Download Earths Changing Surface

8.E.2.2
EARTH’S CHANGING SURFACE
WARM UP
Where does sea floor spreading occur?
 A. where 2 oceanic plates collide
 B. where an oceanic and continental plate
collide
 C. where 2 oceanic plates move apart
 D. where two continental plates move apart

QUIZ
1. _________ boundary is when 2 plates move
away from each other.
 2. _________ is when 2 oceanic plates move
apart.
 3. ________ occurs along the boundary of sea
floor spreading.
 4. Breaks or cracks in earth’s surface are called
_____
 5. Earthquakes occur as a result of _______
boundaries.

EARTH’S CHANGING SURFACE
What you already know:
 2 processes build up earth’s surface: folded
mountains and volcanoes

BREAKING DOWN EARTH’S SURFACE

Weathering- breaks rock into smaller pieces
2
types
Mechanical- breaking down rock by physical
means (water/wind causes rock to scrape
together, plants, and freezing water)
Chemical - breaking down rock as a result of
chemical reactions (runoff containing chemicals,
oxygen reacting to cause rocks to rust, acid rain,
BREAKING DOWN EARTH’S SURFACE

Erosion- a process by which weathered rock is
picked up and moved to new places
 Agents
of erosion: moving water, glaciers, wind, and
gravity
 Water
is a major agent: beach erosion, rivers
carving valleys
BUILDING UP EARTH’S SURFACE
Deposition- the dropping of pieces of
weathered rock carried by water, wind or ice
 Deposited material is called sediment

 Sediment
builds up to form landforms
 Floodplain- wide, flat area of land formed by
repeated floods
 Dune- a hill of sand deposited by wind