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EARTHQUAKES ANDVOLCANOES
By:
Muhammad Saghir(004)
Sumbal Zahid(013)
Ayesha Siddiqa(017)
Presented To:
“Miss. Huma Naeem”
WHAT IS AN EARTHQUAKE AND VOLCANO?
Moment of CrustRupture of Crust
FORMATION OF EARTHQUAKE
Two blocks of the earth suddenly slip past one another.
Terms related:• fault plane• hypocenter• epicenter • foreshock• mainshock• aftershocks
TYPES OF EARTHQUAKE
Three main types of fault that may cause an earthquake.
• Normal
• Reverse
• Strike-slip
Lithosphere of Earth is broken into plates
• Study of movement and interaction of plates:
Plate Tectonics• 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
•Ground shaking
•Tsunamis
•Landslides and Rockfalls
•Subsidence and lateral spreading
•Liquefaction
Earthquake Hazards
TSUNAMISTSUNAMIS 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
The greater the viscosity the more gas in the magma. There are three basic types of magma:
Andesitic Magma
Rhyolitic Magma
Basaltic Magma
FORMATION OF VOLCANOES
Chemical composition (largely silica dioxide - sio2 - content)AndGas content (largely water vapor and co2).Sio2 content controls the viscosity of a magma.
MagmaType
ChemicalComposition
Temperature(degrees C)
Viscosity Gas Content
Basaltic
45-55% SiO2;
High in Fe, Mg, Ca; Low in K, Na.
1000 - 1200
Low Low
Andesitic
55-65% SiO2;
Intermediate Fe, Mg, Ca, Na, K
800-1000 Intermediate
Intermediate
Rhyolitic
65-75% SiO2;
Low in Fe, Mg, Ca; High in K, Na
650-800 High High
Large amounts of gas and a high viscosity (sticky) magma will form an explosive eruption Think about shaking a
carbonated drink and then releasing the cap.
Small amounts of gas and low viscosity (runny) magma will form an effusive eruption Where the magma just
trickles out of the volcano (lava flow).
TYPES (ON BASIS OF ERUPTION
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
Composite
Cinder Cone
Shield
• 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.Mt. Rainier, 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.
Mt. St. Helens, Washington
Mt. Fuji, Japan
• 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.
SHIELD VOLCANOS
Photograph by J.D. Griggs on January 10, 1985
Muana Loa Volcano – the world’s largest volcano.
• Over 30,000 feet above sea level.• Most active and planet's largest volcano
• Circular or oval cones.
• Range from several meters to over 300 m in height
• Small volcanoes.
• Structurally weak.
• Steep conical hill formed above a vent.
• Made from a pile of rock pieces
Mount Edziza, British Columbia• Dominated by viscous,
gaseous magmas.
• Relatively cool basaltic
magmas or andesitic
magmas predominate..
• Low silica lava
• “Fire-fountain” eruptions
• Commonly found on the
flanks of shield volcanoes
Floreana Island, Galapagos
Pu'u ka Pele, Hawaii(on the flanks of Mauna Loa)
Puu OO, Hawaii
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.
Volcanic Hazards
• Pyroclastic flow
• Lahars/Mud flows
• Pyroclastic fall
• Lava flow
• Ash flow
• Land sliding
• Noxious Gas
• Earthquakes
LAHARS
Water saturated slurry of
ash and other volcanic
debris that flows down
slope.
Pyroclastic Flow:
• A pyroclastic flow is a fast-
moving (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.
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.
WORLD WIDE EARTHQUAKES AND VOLCANOES
Railway track disturbed by Earthquake.
• 2010 Chile earthquake. • Magnitude of 8.8.• Is at a convergent plate boundary that generates megathrust earthquakes.
Alaska Earthquake 1964
• Fault between
the pacific and
north
American
plates rupture
d.
•
• Shifts created
large tsunamis
(up to 220
feet (67 m) in
height.
• Liquefaction.
LossesThe number of deaths from the earthquake totalled 131; 115 in Alaska and 16 in Oregon and California.
Great East Japan Earthquake
• 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 wider than before.
Effect Of Earthquake On Tokyo Tower.
• 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.
Mt. Fuji, Japan• A Stratovolcano that has erupted 16 times since 781 AD.• The most recent eruption was in 1707-1708•0.8 cubic km of ash, blocks, and bombs were ejected during that eruption.
• 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.
•
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.
Mount Pinatubo, Luzon, Philippines – 1991
• 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
• 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
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
• 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.
Ash coming out of the Eyjafjallajkull Volcano in the recent eruption that created havoc in European airspace
Eyjafjallajkull Glacier
Eyjafjallajkull volcano
Iceland's Eyjafjoll Volcano:
• Iceland’s largest volcanoes
• A strato-volcano.
• Dormant beneath the Eyjafjoll
glacier.
• In year 1823, a fairly gentle
eruption with some local
flooding occurred
• European air travel was
severely disturbed
• Eruption began on march 20th
2010,
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.
1935 Balochistan Earthquake
• 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.
• Magnitude of 7.2 rocked south-western 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.
2011 Pakistan Earthquake
2005 Kashmir Earthquake
• 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.
13th Deadliest Earthquake
Volcanoes of Pakistan:
Tor Zawar
• 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.
• Trachybasalt and basaltic-andesite in composition.
Wednesday, February 03, 2010
Chandragup is a mud volcano located in Balochistan, Pakistan
Malan Island is an offshore mud volcano located in theArabian 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.
This was All from the Presentation ……..
Thankyou