Milk boils and flow over a saucepan rim. A volcano erupts: it bursts from the earth. Why? . This happens because steam expands ( swells up ) . When Milk boils at 100°C , the water in it turns into steam. The steam expands, forcing the milk to rise and spill over. A volcano erupts when, deep in the earth, huge rocks rub against each other, causing heat. The rocks heat up to several thousand degrees centi-grade. They melt , and the water and gases in them expand and push molten rock (magma) towards the earth’s surface. A channel, or vent, is formed by the moving magma. The magma explodes at the surface forming a large hole or crater. Hot Ash and fiery lava (molten magma) boils over the crater rim. Starting as a hole in the ground, a volcano can grow into a cone-shaped mountain.
EARTHQUAKES CITIES FALL LIKE HOUSE OF CARDS
when the earth trembles, or quakes, and cracks appear in the surface, building crumble. They collapse like houses of cards. When a child bumbs against one card , all the others tremble and then collapse in a jumble. The picture of the collapsed city shows the earthquake damage to Argolis (Argos) , one of the oldest cities of Greece. On August 9, 1953 , the earth trembled. Houses, wall and buildings collapsed into rubble. 800 people died in that earthquake. Scientists have been trying to explain earthquakes for a long time. Now they believe that the earth’s surface (the solid mantle and the crust) is made of several huge slabs, which they call plates . These plates move, sometimes only a few centimeters, apart or towards each other. The constant movement of the plates cause the Earth’s surface to wrinkles and split. This form continent, oceans and mountains. The movement also cause volcanoes, tidal waves and earthquakes. One famous earthquake took place in San Francisco , California, in 1906. That city is built on the edge of an enormous plate which carries all of North and South America and half of the Atlantic ocean. Where this plate slides against the Pacific ocean plate, there is a fault. A fault is a gap or crack in the earth. Earthquake happens along faults when two plates move . Then the earth trembles with the movement, cracks open in the soil , and cities can collapse.
EARTH’S CHANGING FACE.
The earth’s surface is not like a smooth ball or sphere. it is very rugged in the places , and almost two-thirds of the surface is under water. The highest mountain stretches up to 8,848 metres above sea level. The deepest ocean trench reaches about 11,000 metres below sea level. The thin crust of the earth is made up of two layers of rocks . The crust is about 35 kilometers thick under the continents, but only about five kilometers metres thick under the seas. The top part of the crust is divided into plates of rock. These plates shift and move upon the lower layer, mountain and ocean are formed. Earthquake, volcanoes and geysers are caused. The climate change our planet’s surface too. Wind and rain shift the soil from place to place. Ocean waves and rivers wear down the surface. They cover up old earth or expose new soil. Melting snow forms fast- moving rivers which shift more soil. Ice freezes and cracks the soil. Sheets of moving ice called glacier, slides down mountainslides. Boulder, huge rocks and pebbles are frozen in a glacier.
ARTICLE RESEARCHER: DENNIS THUO : CAPTAIN KENNEDY .K . LAN’GAT : CHARLES KANYUGO : ANN CURRAH. .
ARTICLE NARRATED BY: DENNIS THUO AND ANN CURRAH.
ARTICLE FOREWORD BY : JAMES BURKE AND ELIJAH MACHETE .
ARTICLE SUPERVISOR : LEUTINANT COLONEL OSCAR .M. BOSKO .
ARTICLE DIRECTOR: CHARLES KANYUGO.
ARTICLE WRITTER: CHARLES THE BULLET EATER .