or non-existent. (http://library.thinkquest.org/)
We have dense visibility in the atmosphere, sometimes on a daily basis, just not caused from a volcanic eruption, but a weather phenomenon called fog. When the atmosphere becomes saturated with moisture {saturation - when air contains as much water vapor as it can hold}; moisture becomes visible water droplets in the form of fog and clouds. The fog is the saturation of the atmosphere below 50ft of the troposphere and clouds from 50ft above the troposphere. (http://wings.avkids.com/Book/Atmosphere/instructor/clouds-01.html)
E>A The large and loud eruption of Mt. Pinatubo caused the atmosphere to be filled up with volcanic material, such as lava, rock, volcanic ash and volcanic gases (sulfur dioxide), which almost completely consumed the oxygen that was in the atmosphere. The eruption allowed this volcanic material to “spew” out into the atmosphere. The “spewing” out of the volcanic material came from the gaseous build up inside the Earth. Think about when you shake up a can soda and open it; the force that is built up from the carbonation inside the soda causes a combustion which spews the drink everywhere ( If you work with children, I am sure this is something common to your world, especially at snack time, Ha!). This is similar to the build up of gases in the volcano. When the gases build up with no where for the gas to escape to the eruption is louder, larger, and produces more materials that is sent out or “spewed” out of the volcano. (Http://library.thinkquest.org/) However, some volcanic gases may not be carried away, and instead settle to the ground. In 1986, carbon dioxide released from the Lake Nylos, a volcanic crater in Cameroon, settled in a nearby low-lying area, asphyxiating at least 1700 villagers and animals. (Http://www.cotf.edu/ete/modules/volcanoes/vhazards3.html)
E>A The volcano’s eruption can cause the atmospheric temperature to drop or cool dramatically. Gases and solids injected into the atmosphere cause a thick cloud of gas which blocks out the Sun for a period of time. When the Sun is blocked the temperature is not being warmed by the Sun’s rays. Think of when you working outside in the Sun at noon time. All of a sudden clouds began to roll in a what happens? When the clouds cover up the Sun the temperature or the air seems to feel cooler. It is cooler because the Sun’s rays cannot penetrate the cloud that is covering it up. (http://.wings.avkids.com/Book/Atmosphere/instructor/clouds-01.html) After the eruption of Mt. Pinatubo, in June of 1991, the sulfuric acid clouds encircled the Earth, resulting in higher levels of atmospheric sulfuric acid worldwide. The effect this had is that many of the Sun’s (heat energy and light) rays were absorbed, blocked, and /or reflected back into space. The result was cooler temperatures worldwide (NASA’s Earth Science Enterprise CD-ROM)
E>A An explosive eruption like Mt. St. Helens emitted a cloud of ash, rock, and gases with temperatures within the cloud of 500 degrees Fahrenheit. This intense heat was sufficient to kill, burn, and cause fires when it came in contact with anything in it’s path. (Http://www.cotf.edu/ete/modules/volcanoes/vnarrative2.html)
E>A
A volcanic eruption can have a warming effect on the Earth. The water and carbon dioxide released by a volcanic eruption, in gaseous form, absorb the heat radiation emitted from the ground and hold it in the atmosphere causing the air below to get warmer. This is generally local and short term. However, it could have a greater effect if there were multiple major eruptions over long periods of time. (Http://www.cotf.edu/ete/module/volcanoes/vclimate.html)
E>A The type of eruption can determine its effects on global cooling. Factors involved: include the amount of gases released, the strength of the blast, the angle from which the aerosols are ejected, and the latitude of the erupting volcano. When the gases are emitted from the side of a volcano, the majority of the released sulfur dioxide stays in the troposphere and is not widely dispersed. However, gases ejected vertically out of the top o f a volcano in an explosive blast are more likely to enter the stratosphere where they will be carried by the wind belts (i.e. the jet stream). Those wind belts, at high latitudes, tend to interact less with the wind belts elsewhere around the planet. However, there is a great amount of mixing of the wind belts at mid and low latitudes, so explosive volcanic eruptions there tend to have more of global effect on weather. (Welcome to NASA’s Earth Science Enterprise Activity Supplement). Mt. Pinatubo is at low latitude and it’s eruption had a major effect on global cooling. Not all large volcanic eruptions cause or contribute to global cooling. The eruption of El Chichon in southern Mexico, in 1982, seemed to have little global effect. However, scientist think this may be because El Nino (a Pacific Ocean weather phenomenon which causes worldwide weather variations) may have canceled out its effect. (NASA Fact Sheet: Volcanoes and Global Climate Change).
E>A The eruption of a volcano can send large amounts of volcanic material into the atmosphere suspending particles, such as dust and ash in the troposphere and stratosphere which can block the earth’s sunlight, thus reducing solar radiation and lowering global temperatures and causing a haze effect. The haze effect often generates exceptionally red sunsets due to the scattering of red wavelengths by submicron-size particles in the stratosphere and upper troposphere which led to beautiful sunsets worldwide. (Http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html)
E>A The volcano’s eruption would cause a reduction in the oxygen that is in the atmosphere. The gaseous clouds, made mostly of sulfur dioxide, would rise into the atmosphere completely consuming or greatly depleting the oxygen that is in the atmosphere. (http://earthobservatory.nasa.gov/Study?Volcano/)
E>A
The volcano’s eruption spewed volcanic material into the atmosphere causing further loss of the ozone ( a thin layer of a form of reactive oxygen). (http://library.thinkquest.org). When the eruption happened volcanic gases, made mainly of sulfuric dioxide, spewed upward into the troposphere and stratosphere where they converted to aerosols of sulfate particles. These aerosols (small particles of liquid and solid matter suspended in air) are thought to contribute to ozone loss.. The ozone is located in the upper stratosphere and when the cloud, from the volcanic eruption, formed and blocked the Earth from the Sun much of the sun’s heat energy and light rays were absorbed, blocked, or reflected back into space. The resulting cloud coverage encircled the Earth for two years, first in a narrow band, then dispersing outward. The ozone level over the polar region of the Southern Hemisphere reached the lowest recorded level. [NASA’s Earth Science Enterprise CD-ROM].
E>A The sulfur dioxide emitted from a volcanic eruption can reach the stratosphere where it converts to sulfuric acid. (http://earthobservatory.nasa.gov/Study/Volcano/) These aerosols are attracted by chlorofluorocarbon (CFCs) in the stratosphere which in turn intensify the destruction of ozone molecules. (NASA’s Earth Science Enterprise Activity Supplement) (http://earthobservatory.nasa.gov/Study/Volcano/) .
E>L After an eruption, fallen ash from the erupted volcano smothers everything it touches, but in the long term, it acts like a rich fertilizer for the soil and many crops. (Http://encarta.msn.com/encnet/repages/refarticle.aspe?refid=7615)
E>L Volcanoes produce lahars. Lahars are mud flows that consists of small rock particles, including sand and silt-sized particles. They can also transport large boulders. Lahars reshapes the landscape by forcing the formation of new river channels and damming new lakes. They damage everything in their path. (Http://volcanoes.usgs.gov/Haxards/What/Lahars/LaharTerm.html)
E>L Volcanoes produce lava. Lava is magma or molten rock that reaches to the Earth’s surface forced out from heat and pressure on the magma. The lava flow is a stream of lava that flows from a vent or opening in a volcano. The stream may be narrow or it may spread out wide. On steep slopes, some lava flows can reach speeds as high as 30 to 40 km per hour. As lava moves, it cools and hardens forming igneous rocks on the Earth. (Science Insights Textbooks. Addison-Wesley Publishing Company (1996). (Taylor, B. (1992). Mountains and Volcanoes, pgs. 45-53)
E>H Mt. Pinatubo affects Global Water Cycle. The presence of airborne materials from Mt. Pinatubo’s eruption affect the water cycle. These effects have been interpreted differently. Satellite observations initially showed a slight cooling, but later analysis implied warming. A warmer Earth speeds up the global water cycle (H): the exchange of water among the oceans, atmosphere and land. Higher temperatures cause more evaporation and soils tend to dry out faster. Increased amounts of water in the atmosphere will mean more rain or snow overall (H). http://clinton2.nara.gov/Initiatives/Climate/last100.html E>H We (the US) may be seeing the first signs of changes in the water cycle. Precipitation in the US has increased about 6%, while the frequency of intense precipitation events (heavy downpours of more than two inches per day) has increased by 20%. Such events can cause flooding, soil erosion, and even loss of life. In some midcontinental areas, increased evaporation has led to drought because the heavy rains fell elsewhere. http://clinton2.nara.gov/Initiatives/Climate/last100.html
E>H The June 1991 eruption of Mount Pinatubo was global. Slightly cooler than usual temperatures recorded worldwide and the brilliant sunsets and sunrise have been attributed to this eruption set fine ash and gases high into the stratosphere, forming a large volcanic cloud that drifted around the world. The sulfur dioxide (SO20 in this cloud – about 22 million tons) combined with water to form droplets of sulfuric acid, blocking some of the sunlight from reaching the Earth and thereby cooling temperatures in some regions by as much as 0.5 degrees C. An eruption the size of Mount Pinatubo could affect the weather for a few years. http://vulcan.wr.usgs.gov/Outreach/AboutVolcanoes/do_volcanoes_affect_weather.html
E>H Volcanoes Haze Cause Rain. Some research indicates a warmer Earth. Other research seemed to state the opposite. For Mt. Pinatubo, it was also said that the mild cooling effect of these eruptions helped to decrease the effect of global warming. The slight decrease in global temperatures in the few years following a volcanic eruption is caused by the presence of aerosols in the atmosphere. These particles are light in color and reflective in nature. This aerosol layer resembles a “haze.” The effects of this haze can cause increased rainfall and snowfall (H). The aerosols act as condensation nuclei upon which cloud droplets can cling, thus forming precipitation. The amount of moisture formation is proportional to the concentration of aerosols in the atmosphere. http://bigmac.civil.mtu.edu/home/classes/ce459/public/p14/climate.html
E>H Volcanic eruptions can cause tsunamis. Tsunamis are large sea waves that have long wave periods. Volcanic earthquakes and explosions produce these waves. Tsunamis transmit energy to areas outside the reach of the volcanic eruption itself. With volcanoes, the most efficient method of tsunami formation includes a disruption of a body of water by the collapse of all or part of the volcano, and explosion, landslide, avalanche, or an earthquake. In other words, shock waves due to rapidly moving volcanic material and lahars or pyroclastic flows have entered the sea. Earthquakes may accompany the volcano before, during, or after the eruption. If a landslide occurs on the shores of an island, due to lava flows and lahars, the volcanic materials will flow into the surface of the ocean causing the water above to be thrown into an up and down motion creating a series of large waves, tsunamis. As the tsunamis approach the shore of a nearby island, or the Volcano Island for that matter all the energy stored in the deep waves transfers upward. The waves height increase and huge breakers come crashing onto the shore one after the other. http://www.tsunami.org/faq.htm http://www.ngdc.noaa.gov/seg/image/geohazards_v3/document/648001.htm http://www/geo.mtu.edu/volcanoes/hazards/primer/sur.htm
E>H Glaciers Connection with Volcanic Actvity. It is suspected that very large volcanic eruptions may be associated with periods of glaciation on Earth. Research suggests that volcanic eruptions, coupled by cooling periods already in progress, may increase the effects of ice ages. http://bigmac.civil.mtu.edu/home/classes/ce459/public/p14/climate.html
E>H Volcanic gases are said to be the source of all the water (and most of the atmosphere) that we have today. The process of adding to the water and atmosphere is pretty slow, but if it had not been going on for the past 4.5 billion years or so we would be pretty miserable. Aerosols are tiny liquid and solid particles suspended in the air. These can come directly from volcanic eruptions. It is very difficult to form cloud droplets without small aerosol particles acting as “seeds” to start the formation of cloud droplets. According to theory, as aerosol concentration increases within a cloud, the water in the cloud gets spread over many more particles, each of which is correspondingly smaller. Smaller particles fall more slowly in the atmosphere and decrease the amount of rainfall. In this way, changing aerosols in the atmosphere can change the frequency of cloud occurrence, cloud, thickness, and therefore precipitation amounts. http://eospso.gsfc.nasa.gov/ftp_docs/Aerosols.pdf
E>H Another 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. We do not quite know how the lightning is caused but it probably involves the particles moving through the air and separating positively and negatively and negatively charged particles. http://volcano.und.nodak.edu/vwdocs/frequent_que
E>H Another problem that is seen in Hawaii’s involves the formation of vog, or volcanic fog. The ongoing eruption is very quiet, with lava flowing through lava tubes and then into the ocean. Up at the vent is an almost constant plume of volcanic fume that contains a lot of sulfur dioxide. This SO2 combines with water in the atmosphere to form sulfuric acid droplets that get carried in the trade winds. http://volcano.und.nodak.edu/vwdocs/frequent_questions/top_101/oldEffects.html
E>H The eruption of volcanoes causes vog (volcanic fog) and leads to acid rain. Most gases released during eruptions of volcanoes consist of water vapor, which condenses as steam. Other gases such as carbon dioxide, sulfur dioxide, hydrogen sulfide and hydrochloric acid are also given off. Inside the volcano, when pressure is high, the SO2 is dissolved in molten rock or magma. When it rises toward the surface the SO2 escapes. (SO2 is a poisonous gas that irritates the skin and tissues and mucous membranes of the eyes, nose, and throat.) When sulfur dioxide is mixed with oxygen and water, or moisture, in the atmosphere it produces volcanic smog, called vog, and acid rain. Vog is a visible haze consisting of gas plus a mixture of tiny liquid and solid particles called aerosols. The aerosols in vog are composed of sulfuric acid and other sulfate compounds. Combined with the moisture in the atmosphere tiny sulfuric droplets are formed and fall as acid rain. Acid rain is a term coined by Robert Smith, a British chemist in 1872, to describe the nature of precipitation containing significant sulfuric acid. So the term describes precipitation including rain, sleet, hail, and snow that is acidic. According to James R. Craig, author of “Resource of the Earth,” it appears that natural phenomena such as volcanoes result in more sulfuric oxides in the atmosphere than human activities. http://snrs.un1.edu/amet498/drake/effects.html http://geopubs.wr.usgs.gov/fact-sheets/fs169-97 http://davem2.cotf.edu/mtpe/courses/idaho/isphere/isvolcanoes/0029.html
E>H Lahars (also called volcanic debris flows or mudflows) are mixtures of water-saturated rock debris that flow down slope under the force of gravity. Rocks within a volcano may be saturate, or water may be supplied by rainfall, by rapid melting of snow or ice, or by a debris-dammed lake or Crater Lake. Mudflows or debris flows are composed mostly of volcanic materials on the flanks of a volcano are called lahars. These flows of mud, rock, and water can rush down valleys and stream channels at speeds of 20 to 40 miles per hour and can travel more than 50 miles. Some lahars contain so much rock debris (60 to 90% by weight) that they look like fast-moving rivers of wet concrete. Close to their source, these flows are powerful enough to rip up and carry trees, houses, and huge boulders miles downstream. Farther downstream they entomb everything in their path in mud. http://vulcan.wr.usgs.gov/Glossary/Hydrology/description_hydrologic_hazards.html
E>H The melting of snow can produce floods related to volcanoes and ice during eruptions of ice-clad volcanoes, by heavy rains that may accompany eruptions and by transformation of lahars to stream flow. Floods carrying unusually large amounts of rock debris can leave thick deposits at and beyond the mouths of canyons and on valley floors leading away from volcanoes. Eruption-caused floods can occur suddenly and can be of large volume; if rivers are already high because of heavy rainfall or snowmelt, such floods can be far larger than normal. http://vulcan.wr.usgs.gov/Glossary/Hydrology/description_hydrologic_hazards.html
E>H In active volcanic areas, groundwater can affect intrusive and eruptive activity by influencing cooling rates, modifying the strength of rocks in the volcanic edifice, and converting thermal energy of magma to explosive mechanical energy. One of the greatest hazards posed by groundwater exists when it is heated by magma and violently released, as eruptions of either pure steam or steam mixed with fragmented magma or country rock. http://vulcan.wr.usgs.gov/Projects/Mastin/framework.html
E>B The most serious nearby environmental effect is the burial of either ash, mud, or lava. In many cases these materials bury the area under tens of meters. Anyone or anything caught by them would be killed. At Mt. Pinatubo the huge amount of ash deposited high on the slopes has caused way more damage to the lower areas than the original eruption did.
E>B Volcanoes effect people in many ways, some are good, some are not. For example, volcanoes affect people in a negative way when their houses, building, roads, and fields are covered by ash. The heavy amount of ash can cause houses to collapse. Therefore, people lose their homes due to the event. A positive way the volcanoes can help people is that it can produce very rich soils for farming. Therefore, the volcano helps farmers by providing food and income. Http://volcano.und.edu
E>B The event of a volcano eruption can cause negative effects on livestock and other mammals. For example, lava flows, pyroclastic flows, tephra falls, atmospheric effects, gases and tsunami can kill livestock and other mammals. They can also die from famine, forest fires, and earthquakes caused by or related to the eruptions. Aquatic life can also be affected by the eruptions due to an increase in acidity, increased turbidity, change in temperature, and/or a change in food supply. These factors can damage or kill fish. Therefore, causing a problem in the food chain. Eruptions can also influence bird migration, roosting, flying ability, and feeding activity. Thus, causing a problem in the life cycle of a bird. The impact of eruptions on insects depends on the size of the eruption and the stage of growth of the insect. For example, ash can is very abrasive to wings. The entire negative affects on the livestock and mammals could cause problems for humans as well. For example, the lack of livestock and mammals could put a damper on the food chain for humans. The fires that result from the eruptions could destroy all crops, vegetation and plant life in that area. Therefore, food supplies would be diminished. http://pubs.usgs.gov./gip/volc/people.html
E>B When a volcano erupts, it will literally kill any organisms in its path. Dust and smoke will snuff out the air in immediate areas choking living organisms. Boiling hot liquid lava will disintegrate any being in its path. Secondary effects of a volcanic eruption on life forms would be that lava and dust would destroy habitats making it impossible for living things to survive even if they survive the initial eruption. http://volcano.und.edu
E>B Dust, smoke, ash, and debris from volcanic eruptions can cause severe secondhand effects on civilization. For example, dust from the eruption could cause different lung diseases and illnesses as well as different complications involving organisms with respiratory tracts. The different types of debris from the eruption could cause people and animals to have problems breathing, therefore, if it is not taken care of people and animals could parish.
E>B Mudflows can damage the biosphere in many ways. For instance, mudflows can occur when rain falls through clouds containing high levels of ash or when waters are dammed during an eruption. The flows could wipe out huge sections of crops, vegetation, plants, and animals. All of these sections are useful to humans in a variety of ways. Therefore, the food chain and life cycles of the biosphere would be affected. http://volcano.und.edu
E>B Volcanic eruptions have a negative effect on animals. For example, for the animals that do survive the eruption their food chain is affected. Their drinking water is contaminated from all the gases and debris. Therefore, any animal that drinks from the water source will die. The aquatic animals also suffer from this because of the acidity in the water. http://volcano.und.edu
E>B Volcanic eruptions also release toxic gases. Therefore, it will have an affect on the entire biosphere. The cracks in the ground after an eruption enable gases to escape. Some of the gases the are released are carbon dioxide, sulfur dioxide, hydrogen sulfide, and hydrogen. The combining of water droplets and sulfur dioxide then produces acid rain. Thus, contaminating all water supplies for animals and people. Vast amounts of carbon dioxide can also be detrimental to people and animals.
E>B A positive effect of volcanic eruptions to plants is that the ash from the eruption can provide nutrients to the surrounding soil. The volcanic ash contains minerals that are very beneficial to plants. Therefore, the plants will be able to regenerate and thrive. http://volcano.und.edu
SPHERE TO EVENT REACTIONS:
A>E The atmosphere is made up of many layers and our climate is directly related to these layers. (http://csep10.phys.utk.edu/astr161/lect/earth/atmosphere.html) Wind caused from unstable atmospheric pressure, at the time of a volcanic eruption, could cause winds to spread the volcanic material even further than the combustion of the eruption. The winds produced from the unstable airmass could cause volcanic gases to spread to all layers of the atmosphere thus blocking out the sun for hours. (http://library.thinkquest.org/17457/volcanoes/effects.pinatubo.php) Millions of tons of ash can be carried by winds for hundreds or thousands of miles. (Http://www.cotf.edu/ete/modules/volcanoes/vnarrative2.html)
A>E Winds, produced in the atmosphere, can increase or diminish the effect of an explosive volcanic eruption. If the ash is carried, carried by the wind, is then dropped into populated areas the effects on people, machinery, and crops can be intensified. (Http://www.coft.edu/ete/modules/volcanoes/vnarrative3.html)
A>E If the unstable atmosphere produced rain at the time of the eruption, water droplets and sulfur dioxide, carbon dioxide, hydrogen sulfide and hydrogen would mix producing acid rain. (Http//library.thinkquest.org/) (Http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html)
A>E The air in the atmosphere, can be cooled or heated from many weather changes, seasons, clouds, etc. (Http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html) and (http://www.wings.avkids.com/Book/Atmosphere/instructor/clouds-01.html) and with this cooling effect the air could, perhaps, cool the volcano, especially the lava, over a period of time.
B>E People use volcanic products as construction materials. Some of these materials are used as cleaning agents and as raw materials for many chemical and industrial uses. The internal heat associated with some young volcanic systems has been harnessed to produce geothermal energy. http://pubs.usgs.gov
B>E The Isle of Surtsey didn’t exist until 1963. A volcano under the sea erupted causing and island covering 2.4 Km to grow. The highest point is 170 m above the sea. Geologists found that in only two years’ time, the island was already inhabitant by many birds, insects, and plants. http://www.oink.demon.co.uk/topics/vframes.htm
L>E: It is the activities of the lithosphere that produced Pinatubo. Because the Philippine plate is being pushed under the Asian plate, the subduction zone created the Philippine Islands and their stratovolcanoes. The sinking of the oceanic plate into the athenosphere generates magma under the continental crust. As the magma builds, it rises through the crust to form volcanoes. Because the magma in subduction zones is very thick, most of the volcanoes in these areas are stratovolcanoes, produced by repeated and explosive eruptions.
L>E: The mantle of the earth contains magma, or partially melted rock. This same mantle supports seven large plates and over 20 smaller plates of the lithosphere, commonly referred to as plate tectonics. These plates, because they sit atop the fluid or semi-fluid magma, are moving at a rate of a few inches per year. Sometimes these plates collide or are forced apart. When this occurs, the mantle is weakened, and when magma escapes from these open areas, new material is added to existing plates and also the magma. The material added to the magma, along with the already present carbon dioxide, steam, nitrogen and hydrogen, form a reservoir of magma near the surface of the earth. As these gases and material expand, pressure builds. This action forces the magma to a weak area or an existing area on the earth's surface. Koeth,R.(1988). Volcanoes. Poyner,M,(1982). Volcanoes: The fiery mountains. 89
H>E Some research suggests that periods of glaciation may cause volcanic eruptions. It is suggested that hydrostatic unloading of the ocean basins during glaciation favors the upward movement of magma and thus may lead to volcanism. During periods of glaciation, oceans are typically smaller and shallower, since a large portion of the available water is frozen in a glacier. Since the oceans has less burden on them, the plates underlying them may shift, which could trigger deep magma bodies, and reactivate them and the fault systems associated with them. This is one way how volcanism might be caused. http://bigmac.civil.mtu.edu/home/classes/ce459/public/p14climate.html
H>E Many of the Earth’s volcanoes are under the sea. The Earth’s crust under the oceans is relatively thin, about 3 miles, compared to the continental crust, which is between 20 and 40 miles thick. Magma is able to force its way up through the thin crust, particularly at plate edges. The hot molten lava explodes when it hits the cold seawater. The cold water cools the molten lava and thus islands can form. In November 1963, a fisherman saw a great column of smoke and ash rise from the sea southwest of Iceland. The next day a new island appeared and it continued to grow. An erupting volcano that was cooled off by seawater cause H>E The eruption of a volcano can produce many interesting features, especially when cooled off by water. When lava flows into the ocean, it is quickly cooled into a shape known as pillow lava. Volcanoes by Paul P. Sipiera
H>E Volcanic bombs can occur if water is present in lava during an eruption. A volcanic bomb is when fragments of rock are hurled into the air. This rock includes pieces of hard, solid rock that is ejected during an eruption. These volcanic bombs can travel for miles into nearby cities and towns.
H>E Rainfall after an eruption can cause numerous problems. The rainwater can mix with fallen ash to cause dangerous flows of mud. After the eruption of Mount Pintubo, mudflows engulfed roads, bridges, and several villages. Not only was the eruption bad enough but the rainfall caused even greater destruction. Closer look at Volcanoes by Jen Green.
CAUSAL CHAINS (SPHERE TO SPHERE REACTIONS)
E>A>B>H The eruption of the volcano would cause volcanic material, such as dust, ash, and volcanic gases to spread into the atmosphere, blocking the sun and causing the surface temperature of the Earth to cool, as well as, the volcanic material would consume or deplete the oxygen in the atmosphere directly surrounding the volcano, which would make it hard for living things to breath. Death could come from this. (http://earthobservatory.nasa.gov/Study?Volcano/) (http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html)
E>A>H The volcanic eruption would cause severe secondhand effects when rain falls through the clouds that contain this volcanic mixture of sulfur dioxide, carbon dioxide, hydrogen sulfide, and hydrogen would mix causing acid rain to fall and contaminate all the water supplies for all living things.
E>A>L A volcanic eruption would send all types of volcanic material into the atmosphere therefore disturbing the atmospheric pressure causing weather patterns to be effected greatly for years to come which, of course, could cause rain and wind to fall or blow the volcanic material onto the land causing contamination of the soil. (http://library.thinkquest.org/) (http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html)
L>H>B>A>B>L>B Tectonic plates, which have been pushing against each other for years, adds new material to the magma already beneath the plates. After so much new material has been added, expansion of the magma coupled with various gases formed from melted material, applies enormous pressure to a weak area in the lithosphere and magma is forced out of the opening. Any moisture in the material is quickly converted to steam from the intense heat of the material. Magma also contains non-poisonous gases such as carbon dioxide and chlorine are also contained in the magma and these gases are lethal to living organisms. Large amounts of sulfuric gas expelled into the atmosphere can cause a chemical reaction in which clouds can produce drops of sulfuric acid or acid rain, which is harmful to all living organisms. These same clouds not only absorb sunlight, but reflect the light back into space because of its density. As the gases are lighter than the magma, they are emitted into the atmosphere before the magma reaches the surface and transforms into lava. Depending on the amount of gases contained within the magma, eruptions may be subtle or violent. The more gas in the magma, the more violent the eruption and vice versa. In the majority of volcanic eruptions, pieces of tephra or ash are emitted into the atmosphere as well. Large amounts of ash can absorb heat from the sun, which in turn can cause lower surface temperatures and affect living organisms such as plant growth. On the upside, a small amount of time transforms ash into fertile soil because as contains nutriucious plant food such as phosphorus, potassium and calcium. Source: Harris,S.(1979).Volcanoes.Franklin Watts:NY.
E>L>H>B: When a volcano erupts near the sea or ocean, it sends debris-avalanches down the slopes into the water causing tsunamis, which are extremely dangerous and deadly to humans, animals, and structures in its path. Tsunamis are large sea waves that have long wave periods. With volcanoes, the most efficient method of tsunami formation includes disruption of a body of water by the collapse of all or part of the volcano, landslide or debris avalanche. These debris avalanches carry volcanic material such as ash (small fine rock particles that will not dissolve in water), lava(magma that reaches the Earth's surface), and large boulders. These debris avalanches can be caused by pyroclastic flows(hot mixtures of volcanic fragments that sweep along close to the ground) and lahars(mudflows caused by a mixture of volcanic debris and melted snow and ice). The rapidly moving volcanic material from pyroclastic and lahars flows, which can include huge boulders, entering the sea, therefore, cause shock waves known as tsunamis. These shock waves work like when throwing a stone in a pond. When you throw the stone in the water it creates a ripples. A tsunami is like the ripples, set by the stone, except these are massive amounts of material setting off huge ripples. For example, when volcanic debris enters the sruface of the ocean it causes the water above to be thrown in an up and down motion creating a series of large waves, hence tsunamis. As the waves in the tsunami reach shore, they slow down due to the shallowing sea floor, and the loss in speed is accompanied by a dramatic increase in wave height. The waves scrunch together and heave upward. Theses waves can sometimes empty harbors leaving fish to die in the mud and then return with a huge wave crashing 50 to 1000 feet inland. These tsunamis crush homes and buildings. They also drown people and animals in its path. For example, the most recent volcanic eruption that caused a tsunami occurred on the island of Krakotoa in the Western Pacific. The island was composed of three supposedly inactative volcanoes, which erupted in 1883. The Indonesian island which was 800 meters above sea level was blown apart leaving only one third of the island. This eruption caused 13 cubic kilometers of rock to collapse into the subsurface of the magma chamber. This caused an up and down movement in the water causing waves to form one after another. On the islands of Krakatoa and Java nearly 30,000 people died due to the tsunamis generated by the volcanic eruption, debris avalanche and a portion of the mountain collapsing . http://visearth.ucsd.edu/ http://www.aolsvc.worldbook. Casual Chains Listed: (Volcanoes & Atmosphere)
SUMMARY
Volcanoes are one of nature’s phenomenal events that cause mass destruction and lasting effects on the Earth, all of the Earth’s spheres. Volcanoes leave reminders that we are only human and there are some things that we cannot control, no matter how powerful we may be.
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