The location of tectonic activity

••Identify, describe and explain the patterns of

Earthquakes and Volcanoes

Can you name the places where volcanoes and earthquakes occur?

True or false?

• Volcanoes and earthquakes happen all over the world.

• Volcanoes are found in narrow belts.• Volcanoes are found along the East Coast

of North and South America.• Volcanoes are found along the West Coast

of North and South America.

Where do earthquakes and volcanoes occur?

Skills Builder 1

(a) Earthquakes occur in broad belts. Tend to be found in the middle of oceans e.g. Atlantic or along the edges of continents e.g. West coast of North America. Can also occur just off-shore of continental landmasses, e.g. western Pacific Ocean. There are some exceptions; there are earthquakes inland such as in eastern Africa.

(b) Volcanoes also occur in broad belts. Found along the edges of continents e.g. West coast of South America. Can be found just off-shore of continental landmasses, e.g. western Pacific Ocean. Anomalies include cluster of volcanoes in the mid-Pacific around Hawaii and band of volcanoes inland in eastern Africa.

N.B. Able students might note that earthquakes and volcanoes often

occur in the same locations.

• On the diagram, mark and name: the North American Plate, the Caribbean Plate, the Pacific Plate, the African Plate, the Eurasian Plate, the Arabian Plate, the Indo-Australian Plate. Check your answers using Figure 4 (student book p.101)

The structure of the Earth

• Annotate (label) this diagram using the following words:

Inner coreOuter core

MantleCrustPlates

Plate boundary

TASK 1

The Structure of the EarthFACTS

• The inner core is the centre of the earth, made of solid iron and nickel, it is the hottest part with a temp. of 5500oC

• The outer core is made up of liquid iron and nickel• The mantle is made up of semi-molten rock,

partially melted rocks are called magma, temperatures reach 5000oC here.

• The crust is the thinnest layer, and is made up of solid rock, it is the outer layer, like skin of an apple

Tectonic Plates• The Earth’s crust is divided up into

plates• These plates ‘float’ or move very slowly

(a few mm per year) on the molten material of the mantle. This movement is caused by convection currents in the mantle.

Explain the difference between continental crust and oceanic crust

• On the diagram below, mark and name: Inner core, Outer core, Mantle, Trench, Ridge. Check your answers using student book pp.101–102.

Plate tectonics

• The place where two plates meet is called a plate boundary, most earthquakes and volcanoes happen here in a narrow belt called ‘zones of activity’

Image of the world 160 million years ago

Image of the world 80 million years ago

Image of the world today

Evidence

Evidence

Add to you description

b. Why do volcanoes and earthquakes happen in these locations

Neatly add these correct labels:

Generally explosive volcanic eruptions. Magma rising to form volcanoes.

Plate being forced into the mantle Deep, violent Earthquakes

One plate is denser than the other so sinks. Plate melting.