What is the Earth made of? Mud and stones and water?

This unit is called changing Earth To start with, we will look at the structure of the earth. The next 2 weeks will be looking at different types of rocks are formed; and then we will look at how rock is taken from the earth, by quarrying, and the effects of this on the people and the environment. After that we will look in a bit of detail as to what and how changed the shape of the earth’ surface. Having established the what and the how, we will then look at river and how the features form. In the final week we will look at why things go wrong, as when rivers flood. I am hoping that as part of this last section, you will be able to persuade your parents to take you on a trip to a river where you can look at some of its features and take a picture or 2, and maybe collect some measurements. This is an official homework, by the way and you will be given time over half term to complete it.

The Structure of the Earth A thin crust - 10-100km thick and not very dense A mantle – extends almost halfway to the centre, hot and dense A core – made of molten nickel and iron. Outer part is liquid and inner part is solid. Gets hot due to radioactive decay. The Earth is believed to be 4500 million years old

The structure of the earth The inner core is in the centre of the earth and is the hottest part of the earth. The inner core is solid. It is made up of iron and nickel with temperatures of up to 5500°C. With its immense heat energy, the inner core is like the engine room of the Earth. The outer core is the layer surrounding the inner core. It is a liquid layer, also made up of iron and nickel. It is still extremely hot here, with temperatures similar to the inner core.

The structure of the earth The mantle is the widest section of the earth. It has a diameter of approximately 2900km. The mantle is made up of semi-molten rock called magma. In the upper parts of the mantle the rock is hard, but lower down, nearer the inner core, the rock is soft and beginning to melt. The crust is the outer layer of the earth. It is a thin layer between 0-60km thick. The crust is the solid rock layer upon which

This is what is happening in the mantle – shows why the plates move

Plates and plate boundaries The earth's crust is broken up into pieces. These pieces are called plates. Heat rising and falling inside the mantle creates convection currents. The convection currents move the plates. The movement of the plates, and the activity inside the earth, is called plate tectonics. Plate tectonics cause earthquakes and volcanoes. The point where two plates meet is called a plate boundary. Earthquakes and volcanoes are most likely to occur either on or near plate boundaries.

If the plates are moving, were the continents always where we see them today? No and there is lots of evidence for this The process is called continental drift Evidence for this: Mountain chains match up Fossils match up The continents fit together like a jigsaw (not perfect because of erosion!)

Continental Drift

Continental Drift

Continental Drift

Continental Drift