The Wonders of Planet Earth

The perpetual cycle of change which has created the incline of the Earth, with all its rugged and Fascinating variety usually happens too belatedly to be noticed. But occasionally it is rapid and Violent. Volcanoes disgorge molten lava, earthquakes draw open the landscape, landslides, carry forward Whole mountainsides. Then human beings extend aware of the awesome forces that are shaping Their planet. These forces are fuelled by trinity powerful sources of energy love from within the Earth, heat from the Sun, and the force of gravity.Every landform in the world has been shaped by these ttu. ee energy sources. the continents that drift crossways the surface of the globe, setting off volcanoes and earthquakes and Building mountains. are driven by heat from the Earths interior which has a temperature of about 5000C (9000F). Most of this heat is created by the breakdown of radioactive elements. Earth is unique among the planets of the Solar body in having liquid body of water on the surface and water has a major role in shaping the planet.The warmth of the Sun evaporates water from seas and lakes. The vapor rises and condenses to form clouds and then falls again as rain down and snow. It is then that its landscaping powers begin, weathering carrys and washing away the loose material. or rubbing down the landscape under the power of a glacier. The Suns heat withal produces the rain and the waves that scour the land. The third force gravity causes the tides, which nibble away at the edges of continents, and landslides. hich alter the shape of mountains. Under the influence of gravity. rain full treatment its way downwards as streams and rivers, carving the terrain. On its journey, it carries fragments of rock and back to be deposited on the ocean floor. And over thousands of years more rock which may then be buckled and lifted up by causa of the Earths crust to form new mountains. source Readers Digest, Discovering the Wonders of our World A tie to natures Sciences marvels