CHAPTER 4 – INTRODUCING EARTH

WHAT ARE THE MAIN PARTS OF THE EARTH SYSTEM?

A system is a group of parts that work together as a whole

The Earth system involves a constant flow of matter through different parts.

In your groups come up with two systems that you are made of a constant flow of matter (in these systems nothing is ever created or destroyed it only changes form). Write it on your white board Water cycle and Rock cycle

This constant cycle of matter through the Earth system is driven by energy.

Energy is the ability to do work. There are two main sources of the Earth’s energy.

1. Heat from the sun2. With your group come up with one answer that tells what the other source is and write it on your white board.Heat flowing out of the Earth as it cools.

How do these two sources of energy differ?They flow in opposite directions

PARTS OF THE EARTH SYSTEM

The Earth system has four main spheres: the atmosphere, the hydrosphere, the geosphere, and the biosphere. As a major source of energy for Earth processes, the sun can be considered part of the Earth system as well.

Humans greatly affect these systems. With your group list one way that humans affect each sphere. Write it on your white board.

P138-139

Read the section about each sphere – highlight the definition and write at least one way that they interact with other systems.:

Atmosphere Geosphere Hydrosphere Biosphere

FEEDBACK WITHIN A SYSTEM

When feedback occurs, a system returns- or feeds back – to itself data about a change in the system.

Feedback demonstrates how changes in one part of the Earth system might affect the other parts.

FORCES THAT SHAPE EARTH

CONSTRUCTIVE AND DESTRUCTIVE FORCES

Lands are constantly being created and destroyed by competing forces. Forces that construct, or build up , mountains are called constructive forces.

Constructive forces shape the land’s surface by building up mountains and other landmasses

Can you think of any constructive forces? Write one on your white board.

Volcanoes build up Earth’s surface by spewing lava that hardens into rock. Earthquakes build landmasses by lifting up mountains and rocks.

ANSWER WITH YOUR GROUP ON THE WHITE BOARDS Why don’t mountains just keep building up

higher and higher? The constructive forces that build them

change. Competing destructive forces have the opposite effect of constructive forces and keep them in balance

How does wind act to destroy land? Blowing wind carries sand that wears away

rock. It picks up rock particles and carries them away.

Can humans be destructive forces? How? Yes. They break up and clear away rocks and

soil to get raw materials and build roads and structures.

Because forces such as ice, rain, wind and changing temperatures wear down, or destroy, landmasses, they are called destructive forces.

Destructive forces destroy and wear away landmasses through processes like erosion and weathering.

Can you think of any destructive forces? Write one on your white board.

Erosion is the wearing down and carrying away of land by natural forces such as water, ice, or wind.

OUR CHANGING PLANET

TICKET OUT THE DOOR

ON an index card, explain how constructive and destructive forces are related to two spheres (atmosphere, geosphere, hydrosphere, biosphere) of the Earth system.

Homework: P139 and 141 assess your understanding

THE EARTH SYSTEM

Read “Yellowstone’s 1988 Forest Fire and answer the questions that follow in your science notebook.

QUIZ REVIEW(P141F):

Answer the questions in your notebook as your teacher reads them out loud.