Download Plate Tectonic Theory

Plate Tectonic Theory
Alfred Wegener is the man who studied this
• All continents used to fit together like puzzle pieces (called
it Pangaea)
The continents a long time ago
The continents now
See the Continents & oceans are on top of plates that are
STILL drifting (Get it?- Continental drifting)
• Plates
movingmountainsHow
can cause volcano
eruptions,
earthquakes,
plates
move- Plate
•
Boundaries – look at the arrows to see which way the plates
are moving
Continental Drift Theory Evidence
W egener also
prop osed that
continental drift
theory could be
supported by the
following eviden ce:
S imilar fossils on
neighb oring
coastlines
S imilar rock
laye rs on
neighb oring
coastlines
Mat ching of
coastline sh apes
Rock Layer Evidence
• That rock layers and geological features
on now distant continents match up where
they were once joined.
Matching of coastline shapes
Evidence
• That the continents are shaped in ways
that could have once fit together.
• Notice the
similarities in the
rock layers.
Fossil Evidence
• Pay close attention to the fossil remains of the
organisms. On which continents are the same types of
fossils found?
Convection
currents
If something like air or magma is
heated it rises and when it cools it
sinks.
LOOK for these arrows TO LET YOU KNOW
IT’S CONVECTION CURRENTS
This is called a rising and sinking action that
happens inside Earth’s mantle when magma
is heated inside Earth’s HOT core and it rises and sinks
when it cools.
Convection currents cause PLATE MOVEMENT!!!
C onvergent boundary of two continental plates. F orms
H imalayas
a ______
folded mountain range. Examples: ___________,
Appalachians
A lps, ______________
Convergent boundary of two oceanic plates.
Creates an island
________
arc and a trench
_____. Example: _____
Japan
Divergent boundary of two continental plates.
Creates a __________.
Example: _____________
rift valley
East African Rift
Transform-fault boundary where the North American
and Pacific plates are moving ____
past each other.
San Andreas Fault in California
Example: ________________
Convection Currents
Curre nts
These c onvec tion c urrents are resp onsible for plate
mov ement
Pla
Platte
eB
Bo
ound
unda
aries
ries
• D ive rg e n t Bo u n d a ry – m o vin g a_p_art
___
to ge
• C on ve rg e n t B ou n d a ry – m o vin g __
_ _th_e_r_ _
• T ra n sfo rm F a ult B ou n d a ry – m o ving
e r_ _ _ _
_ _ _s_ide
__w_a_ys
_ _p_as
__t e_a_ch
_ _oth
__ _
ROCK LAYERS- Just remember
if the layers are NOT disturbed, the oldest layers
will be at the bottom, Younger layers are at the
top.
This is the Law of
Superposition.
In this diagram, glacial deposits-youngest, Granite- oldest
If the layers are disturbed, they kind of shift around a bit. You might see layers
that overlap because of plate folding and faulting.
These rock layers are look like this
because of folding and faulting due to
plate tectonics (plates moving around)
TYPES OF ROCK
3 MAJOR TYPES
All come from
IGNEOUS
ROCK- rock that
comes from cooled
magma
Sedimentary Rockigneous rock that erodes or weathers
because of wind and water. The
sediment (broken down rock) washes
away and ends up at the bottom of
lakes, streams, and oceans.
Metamorphic rock- this kind of rock forms
because igneous and sedimentary rock get put
under a lot of heat and pressure and changes its
form.
Marble is a type of metamporhic rock
A pretty cool diagram
that shows you how all 3
rock types are formed.
Pay attention to “A” as you see it pushing through
the other rock layers. “A” will usually be the
YOUNGEST layer. (This is an igneous
INTRUSION)
Look at layers D, E, F, G, and H. These layers are
not the same across because they have been
“broken” due to the rock layers FAULTING
The Four Layers of
Earth
The Earth is
composed of four
different layers:
The crust is the layer
that you live on.
The mantle is much
hotter and has the
ability to flow.
The outer core and
inner core are even
hotter with very great
pressures!
Hot spots are places in the earth’s mantle where the hot rock or
magma, continually rises and melts through a plate..
You won’t find a hot spot between the boundary of 2 different
plates. You find hot spots breaking through the middle of a plate,
whether that is in the middle of a continental plate like
Yellowstone or in the middle of an oceanic plate like Hawaii
• If a hot spot is below the ocean floor, it may
create a volcanic island.
Ex. Hawaiian islands
• The hot spot doesn’t move. The PLATES
are moving so that means the hot spot in
Hawaii changes as it continues to make new
islands.
• This is a picture of a
GEYSER in Yellowstone
National Park (in United
States). There are more
than 500 geysers in
Yellowstone national
park.
• GEYSERS are water
sources over hot spots that
become heated and
periodically shoot HOT
water and steam into the
air.
Big Bang
Theory
This is just a theory they came up with to explain how the universe
was formed over 13.7 billion yrs ago (theories can be proven wrong if somebody finds some
more information)
Says there was this big explosion from some tiny little particles that
came together…BOOM!...we get the start of the universe
o Everything in the universe started from the Big Bang…stars,
planets, galaxies
o
Red Shift-everything is expanding or getting bigger (this is what
the universe is doing)
Blue Shift- things are coming inward or getting smaller
Formation
of Stars
Gravity pulls hydrogen gas and dust into a
single spinning cloud.
As the particles crash into each
other, the matter heats up….about
15 million degrees- that’s really
hot!
This is called
Fusion…..
The mass begins to shine brightly.
A star is born!
……a brand new star….notice the color
Hydrogen in stars FUSES together
and releases HUGE amounts of
ENERGY. This is called FUSION!
Stars contain hydrogen that fuse together to
release huge amounts of energy (FUSION)
Age and Temperature of Stars
The Color of a Star can tell you a couple of things about a star:
1. the relative age
2. the temperature
Stars
Blue stars are the
youngest and hottest
Yellow stars are middle
age and medium
temperature (Our Sun is
a middle aged star)
Red stars are the oldest
stars and are cool in
temperature
Colors a nd Temperatures
Blue
Hottest
Yellow
Medium tem pera tu re
Su n
Red
Coolest
What happens when a star gets old?
The fuel runs out, no more fusion can take place,
gravity collapses the core of the star
How long will a star live?
Our sun, a medium sized star, will live
about 10 billion years.
Small stars will live about 100 billion years.
Large stars will only live a few billion years..
The iron core absorbs energy instead of releasing it….
The star breaks apart in a massive
EXPLOSION!!!
The star is now a
SUPERNOVA!
Convection Currents and
Tornadoes (Over LAND)
What is a tornado?
A
tornado is a
violent whirling wind
that moves across
the ground in a
narrow path.
How a re Tornadoes formed?
Late
in the day , when earth’s surf ace is
very warm, con vectio n (The f low of h ea t
thro ug h a materia l, ca using ho t pa rts to
rise a nd co oler parts to sin k.) can get
very stro ng. This ca n lead to a to rnado .
Where Do Tornadoes Happen?
Tornadoes
happen where dry, cold air
masses mix with warm, moist air masses.
More
tornadoes occur in the United
States than in any other country,
especially in the area known as
TORNADO ALLEY.
A tornado can flatten and destroy ANYTHING in its path!
Here are pictures of the devastating aftermath of the tornado that just hit Lake Township,Ohio…
Tornadoes
Tornadoes form
when warm moist
air meets cool dry
air. When the 2 air masses meet, they create an
unstable atmosphere with strong and violent winds.
ConvectionCurrents
and
HURRICANES!(Over Water)
Development of Hurricanes
They develop most often in the late summer
when water temperatures are warm
enough to provide the necessary heat and
moisture to the air.
The StepsinHurricane Formation
1. Warm air above the
water rises and cools to
form clouds.
2. More warm air comes in
from all sides to
replace the air that was
rising. (This inward
wind rotates . This is
why hurricanes look
like pin-wheels)
3. Hurricanes use energy from the warm ocean water
to grow stronger. As long as it has warm water a
hurricane will continue to grow.
Hurricane Katrina
Different Termsfor aHurricane
• Hurricanes are called by different names in the
different regions of the world
–In
In the Atlantic or Eastern Pacific Ocean
• They are called..."hurricanes
called..."hurricanes"
hurricanes"
– Western North Pacific and
Philippines
• called "typhoons
"typhoons“
typhoons“
– Indian and South Pacific Ocean
•They
They are called… "cyclones
"cyclones"
cyclones"
Lake Effect Snow
How is lake-effect snow formed?
As the cold air flows over the warm lake water, the warm water heats the air's bottom layer as
lake moisture evaporates into the cold air. Since warm air is lighter or less dense than cold air, the
heated air rises and begins to cool. As the air cools, the moisture that evaporated into it condenses
and forms clouds and snow begins falling from the cloud if the air is humid enough.
Cold air moves over warm water
and is warmed from below. Moisture
Warm moist air rises downwind of lakes and forms
evaporates in the air.
heavy snow.
Lake Effect Snow
You’ll more than likely be asked to know this!
This is when you have VERY cold dry air moving over a lake
that is warmer…the air picks up the moisture from the lake and
then dumps off that extra moisture it picked up as a whole lot of
SNOW on whatever poor city is sitting next to that lake!!
They like to give you OHIO and ask you what city will get
more lake effect snow. ALWAYS pick the city that is closest
to the lake and more to the east of the lake (that would be the
right side)
Take a look at the storm system (in green) moving across the
lake. Which city IN OHIO do you think is going to get hit the
worst with snow?
Tsunami (Soo-Na-Mee) EARTHQUAKE UNDER
WATER CAUSING A HUGE WAVE!
What Causes a Tsunami?
Tsunami means "harbor wave" in Japanese. A tsunami is formed in the sea. It is triggered by a disturbance in
the ocean floor. Most tsunamis are caused by earthquakes.
Arid
Means
something is
dry
Deserts are called
ARID because IT
GETS VERY LITTLE PRECIPITATION (any form
of water).
Droughts can cause arid conditions because there is
little to no rain.
Erosion
Erosion happens when materials in the landscape are
moved from one place to another.
Farmers will plant “cover crops” like this one to stop
their soil from eroding or washing away before they can
plant their next crop
wash
This cliff can have wind and
water erosion. You’ll have
pieces of the cliff erode or
away.
The Ozone Layer
This is a layer that surrounds our Earth and protects us from the Ultraviolet
(UV) rays of the sun. Too much UV from the sun can cause skin cancer
and just make you sick!
We must stop using things that destroy the ozone layer. If we keep
tearing up (DEPLETING) our ozone layer we won’t be protected from the
UV rays. NO CFCs!!!!
These are bad!!!
A GIANT
UMBRELLA OVER THE
EARTH
We can protect ourselves from the harmful
UV rays by wearing sunblock and the right protective clothing.