Volcanoes - Junior Cycle

What is a volcano?

A rupture in the earths crust the allows lava, ash and gases to escape from the magma chamber below the earth's surface

Where do volcanoes happen?

Usually near tectonic plate boundaries but can also be formed near hotspots

What is a hotspot?

Where molten lava is very near the earths crust

What is the structure of the earth?

Inner core
Outer core
Mantle
Crust

What are the two types of crust?

oceanic and continental

What is an oceanic crust?

Found under the sea
Thinner
More dense
Can be destroyed

What is a continental crust?

Found on land
Thicker
Less dense
Permanent

How do the Earth's plates move?

Convection currents in the mantle

What are the parts of a volcano?

Magma chamber
Main vent
Crater
Ash and cinder cloud
Lava flow
Secondary vent
Layers of lava

magma chamber

Where molten rock is stored beneath the ground

Vent

A channel through which magma travels to the surface

Secondary vent

Some magma may escape through the side of the volcano. Especially if the main vent was blocked.

crater

A bowl shaped area that may form at the top of a volcano around the vent.

What are the advantages of why people live near volcanoes?

Rich fertile soil.
Geothermal energy.
Tourism.
Precious metals and minerals.

What are the disadvantages for living near a volcano?

Risk.
Takes time for soil to develop.
High installation cost for geothermal energy.
Tourism can change places.
Economic activity can suffer.
Lava can damage landscapes.

Constructive plate boundary

It happens where two plates are pulled apart by convection currents. Molten magma comes to the surface through a crack called a fissure. This creates new land.

Destructive plate boundary

Convection currents cause two plates to collide. The heavier plate sinks into the mantle and is destroyed. The lighter plate buckles upwards, creating fold mountains and sometimes volcanoes.

Conservative plate boundary

Two plates are moving alongside each other, either in opposite directions or in the same direction but at different speeds. This causes friction and the energy released creates an earthquake.

Name a real world example of a constructive plate boundary

Mid-Atlantic Ridge runs through Iceland

Name a real world example of a destructive plate boundary

Andes Mountains in South America

Name a real world example of a conservative plate boundary

San Andreas Fault, USA

Features found at constructive plate boundaries

New land
Volcanoes
Mid-ocean ridges
Volcanic islands
Earthquakes

geyser

A fountain of hot water and steam that erupts from the ground

Features found at destructive plate boundaries

Fold mountains
Volcanoes
Earthquakes

Features found at conservative plate boundaries

Earthquakes

active volcano

a volcano that is erupting or has shown signs that it may erupt in the near future

dormant volcano

A volcano that has not erupted for a long time, but may erupt again one day.

extinct volcano

A volcano that has not erupted for thousands of years and probably will not erupt again.

fissure

a narrow opening or large crack in the ground

mid-ocean ridge

An underwater mountain range that forms under the ocean as a result of volcanic activity

Pacific Ring of Fire

region around the Pacific Ocean where most of the volcanoes and earthquakes on Earth occur regularly

continental drift

the gradual movement of the continents across the earth's surface through geological time.

Pangaea

The name of the single landmass that broke apart 200 million years ago and gave rise to today's continents

Plate Tectonic Theory

A theory stating that the earth's surface is broken into plates that move.

Example of dormant volcano

Mount St Helens

Example of a Active volcano

Mount Etna

Example of an extinct volcano

Slemish, Co. Antrim

Eyjafjallajokull

Eruption of this Icelandic volcano caused the cancellation of thousands of trans-Atlantic and European airline flights

The 3 P's responding to volcanoes

Prediction
Planning
Preparation

Volcanologist

a scientist who studies volcanoes

Country known as the Land of Ice and Fire

Iceland