Carib Studies Presentation

7/30/2019 Carib Studies Presentation

1/12

Group presentation

Subject: Caribbean Studies

Lecturer: Ms.Cummings


2/12

What is a volcano?volcano is an opening, or rupture, in a planet's surface or crust,which allows hot magma, volcanic ash and gases to escape frombelow the surface.

There are three main types of volcanoes:

Active volcano-This is a volcano which have erupted In recenttimes and has the potential to undergo eruption again.

Dormant volcano-These are volcanoes that are not currently

active, but could become restless or erupt again. Extinct volcano-These are volcanoes that have not erupted over

hundreds of years and is not expected to erupt again.


3/12

How are volcanoes formed?The theory of plate tectonics is a major factor whichinfluence the formation of volcanoes. The theorystates that the Earth`s tectonic plates are drifting fromplace to place breaking apart, colliding, and grindingagainst each other. Volcanoes however only appears atplate margins where breaking apart occurs (divergent)and colliding (convergent).


4/12

PLATE MARGINS WHERE VOLCANIC

ACTIVITIES OCCUR.Convergent boundary

As the two plates collide one of the plates submerge below the next. Thesubmerged area of the plate is exposed to the high temperatures andpressure in the mantle (which is molten) which causes the crust to melt.The molten magma then returns to the Earth`s surface when it ispressurized by the mantle and the outer core.


5/12

PLATE BOUNDARIES CONTINUED

Divergent Boundary

As the plates move away from each other there is a

thin area formed between the intermediate plates.This area is where the magma in mantle pushes on andthus cause the area to loosen and form volcanic coneswhich will later form active volcanoes.


6/12

STRUCTURE OF A VOLCANO

A composite volcano is the most common type ofvolcano. This image shows the common features whichoccurs in a typical composite volcano.


7/12

DIFFERENT KINDS OF VOLCANOES

There are four kinds of volcanoesCinder Cones Cinder cones are circular or oval cones made up of small

fragments of lava from a single vent that have beenblown into the air, cooled and fallen around the vent.

CompositeVolcanoes

Composite volcanoes are steep-sided volcanoescomposed of many layers of volcanic rocks, usuallymade from high-viscosity lava, ash and rock debris.

Shield

Volcanoes

Shield volcanoes are volcanoes shaped like a bowl orshield in the middle with long gentle slopes made bybasaltic lava flows. Basalt lava flows from these

volcanoes are called flood basalts.

Lava Volcanoes Lava domes are formed when erupting lava is too thickto flow and makes a steep-sided mound as the lava pilesup near the volcanic vent.


8/12

TERMS ASSOCIATED WITH

VOLACNOESPYROCLASTIC FLOW-A pyroclastic flow is a fluidized mixture of solid to semi-solid

fragments and hot, expanding gases that flows down the sides of a volcano. Thesefeatures are heavier-than-air emulsions that move much like a snow avalanche,except that they are fiercely hot, contain toxic gases, and move at phenomenal,hurricane-force speeds. They are the most deadly of all volcanic phenomena.

LAHAR-A lahar is a type of mudflow or debris flow composed of pyroclastic material,rocky debris, and water. The material flows down from a volcano, typically along ariver valley. It is very dangerous because it's consistency and the way it acts is verymuch like cement. It is liquid when it's moving, but when it stops, it solidifies.

PUMICE-Pumice is a light, porous volcanic rock that forms during explosive

eruptions. It resembles a sponge because it consists of a network of gas bubblesfrozen amidst fragile volcanic glass and minerals. All types of magma (basalt,andesite, dacite, and rhyolite) will form pumice.


9/12

EFFECTS OF VOLCANOES ON THE

ENVIRONMENT

Volcanoes causes many devastating effects on the environment and it`spopulation(including humans and animals). Different compositions ofthe volcano causes different effects. Lava flow causes destruction toeverything in it`s path. The hot liquid scorch and burn anything closeto it.

The ash from the volcano affects a larger area of the environment thanall the other compositions of the volcano. The ash can be carried by the

wind because it is composed of gases of low densities. The ash causesdamage to: water sources, livestock, crops, humans, and also birds.

Acid rain is formed when rainfall interacting with volcanic gases withinthe ash plume may produced acids which fall as acid rain. Continueddegassing at the vent may lead to ongoing acid rain even after ash fallceases (volcano stops erupting).


10/12

HOW VOLCANOES AFFECT SOIL

FERTILITY?


11/12

SAFETY TIPS ABOUT VOCANOESPLAN FOR A VOLCANO: First of all, have a disaster plan and know whether or

not you are at risk for danger. Be prepared for mudslides, flash floods,earthquakes, ash falling, acid rain and tsunamis. Don't forget, know all of yourevacuation routes.

DURING A VOLCANO: Follow the evacuation routes. Avoid areas which slopefrom the origin of the volcano. If your caught indoors, close all windows anddoors, bring animals inside. If youre trapped outdoors, seek shelter indoors. Ifyoure caught in falling rocks, roll into a ball and protect your head. If yourecaught near a stream, be aware of mudflows and move to higher ground.Protect yourself when ash falls by wearing long-sleeved shirts and long pants.Use goggles to protect your eyes. Wear a dust mask.

AFTER A VOLCANO: Cover your mouth and nose. Volcanic ash can irritateyour respiratory system. Wear goggles and protect your eyes. Keep your skincovered. Clear roofs of ash, because the ash is very heavy and can cause thebuilding to collapse.


12/12

END OF PRESENTATION

DONE BY: AUDEL HOWARD

Carib Studies Presentation

Documents

Transcript of Carib Studies Presentation