Transcript DE Science Elementary School Earth`s Changing Surface Review

DE Science
Elementary School
Earth’s Changing Surface Review
Formation of Landforms—The Key Ideas
• Wind, water, and ice shape the Earth by transporting rocks and
soil across Earth's surface.
• Canyons are carved from the landscape over a long period of
time by rivers eroding away rock.
• Dunes form as winds cause sand to pile up. The sand can come
from such sources as rock falls from sea cliffs, or sand can be
transported hundreds to thousands of miles by streams, rivers,
and oceans.
• Deltas are located at the mouth of a river that flows into a larger
body of water. The river slows and the sand drops out of the flow,
building up over time to form a delta.
• Human activities can impact landforms. For example, Dams and
levees can block the flow of sedimentary materials into a delta,
preventing it from replenishing itself.
Formation of Landforms—Using DE Science Content
• Exploration: Forces That Shape the Earth
• Video Segment: Eroding Power of Swiftly Flowing
Streams: Gorges, Canyons, and Valleys
• Video Segment: Castleton Tower: Clues in the Rock
• Video Segment: Scientists’ Warnings
Waters of the Earth – The Big Ideas
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Lakes, ponds, streams, rivers, and wetlands are all freshwater.
Lakes and ponds form where water lies in low areas. Streams and
rivers form where rain or snowfall run off from higher areas to lower
areas.
Rivers flow into oceans, lakes or estuaries.
Estuaries are river basins that have become lower than sea level and
have a mix of saltwater and freshwater.
Both estuaries and wetlands serve as protective areas where small
organisms and young organisms can survive.
Wetlands can contain saltwater, freshwater, or brackish water, which
is a combination of both.
Wetlands form near the edges of larger bodies of water or when a
lake, pond, or estuary becomes very shallow.
Ocean basins are large low areas of Earth filled with saltwater.
The sea floor has mountains, plateaus, and plains.
Waters of the Earth – Using DE Science Content
• Exploration: Waters of the Earth
• Video: What Is It Like at the Bottom of the Ocean?
• E Book: Earth’s Oceans
Glaciers – The Big Ideas
• A glacier is a large mass of moving ice that exists all
year.
• During the last ice age, a glacier covered much of North
America.
• Glaciers are one cause of large-scale erosion and
deposition, leaving a valley as a result.
• Glaciers normally expand or contract over thousands
years.
• In recent decades, many glaciers have shrunk
significantly.
Glaciers – Using DE Science Content
• Exploration: Glaciers
• eBook: The Life Cycle of Glaciers
• Video: Glaciers
Time Line in Geology – The Big Ideas
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Scientists divide Earth’s history into a geologic
time line.
In geologic time the smallest units are
measured in millions of years.
A million years is such a long time that it is
hard to comprehend.
The fossil record covers hundreds of millions of
years in Earth’s history.
Time Line in Geology – Using DE Science Content
• Exploration: Time line in Geology
• Video: Organizing Earth’s Past
• E Book: Earth’s Time Line
Life on Earth Over Time – The Big Ideas
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The fossil record shows that Earth’s species have
adapted and changed over millions of years.
The theory of evolution is based on the fossil
record and observations of species adapting and
changing.
Sudden changes in the fossil record indicate that
mass extinctions killed off some species.
The most widely accepted theory for mass
extinctions is a rapid change in the environment
from the impact of large meteors on Earth.
The fossil record shows that modern humans have
existed for much less than a million years.
Life on Earth Over Time –
Using DE Science Content
• Exploration: Life on Earth Over Time
• Virtual Lab: No Bones About It
• Video: Theories About Why Dinosaurs Became Extinct
Frozen in Time – The Big Ideas
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Some organisms have been found
completely intact, frozen in glaciers.
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Ice cores from the Arctic and Antarctic
contain evidence of living things and climate
conditions from tens of thousands of years
ago.
Frozen in Time – Using DE Science Content
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• Exploration: Frozen in Time
• Reading Passage: Drilling Back in Time
•Video: The Wooly Mammoth
Fossils – The Big Ideas
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Fossils are the remains, imprints, or traces of
prehistoric organisms.
The rock layer containing a fossil provides
information about a fossil’s age.
Fossils form when remains are replaced with
minerals or an organism leaves space in
sediment.
Preserved footprints, trails, or burrows of
prehistoric animals are trace fossils.
A fossil may give information about an area’s
environment during a period of Earth’s history.
Fossils – Using DE Science Content
• Exploration: Fossils
• Reading Passage: Make Your Own Fossil
• Video: What Are Fossils?
Rocks – The Big Ideas
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Rocks can be broken down into smaller pieces.
Rocks are made up of one or more than one mineral.
Based on how they are formed, rocks are classified into
three groups: sedimentary, igneous, and metamorphic.
Sedimentary rocks are made up of tiny pieces of shells,
rocks, sand, or other materials.
Igneous rocks are made when melted rock cools and
hardens.
Metamorphic rocks form under heat and pressure.
When rocks are created, changed, and destroyed, it is
called The Rock Cycle.
Rocks – Using DE Science Content
• Exploration: Rocks
• Video: Rocks: An Introduction
• Video: The Rock Cycle
Fossil Fuels – The Big Ideas
• Much energy comes from burning fossil fuels in
electric power plants and automobiles.
• Unless used carefully, fossil fuels produce pollution
as they are burned.
• Fossil fuels are a non-renewable energy resource
from a limited supply.
• Coal, petroleum, and natural gas are fossil fuels
formed from the remains of plants and animals.
• Conserving energy helps save non-renewable
resources and reduces pollution.
Fossil Fuels – Using DE Science Content
• Exploration: Fossil Fuels
• Virtual Lab: How Big is Your Footprint?
• Video: What Are Fossil Fuels?
Sunlight – The Big Ideas
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Sunlight is the source of energy for heat
and light on Earth.
Energy in almost every plant and animal
originates from the sun.
Sunlight is a renewable resource.
Humans capture and use sunlight directly,
but we are still trying to improve our
methods.
Sunlight – Using DE Science Content
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Exploration: Sunlight
Virtual Lab: How Big is Your Footprint?
Video: Trapping the Sun’s Energy
Alternative Energy Resources—
The Key Ideas
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We can get energy from a variety of natural
resources.
Renewable energy resources can be replenished
by natural processes.
Common renewable energy resources include
wind, solar, hydroelectric, geothermal, and
biofuels.
Alternative Energy Resources—
Using DE Science Content
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Exploration: Power Up
Virtual Lab: How Big Is Your Footprint?
Video: Alternatives to Fossil Fuels