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From: Cat
Date: 10/6/02
Time: 11:50:07 PM
Remote Name: 212.140.117.108
The Atmosphere & Volcanoes
Information on Specific Sphere 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.
Volcanoes:
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 out-poured 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. 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.
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. 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.
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 of 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/)
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) Winds 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 and clouds of dust and volcanic material 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 by the wind and 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.
SUMMARY Volcanoes are one of nature’s phenomenal events that cause mass destruction and lasting effects on the Earth and 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.
Resource/Bibliography: http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html http://www.daac.gsfc.nasa.gov/CAMPAIGN_DOCS/ATM_CHEM/atmospheric_structure.html http://csep10phys.utk.edu/astr161/lect/earth/atmosphere.html http://library.thinkquest.org/17457/glossary/glossary.html http://library.thinkquest.org/ http://earthobservatory.nasa.gov/Study/Volcano/) http://wings.avkids.com/Book/Atmosphere/instructor/clouds-01.htlm http://www.ace.mmu.ac.uk/Resource/Teaching_Packs/Key_Stage_3/Air_Quality/information.html http://library.thinkquest.org/17457/volcanoes/effects.pinatubo.php http://www.cotf.edu/ete/modules/volcanoes/vclimate.html) Http://www.cotf.edu/ete/modules/volcanoes/vnarrative3.html) http://www.cotf.edu/ete/modules/volcanoes/vnarrative2.html)
Welcome to NASA’s Earth Science Enterprise Activity Supplement NASA Fact Sheet: Volcanoes and Global Climate Change NASA’s Earth Science Enterprise CD-ROM NASA’s Earth Science Enterprise Activity Supplement