Science Starter
Open your ISN to page 10 and answer
the following questions…
1. To which sphere do all of Earth’s
living things belong?
2. To which sphere do mountains,
valleys, and other pieces of land
belong?
Constructive and
Destructive Forces
OBJ: Summarize the effects of
constructive and destructive forces
Constructive Forces
• Forces that construct, or build up are
called constructive forces.
• Constructive forces shape the land’s
surface by building up landmasses.
• Earthquakes actually build landmasses
by lifting up mountains and rock.
Destructive Forces
• Forces that destroy and wear away
landmasses through processes like erosion
and weathering are called destructive
forces.
• Weathering is the process by which rain, ice,
wind, heat, and cold teat apart rock that is
exposed.
• Erosion is the wearing down and carrying
away land by natural forces.
Don’t be fooled…
• Lands are being constantly created and
destroyed by the two competing forces.
• Volcanic eruptions are considered both
constructive and destructive …. WHY?
• Can humans be destructive forces?