Volcanoes-Enviromental Hazards,Effects and Remedies

8/6/2019 Volcanoes-Enviromental Hazards,Effects and Remedies

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VOLCANOGroup-8 Presents

A Q E E L - 0 7S A L A R- 1 7RI A Z - 2 3H A RO O N - 1 2

SHAMSHAD-02MANNAN-49 ( s )ASAD ( s )


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VOLCANOGroup-8 Presents

A Q E E L - 0 7

S A L A R- 1 7RI A Z - 2 3H A RO O N - 1 2

SHAMSHAD-02

MANNAN-49 ( s )ASAD ( s )


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Volcano

---is an opening ora vent through

which magmaand

the dissolvedgases in it are.discharged

Magma ( - )a red hot liquid rock inside the earth


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CAUSES


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,During subduction the subductedoceanic plate is heated as itplunges into the mantle and at

- ,depth of 80 120 km melting beginsand volcanoes are produced whichare parallel to the subduction.zone

Subduction zones


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Hot spots

Magmas at hot spotsare derived fromdeep within the.mantle

The magmas are fed bydeep mantle plumeswhich are stationary

relative to thedrifting tectonic

.plates


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Plate tectonics and

volcanism


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Global distribution of volcanoes


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TYPES

Up to 30 Degree slope

Less than 10 Degreeslope

30-40 Degree slope


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VOLCANIC ERUPTIONS Non-explosive Eruptions Low gas content and low viscosity

magmas

basaltic magmas

If the viscosity is low, non-explosive eruptions usually

begin with fire fountains due torelease of dissolved gases.

Lava flows are produced on thesurface and these run likeliquids down slope.

If the viscosity is high, but the gas

content is low, then the lavawill pile up over the vent toproduce a lava dome orvolcanic dome.

Explosive Eruptions High gas content and high

viscosity

Andesitic to rhyolitic magmas

Explosive bursting of bubbles willfragment the magma into clots

of liquid that will cool as theyfall through the air. These solidparticles becomepyroclasts(meaning - hot fragments) andtephra orvolcanic ash, whichrefer to sand- sizedor smaller

fragments


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HAZARDS

Size of eruptionComposition of eruptionEnvironment of eruption

Primary hazards:

Lava flow

Pyroclastic flows /surges

Ash and tephra fall

Gases

Volcanic earthquakes

Secondary hazards:

Lahars & landslides

Acid rain

Tsunamis


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Destroy immobile object in( , )path houses roads Deaths by lava flows are

( )uncommon move slowly

Block roads and highways Bury homes and agriculturalland

,Dam rivers change river

, ,courses kill resident fish

act as a barrier to.migrating fish

LAVA FLOWS


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PYROCLASTS

, ,Extremely destructive destroy buildings,trees or any objects in their path by,impact burial or fire

,On margins of pyroclastic flows death andserious injury to people and animals may

result from burns and inhalation of hot.ash and gases

Pyroclastic flows may also interact with.snow and ice to generate lahars


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Transportation

BuildingsCommunicationHealth

Power facilities and distribution systemsAgriculture Waste Water systems

ASH FALL


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Ash Transportation

Poor visibility Airborne ash can obscure

sunlight to cause

temporary darkness andreduce visibility to zero During such conditions

vehicle headlights andbrake lights are often

ineffective and barelyvisible to other drivers

Roads & Highways


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Slippery surface When ash on roads become

, -wet the mud like mixturecan cause vehicles tolose traction and drivers

to lose control of.steering

,During such conditionsthe braking ability of

vehicles may besignificantly reduced

Ash Transportation

Roads & Highways


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Road markings covered Ash deposits thicker than about 1 mm will

obscure or completely cover markings on

, ,roads that identify lanes road shoulders,direction of travel and instructions to( , ).drivers for example stop or slow

, When such road markings are not visibledrivers may become confused and

.disoriented

Ash Transportation

Roads & Highways


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&Abrasive clogging effect on vehicles Brakes and moving parts of vehicles are

vulnerable to abrasion and clogging from

. , -ash Also the tiny ash easily clog air,filtration systems on vehicles which canlead to overheating and engine failure

Ash Transportation

Roads & Highways


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-Deposition of material on hot section.components

-Erosion of compressor blades and rotor path.components

Blockage of fuel nozzles and cooling.passages -Contamination of the oil system and bleed

.air supply .Opacity of windscreen and landing lights .Contamination of electronics

.Erosion of antenna surfaces -Plugging of the pitot static system whichindicates the airspeed of the aircraft

Ash Transportation

Aircraft


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Damage to buildings andbuilding systems fromvolcanic ash can

range from completeor partial roof

collapse leading towidespread injuries

and deaths to lesscatastrophic damage

of exterior materials,and interior rooms

including appliances,and computers floor,coverings andelectrical andmechanical systems

Ash BUILDINGS


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Electrically charged ash can cause

interference to radio waves and renderradio and telephone systems inoperative

Any ash entering telephone exchanges can, ,cause abrasion corrosion or conductivity

damage to electrical and mechanical

systems . .During most natural disasters i e volcaniceruption telephone and radio

communications are susceptible tooverloading by public and emergency.services use

Ash

COMMUNICATION


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nasal irritation ,throat irritation and sore throat sometimes accompanied

by dry coughing -people with pre existing chest complaints have developed

severe bronchitic symptoms which lasted some days beyond( , , ,exposure to ash for example cough wheezing or

)shortness of breath ;airway irritation of people with asthma or bronchitis

common complaints of people with asthma include, ,shortness of breath wheezing and coughing

breathing becomes uncomfortable

Ash HEALTH


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Eye symptoms eyes feel irritated sticky discharge or tearing corneal abrasions or scratches inflammation of the eye sac that surrounds the eyeball

, ,due to the presence of ash which leads to redness,burning of the eyes and photosensitivity

Ash HEALTH


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Free crystalline silica in volcanic ash Volcanic ash may contain varying proportions of free( , )crystalline silica silicon dioxide SiO2 in the form of

, , .quartz cristobalite or tridymiteminerals Exposure torespirable particles of free crystalline silica can lead,to silicosis a disease resulting in scarring of the lungs

.and impairment of their function

Ash HEALTH


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. .Ash falls destroy pastures i e no food will be

available to the livestock -Natural water sources and man made ponds may be

, -temporarily contaminated by ash and waterpumping equipment can be damaged by the abrasive

.rock particles Ash falls may be poisonous to livestock and result

, ,in clinical diseases including hypocalcaemiafluorosis and intestinal damage and secondarymetabolic disorders

Ash AGRICULTURE


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Ash from Etna

volcano on thesurface ofcitrus fruit

made ituneconomical to

produce juicebecause it wastoo expensive toclean the fruit

( )image courtesy of La Sicilia


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( Waste water systems sewage and storm

)water are vulnerable to damage fromvolcanic ash because the tiny rock,fragments can block pipes and canals

increase wear on pumps and other-machinery and interfere with water

.treatment processes

Ash WASTE WATERSYSTEM


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,The different volcanic gases effect the earth

.people and animals in different ways

:Some are discussed below Carbon dioxide

Sulfur dioxide

Chlorine .Fluorine

EFFECTS OF VOLCANIC

GASES


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Carbon dioxide can add to the effects of global.warming which contributes to the greenhouse effect

Carbon dioxide behaves like a glass shield over the

.earth The sun's rays penetrate the carbon dioxide gas butthe carbon dioxide shield prevents heat from

.escaping into the atmosphere Volcanoes contribute about 110 million tons of carbon

.dioxide per year

Carbon dioxide

(Greenhouse effect)


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Volcanic eruptions enhance the haze effect to

,a greater extent than the greenhouse effectand thus they can lower mean global.temperatures by sulfur dioxide gas

,In the cold lower atmosphere it is convertedto sulfuric acid by the sun's rays reacting

with stratospheric water vapor to form.sulfuric acid aerosol layers The aerosol remains in suspension long after

solid ash particles have fallen to earthand forms a layer of sulfuric acid droplets

.between 15 to 25 kilometers up

Sulfur dioxide Haze effect


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Chlorine is emitted from volcanoes in the

( ),form of hydrochloric acid HCl whichbreaks down into chlorine and chlorine( ) .monoxide ClO molecules

The sulfate aerosols furnish sites forchemical reactions that release the

.chlorine atoms The reactive chlorine atoms proceed to

,destroy ozone with each chlorine atom being.recycled many times

Chlorine ozone depletion


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Fluorine gas can condense in rain or on ash

particles and coats grass and pollutes.streams and lakes with excess fluorine -Animals that eat grass coated with fluorine

.tainted ash are poisoned ,Small amounts of fluorine can be beneficial

,but excess fluorine causes fluorisis anaffliction that eventually kills animals by.destroying their bones

Fluorine Fluorisis


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Acid rain is a rain or any other

form of precipitation that is,unusually acidic meaning that it

possesses elevated levels of( ).hydrogen ions low pH

H2O (l) + CO2 (g) H2CO3 (aq)

H2O (l) + H2CO3 (aq) HCO3 (aq) + H3O

+ (aq)

ACID RAIN
http://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Hydrogen


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Soils Soil biology and chemistry can be seriously

.damaged by acid rain Some microbes are unable to.tolerate changes to low pHs and are killed The

(enzymes of these microbes are denatured changed

) .in shape so they no longer function by the acid The hydronium ions of acid rain also mobilize,toxins such as aluminium and leach away

essential nutrients and minerals such as.magnesium

ACID RAIN-

EFFECTS


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Forests and other vegetationHigh altitude forests are especially

vulnerable as they are often surroundedby clouds and fog which are more acidic

.than rain

Effect on food crops is minimized bythe application of lime and fertilizers.to replace lost nutrients

,In cultivated areas limestone may alsobe added to increase the ability of the

.soil to keep the pH stable

ACID RAIN-

EFFECTS


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ACID RAIN-

EFFECTSOther adverse effectsAcid rain can also damage buildings,and historic monuments especially

those made of rocks such aslimestone and marble containing

.large amounts of calcium carbonateAcids in the rain react with thecalcium compounds in the stones to

,create gypsum which then flakes.off


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VOLCANO


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As magma is pushed into a volcano from the magma,chamber below via the magma vent the volcanoinflates causing slopes to become over

;steepened and unstable this can result in,larger more explosive eruptions than would

.otherwise be expected Ground shaking associated with magma ascent can

.also trigger a collapse Landslides generated during volcanic eruptions at-snow and ice covered volcanoes can be especially

: ,dangerous As a landslide moves down slope thelarge blocks break into smaller and smaller,pieces when combined with water from melting

,snow or ice can transform the landslide into a

,debris avalanche carrying it farther than a- .similar sized rock avalanche

LANDSLIDES AND DEBRIS

AVALACHES


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Volcanic earthquakes may be small events detectable

,only by instruments or larger events associated.with explosive eruptions They may serve as a useful indicator that a volcano

,is coming to life and can be used to help predict.when a volcano may erupt

Earthquakes large enough for humans to feel may.damage property

EARTHQUAKES


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Volcanic eruptions along coastlines can generatetsunamis due to seismic activity or landslides.into water

,For example an 1883 eruption of Augustine volcanoin Alaska involved a collapse of a portion of the

,volcano into Cook Inlet resulting in a localized.tsunami that was about 15 m high Far greater, , ,damage including about 36 000 deaths was caused

by the 1883 eruption of the Indonesian volcano,Krakatau which caused massive tsunamis to strike

.the coasts of nearby Java and Sumatra

TSUNAMIS


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Geothermal resources

Fertile soil Spectacular scenery Tourism

Positive effect of Volcanoes


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Volcanoes provide resources for

,energy extraction also called.geothermal resources Heat from the earth's crust is being

.converted to energy The big advantages to this type of

energy are that it is very cleanand the resources are nearly.inexhaustible

Geothermal resources


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When a volcano erupts it throws out a lot of

.ash At short notice this ash can be very harmful to

,the environment but on the long term the ash, ,layer which contains many useful minerals will

.be converted to a very fertile soil

Nearly everywhere volcanoes are located people.use the rich soil for farming

Even after an eruption people still return.because of the fertile soil around the volcano

Fertile soil


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Volcanoes can produce

very spectacularscenery like thebeautiful sunsets

caused by explosive.eruptions

Other features include,stunning eruptionsbeautiful lava

.fountains etc

Spectacular scenery


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A big economical

advantage ofvolcanoes is that

they generate.tourism

A country such as

Hawaii is getting alot income from.tourism

Tourism


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Hazard management
http://volcanoes.usgs.gov/About/What/Monitor/monitor.html


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-Tiltmeter measures the

expansion of thevolcano

-Seismograph determinesearthquakes

Correlation-spectrometers measures

amounts of sulfurdioxide

Remote sensing and GPS

TOOLS


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HAZARD MITIGATION

Awareness of whether the volcano in

their regions are dorment or active effective warning and evacuation

procedure

careful monitoring look out for temperature increase magma releases gases movement of magma produces

earthquakes and vibrations swelling of volcano's slope


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;The most obvious don't build any sort of town

!around a volcano

.Spray the oncoming Lava flow with seawater This.was done in Iceland during an eruption in 1983

Military bombings to divert Lava flows Build walls in the way of the lava to block the

flow

Cool lava by breaking down the roof and sides of. ( )the tube feeding the lava flow Not tested yet .Have an evacuation plan .Educating the community / .Dig trenches away from nearby towns villages

HAZARD MITIGATION


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Q?Q?Only Few People On Earth Can Say Beautiful Landscapes Their

Offices,

We Are One Of Them

Volcanoes-Enviromental Hazards,Effects and Remedies

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