Transcript What are earthquakes?

1. What are
earthquakes?
1.
•
•
Earthquakes are
movement of earth’s
crust caused by plates
shifting and releasing
stored energy
Rocks on either side of a
fault snag and build up
pressure
When the rocks break ...
shake, rattle and roll!
2. What are seismic
waves?
2. Seismic waves are
shock waves in the
earth caused by an
earthquake.
3. What are P waves?
3. P waves are primary
waves. They are fast
and longitudinal
( push and pull forces)
•
P waves are the to 'arrive'
at a seismic station. The P
wave can move through
solid rock and fluids, like
water or the liquid layers of
the earth. It pushes and
pulls the rock it moves
through just like sound
waves push and pull the air.
4. What are S waves?
4. S waves are secondary
or shear waves. They are
slower. S waves are
transverse- move from
side to side.
S waves move rock
particles up and down,
or side-to-side—
perpendicular to the
Direction of the wave.
5. What are L
waves?
5. L waves are “love waves”
•
•
Named after a
British scientist who
calculated a
mathematical model
for a wave.
L Waves are the
fastest waves and
move from ground
to side to side. In
other words, they
are P or S waves
that hit the surface.
6. What is the focus
of an earthquake?
7. What
is the epicenter?
6. The
focus is
where rocks first
break and move.
7. The Epicenter is the
point on earth’s surface
directly above the focus.
Earthquakes
8. What is a
seismograph?
8. A seismograph is
an instrument used
to record seismic
waves.
Earthquake Scales
9. What is the
Richter Scale?
9. A Richter Scale
measures the total
energy released by
an earthquake
b) +1 means x32
Earthquake Scales
10. What is
10. The Mercalli Intensity Scale is
the Mercalli
Intensity
Scale?
a scale that measures the
intensity of an earthquake. The
scale quantifies the effects of
an earthquake on the Earth's
surface, humans, objects of
nature, and man-made
structures on a scale of I
through XII, with I denoting a
weak earthquake and XII one
that causes almost complete
destruction.
Earthquake Zones
11. Where
are the 3
major
earthquake
zones?
11.
• Ring of Fire- is located around
the edge of the Pacific Ocean.
• Mid-Atlantic Ridge- this zone
is caused by sea floor
spreading
• The Mediterranean –Asiatic
Belt- occurs because
continental plates are
colliding.
Earthquake Evidence
12. Describe 12. Ground level earthquake
evidence is side to side or up
ground
and down shifts of the ground.
level
The earth has moved mostly
earthquake
slow and steady and is called
evidence
creep
Earthquake Evidence
13. Describe 13. There are 5 descriptions:
landscape • Slide – rapid down slope
movement of soil, debris, &
evidence of
rock
earthquakes
• Scarp – cliff made by uplifted
.
or subsided earth
Earthquake Evidence
13.
13.
• Fissures – long cracks in soil
or rock
• Tsunami – an ocean wave
caused by earthquakes
a) can be 30m high at the
shore
• Buildings on loose soil have
more damage.
Volcanoes
14. What is
a volcano?
14. A volcano is any opening in
the earth’s crust that release
molten rock.
Volcanoes
15. What is
a vent?
16. What is a
crater?
15. An opening through which
material reaches the
surface
16.
A crater is a
hollowed out area in the
top of a volcano
Volcanoes
17. What is
the pipe?
17. The pipe is a long
crack through which
magma moves
18. What is
the magma
chamber?
18. A chamber with a
pocket of magma.
Volcanoes
19. What is an 19. An active volcano has
active
erupted during the last
volcano?
century.
20. What is a
dormant
volcano?
20. A dormant volcano has not
erupted for hundreds of years,
but it believed that it has the
ability to erupt.
http://www.geocodezip.com/v2_activeVolcanos.asp
Volcanoes
21. What is an 21. A volcano is considered
extinct
extinct if it has not
volcano?
erupted for thousands of
years.
http://hvo.wr.usgs.gov/volcano
es/maunakea/
Volcanoes
22.List the
sequence of
events when
a volcano
erupts?
22. Lava flows out –usually gently
and quietly
2) Then an explosion of debris
occurs. The following are
products of a volcano
•
pyroclasts – fragments of
broken rock from a volcano
• ash – hot fine-grained
material
• bombs – large molten or
semimolten chunks
Volcanoes
23. What are
cinder cone
volcanoes?
23. A cinder cone formed from
ash and cinders in explosive
eruptions. Cinder cones
volcanoes are smaller, coned
shaped, and steep slopes.
Example:
• Paricutín, Mexico
Volcanoes
24. What are
shield
volcanoes?
24. Shield
volcanoes are from
from lava flow eruptions. They
have broad with gentle slopes.
• An example is
Muana Loa, Hawaii
Volcanoes
25. What are
composite
volcanoes?
25. Composite volcanoes are formed from
alternating layers of lava and pyroclasts.
Characteristics include:
•
They are explosive and have
lava eruptions
• They are large with steep
slopes
Examples:
Mt. Fuji, Japan & Mt. St.
Helens, Washington
26. Case study: Pompeii
26.
•79 CE
•Site was not discovered until 1748
•Provided archeologists
extraordinary details about daily life
in Roman Empire
•Some believe that volcano took 2
months to completely bury the town
as people were “found” wearing
winter clothing in the summer, dates
of minted coins and letters
•Populist tourist site in S. Italy
27. Case study: Mt. St. Helen
27.
•Erupted 05/18/1980.
Caused by an earthquake
on 03/20/1980.
•Most deadliest and costly
volcano in US history.
•“Glacier mountain”
•Due to the eruption, at the
top of the mountain is a 1
mile long horseshoe
crater.
•Volcano “steamed” until
January 2008
Igneous Rock Features
28. What are batholiths?
28. Large intrusive igneous
rock body that forms when
magma being forced upward
toward Earth’s crust cools
slowly and solidifies
underground.
29. What is a dike?
29.Magma that is
forced into a crack
that cuts across layers
and hardens.
30. What is a volcanic neck?
30. Solid igneous core
of a volcano left
behind after the softer
cone has been eroded.
31. What is a
Igneous
caldera?
31.
Large, circularRock Features
shaped opening
formed when the
top of a volcano
collapses. Crater
Lake is an example