Constructive and Destructive Forces
Study Guide
1. Define all the vocabulary and definitions:
*Plate:pieces of earth’s crust that fit together like a puzzle
*Fault: crack in earth’s surface, where earthquakes or mountains usually
form
*dam: human made structure across a river that stops the flow of water. A
lake forms.
*levee: human made structure. Wall of earth or concrete that prevents
floods. Channels water.
*epicenter: point on earth’s surface where we feel the most damage from
an earthquake.
*magma: molten rock underneath the crust
*lava: magma that reaches earth’s surface
*volcano: mountain made of lava, ash, and other materials
*earthquake: the sudden of movement of earth’s crust or sudden release of
energy on the earth’s crust
*jetty: human made wall that sticks out into the ocean. prevents beach
from eroding
*seismologist: scientist who studies earthquakes
*erosion: carrying away of sediment by wind, water, ice, gravity
*deposition: dropping off and piling of sediments
*weathering: breaking down of earth’s crust or rock
2. Write and describe what constructive and destructive forces are and give
examples.
Constructive force: is a force that builds up the land ex. volcano, floods,
earthquakes, deposition
Destructive force: force that breaks down earth’s crust ex. volcano,
sinkhole, tornado, tsunami, hurricane
3. How can an earthquake be constructive and how can it be destructive?
Constructive: forms new landforms such as mountains
Destructive: destroy cities, buildings, and can take lives
4. What is the difference between lava and magma?
lava is magma when it reaches earth’s surface, magma is beneath the
surface
5. How can volcanoes help build up new land?
Lava can build up and form layers of new earth.
lava cools and hardens and builds up the land.
6. How can we save our beaches? Give an example of a human intervention.
Build more jettys to prevent erosion. Dig and place sand on the beaches
(beach restoration). Plant sea grass to grow roots which will prevent
erosion.
7. How can we control flooding? Give 2 examples and describe how they help
control flooding. Build a dam, which will form a lake and excess water can
build up. Build levees, which will hold back excess water. Flood plains give
room for flooding into open land.
8. Draw and label Earth’s layers.
Plates float on the mantle.
The crust is made of plates.
9. What are the causes of weathering? Causes of erosion?
weathering: plants, wind, water, ice
erosion: wind, water, ice, gravity