Tectonic Activity

Unit 1

Which one are we

like?

Structure of the earth

Structure of the earth The CoreTemperatures about 6000C but due to huge

pressure solid (hotter than the surface of the sun)

Mantle Consists of melted rocks. Temperatures

around 3500C. The mantle tends to creep and flow like a ‘toffee’ like mixture.

Crust A thin layer on the outside of the earth. The

crust is broken into smaller pieces, these pieces are known as plates. Plates float on the mantle and can move around.

PlateA huge section of the earths crust that floats

on the mantle

There are two types of plate

Oceanic plates (sea crust)A thin layer between 6-10KmDense (or heavy)Young rock (basalt)

Continental Plates (land crust)Thicker, between 20-70km (thickest

under mountainsLight ( not as heavy)Old rock (granite)

Why do plates move?

Any Ideas?

Use Complete Geography p6+7 and this link to help you draw and explain why plates move http://www.sln.org.uk/geography/schools/blythebridge/animations.htm

Test Yourself

1. Answer the questions on p7 of Complete Geography

2. http://www.bbc.co.uk/schools/gcsebitesize/geography/platetectonics/