Post on 04-Jun-2020
Chapter 1: Plate Tectonics Section 1: Earth’s Interior
Exploring Inside the Earth
* Geologists have used two main types of evidence to learn about Earth’s interior: * Direct Evidence – rock
samples * Indirect Evidence –
seismic waves
Important Factors When Traveling to the Center of the Earth
* Temperature * The deeper you travel
the higher the temperature becomes.
* Pressure * The deeper you travel
the greater the pressure becomes.
Layers of the Earth’s Interior
* The 3 main layers of the Earth are the Crust, the Mantle and the core.
* These layers vary greatly in size, composition, temperature and pressure.
The Earth’s Crust
* The crust can be looked at as the Earth’s skin. * The crust includes dry land and the ocean floor. * Oceanic Crust – water * Ex. Basalt * Continental Crust – land * Ex. Granite
The Earth’s Mantle
* Earth’s Mantle is made up of rock that is very hot, but solid. * Scientists divide the mantle into layers based on the physical characteristics of the layers: * Lithosphere * Asthenosphere * Lower Mantle
The Earth’s Core
* The core is mostly made of the metal’s iron and nickel. It consists of two parts: * Outer Core * Layer of molten metal that surrounds the inner core * Behaves like a liquid
* Inner Core * Dense ball of solid metal * Extreme pressure squeezes the atoms of iron and nickel so much that they cannot spread out and become liquid
The Core & Earth’s Magnetic Field
* Scientists think that movements in the liquid outer core are what cause Earth’s magnetic field.
Chapter 1: Plate Tectonics Section 2: Convection and the Mantle
Types of Heat Transfer
* Radiation: * The transfer of heat through space. * There is NO direct contact between a heat source and an object. * Ex. Sunlight
Types of Heat Transfer
* Conduction: * The transfer of heat within a material or between materials through touching. * Ex. A Spoon is heated up through conduction by the touching of the hot liquid in the pot.
Types of Heat Transfer
* Convection: * The transfer of heat by movement of currents. * Caused by differences in temperature and density. * Density – a measure of how much mass there is in a volume of a substance.
Convection Currents
* Heating and cooling of a fluid, changes in the fluid’s density and the force of gravity all combine to set convection currents in motion. * Convection currents
continue as long as there is heat. * Heat from the core and the
mantle itself cause convection currents to happen within the Earth’s interior.