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Notes
for Chapter C-1 The Changing Earth
Lesson 1 What Are the
Earth's Layers?
1. The atmosphere, the hydrosphere, and the lithosphere are the three parts
of the earth that are visible from space. The atmosphere is mostly gas, the
hydrosphere is mostly water, and the lithosphere is mostly solid.
2. The earth is made of three layers: a thin, rigid outer crust; a hotter,
mostly solid mantle; and a melted outer core with a white-hot, solid inner core.
Vocabulary –atmosphere,
hydrosphere, lithosphere, crust, mantle, core
Lesson 2 How Does the Earth's Crust Move?
1. Scientists hypothesized that continents had moved based on the jigsaw fit
of the continents, on fossil evidence, and on the locations of coal deposits,
ancient mountains, and deposits left by glaciers.
2. The theory of plate tectonics states that the earth’s surface is composed
of plates made up of the crust and the top rigid part of the mantle. Plates
float on the mantle below and slowly move due to forces deep within the earth.
3. Earthquakes, volcanic eruptions, and mountain formation are some of the
events caused by plate movements.
Vocabulary – plate tectonics, plate
Lesson 3 What Changes the Earth's
Surface?
1. During the process of weathering, rocks are broken down by air, ice,
water, chemicals, and living things.
2. During the process of erosion, weathered rocks and soil are moved by water,
wind, and ice. Flowing water is the main cause of erosion.
3. During the process of deposition, eroded materials are deposited in locations
such as river valleys, deltas, and beaches.
Vocabulary – weathering, erosion,
deposition
Lesson 4 How Do Rocks Reveal Changes on
the Earth?
1. The rock cycle describes the processes by which igneous, sedimentary, and
metamorphic rocks can be changed from one type to another.
2. By studying fossils scientists learn about how the earth has changed.
3. The remains of dead organisms form fossils if they are trapped in layers of
sedimentary rock.
Vocabulary – rock cycle, igneous rock,
sedimentary rock, metamorphic rock, mineral
