THE-EARTHS-INTERNAL-HEAT.pdf

THE EARTH’S INTERNAL HEAT ACTIVITY SCENARIO: A cube of ice placed into the hand of a man. Over time, the ice cube melted in his hands. Why?  WHAT IS HEAT ENERGY? The result of the movement of tiny particles called atoms, molecules or ions in solid, liquids and gases. Heat energy can be transferre...

THE EARTH’S INTERNAL HEAT ACTIVITY SCENARIO: A cube of ice placed into the hand of a man. Over time, the ice cube melted in his hands. Why?  WHAT IS HEAT ENERGY? The result of the movement of tiny particles called atoms, molecules or ions in solid, liquids and gases. Heat energy can be transferred from one object to another. The transfer or flow due to the difference in temperature between the two objects is called heat. Heat energy plays a vital role in our planet. It is one of the extreme factors in what makes the world livable. Earth must be hot inside. The heat inside of our planet moves continents, build mountains and causes earthquakes. But where does all this heat inside the earth come from?  SOURCES OF HEAT IN OUR PLANET 1. PRIMORDIAL HEAT The internal heat energy that gradually gathered together by means of dispersion in the planet during its few million years of evolution The major contribution of this internal heat is the accretional energy. accretional energy – the energy deposited during the early formation of a planet. The core is a storage of primordial heat that originates from times of accretion when kinetic energy of colliding particles was transformed into thermal energy. This heat is constantly lost to the outer silicate layers of the mantle and crust of the earth through convection and conduction. In addition, the heat of the core takes tens of thousands of years to reach the surface of the earth. Today, the surface of the earth is made of a cold rigid rock since 4.5 billion years ago, the earth’s surface cools from the outside but the core is still made of extremely hot material  SOURCES OF HEAT IN OUR PLANET 2. RADIOGENIC HEAT- the thermal energy released as a result of spontaneous nuclear disintegration. It involves the disintegration of natural radioactive elements inside the earth – like Uranium, Thorium and Potassium. Radioactive elements exist everywhere on the earth in a fairly significant concentration. Without the process of radioactive decay, there would be fewer volcanoes and earthquakes – and less formation of earth’s vast mountain ranges the flow of heat from Earth's interior to the surface and it comes from two main sources in equal amounts: the radiogenic heat produced by the radioactive decay of isotopes in the mantle and crust, and the primordial heat left over from the formation of the Earth.  Identify the sources of internal heat by writing RH for radiogenic heat and PH for primordial heat. ____1. Presence of different isotopes of heat producing element in the mantle and crust. ____2. Internal heat accumulated by dissipation of planet. ____3. Release of accretional energy. ____4. Processes involved in mantle convection. ____5. Release of thermal energy as a result of spontaneous nuclear disintegration. THREE PROCESSES OF HEAT TRANSFER 1. CONDUCTION 2. CONVECTION 3. RADIATION SCENARIO 1 Chocolate candy in your hand will eventually melt as the heat from your body is released and makes it melted. SCENARIO 2. A heater in the hot air balloon heats the air. The air inside is trapped causing the balloon to rise  THREE PROCESSES OF HEAT TRANSFER 1. CONDUCTION- governs the thermal conditions in almost entire solid portions of the Earth and plays a very important role in the lithosphere. the process by which heat energy is transmitted through collisions between neighboring atoms or molecules  THREE PROCESSES OF HEAT TRANSFER 2. CONVECTION- involves transfer of heat by the movement of mass. Convection dominates the thermal conditions in the zones where large quantities of fluids (molten rocks) exist, and thus governs the heat transport in the fluid outer core and the mantle.  THREE PROCESSES OF HEAT TRANSFER 3. RADIATION-The process of heat exchange between the Sun and the Earth through radiation, controls the temperatures at the Earth's surface.