2. WHAT IS AN EARTHQUAKE AND
VOLCANO?
Moment of Crust
Rupture of Crust
3. FORMATION OF EARTHQUAKE
Two blocks of the earth
suddenly slip past one
another.
Terms related:
• fault plane
• hypocenter
• epicenter
• foreshock
• mainshock
• aftershocks
5. Lithosphere of Earth is
broken into plates
• Study of movement and
interaction of plates:
Plate Tectonics
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•
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Zones of plate-edge
interactions are
responsible for most
earthquakes, volcanoes
and mountains
Divergence zones
– Plates pull apart
during seafloor
spreading
Transform faults
– Plates slide past one
another
Convergence zones
– Plates collide with one
another
The tectonic plates of the world were
mapped in the second half of the 20th
century
6. Earthquake Hazards
• Ground shaking
• Tsunamis
• Landslides and Rockfalls
• Subsidence and lateral spreading
• Liquefaction
7. TSUNAMIS
TSUNAMIS CAN BE GENERATED
BY:
•
Large Earthquakes (megathrust
events such as Sumatra, Dec.
26, 2004)
•
Underwater or near-surface
volcanic eruptions (Krakatau,
1883)
•
Large landslides that extend into
water (Lituya Bay, AK, 1958)
•
Large undersea landslides
(evidence for prehistoric undersea
landslides in Hawaii and off the
east coast of North America
8. FORMATION
OF VOLCANOES
Chemical composition
(largely silica dioxide sio2 - content)
And
Gas content (largely
water vapor and co2).
Sio2 content controls
the viscosity of a magma.
The greater the
viscosity the more gas
in the magma.
There are three basic
types of magma:
Andesitic
Rhyolitic
Basaltic
Magma
Magma
Magma
10. TYPES (ON BASIS OF ERUPTION
Large amounts of gas and a
Small amounts of gas and low
viscosity (runny) magma will form
high viscosity (sticky)
an effusive eruption
magma will form an
explosive eruption
Where the magma just trickles
out of the volcano (lava flow).
Think about shaking a
carbonated drink and then
releasing the cap.
11. 3 States of Volcanoes:
Extinct Volcanoes
e.g. Zuidwal volcano in the
Netherlands, Emperor seamount
chain in the Pacific Ocean etc.
Dormant Volcanoes
e.g. Kilauea (Hawaii)
Mt. Etna (Italy)
Active Volcanoes
e.g. Mauna Loa etc.
Fourpeaked volcano, Alaska, in
September 2007, after being thought
extinct for over 10,000 years
12. Composite
Cinder Cone
Shield
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•
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•
Mt. Rainier, Washington
Tens of miles across and ten
thousand or more feet in height.
Tall cone shaped.
High in silica
High viscosity magma
High levels of gas
Highly explosive.
Formed by layers of lava and ash.
Caused by viscous magma.
Actually, a mix of basaltic and
rhyolitic magmas in many cases.
13. Mt. Fuji, Japan
Mt. St. Helens, Washington
•
After an eruption a large caldera
remains.
•
Crater lake is a caldera that remains
following an explosive eruption 7,700
years ago
•
The eruption was 42 times more
powerful than Mt. St. Helens.
14. SHIELD VOLCANOS
•
Huge in size
•
A broad shaped, gently
sloping cone is formed, but
have low slopes.
•
Flattened mound
•
Resembles a warrior’s
shield.
•
Low silica level.
•
Dominated by fluid, high
temperature, low viscosity
basaltic magma
•
High or low levels of gas.
•
No pyroclastic material. This
makes the eruption relatively
safer.
15. Muana Loa Volcano – the world’s largest volcano.
Photograph by J.D. Griggs on January 10, 1985
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•
Over 30,000 feet above sea level.
Most active and planet's largest volcano
16. •
•
Relatively cool basaltic
magmas or andesitic magmas
predominate..
•
Low silica lava
•
“Fire-fountain” eruptions
•
Commonly found on the flanks of
shield volcanoes
Steep conical hill formed above
a vent.
•
•
Structurally weak.
•
gaseous magmas.
Small volcanoes.
•
Dominated by viscous,
Range from several meters to
over 300 m in height
•
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Circular or oval cones.
Made from a pile of rock pieces
Mount Edziza, British Columbia
17. Puu OO, Hawaii
Pu'u ka Pele, Hawaii
(on the flanks of Mauna
Loa)
Floreana Island, Galapagos
18. Lava domes
•
Lava is too viscous to
flow to a great distance.
•
Lava pile within.
•
When a lava dome is
grown to a significant
extent, it shatters the
outer surface, which
results in spilling loose
fragments towards its
sides.
•
Found on the flanks of
larger composite
volcanoes.
19. Volcanic Hazards
•
•
Ash flow
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Land sliding
•
Noxious Gas
•
flows down slope.
Lava flow
•
and other volcanic debris that
Pyroclastic fall
•
Water saturated slurry of ash
Lahars/Mud flows
•
LAHARS
Pyroclastic flow
Earthquakes
20. Pyroclastic Flow:
•
A pyroclastic flow is a fastmoving (up to 700 km/hr)
extremely hot (~1000°C) mass
of air and tephra that charges
down the sides of a volcano
during an explosive eruption.
•
Cinders.
•
Ash and dust.
Pyroclastic flow at Mount St. Helens,
Washington, August 7, 1980.
21. Volcanic ash fall
during mid-day with
the eruption of
Mount Pinatubo in
the Philippines.
Pahoehoe: Lava with a ropelike surface
texture due to partial cooling as the lava
flowed. Relatively hot, low viscosity
lava.
A hot, gaseous cloud of ash that
flows down slope Flow speeds
can reach 160 km/hr and
temperatures can exceed 600
degrees C.
22. WORLD WIDE EARTHQUAKES AND
VOLCANOES
• 2010 Chile earthquake.
• Magnitude of 8.8.
• Is at a convergent plate
boundary that generates
megathrust earthquakes.
Railway track disturbed by
Earthquake.
23. •
Fault between
the pacific and
north American
plates ruptured.
•
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Shifts created
large tsunamis (u
p to 220 feet (67
m) in height.
•
Alaska Earthquake 1964
Liquefaction.
Losses
The number of
deaths from the
earthquake totalled
131; 115 in Alaska
and 16 in Oregon
and California.
24. Great East Japan
Earthquake
Effect Of Earthquake On Tokyo Tower.
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Nuclear and conventional
power plants went offline.
1000 aftershocks.
15,882 deaths, 6,142 injured.
129,225 buildings totally
collapsed, with a further
254,204 buildings 'half
collapsed.
•
Magnitude 9.03
Undersea megathrust
earthquake off the coast
of japan.
The quake moved portions
of northeastern japan by as
much as 2.4 m (7.9 ft) closer
to north America, making
portions of japans' landmass
25. Mt. Fuji, Japan
• A Stratovolcano that has erupted 16
times since 781 AD.
• The most recent eruption was in 17071708
•0.8 cubic km of ash, blocks, and bombs
were ejected during that eruption.
26. •
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Just southeast of Hawaii is an
undersea volcano known as loihi
Until 1996 loihi was thought to be an
inactive seamount.
It began erupting in 1996 and the
eruptions were preceded by a cluster
of small earthquakes indicating the
movement of magma.
The modern active island rests
close to the hot spot and its shield
volcanoes are fed from the magma
that the hot spot generates.
27. •
•
•
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The Kilauea volcano erupted, with a fissure throwing lava up more than 20 meters
towards the sky in a dazzling display of volcanic power
•
Lava 65 feet
in the air.
Sulphur oxide
and other
volcanic gases
are continuing
to erupt .
Kilauea is the
youngest
volcano in
Hawaii and
could be the
world’s most
active volcano
and has
erupted 34
times since
1952.
Has been
erupting
consistently
since January
1983.
28. Mount Pinatubo, Luzon,
Philippines – 1991
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Stratovolcano.
Explosive eruption.
Ejected more than 1 cubic
mile (5 cubic kilometers) of
material into the air and
created a column of ash that
rose up 22 miles (35 km) in
the atmosphere. Ash fell
across the countryside, even
piling up so much that some
roofs collapsed under the
weight.
Nevado del Ruiz Volcano,
Colombia—1985
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Second most devastating volcanic
eruption in the twentieth century.
Result of a lahar.
An ice-cap volcano.
Ice melted and a huge flood.
Boulders 32 feet-high still litter the
landscape around Nevada del Ruiz
29. NOVARUPTA, ALASKA
PENINSULA – JUNE, 1912
•
Largest volcanic blast of the
20th century
•
The powerful eruption sent 3
cubic miles (12.5 cubic km) of
magma and ash into the air,
which fell to cover an area of
3,000 square miles (7,800
square km) in ash more than a
foot deep.
•
Caused global temperatures to
drop by about 1 degree
Fahrenheit (0.5 degree Celsius)
MOUNT ST. HELENS,
USA—1980
•
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Large earthquake at 8:32 that
morning measuring.
5.1 on the richter scale,
•
of ash rose up to 15 miles into
the atmosphere.
•
$1 billion worth of damage to the
lumber and agricultural industries.
30. Iceland's Eyjafjoll Volcano:
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Iceland’s largest volcanoes
•
A strato-volcano.
•
Dormant beneath the Eyjafjoll
Eyjafjallajkull volcano
glacier.
•
In year 1823, a fairly gentle eruption
with some local flooding occurred
•
European air travel was severely
Eyjafjallajkull Glacier
disturbed
•
Eruption began on march 20th 2010,
Ash coming out of the Eyjafjallajkull
Volcano in the recent eruption that
created havoc in European airspace
31. Earthquakes in Pakistan
• History has shown us that
Pakistan is indeed situated
near highly active fault line
that could put risk to more
than 170 million people
living in the country.
32. 1935 Balochistan Earthquake
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Magnitude of 7.7
30,000 and 60,000 people
died from the impact
Deadliest earthquakes that
hit South Asia.
Camps can be seen during the post-1935 earthquake.
2011 Pakistan Earthquake
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Magnitude of 7.2 rocked southwestern Pakistan.
At sparsely populated areas
thus was not disastrous.
Earthquake was felt in India,
Iran, Bahrain, Afghanistan,
Oman, Qatar and united Arab
emirates. 2 women died due to
this earthquake in Pakistan due
to heart attack.
33. 13th Deadliest Earthquake
2005 Kashmir Earthquake
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Location: Muzafferabad, AJK
Magnitude 7.8
Saturday, October 08, 2005 at
08:52:37 AM
Distance: 105 km (65 miles) NE
of ISLAMABAD, Pakistan
73,000 people were killed and
more than 3.3 million made
homeless.
Economic down fall.
Pak declared as failed state.
34. Volcanoes of Pakistan:
Tor Zawar
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The only known
volcanic activity in
Pakistan was in January
2010.
A small fissure eruption
in the Ziarat region of
west-central Pakistan
produced a small lava
flow in an area with no
previous volcanic
activity.
Wednesday, February 03, 2010
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Trachybasalt and basalti
c-andesite in
composition.
Chandragup is a mud volcano located
in Balochistan, Pakistan
35. Malan Island is an offshore
mud volcano located in the
Arabian Sea, 3 kilometers off
the coast of Balochistan,
Pakistan. It rose out of the
water overnight in March
1999.
Jebel e Ghurab, is located in
Balochistan, Pakistan. It is a
mud volcano.
Neza e Sultan, is located in
Chagai District, Balochistan,
Pakistan. Neza e Sultan is an
extinct volcano and only the
magma chamber remains
and it looks like a spear.
36. This was All from the
Presentation ……..
Thankyo
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