Chapter 1
Earth Science
Course: Elementary Education Multiple Subjects 5001
Subject: Elementary Education Science Subtest 5005
Chapter: Earth Science
1. Structure and Properties of the Solid Earth (Geosphere)
The solid Earth, or geosphere, refers to the rigid outer part of the Earth and all the rock material beneath it. Understanding this system is critical for explaining earthquakes, volcanoes, mountains, and Earth’s changing surface.
a. Earth's internal layers
The Earth is structured in four main layers, each defined by composition, density, temperature, and behavior:
- Crust: The outermost layer made of solid rock. It is divided into:
Oceanic crust: Thinner (~5-10 km), dense, mostly basaltic
Continental crust: Thicker (~30-70 km), less dense, mostly granitic The crust contains landforms, soil, fossil records, and natural resources. It’s where we build infrastructure and grow food.
- Oceanic crust: Thinner (~5-10 km), dense, mostly basaltic
- Continental crust: Thicker (~30-70 km), less dense, mostly granitic The crust contains landforms, soil, fossil records, and natural resources. It’s where we build infrastructure and grow food.
- Mantle: Extends from the base of the crust to a depth of ~2,900 km.