6 Shifting Liquid crust outer mantle Planet Earth is not solid In fact most of it is a churning simmering mass of white-hot rock called magma The magma floats in the outer core layer but is also present in the upper mantle This magma sometimes finds its way to the surface inner mantle outer core inner core Liquid and rOck The inner core is extremely hot In fact this central area of Earth is even hotter than the surface of the Sun Made of iron and nickel the pressure from above keeps it solid Surrounding the inner core are the outer core and inner and outer mantles and above them the surface layer of Earth called the crust A flOating crust We talk about being on solid ground but the EarthGs crust is only about 18-40 miles thick on land and up to 10 miles thick under the oceans The crust is not a single layer as you might expect It is made up of pieces known as tectonic plates that float on the upper part of the mantle
tectOnic plates As the plates have moved over millions of years theyGve bumped into and pulled apart from each other Different plates act in different ways to create mountains Those under the sea usually sink under those carrying continents They push up the continental plates Those plates carrying continents bump into each other and the edges buckle Sometimes plates rub against each other and cause earthquakes 7 KEY WORDS magma core mantle crust tectonic plate earthquake Movement in the tectonic plates causes great mountain chains to be formed
8 Warm Climates Our climate is determined by the way the warmth of the Sun reaches Earth In summertime the Sun is high in the sky and we are warmer than in winter In winter the Sun’s heat travels further through Earth’s atmosphere and loses some of its heat HOw hOt On a bright day the Sun can heat up rocks to very high temperatures Sometimes the weather is hotter than it feels because a summer breeze cools us down Meteorologists need to measure temperature accurately so they fix a thermometer in a ventilated box Their reading shows the air temperature in the shade and out of the wind KEY WORDS climate temperature meteorologist thermometer Equator Tropic of Cancer Tropic of Capricorn Weather stations pick up satellite information about the world’s changing climate
9 HOt arOund the middle The Equator is the name given to an imaginary line that runs around the middle of the planet This marks the hottest regions on Earth Just over 1,600 miles north of the Equator thereGs another imaginary line around Earth called the Tropic of Cancer At the same distance to the south is the Tropic of Capricorn The tropics mark the limits of where the Sun passes directly overhead in June and December each year Places between the tropics have warm climates The Libyan desert has reached the highest temperatures ever recorded on Earth HOttest place On Earth The hottest temperature ever recorded on Earth was 136 F This was in 1922 at a weather station at Al Aziziyah in north-western Libya The ground surface can get much hotter than the air Some years ago the NASA satellite fAquaG recorded a surface temperature of over 158 F in the Lut desert in eastern Iran
