Volcanic Eruption and Climate Change

8/11/2019 Volcanic Eruption and Climate Change

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Volcanic eruption and climate change

Volcanic eruption, it triggers fear when it is mentioned. This shows how bad the effect of

volcanic eruption can cause to human being, or even worst, the environment that we have been

living in for millions of years. To be precise, volcanic eruption is a sudden occurrence of violent

discharge of large amount of hazardous particles, such as larvae and steam into the environment.

The steam released constitute of sand particles, fine and course, carbon dioxide, hydrogen

sulphide, water vapour, sulphur dioxide and some other harmful materials. A volcano is a place

on earths surface where hot molten rocks break. A vent or chimney connects the magma from

the earths crust to the earths surface. There are three major types of volcanoes that exist in the

world, which are active volcanoes, dormant volcanoes and the extinct ones. They are classified

by their frequency of eruption. Active volcanoes are those that erupt continuously or regularly.

Dormant volcanoes are volcanoes that erupted in historical times but are now more quiet and the

frequency of eruption is much more lesser than the active ones whereas extinct volcanoes are

those which erupted in historical times but is now considered unlikely to erupt again. Just likehot air, the hot molten rocks have lower density than the crustal rocks. This is due to the long

period of heating effect by the means of convection within the crust. As what we all know, the

pressure within the crust is tremendously high. All these sum up to the great increase of

temperature of magma. After exceeding a certain limit, magma breaks through the vent and

flows into the environment. What control the violence of an eruption? This has been studied by

geologist for years and they came out with some conclusions. Volcanoes are characterised by

different eruptions and styles, from effusive eruptions where the lava is outpoured on to the

ground to explosive eruptions where volcanic lava blocks and ashes are ejected into the

atmosphere with high speed. These are all controlled by the pressure in magma chamber,

viscosity of the magma and the diameter of the conduits of volcanoes.

Volcanic eruptions release large amount of carbon dioxide into the environment. Carbon dioxide

is one of the greenhouse gasses. What are greenhouse gasses? During old times, when sunlight

strikes the earths surface, some of it is reflected back to the outer space by the surface. This

helps in maintaining the desirable temperature of the surface of the earth for all organisms to live

in. However, as time passes, carbon dioxide concentration in the atmosphere increases gradually

due to anthropogenic activities and volcanic eruptions. Heat from the outer space is absorbed and

trapped within the greenhouse gasses, disabling it to be reflected back to outer space. Overtime,

this increases the temperature of the earths surface causes global warming to take place and

eventually climate change. Is this what we want our future generation to go through? Nowadays,

global warming is a major issue widely discussed by people all around the world. They believe

that this is the main cause that endangers the environment. Global warming leads to some main

subject matters. It causes ice caps in poles to melt and hence increases the sea level at some

regions. Flood is then happened at areas where it was never a problem encountered by them

before. This problem worsens when sinking of islands which are at lower attitudes occurs. For an

example, Maldives is an island that is just barely above the sea level. It is now undergoing the


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Another volcanic hazard is the pyroclastic flow formed. . A pyroclastic flow is a concentrated

avalanche of material, formed from an eruption of volcano. It is a fast moving superheated gas.

Because of its high proportion of gases to rocks, it can travel far can fast and somehow causes

disaster to happen. It flattens trees and forests by destroying them or burying them underneath.

Pyroclastic flows are more likely to follow valleys and other depressions, and their deposits infill

this topography. This can be related to the history of Pompeii. Pyroclastic flows of poisonous gas

and hot volcanic debris engulfed the cities of Pompeii, suffocating the inhabitants and burying

the buildings. The cities of Pompeii remained buried and undiscovered for almost 1700 years

until excavations continue today and provide insight into the life during Roman Empire. Think

about it, when cities disappear from the Earths surface, species of animals will undergo

extinctions. Mass extinctions will soon take place. The sudden changes of the surroundings cause

animals to have not enough time to adapt and soon be eliminated from the nature.

In addition, volcanic emissions give out a great amount of hazardous gases, such as H2S, SO2

and etc. sulphur contained gases can quickly oxidize to sulphur dioxide once they are given out

into the stratosphere, which is the lower part of the atmosphere. This gas magnificently affects

the chemical composition and the optical properties of the stratosphere. Sulphur dioxide absorbs

ultraviolet and infrared radiation, producing very strong localized stratosphere heating. It will

abrupt the temperature of the Atmosphere. Because of the properties of the sulphur, they are

quickly attached to the acid aerosols in air to form aerosols clouds. This will not only cause acid

rain, but will also leads to serious air pollution and hence change in climate. Sulphur dioxide

droplets take several years to settle out and they are capable to decreasing the troposphere

temperatures because they absorb solar radiation and scatter it back to space. Together with the

global warming effect caused by volcanic eruptions stated above, its well proven that volcanic

activities totally disturb the balance of the temperature of the earths surface. It causes someregions to undergo changes that they never experience before. Example of region that went

through global cooling is area around Laki volcano. The eastern U.S. recorded the lowest-ever

winter average temperature in 1783-84, about 4.8OC below the 225-year average. Europe also

experienced an abnormally severe winter. Benjamin Franklin suggested that these cold

conditions resulted from the blocking out of sunlight by dust and gases created by the Iceland

Laki eruptionin 1783. The Laki eruption was the largest outpouring of basalt lava in historic

times. Franklin's hypothesis is consistent with modern scientific theory, which suggests that large

volumes of SO2 are the main culprit in haze-effect global cooling.

Other than that, due to the large amount of dangerous chemical compositions is released duringeruptions, water pollution can be induced. This often happened to the rivers and oceans which

are near to the area of volcanoes. Water pollution is the contamination of water by hazardous

chemicals. Dont u know that rain is formed due to the evaporation of ocean and rivers water?

So when the polluted water rises to the air, it will disturb the whole water cycle. Effect of acid

rain is enhanced. Acid rain damages forest and soil. As what we all know, forest is a huge carbon

sink. It helps in maintaining the temperature of the Earths surface by taking in greenhouse gas


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such as carbon dioxide to lower the effect of global warming. When forests are gone, imagine

how will these affect our environment?

In addition, volcanoes can induce the happening of tsunami. When a land-based volcano is breakdown and collapse after an eruption, large amount of ash and debris is forced into the water. This

sudden change and displacement of water columns transfer to kinetic energy and waves are

resulted. Tsunami can also be induced by volcanoes which are under the ocean. When

underwater volcanoes erupt, large amount of heat is given out and this causes the ocean to be

heated up. There goes tsunami happening due to the fast and random motion of water molecules.

Tsunamis are some of the most devastating natural disasters known to man. Think of a flood

with its source being an ocean and you can grasp a little of how much devastation tsunamis can

create. The force of it is able to sweep away everything that in its path, building or even worse

forests. Forests are previous reservoir to mankind. It compensates all the carbon dioxide given

put by anthropogenic activities. Forests are large carbon sink that we could ever ask for. The lossof forests cause by tsunamis enhances the changes of climate in a bad way. Last but not least,

when a tsunami wave comes ashore, it can affect a huge area of land, transforming the landscape.

Tsunami wave throws salty seawater over the land. Too much salt is bad for living things, so if

soil becomes too salty, crops cannot grow or will not grow well. The force of a tsunami can also

ruin pipelines and factories. This lets out sewage, oil, or dangerous chemicals into the

environment. It can take many years. for the environment to restore back to normal.

Many areas at risk from earthquakes also face the threat of volcanic eruptions. More than 500

million people live close to the 550 active volcanoes areas on the Earth. The term active for

volcanoes is actually misleading, though as volcanoes thought to be extinct and is finallybringing spring to life. The danger of dormant volcanoes is never predictable. The obvious

example is Mountain Pinatubo in Philippines. It was recorded that its last few eruptions before

the one in 1991 was few hundred years ago, is now one of the most disastrous eruptions. Based

on research done by the experts, about 60 volcanic eruptions occur on land each year, but this

represents only about 20% of the total activities. This shows that volcanic eruptions are

unpredictable. Hence, ways in preventing damage caused by volcanic eruptions must be done.

Prevention is better than cure. Moreover, the damage caused by the eruptions is sometimes

beyond our expectation. We must all do something about it to make the world a better place.

Inventions of new ways to avoid losses due to eruption must be done and scrutinized by

everyone. Knowledges by all matters to make this happens, no one should be left out in this.

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Volcanic Eruption and Climate Change