Ch 1 2 A View of Earth

Warm Up 9/13
1. What is the study of the atmosphere and the
processes that produce weather and climate?
According to the nebular hypothesis, our solar
system formed from a huge rotating cloud made
mostly of ________.
Hydrogen and Helium
The area of Earth science that examines the
physical and biological changes that have occurred
in Earth’s past is called ____.
Historical Geology
A View of Earth
Chapter 1, Section 2
Earth’s Major Spheres
• Earth can be thought of as consisting of four major
spheres: the hydrosphere, atmosphere, geosphere,
and biosphere
Hydrosphere – the water portion of Earth
Atmosphere – the gaseous portion of a planet;
the planet’s envelope of air
Geosphere – layer of Earth under both the
atmosphere and the oceans
Because the geosphere is not uniform, it is divided
into three main parts based on differences in
composition—the core, the mantle, and the crust
Biosphere – all life on Earth; the parts of the solid
Earth, hydrosphere, and atmosphere in which living
organisms can be found
Earth’s Layered Structure
Concept Check
• What are Earth’s four major spheres?
• The hydrosphere, atmosphere, geosphere,
and biosphere
Plate Tectonics
• There are two types of forces affecting Earth’s
• Destructive forces such as weathering and
erosion work to wear away high points and
flatten out the surface
Constructive forces such as mountain building
and volcanism build up the surface by raising
land and depositing new material in the form of
The theory that finally emerged, called plate
tectonics, provided geologists with a model to
explain how earthquakes and volcanic eruptions
occur and how continents move
Earth’s Major Plates
Concept Check
• What is the difference between destructive
forces and constructive forces?
• Constructive forces build up the surface
material, whereas destructive forces
destroy surface material
• Read Chapter 1, Section 1 (pg. 2-5)
• Do Section 1.1 Assessment #1-7 &
Connecting Concepts (pg. 5)
• Read Chapter 1, Section 2 (pg. 7-10)
• Do Section 1.2 Assessment #1-9 (pg. 10)