Chapter 1 Section1 Earth’s Interior The Science of Geology Geologists – scientists who study the forces that make and shape the planet Earth Rock – the material that forms Earth’s hard surface Geologists study: the processes that create Earth’s features search for clues about Earth’s history study the chemical and physical properties of rock map where different types of rock are found describe landforms Geology – the study of planet Earth 2 Types of Forces that Change the Earth’s Surface: 1. Constructive – forces that shape Earth’s surface by building up mountains and landmasses 2. Destructive – forces that slowly wear away mountains and eventually every other feature on Earth’s surface Continents – 7 great landmasses surrounded by oceans Seismic Waves – the indirect evidence geologists use to study Earth's interior; created when earthquakes occur

Journey to the Center of the Earth 2 things that increase as you go towards Earth’s center: 1. Temperature 2. Pressure Pressure – the force pushing on a surface or area Earth’s 3 Main Layers: 1. Crust 2. Mantle 3. Core Each layer has its own conditions and materials

The Crust A layer of rock that forms Earth’s outer skin; Earth’s thinnest layer Includes: the soil and water rocks and mountains dry land and ocean floor The crust is thinnest beneath the ocean The crust is thickest beneath high mountains basalt 2 Types of Crust: 1. Oceanic Crust – the crust beneath the ocean, consists mostly of dense rock such as basalt Basalt – a dark, dense rock with a fine texture 2. Continental Crust – the crust that forms the continents, consists mostly of less dense rock such as granite Granite – a rock that has larger crystals than basalt, is less dense and is usually a light color granite

The Mantle Below the crust Largest layer Solid material Layer of hot rock Contains 2 specially named areas 1. Lithosphere –all of the crust and the uppermost part of the mantle together; hard, rigid layer “Lithos” – in Greek means stone 2. Asthenosphere – part of the mantle below the lithosphere; somewhat soft, bends like plastic “asthenes” – in Greek means weak

The Core Below the mantle Consists of 2 parts Both parts made of Iron and Nickel Innermost layers 1. Outer Core – layer of molten material (thick liquid); surrounds the inner core 2. Inner Core – dense ball of solid metal; extreme pressure squeezes Iron and Nickel atoms together so much they cannot spread into a liquid

Earth’s Magnetic Field Currents in the liquid outer core spin the solid inner core Inner core spins slightly faster than the rest of the planet Spinning movement creates Earth's magnetic field Magnetic field effects the whole Earth Earth acts like a giant bar magnet Compass needle aligns with Earth’s magnetic field North seeking end of needle points to Earth’s magnetic north pole