ST IVO SCHOOL GEOGRAPHY DEPARTMENTREVISION FOR YEAR 9 VOLCANO EXAMPhotos Courtesy of www.geographyphotos.com & R Chambers

Structure Of The Earth

At a constructive plate boundary, two plates move apart. As the two plates move apart, magma rises up to fill the gap. This causes volcanoes at this type of boundary. However, since the magma can escape easily at the surface the volcano does not erupt with much force. E.g. Mid-Atlantic Ridge.Constructive Plate Boundary

A destructive plate boundary is found where a continental plate meets an oceanic plate.The oceanic plate subducts (sinks) under the continental plate because it is denser. Friction melts the plates. This melted plate is now hot, magma. If it reaches the surface, the liquid rock forms a volcano.E.g. Nazca and South American PlateDestructive Plate Boundary

Conservative plate boundaries exist where two plates slide past each.No volcanoes are found along these plate boundaries, but earthquakes do occur.E.g. San Andreas Fault, San Francisco Conservative Boundary

Collision boundaries occur when 2 continental plates move together. This causes the material between them to buckle and rise up, forming fold mountains.E.g. HimalayasCollision Boundary

STRUCTURE OF A VOLCANOSteam, Ash, GasVolcanic BombsCraterSecondary ConeLava FlowVentMagma Chamber

MineralsGeothermal EnergyTourismWhy live nearvolcanoes?Fertile SoilScientific Research

Montserrat Case StudyMontserrat is found in the Caribbean and is part of the Leeward Islands.It is part of a island arc and was formed by volcanic eruptions.North American Plate

After 2 years of rumbling a huge eruption occurred on July 25 1997.In July 1995 the dormant volcano of Soufriére Hills started to rumble back to life.Montserrat is a Caribbean island famous for beautiful beaches and sea.Background Information

Underneath Montserrat the North American plate is slowly being forced under the Caribbean plate.The Soufrière Hills Volcano produces a thick sticky lava.Montserrat is situated on a destructive plate boundary.The lava was thick and it built up at the top of the volcano in a dome until it collapsed.Causes of the Eruption

Airport was evacuated and closed.Capital City (Plymouth) almost totally destroyed and evacuated.19 people killed and many more injured.A total of at least 4 square kilometres of land was covered by the pyroclastic flows and surges.People evacuated to the north of the island.Rich farmland destroyed by mudflows and covered by layers of ash.Destroyed between 100 -150 houses.About 8000 residents left the island to live somewhere safer.The southern part of the island is off limits and people are fined if they are found there.Effects of the Eruption

INSTRUCTIONSThere are 10questions for you to have a go at – as you work through the slides, write down the number of the question and your answer.At the end of the 10 questions – there are slides with the correct answers on for you to check your answers – GOOD LUCK!

Question 1.Which of the following is an example of a volcanic eruption?Montserrat – 1997 San Francisco – 1989 Kobe – 1995 Tokyo - 1919

Question 2.Montserrat occurred at a.. destructive boundary constructive boundary collision boundary conservative boundary

Question 3.Re-arrange the following to give the correct order explaining the eruption of a volcano friction between plates and heat from the earth causes melting of the oceanic plate two plates move towards each other subduction of the lighter oceanic plate occurs molten magma rises and erupts

Question 4.A constructive boundary is.. where two plates move side by side where two plates move together where two plates move away from each other.

Question 5.A collision boundary is where an oceanic and a continental plate meet two continental plates meet two oceanic plates meet two plates move away from each other

Question 6.At this boundary two plate move apart from each other collision boundary constructive boundary destructive boundary conservative boundary

Question 7.At this boundary two plates of continental crust meet collision boundary constructive boundary conservative boundary destructive boundary

Question 8.Here an oceanic and continental plate move together.. destructive Boundary constructive boundary conservative boundary collision boundary

Question 9.The outer layer of the earth is called the.. crust mantle core

Question 10.This process occurs where two plates meet together.. precipitation subduction transpiration divergence

Answers SlideQuestion 1.Which of the following is an example of a volcanic eruption?Montserrat – 1991 San Francisco – 1989 Kobe – 1995 Tokyo - 1919

Answers SlideQuestion 2.Montserrat occurred at a..destructive boundary constructive boundary collision boundary conservative boundary

Question 3.Re-arrange the following to give the correct order explaining the eruption of a volcanoAnswers Slide friction between plates and heat from the earth causes melting of the oceanic plate two plates move towards each other subduction of the lighter oceanic plate occurs molten magma rises and erupts3124

Answers SlideQuestion 4.A constructive boundary is.. where two plates move side by side where two plates move togetherwhere two plates move away from each other.

Answers SlideQuestion 5.A collision boundary is where an oceanic and a continental plate meettwo continental plates meet two oceanic plates meet two plates move away from each other

Answers SlideQuestion 6.At this boundary two plate move apart from each other collision boundaryconstructive boundary destructive boundary conservative boundary

Answers SlideQuestion 7.At this boundary two plates of continental crust meetcollision boundary constructive boundary conservative boundary destructive boundary

Answers SlideQuestion 8.Here an oceanic and continental plate move together..destructive Boundary constructive boundary conservative boundary collision boundary

Answers SlideQuestion 9.The outer layer of the earth is called the..crust mantle core

Answers SlideQuestion 10.This process occurs where two plates meet together.. precipitationsubduction transpiration divergence