Download CHANGING EARTH NOTES

CHANGING EARTH
NOTES
Key Idea: Interaction over short and long times
brings continuous change to the lithosphere.
I. Continental Drift
** What was the continental drift hypothesis and what
evidence was there for it?
A. Wegener
- Suggested by ___________________________
- Hypothesis: Proposed that the land used to be
connected and that the ____________________
moved to their current position. He named this giant
continent ______________________.
B. Evidence
Initial Evidence that Continents were Once Joined
- ________________________________
- ________________________________
- ________________________________
- ________________________________
- ________________________________
10
II.
More Evidence
** What evidence was discovered after Wegener’s death?
Newer Evidence that the Plates are Moving
- 1940’s : _________________________:
__________________________________
- 1960’s: _________________________:
__________________________________
- ___________________________________
- ___________________________________
- ___________________________________
III. Plate Tectonics Theory
**What was Wegener’s hypothesis updated to and what
force was discovered to support it?
-VW: tectonics:
____________________________________
______________________________________
-VW: scientific theory:
- is an __________________ of observations or
events that is based on _____________________
gained from many observations and investigations
(a ________________ ________________).
- Is generally accepted as true until disproved.
11
Revised June 2014
-VW: lithosphere:
______________________________________
______________________________________
A: The Theory:
- Theory of ____________________ : moving
tectonic plates, not just continents, is the present
theory.
- The ____________________ is broken into these
plates.
- There are about __________ plates and they move
about ________________ a year.
B: The Force:
-The force that moves the plates (that Wegener could
not explain) is basal drag, caused by
__________________ _______________.
-This happens in the “plastic” _________________.
- Ridge push and slab pull are also forces acting on the
plates.
-VW: density: (D = M/V)
______________________________________
______________________________________
12
Revised June 2014
- VW: convection - The transfer of _________________
energy by the movement in a ______________
or a ___________, such as magma, water, or air.
- As particles are heated they move _____________ ,
become ____________ dense, and
_____________.
- There they get _________________, move
______________ , become _____________
dense, and _____________.
** QUIZ ONE**:
Date_____________ , _________ _____
Pages: ________ - _________
IV. Plate Movement
** How does the movement of Earth’s plates explain
landforms, earthquakes, and volcanoes?
-Plates may _________________, ___________
______________, or _____________________
past each other.
13
Revised June 2014
- _____________________ __________________,
________________, _________________,
________________________ (ocean basins),
or ___________- ________________
________________ are geological features that
may result.
Direction Result
Crust
 
New crust
Boundary
created
Crust is neither

created nor
destroyed
Crust may be

destroyed
14
Revised June 2014
VW: Mid-Ocean Ridge – ______________________
________________________________________
VW: Trench – _____________________________
________________________________________
V. Geological Events:
** What events happen because the plates move?
A) Mountain Formation
- Displaced _________________________
____________________ suggest past crustal
movement.
1. _______________ Mountains
(pushed up on each side)
2. ________________ Mountains
(magma pushed up from underneath)
3. ________________Mountains
(cracked and then pushed up)
4. ________________ Mountains
(erupting or has erupted in the past)
5. ________________ Mountains
(the summit has eroded away)
15
Revised June 2014
B) Earthquakes
- ________________________ of Earth’s
crust along lithospherical plate boundaries
- Fault: results from ____________________
______________________ movement.
- Most happen at ___________________
_____________________________
- An earthquake’s ________________ is
measured on a ________________ and
rated on a ________________ Scale
- Underwater earthquakes are one cause of
________________.
- Earthquake Waves are used to infer what the
Earth’s ______________ are composed of.
- P waves are primary waves and S waves are
secondary waves - both produced during
earthquakes. ___ __________ travel at
slower speed.
- Earthquake Safety
- If inside: get under a _______________ /
stay away from __________________.
- If outside: get in an ________________/
away from ______________________.
16
Revised June 2014
C) Volcanoes
- An opening in the surface of one of Earth’s
plates through which ______________
rises.
- One plate ________________ beneath
another at a plate boundary. The sinking
crust ______________________ into
magma.
- Pressure builds up from ______________
trapped in magma.
- Many happen on the _________________
__________________________ (Ring
of Fire). Others happen at Hot Spots.
- Magma – molten rock __________ Earth’s
surface.
- Lava – magma that ______________ the
surface.
D) Geysers
- Magma trapped in the lithosphere heats
ground water. ________________
spews from the crust.
17
Revised June 2014
** QUIZ TWO**:
Date_____________ , _________ _____
Pages: ________ - _________
VI. Maps
** How can maps help us understand Earth?
Be able to……
……. read latitude and longitude
18
Revised June 2014
….. read topographic maps
- Shows ________________________ above
sea-level.
- Contour lines – find the intervals
- The closer the spacing, the _________________
the mountain.
- Know how to use the distance key.
** UNIT TEST**:
Date_____________ , _________ _____
Pages: ________ - _________
19
Revised June 2014