Download Earthquakes PPT

Layers of the Earth: REVIEW
• LITHOSPHERE
• Oceanic Crust
• Continental Crust
• ASTHENOSPHERE
• Upper layer of the Mantle
• Where CONVECTION occurs
• Mantle
• Outer Core
• Inner Core
OCEANIC Crust
-MORE DENSE
-Mostly Made of Basalt
CONTINENTAL Crust
- LESS DENSE
- Mostly Made of Granite
BASALT is MORE dense
than granite.
Therefore, Continental
Crust
“RIDES”
On Oceanic Crust
Plate Interactions - REVIEW:
CONVERGENT >>>> <<<<<
• Oceanic to Oceanic – Mid Ocean Ridges
• Continental to Continental – Mountains
• Oceanic to Continental –
Volcanoes & E-Quakes
DIVERGENT <<<<< >>>>>
• Sea Floor Spreading (New Earth)
• Volcanoes
TRANSFORM ----------
---------• E-Quakes
SUBDUCTION ZONES:
“SUBDUCT” – To Go Beneath
Oceanic Crust is MORE DENSE and SUBDUCTS beneath
CONTINENTAL CRUST
Subduction Zone faults are the LONGEST and WIDEST in the
world.
E-Quake size is directly related to Fault size
HUUUUUGE Boundaries – Generate Large E-Quakes
Ring Of Fire
SUBDUCTION ZONES occur all around
the edge of the Pacific Ocean.
Responsible for the world’s
• BIGGEST E-Quakes
• MOST TERRIBLE TSUNAMIS
• Some of the WORST VOLCANIC
ERUPTIONS
Earthquakes
Plate boundaries are made up of
many FAULTS.
A FAULT is a BREAK in the Earth’s
CRUST.
Most Earthquakes occur along
FAULT LINES.
**Not all cracks in rocks are faults.
A FAULT IS DEFINED BY THE
MOVEMENT OF ROCK OCCURINGON
EITHER SIDE.
When the MOVEMENT is SUDDEN, the
ENERGY released causes an
EARTHQUAKE.
San Andreas Fault line viewed from Space
ENERGY is STORED when FAULT edges are STUCK
together
FORCE of MOVING blocks < FORCE of FRICTION
ENERGY is RELEASED and RADIATES outward in all
directions
https://www.iris.edu/hq/inclass/animation/earth
quake_wave_analogies_like_ripples_on_water
Energy released during the Taiwan
Earthquake
3 Types of Faults : Classified by HOW the two slabs of rock MOVE relative to each other.
Strike-Slip – Vertical Fractures where plates
move HORIZONTALLY past each other
(side-to-side motion)
Normal – Develop where land is PULLING
APART or stretching. One block of land SLIPS
DOWN relative to the other.
Reverse – Develop where land is being
COMPRESSED. One block of land is PUSHED
UP relative to the other.
Seismic waves are the waves of energy caused by the sudden breaking of rock.
Travel through
Earth’s INNER
layers
Travel along the
Earth’s SURFACE
BODY
WAVES
P Waves:
FASTEST
First to Arrive
Move through
SOLIDS & FLUIDS
Pushes and Pulls
Rock
Animals Can
Hear them
S Waves:
SLOWER
SECOND to arrive
Can only move
through SOLIDS
Moves UP & DOWN
or SIDE- to -SIDE
Arrive AFTER
Body Waves
Earthquakes
RADIATE
ENERGY as
waves.
SURFACE
WAVES
Love:
FASTEST
Moves Ground
from side-to-side
Responsible for
DAMAGE and
DESTRUCTION
Rayleigh:
ROLLS along the ground.
Moves ground UP & DOWN
LARGER than other waves
Creates SHAKING we feel
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1009/es1009page01.cfm
Richter Scale
Major factors that affect the intensity of an
earthquake.
The greater the magnitude, the greater the intensity
near the epicenter.
A single earthquake can produce a range of intensities
from I to XII.
The intensity decreases as the distance from the
epicenter increases until there is no affect felt by the
earthquake.
Earthquakes can have a range of intensities but only
one magnitude.