Earth’s Interior Study Guide
How do geologists know what is in Earth’s interior?
How do geologists know what is in Earth’s interior? Geologists gather indirect evidence from seismic waves generated during an earthquake. In order to understand Earth’s interior, geologist use direct and indirect evidence. Geologists gather direct evidence from drilling holes into Earth’s crust and collecting rock samples.
Zenolith: mantel rocks which are exposed by earthquakes
Seismic Waves Vibrations that travel through Earth carrying the energy released during an earthquake.
Earth’s Layers
Crust The layer of rock that forms Earth’s outer crust. Continental Crust - Granite Oceanic Crust - Basalt Granite Basalt
Mantel The layer of hot, solid material between Earth’s crust and core. The mantel has three layers: lithosphere, asthenosphere, and the lower mantel.
Lithosphere The uppermost part of the mantel and the crust together form the ridged layer called the lithosphere. Lithos means “stone”.
Asthenosphere Located below the lithosphere, the asthenosphere is soft and can bend like plastic. Asthenes means “weak”
Compare and contrast the asthenosphere with the lithosphere The asthenosphere and lithosphere are similar in that they are both part of the mantel. They differ in that the lithosphere is the rigid uppermost part of the mantel that includes the crust. The asthenosphere is located below the lithosphere and is soft similar to plastic. .
Core The core is made mostly of iron and nickel and consists of two parts, the outer core and inner core.
Outer Core Is a layer of molten metal that surrounds the inner core.
Inner Core The inner core is a dense ball of solid metal.
Pressure Results from a force pressing on an area. Because of the weight of the rock above, pressure inside the Earth increases as you go deeper.