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EQ Seismology and Risk Assesment

Lab Manual

Submitted By:

Faisal Hayat (2011-GE-56)

Submitted To:

Ma’am Engr. Maryam

Department of Geological Engineering

University of engineering and Technology Lahore

2011-GE-56

LAB#01 (A)

Objective:

To Record the most hazards earthquakes in the world based on its

magnitude, fault name and in their location.

Related theory:

Earthquake:

Earthquake is caused by the release of built-up stress within rocks along geologic faults or by

the movement of magma in volcanic areas.

Magnitude of earthquake:

Earthquake magnitude is a measure of the “size,” or amplitude, of the seismic waves generated

by an earthquake source and recorded by seismographs. Richter magnitude scale is used to find

out the magnitude of the earthquakes.

Intensity of an earthquake:

The intensity of an earthquake at a particular locality indicates the violence of earth motion

produced there by the earthquake. It is determined from reported effects of the tremor on human

beings, furniture, buildings, geological structure, etc. Marcalli intensity meter is used while

predicting the intensity of earthquake.

Fault:

A crack in the earth's crust resulting from the displacement of one side with respect to the other;

"they built it right over a geological fault". Fault may be divided into a lot of types.

Earthquake hazard:

An earthquake hazard is anything associated with an earthquake that may affect the normal

activities of people and their community.

Causes of Earthquake:

Two theories are given which explain the cause of earthquake.

Plate tectonic theory

Elastic rebound theory

Both the theory explains the causes of earthquake most efficiently.The most of the earthquakes

occours due to interplate boundaries(about 99%), while some of them occours due to intraplate

(about 1%).

Some Hazardous Earthquakes occurred in the world

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1) Valdivia earthquake

The 1960 Valdivia earthquake or Great Chilean Earthquake was the most

powerful earthquake ever recorded, rating 9.5 on the moment magnitude scale. It occurred in

the afternoon (19:11 GMT, 15:11 local time), and the resulting tsunami affected southern

Chile, Hawaii, Japan, the Philippines, eastern New Zealand, southeast Australia, and the

Aleutian Islands.The epicenter was near Lumaco (approximately 570 kilometres (350 mi)

south of Santiago, with Valdivia being the most affected city. The tremor caused localised

tsunamis that severely battered the Chilean coast, with waves up to 25 metres (82 ft). The

main tsunami raced across the Pacific Ocean and devastated Hilo, Hawaii. Waves as high as

10.7 metres (35 ft) were recorded 10,000 kilometres (6,200 mi) from the epicenter, and as far

away as Japan and the Philippines.The death toll and monetary losses arising from such a

widespread disaster are not certain. Various estimates of the total number of fatalities from

the earthquake and tsunamis have been published, with the United States Geological

Survey citing studies with figures of 2,231, 3,000, or 5,700 killed and another source uses an

estimate of 6,000 dead. Different sources have estimated the monetary cost ranged

from US$400 million to 800 million (or 2.9 to 5.8 billion in 2011 dollars, adjusted for

inflation). Fig 1.1 shows the destruction caused by vadivia earthquake.

2) Sumatra, Indonesia Earthquake

Location Date Magnitude Epicenter

Valdivia, Chile May 22, 1960 9.5 Near Lumaco

Location Date Magnitude Epicenter

Sumatra,Indonesia December 24, 2004 9.3 West coast of

sumatra

Figure 1.1 Valdivia EQ 1960

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The 2004 Indian Ocean earthquake was an undersea megathrust earthquake that occurred at

00:58:53 UTC with an epicentre off the west coast of Sumatra, Indonesia. The quake itself is

known by the scientific community as the Sumatra–Andaman earthquake. The

resulting tsunami was given various names, including the 2004 Indian Ocean tsunami, South

Asian tsunami, Indonesian tsunami, the Christmas tsunami and the Boxing Day tsunami.

The earthquake was caused when the Indian Plate was subducted by the Burma Plate and

triggered a series of devastating tsunamis along the coasts of most landmasses bordering the

Indian Ocean, killing over 230,000 people in fourteen countries, and inundating coastal

communities with waves up to 30 meters (100 ft) high. It was one of the deadliest natural

disasters in recorded history. Indonesia was the hardest-hit country, followed by Sri

Lanka, India, and Thailand. It is the third largest earthquake ever recorded on a seismograph.

The earthquake had the longest duration of faulting ever observed, between 8.3 and

10 minutes. It caused the entire planet to vibrate as much as 1 centimetre (0.4 inches) and

triggered other earthquakes as far away as Alaska. Its epicentre was between Simeulue and

mainland Indonesia. The plight of the affected people and countries prompted a

worldwide humanitarian response. In all, the worldwide community donated more than $14

billion (2004 US$) in humanitarian aid. Shown in fig 1.2

3) Assam Tibet Earthquake:

The 1950 Assam – Tibet earthquake, also known as the Assam earthquake or Medog earthquake.

The epicentre was actually located near Rima, Tibet. The earthquake was destructive in

both Assam and Tibet, and 1,526 people were killed.

It was the 10th largest earthquake of the 20th century. It is also the largest known earthquake to have

not been caused by an oceanic subduction. Instead, this quake was caused by two continental plates

converging.

Location Date Magnitude Epicenter

Assam - Tibet August 15,1950 8.6 Near Rima,Tibet

Figure 1.2 Sumatra EQ causing Tsunami

Figure 1.3 Asaam EQ

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4) 1906 Ecuador-Colombia earthquake

The 1906 Ecuador-Colombia earthquake occurred at 15:36 UTC on January 31, off the coast

of Ecuador, near Esmeraldas. The earthquake had a magnitude of 8.8 and triggered a

destructive tsunami that caused at least 500 casualties on the coast of Colombia.

The earthquake occurred along the boundary between the Nazca Plate and the South

American Plate. The earthquake is likely to be a result ofthrust-faulting, caused by

the subduction of the Nazca plate beneath the South American plate.

The greatest damage from the tsunami occurred on the coast between Río Verde, Ecuador

and Micay, Colombia. Estimates of the number of deaths caused by the tsunami vary between

500 and 1,500.fig 1.4

5) Kamchatka earthquakes

Location Date Magnitude Epicenter

Colombia January 31,1906 8.8 Near Emeraldas

Location Date Magnitude Epicenter

Colombia January 31,1906 8.8 Near Emeraldas

Figure 1.4 Colombia EQ

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Three earthquakes, which occurred off the coast of Kamchatka Peninsula in far

eastern Russia in 1737, 1923 and 1952, were megathrust earthquakes and caused tsunamis.

They occurred where the Pacific Plate subducts under the Okhotsk Plate at the Kuril-

Kamchatka Trench. The depth of the trench at the point of the earthquakes is 7,000–7,500 m.

Northern Kamchatka lies at the western end of the Bering fault, between the Pacific Plate

and North American Plate or the Bering plate. There are many more earthquakes and

tsunamis originating from Kamchatka, of which the most recent was the 1997 Kamchatka

earthquake and tsunami originating near the Kronotsky Peninsula.fig 1.5

Refrences:

http://earthquake.usgs.gov/earthquakes/world/10_largest_world.php

http://en.wikipedia.org/wiki/Lists_of_earthquakes

Lab#01 (B)

To Record the most hazards earthquakes in the Pakistan based on its

magnitude, fault name and in their location.

2005 Kashmir earthquake:

Figure 1.5 Kamchatka earthquakes

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The 2005 Kashmir earthquake was a major earthquake centered in the Pakistan administered

Kashmir near the city of Muzaffarabad, also affecting and the Khyber Pakhtunkhwa province

of Pakistan. It occurred at 08:52:37 Pakistan Standard Time (03:52:37 GMT) on 8 October

2005. It registered a moment magnitude of 7.6 making it similar in size to the 1906 San

Francisco earthquake, the 1935 Quetta earthquake, the 2001 Gujarat earthquake, and the 2009

Sumatra earthquakes. As of 8 November, the government of Pakistan's official death toll was

75,000. The earthquake also affected countries in the surrounding region where tremors were

felt in Tajikistan and western China, while officials say nearly 1,400 people also died in Jammu

and Kashmir and four people in neighboring Nangarhar Province of Afghanistan. The severity

of the damage caused by the earthquake is attributed to severe upthrust, coupled with poor

construction.

Well over US$ 5.4 billion (400 billion Pakistani rupees) in aid arrived from all around the

world. US Marine and Army helicopters stationed in neighbouring Afghanistan quickly flew

aid into the devastated region along with five CH47 Chinook helicopters from the Royal Air

Force that were deployed from the United Kingdom. Five crossing points were opened on

the Line of Control (LoC), between India and Pakistan, to facilitate the flow of humanitarian

and medical aid to the affected region, and aid teams from different parts of Pakistan and

around the world came to the region to assist in relief. Pakistan-administered Kashmir lies in

the area of collision of the Eurasian and Indian tectonic plates. The geological activity born out

of this collision, also responsible for the birth of the Himalayan mountain range, is the cause

of unstable seismicity in the region. International donors have estimated that about 100,000

died, with an additional 138,000 becoming seriously injured, and 3.5 million becoming

displaced.

Hunza Earthquake 1974:

Location Date Magnitude Epicenter

Kashmir,Pakistan October 8, 2005 7.6 Near Muzaffarabad

Figure 1A.1 Kasmir EQ

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The 1974 Hunza Earthquake occurred in the rugged and

isolated Hunza, Hazara and Swat districts of northern Pakistan at 12:11 UTC on December

28, 1974. The epicentre was located at 35.0 degrees north and 72.8 degrees east. The 6.2

magnitude quake had a shallow focal depth and was followed by numerous aftershocks. An

official estimate of the number killed was 5,300 with approximately 17,000 injured. A total

of 97,000 were reported affected by the tremor. Most of the destruction was centered on the

village of Pattan, located about 100 miles (160 km) north of the capital city of Islamabad. The

village was almost completely destroyed.The epicental region is characterized by steep-

walled narrow canyons and valleys. Most of the population was concentrated along the rivers.

Much of the destruction was caused by the numerous landslides and rockfalls which came

tumbling down from high above. The main road leading into the area was blocked for about

25 miles (40 km) by landslides and rockfalls, hampering relief efforts. The government flew

in emergency supplies by helicopter until the roads were reopened on 13 January.

The earthquake, which reached MMI V in Kabul, Afghanistan, affected some 1,000 square

miles (2,600 km2) of the Indus Valley region. Several nations contributed money and supplies

to aid the inhabitants of the stricken area.

Comments:

Most of the earthquakes occours in Baluchistan and Kashmir areas due to the fact that there

exists the tectonic activity, in between the Eurasian and Indian plate. These plates collides

making the area shake.

Refrences:

http://en.wikipedia.org/wiki/1974_Hunza_earthquake

http://en.wikipedia.org/wiki/2005_Kashmir_earthquake

Location Date Magnitude Epicenter

Hunza,Pakistan December 28, 1974 6.2 35 degrees north

and 72.8 degrees

east

Figure 3A.2 Hunza EQ

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\

Lab#02

To Locate Earthquake Epicenter by using Seismograph and

travel time graph

Focus of an Earthquake:

The focus of an earthquake is the point where the rocks start to fracture. It is the origin of the

earthquake. The epicenter is the point on land directly above the focus.

The focus is also called the hypocenter of an earthquake. The vibrating waves travel away from

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the focus of the earthquake in all directions. The waves can be so powerful they will reach all

parts of the Earth and cause it to vibrate like a turning fork. Fig 3.1

Epicenter of an earthquake:

Directly above the focus on the Earth's surface is the earthquake epicenter. Earthquake waves

start at he focus and travel outward in all directions. Earthquake waves do not originate at the

epicenter. Fig 3.1

Amplitude:

o The amplitude of a seismic wave is the amount the ground moves as the wave passes

by. (As an illustration, the amplitude of an ocean wave is one-half the distance

between the peak and trough of the wave. The amplitude of a seismic wave can be

measured from the signal recorded on a seismogram.) (Noson, et.al., 1988)

o The maximum height of a wave crest of depth of a trough. (USGS National

Earthquake Information Center, 1999)

Focal Depth:

The focal depth refers to the depth of an

earthquake hypocenter. Shown in fig.3.3

Figure 3.1

Figure 3.2

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Frequency:

The frequency is the number of times something happens in a certain period of time, such as

the ground shaking up and down or back and forth during an earthquake.

Seismogram:

A seismogram is a record written by a seismograph in response to ground motions produced

by an earthquake, explosion, or other ground-motion sources. Fig 3.5

Seismograph:

A seismograph, or seismometer, is an

instrument used to detect and record earthquakes. Generally, it consists of a mass attached to a

fixed base. During an earthquake, the base moves and the mass does not. The motion of the

base with respect to the mass is commonly transformed into an electrical voltage. The electrical

voltage is recorded on paper, magnetic tape, or another recording medium. This record is

proportional to the motion of the seismometer mass relative to the earth, but it can be

mathematically converted to a record of the absolute motion of the

ground. Seismograph generally refers to the seismometer and its recording device as a single

unit. ( See also Earthquake ABC and Seismographs - Keeping Track of Earthquakes.). fig 3.6

Figure 3.3

Figure 3.4

Figure 3.5

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Travel Time:

A traveltime curve is a graph of arrival times, commonly P or S waves, recorded at different

points as a function of distance from the seismic source. Seismic velocities within the earth can

be computed from the slopes of the resulting curves. Fig 3.6

Results:

The data taken from the three stations shows that the Epicenter of this earthquake lies near to

Fresno (California), The three stations met a place about 200 KM away from Fresno.

Comments:

The scale taken from the map is :

o 100KM on map = 1.2 cm

o Atleast three stations are required to findout the Epicenter of the Earthquake.

o It is an easy way to calculate the Epicenter.

Refrences:

http://www.kids-fun-science.com/earthquake-focus.html

Lab#03

Figure 3.6

Figure 3.7

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To determine Earthquake magnitude by Scale conversion

diagram (Richter diagram) and given seismograph

Richter Scale:

The Richter magnitude scale was developed in 1935 by Charles F. Richter of the

California Institute of Technology as a mathematical device to compare the size of

earthquakes. The magnitude of an earthquake is determined from the logarithm of the

amplitude of waves recorded by seismographs. Adjustments are included for the variation

in the distance between the various seismographs and the epicenter of the earthquakes. On

the Richter Scale, magnitude is expressed in whole numbers and decimal fractions. For

example, a magnitude 5.3 might be computed for a moderate earthquake, and a strong

earthquake might be rated as magnitude 6.3. Because of the logarithmic basis of the scale,

each whole number increase in magnitude represents a tenfold increase in measured

amplitude; as an estimate of energy, each whole number step in the magnitude scale

corresponds to the release of about 31 times more energy than the amount associated with

the preceding whole number value.

The Epicentral distances are taken from lab#02, while using these values we can find the

magnitude of the earthquake on Richter sacle. This provides an easy way to calculate the

magnitude.

Refrence:

http://earthquake.usgs.gov/learn/glossary/?term=Richter%20scale

Lab#04

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Propagation of seismic waves through different media

Scope:

To find out the propagation of the seismic waves through different media

Seismic Waves:

Seismic waves are of two basic types:

Body waves

I. P waves

II. S waves

Surface waves

I. Love waves

II. Raleigh waves

Propagation of p wave through media :

Consider an infinitely thin long rod. If the rod is constrained against radial straining, then

particle displacements caused by a longitudinal wave must be parallel to the axis of the rod.

Assume that cross- sectional planes will remain planar and that stress will be distributed

uniformly over each other cross-section. The One dimensional wave equation can be written

in the form

The propagation velocity of the waves depends on density and elasticity of the medium. These

waves can travel through any type of material, and can travel at nearly twice the speed of S

waves.

o These waves can pass easily through the solid because of high rigidity of the solids. As

the pattern of P wave is compressional so these waves are capable of being pass quickly.

o In liquids the speed of P waves reduces because of less rigidness of fluids than solid.

o In air, these pressure waves take the form of sound waves; hence they travel at the speed

of sound. Typical speeds are 330 m/s in air

o Velocity tends to increase with depth, and ranges from approximately 2 to 8 km/s in the

o Earth's crust up to 13 km/s in the deep mantle.

Speed of P-waves:

Where K is the modulus of incompressibility, μ is the modulus of rigidity and ρ the density of

the material through which the wave is propagating

S Waves:

Consider an infinitely thin long rod .Torsional waves involve rotation of the rod about its own

axis. For torsional waves, particle motion is constrained to planes perpendicular to the direction

of wave propagation. Suppose the short segment of cylindrical rod, the one dimensional wave.

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S waves can only pass through the solids, they cannot pass through the liquids or fluids because

a fluids and gasses cannot transmit a shear stress and S-waves are waves that shear the material.

Propagation of s waves through a medium depend on the parameters including shear modulus

and density, it don’t in clued modulus of rigidity and as shear modulus of the fluids is zero so

they dies in the fluids. It is this property of S waves that led seismologists to conclude that the

Earth's outer core is liquid, typical values for S-wave velocities within the Earth are between

3.5 and 6 km/s.

Rayleigh waves:

Rayleigh waves, also called ground roll, are surface waves that travel as ripples with motions

that are similar to those of waves on the surface of water. A Rayleigh wave rolls along the

ground just like a wave rolls across a lake or an ocean. Because it rolls, it moves the ground up

and down and side-to-side in the same direction that the wave is moving. However, that the

associated particle motion at shallow depths is retrograde, and that the restoring force in

Rayleigh and in other seismic waves is elastic, not gravitational as for water waves.They are

slower than body waves, roughly 90% of the velocity of S waves for typical homogeneous

elastic media.Rayleigh waves on ideal, homogeneous and flat elastic solids show no dispersion.

However, if a solid or structure has a density or sound velocity that varies with depth, Rayleigh

waves become dispersive. One example is Rayleigh waves on the Earth's surface: those waves

with a higher frequency travel more slowly than those with a lower frequency.

Love waves:

Love waves are surface waves that cause horizontal shearing of the ground. Love waves exist

because of the Earth’s surface. They usually travel slightly faster than Rayleigh waves. It's the

fastest surface wave and moves the ground from side-to- side. They are largest at the surface

and decrease in amplitude with depth. Love waves are dispersive, that is, the wave velocity is

dependent on frequency, generally with low frequencies propagating at higher velocity. Depth

of penetration of the Love waves is also dependent on frequency, with lower frequencies

penetrating to greater depth. Since Love waves travel on the Earth's surface, the strength (or

amplitude) of the waves decrease exponentially with the depth of an earthquake. However,

given their confinement to the surface, their amplitude decays only as, where r represents the

distance the wave has traveled from the earthquake.

Air depending on

temperature

310 360

Weather soil horizon 100 500

Gravel, dray sand 100 600

Loam 300 900

Wet sand 200 1800

Clay 1200 2500

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Water depending on

temperature

1430 1590

Sandstone friable 1500 2500

Sandstone dense 1800 4000

Chalk 1800 3500

Limestone 2500 6000

Marl 2000 3500

Gypsum 4500 6500

Ice 3100 4200

Granite 4000 5700

Wave propagation in anisotropic media:

Wave motion in an anisotropic solid is fundamentally different from motion in an isotropic

solid, although the effects are often subtle and difficult to recognize. There are such a wide

range of three-dimensional variations possible in anisotropic media that it is difficult to

understand the behavior of wave motion without experimentation. Laboratory experiments are

very difficult to construct and extensive numerical experiments have now given many

theoretical insights so that the behavior of waves in anisotropic media is now comparatively

well understood.

P-wave propagation:

In isotropic and homogeneous solids, the mode of propagation of a P-wave is always

longitudinal; thus, the particles in the solid have vibrations along or parallel to the travel

direction of the wave energy.

S-wave propagation

The S-wave moves as a shear or transverse wave, so motion is perpendicular to the direction

of wave propagation: S-waves are like waves in a rope, as opposed to waves moving through

a slinky, the P-wave. The wave moves through elastic media, and the main restoring force

comes from shear effects.

An earthquake radiates P and S waves in all directions and the interaction of the P and S waves

with Earth's surface and shallow structure produces surface waves.

Near an earthquake the shaking is large and dominated by shear-waves and short-period surface

waves. These are the waves that do the most damage to our buildings, highways, etc. Even in

Figure 4.4

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large earthquakes the intense shaking generally lasts only a few tens of seconds, but it can last

for minutes in the greatest earthquakes. At farther distances the amplitude of the seismic waves

decreases as the energy released by the earthquake spreads throughout a larger volume of Earth.

Also with increasing distance from the earthquake, the waves are separated apart in time and

dispersed because P, S, and surface waves travel at different speeds.

Seismic waves can be distinguished by a number of properties including the speed the waves

travel, the direction that the waves move particles as they pass by, where and where they don't

propagate. We'll go through each wave type individually to expound upon the differences.

The first two wave types, P and S , are called body waves because they travel or propagate

through the body of Earth. The latter two are called surface waves they the travel along Earth's

surface and their amplitude decreases with depth into Earth.

References

http://en.wikipedia.org/wiki/Transverse_isotropy

http://facta.junis.ni.ac.rs/phat/phat98/phat98-01.pdf

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.1984.tb05018.x/abstract

Lab#05

To find out the properties of Tsunami by using seismogram of

Tsunami

Figure 4.5

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Underwater Earth Quake:

A submarine, undersea, or underwater earthquake is an earthquake that occurs underwater at

the bottom of a body of water, especially an ocean. They are the leading cause of tsunamis.

The magnitude can be measured scientifically by the use of either the Richter scale or

the Mercalli scale. Understanding plate tectonics helps to explain the cause of submarine

earthquakes. The Earth's surface or lithosphere comprises tectonic plates which average

approximately 50 miles in thickness, and are continuously moving very slowly upon a bed of

magma in the asthenosphere and inner mantle. The plates converge upon one another, and one

subducts below the other. fig 5.1

Landslides:

A landslide, also known as a landslip, is a geological phenomenon which includes a wide range

of ground movements, such as rockfalls, deep failure of slopes and shallow debris flows,

which can occur in offshore, coastal and onshore environments. Although the action

of gravity is the primary driving force for a landslide to occur, there are other contributing

factors affecting the original slope stability. fig 5.2

Meteoroides:

A meteoroid is a small rocky or metallic body travelling through space. Meteoroids are

significantly smaller than asteroids, and range in size from small grains to 1 meter-wide

objects. Smaller objects than this are classified as micrometeoroids or space dust. Most are

fragments fromcomets or asteroids,

while others are collision impact debris ejected from

bodies such as the Moon or Mars. fig 5.3

Figure 5.6

Figure 5.7

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Tsunami:

A tsunami is a series of water waves caused by the displacement of a large volume of a body

of water, generally an ocean or a large lake. Earthquakes, volcanic eruptions and

other underwater explosions (including detonations of underwater nuclear devices),

landslides, glacier calvings, meteorite impacts and other disturbances above or below water all

have the potential to generate a tsunami. fig

5.4

How Tsunami Occurs:

About two-thirds of the earth is covered by the waters of the four oceans. The Pacific Ocean is

surrounded by a series of mountain chains, deep ocean trenches and island arcs, sometimes

called a "ring of fire." The great size of the Pacific Ocean and the large earthquakes associated

with the "ring of fire" combine to produce deadly tsunamis. Tsunami's can occur due to

earthquake's, landslides on the sea floor, land slumping into the ocean, or from large volcanic

eruptions. Most of them are caused by earthquakes. fig 5.5

Types of Tsunami:

There are three main types of tsunami

1) Immediate Waves:

These are generated locally by sudden lateral movements of walls. The water is pushed out of

the way(push effect) and initially has nowhere to go but upwards. This temporary hump then

collapses outwards in both directions, forming an almost instant response to the ground

movement. these waves may climb very high, although the volume involved is not large.

Alternatively, there may be a “pull” effect if a steep wall is dragged away from the water, but

in this case the water will detach from the wall if the wall movement is sufficiently violent.

2) Seismic Seiches:

Figure 5.8

Figure 5.9

Figure 5.10

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These are generated by variations in the local vertical ground displacement (tilting effects).

These waves are called a seiche because the response of the water body is dependent on its

resonance properties, and will take the form of waves recurring at time intervals determined

by the various natural frequencies. This type includes propagating waves generated by the

collapse of Immediate Waves, but these tend to be minor compared with the effects of

seismic tilting.

3) Classical Tsunami:

These waves are open sea waves resulting from the action of gravity following the initiating

short duration disturbance (or “bump”), with particular emphasis on the interaction between

these waves and coastlines. If seabed displacement results from an earthquake, volcanic action,

or submarine landslide,it results into this type of tsunami.

Speed of tsunami:

Tsunami wave speed is controlled by water depth. Where the ocean is over 6,000 meters (3.7

miles) deep, unnoticed tsunami waves can travel at the speed of a commercial jet plane, over

800 km per hour (500 miles per hour). Tsunamis travel much slower in shallower coastal waters

where their wave heights begin to increase dramatically

Wavelength of Tsunami:

The wave length of Tsunami can be calculated by multiplying the value of speed to the time.

The formula is :

Distance= speed × time

Detection of Tsunami:

A tsunami warning system (TWS) is used to detect tsunamis in advance and issue warnings to

prevent loss of life and damage. It is made up of two equally important components: a network

of sensors to detect tsunamis and a communications infrastructure to issue timely alarms to

permit evacuation of the coastal areas. There are two distinct types of tsunami warning

systems: international andregional. When operating, seismic alerts are used to instigate the

watches and warnings; then, data from observed sea level height (either shore-based tide

Figure 5.11

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gauges or DART buoys) are used to verify the existence of a tsunami. Other systems have been

proposed to augment the warning procedures.

The DART System:

In 1995 the National Oceanic and Atmospheric Administration (NOAA) began developing

the Deep-ocean Assessment and Reporting of Tsunamis (DART) system. An array of

stations is currently deployed in the Pacific Ocean. These stations give detailed

information about tsunamis while they are still far off shore. Each station consists of a sea-

bed bottom pressure recorder which detects the passage of a tsunami. (The pressure of the

water column is related to the height of the sea-surface) . The data is then transmitted to a

surface buoy via sonar. The surface buoy then radios the information to the Pacific

Tsunami Warning Center (PTWC) via satellite. The bottom pressure recorder lasts for two

years while the surface buoy is replaced every year. The system has considerably improved

the forecasting and warning of tsunamis in the Pacific.

Tsunami Alerts:

1) Severe ground shaking from local earthquakes may cause tsunamis.

2) As a tsunami approaches shorelines, water may recede from the coast, exposing the ocean

floor, reefs and fish.

3) Abnormal ocean activity, a wall of water, and an approaching tsunami create a loud

"roaring" sound similar to that of a train or jet aircraft.

If you experience any of these phenomena, don't wait for official evacuation orders.

Immediately leave low-lying coastal areas and move to higher ground

Figure 5.12

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Calculations:

d1= 200m

d2= 300m

Speed= V= √gd

Wavelength= vt

Scale:

0.6cm= 1 hour

0.2cm= 0.33 hour= 20 min= 1200sec

Velocities:

V1= √9.81 × 2000 = 𝟏𝟒𝟎. 𝟏 𝒎/𝒔

V2=√9.81 × 3000 = 𝟏𝟕𝟏. 𝟓 𝒎/𝒔

Epicenter Distance:

A= 1200 KM B= 1500 KM

Time to Reach points:

Epicenter of X

Speed of X

For Point A:

T1= 1200

0.1401 = 8565sec

= 142.75 min = 2 hrs, 22 min, 45sec

T2= 1200

0.17155

= 1hr, 56 min, 35sec

For Point B:

Figure 5.13

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T1= 1500

0.1401

= 2hrs, 58 min, 27sec

T2= 1500

0.17155

= 2hrs, 25 min, 44sec

Refrences:

http://en.wikipedia.org/wiki

http://www.ask.com/question/how-does-a-tsunami-occur

http://www.bom.gov.au/tsunami/info/

Lab#06

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To study the attenuation relationship between epicenter distance

and duration

Theory:

Attenuation of earthquake:

The decrease in size, or amplitude, of the waves is called attenuation. Seismic waves also

become attenuated as they move away from the earthquake source. The amplitude is largest

where they are formed and gradually get smaller as they move away.

Causes of attenuation:

1) Geometrical spreading: wavefront spreading out while energy per unit area

becomes less.

2) Multipathing: waves seek alternative paths to the receiver. Some are dispersed and

some are bundled, thereby affecting amplitudes.

3) Scattering: A way to partition energy of supposedly main arrivals into boundary or

corner diffracted, scattered energy

Deep drill holes reveal alternating layers of basalt and sediments. The basalt layers are lava

flows from repeated volcanic eruptions occurring from 3.2 millions years ago to as recently as

2,100 years ago. During times in between volcanic eruptions, soils form and cover the basalt

flows. The soils accumulate from wind blown dust, erosion of rocks due to precipitation in

local drainages, and deposition of sediments from rivers (e.g., the Big Lost River) and

occasional lakes (e.g., Lake Terreton).

The passage of seismic waves through alternating layers of hard basalt (higher seismic

velocities) and loosely consolidated sediments (lower seismic velocities) scatter and dampen

seismic energy. The net effect is to reduce earthquake ground motions by 15 to 25% of the

motions expected for uniform rock (all basalt and no sediment layers). An independent review

panel convened by the State of Idaho and U.S. Department of Energy in 1997 concluded that

alternating layers of basalt and sediments was highly effective in damping ground motion. They

also concluded that the geometries of the sedimentary layers did not cause focusing or

amplification of ground motions.

Damping Process:

The conventional approach to earthquake resistant

design of buildings depends upon providing the building with strength, stiffness and inelastic

deformation capacity which are great enough to withstand a given level of earthquake–

generated force. This is generally accomplished through the selection of an appropriate

structural configuration and the careful detailing of structural members, such as beams and

columns, and the connections between them. In contrast, we can say that the basic approach

underlying more advanced techniques for earthquake resistance is not to strengthen the

Figure 6.1

2011-GE-56

building, but to reduce the earthquake–generated forces acting upon it. Among the most

important advanced techniques of earthquake resistant design and construction are base

isolation and energy dissipation devices.

Base Isolation:

It is easiest to see this principle at work by referring directly to the most widely used of these

advanced techniques, which is known as base isolation. A base isolated structure is supported

by a series of bearing pads which are placed between the building and the building's foundation.

A variety of different types of base isolation bearing pads have now been developed. For our

example, we'll discuss lead–rubber bearings. These are among the frequently–used types of

base isolation bearings. A lead–rubber bearing is made from layers of rubber sandwiched

together with layers of steel. In the middle of the bearing is a solid lead "plug." On top and

bottom, the bearing is fitted with steel plates which are used to attach the bearing to the building

and foundation. The bearing is very stiff and strong in the vertical direction, but flexible in the

horizontal direction. Fig 6.2

Spherical Sliding Isolation

Systems:

As we said earlier, lead–rubber bearings are just one of a number of different types of base

isolation bearings which have now been developed. Spherical Sliding Isolation Systems are

another type of base isolation. The building is supported by bearing pads that have a curved

surface and low friction. Shown in fig 6.3

Attenuation of EQ through

different Media:

The table given below (6.4) shows the velocities of primary waves through different

materials:

Figure 6.2

Figure 6.3

2011-GE-56

Table used for the Intensity, Epicenter distance and the Duration:

Intensity Epicenter distance

(km)

Duration (sec)

1 0 0

0.99 10 1

0.98 20 1.9

0.95 30 3

0.89 40 4.5

0.85 50 5.8

0.74 60 7.8

0.6 70 10

0.4 80 12.5

0.2 90 14.8

0.18 100 15.8

Figure 6.4

2011-GE-56

0.15 110 16.7

0.11 120 18

0.09 130 19

0.05 140 20.1

0.03 150 20.8

0.02 160 21.4

0.01 170 22

Comments:

From the graph attached we have concluded the following interpretations:

Area 1:

In this zone there is low ground shaking, but time duration of wave to pass through medium

is very low, this is due to the presence of hard rock material in this area.

Area 2:

This is very crucial zone, in this zone duration of wave travel is increasing, which is

showing that, there is a transition zone of hard to soft formation in this zone, as the distance

is increasing, due to which ground motion is decreasing, or we can say intensity is

decreasing.

Area 3:

This is the zone at which waves are taking much longer time to pass showing the presence

of soft formation over there, and intensity is almost dead due to increase in epicentral

distance.. So this zone is seismically safe area.

Refrences:

https://inlportal.inl.gov/portal/server.pt/community/inl_seismic_monitoring_program/441/atte

nuation_effects/4378

http://mceer.buffalo.edu/infoservice/reference_services/adveqdesign.asp

Lab#07 (A)

2011-GE-56

To study the techtonic map of Pakistan and to classify different

areas of Pakistan on the basis of seismic danger zone

Plate tectonics:

It is a scientific theory that describes the large-scale motion of Earth's lithosphere. The model

builds on the concept of continental drift which was developed during the first few decades of

the 20th century. The lithosphere, which is the rigid outermost shell of a planet (on Earth, the

crust and upper mantle), is broken up into tectonic plates. On Earth, there are seven or eight

major plates (depending on how they are defined) and many minor plates. Where plates meet,

their relative motion determines the type of boundary; convergent, divergent,

or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation

occur along these plate boundaries. The lateral relative movement of the plates typically varies

from zero to 100 mm annually.

Tectonic set up of Pakistan

Earthquakes and active faults in northern Pakistan and adjacent parts of India and Afghanistan

are the direct result of the Indian subcontinent moving northward at a rate of about 40

mm/yr(1.6 inches/yr) and colliding with the Eurasian continent. This collision is causing uplift

that produces the highest mountain peaks in the world including the Himalayan, the

Karakoram, the Pamir and the Hindu Kush ranges. As the Indian plate moves northward, it is

being subducted or pushed beneath the Eurasian plate. Much of the compressional motion

between these two colliding plates has been and continues to be accommodated by slip on a

suite of major thrust faults that are at the Earth’s surface in the foothills of the mountains and

dip northward beneath the ranges. These include the Main Frontal thrust, the Main Central

thrust, the Main boundary thrust, and the Main Mantle thrust. These thrust faults have a sinuous

trace as they arc across the foothills in northern India and into northern Pakistan. In detail, the

modern active faults are actually a system of faults comprised of a number of individual fault

traces. In the rugged mountainous terrain, it is difficult to identify and map all of the individual

thrust faults, but the overall tectonic style of the modern deformation is clear in the area of the

earthquake; north- and northeast-directed compression is producing thrust faulting. Near the

town of Muzaffarabad, about 10 km southwest of the earthquake epicenter, active thrust faults

that strike northwest-southeast have deformed and warped Pleistocene alluvial-fan surfaces

into anticlinal ridges. The strike and dip direction of these thrust faults is compatible with the

style of faulting indicated by the focal mechanism from the nearby M 7.6 earthquake.

2011-GE-56

Techtonic Map:

Techtonic map is a map which is an easy approach to findout the techtonic activities happening

in the world. Here in this lab we study the techtonic map of Pakistan which includes the five

provinces. The severe seismic danger area is the balochistan and Kashmir area causing deathly

earthquakes. Shown in fig 7.1

Abbreviations used in the

Map:

MKT: Main Karakoram Thrust

MMT: Main Mantan Thrust

MBT: Main Boundary Thrust

Figure 7.14

2011-GE-56

MFT: Main Frontal Thrust

MCT : Main central Thrust

SRT: Salt Range Thrust

Refrences:

http://en.wikipedia.org/wiki/Plate_tectonics

2011-GE-56

Lab#07 (B)

Seismic Danger Zones

The map of Pakistan is divided into different zones according to the seismicity of different

areas. The magnitudes of different earthquakes are given in the map.

Explanations of the map symbols according to the magnitude of earthquakes:

1) Zone of serious seismic danger

This area is safe from the seismic activity due to the fact that this zone is far away

from the significant faults present in Pakistan. The historical background of the zone

also indicates that there has been no significant hazardous earthquake occurred.

M-7 to M-8 Acceleration: 0.3g to 0.8g

The City included in this zone is only

1- Quetta

2) Zone of significant seismic danger

This zone has some affect of seismic activity as it is near to the faulting zone as

compared to low hazardous zone.

M-6 to M-7 Acceleration: 0.15g to 0.3g

The Cities included in this zone are

1- Chaman

2- Khost

3- Sibi

4- Kalat

5- Saidu Sharif

6- Chilas

7- Gilgit

8- Mor Khan

9- Chenab

3) Zone of noticeable seismic danger

This zone is near to the main faults of Pakistan such as MBT, MKT, MMT and

Chaman Fault. So these faults have greater influence on the areas present in this zone.

History of these areas also reveals that this is highly affected by seismic activity. For

example the earthquake of October 2005 affected these areas.

M-5 to M-6 Acceleration 0.05g to 0.15g

The Cities included in this zone are

1- Zhob

2- Dera Ismail Khan

3- Faisal Abad

Figure 1

Figure 15

2011-GE-56

4- Sahiwal

5- Lahore

6- Nowshehra

7- Peshawar

8- Bannu

9- Bela

10- Karachi

11- Dalbandin

12- Nok kundi

4) Zone of least seismic danger

This area is safe from the seismic activity due to the fact that this zone is far away from

the significant faults present in Pakistan. The historical background of the zone also

indicates that there has been no significant hazardous earthquake occurred.

M below-5 acceleration below 0.05g

The Cities included in this zone are

1- Bahawalpur

2- Sukkar

3- Mirpur Khas

4- Khairpur

5- Multan

According to Geological Survey of Pakistan Quetta

Lab#08

Figure 16

Figure 17

2011-GE-56

To study the tectonic map of earth and to mark global earth

quake locations

Theory:

Theory of Plate Tectonics:

It is a scientific theory that describes the large-scale motion of Earth's lithosphere. The model

builds on the concept of continental drift which was developed during the first few decades of

the 20th century. The lithosphere, which is the rigid outermost shell of a planet (on Earth, the

crust and upper mantle), is broken up into tectonic plates. On Earth, there are seven or eight

major plates (depending on how they are defined) and many minor plates. Where plates meet,

their relative motion determines the type of boundary; convergent, divergent,

or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation

occur along these plate boundaries. The lateral relative movement of the plates typically varies

from zero to 100 mm annually.

Driving forces of plate motion:

As stated earlier, in order to fully understand what drives the lithospheric plates of the Earth,

we must first identify and understand the forces involved. A number of forces have been

postulated since the dawn of the tectonic theory, including ridge push, slab pull, trench suction,

collisional resistance, and basal drag (Forsyth et al., 1975; Richardson, 1992). In the past ten

years, many scientists have begun to assume that the boundary and body forces of the plates,

rather than the frictional drag produced by mantle convection, are the most dominant group of

forces driving plate motions.

Tectonic

plates of

earth:

There are

seven or eight big plates on earth and also a number of smaller ones. Some of them are given

under:

1) Nazca Plate

2) North American Plate

3) South American Plate

Figure 8.18

2011-GE-56

4) Eurasian Plate

5) India Australian Plate

6) African Plate

7) Arabian Plate

8) Philippine Plate

9) Antarctic Plate

10) Cocos Plate

11) Pacific Plate

12) Juan De Fuca Plate

World Tectonic Map:

Major Faults in the world:

Plate Type Major Faulting

pacific plate strike slip faulting

north American plate strike slip faulting

south American plate oblique faulting

African plate normal faulting

Eurasian plate normal faulting

Antarctic plate strike slip

2011-GE-56

cocas plate reverse

Nazca plate strike slip

Australian plate strike slip

Indian plate strike slip

USA strike slip

Russia strike slip

China Oblique

Japan Reverse

Saudi Arabia strike slip

Pakistan Reverse

Europe normal

Australia oblique

Indonesia oblique

Iran reverse

India reverse

Turkey strike slip

south Africa normal

2011-GE-56

World Fault Line:

Strike slip fault

A type of fault whose surface is typically vertical or nearly sothe motion along a strike-slip

fault is parallel to the strike of the fault surface, and the fault blocks move sideways past each

other. A strike-slip fault in which the block across the fault moves to the right is described as

a dextral strike-slip fault. If it moves left, the relative motion is described as sinistral. Fig 9.3

Normal fault

A type of fault in which the hanging wall moves down relative to the footwall and the

fault surface dips steeply, commonly from 500 to 900. Groups of normal faults can produce

horst and graben topography. Fig 9.4

Figure 9.3

2011-GE-56

Reverse fault

A type of fault formed when the hanging wall fault block

moves up along a fault surface relative to the footwall. Such

movement can occur in areas where the Earth's crust is

compressed. Fig 9.5

Oblique-slip faults

A fault that has a component of dip-slip and a component of strike-slip is termed an "oblique-

slip fault." Nearly all faults will have some component of both dip-slip and strike-slip, so

defining a fault as oblique requires both dip and strike components to be measurable and

significant. Fig 9.6

Figure 9.4

Figure 9.5

Figure 9.6

2011-GE-56

Lab#09

Using the Edu Shake Software

Proshake:

A powerful, user-friendly program for one-dimensional, equivalent linear ground response

analysis. ProShake is currently being used by more than 200 of the world's top consulting

firms and research institutions. Download a copy of the ProShake Users Manual or, for a

hands-on demonstration of ProShake's interface and capabilities, download a free copy of

EduShake.

EduShake:

A free program for one-dimensional, equivalent linear ground response analysis. EduShake

is equivalent to ProShake, but is restricted to the use of only eight different input motions,

all of which are included with the program.

EduShake Report Data File:

Soil Profile

Profile Name: UET Soil

Water Table: 100.00 ft

Number of Layers: 2

Layer

Numb

er

Material

Name

Thickn

ess

(ft)

Unit

Weigh

t

(pcf)

Gma

x

(ksf)

Vs

(ft/se

c)

Modulus

Curve

Damping Curve Mod.

Param

eter

Damp.

Param

eter

1 Soil 20.00 54.11 1,46

1.98

932.

37

Clay - PI=20-

40 (Sun et al.)

Clay - Upper

Bound (Sun et

al.)

2 Dolerite Infinit

e

57.29 3,13

2.82

1,32

6.40

Gravel (Seed

et al.)

Gravel (Seed et

al.)

2011-GE-56

Input Motion

Number of Motions: 2

Numeber of Iterations: 5

Strain Ratio: 0.65

Tolerance: 5.00%

File Name

No of

Acc.

Values

Max.

Acc.

(g)

Time

Step

(sec)

Cuttoff

Freq.

(Hz)

No of

Fourier

Terms

Layer Outcro

p

2 No

No

Output Locations

Layer No Depth

(ft)

Outcrop

1 0.00 No

Graph B/W Modulus Ratio and Shear Strain (Clay):

Clay - PI=20-40 (Sun et al.)

Mo

du

lus R

atio

Shear Strain (%)

0.0

0.2

0.4

0.6

0.8

1.0

0.00001 0.0001 0.001 0.01 0.1 1 10

2011-GE-56

Graph B/W Modulus Ratio and Shear Strain (Clay):

Graph B/W Damping Ratio and Shear Strain (Gravel):

Clay - Upper Bound (Sun et al.)

Da

mp

ing R

atio

(%

)

Shear Strain (%)

0

10

20

30

40

0.00001 0.0001 0.001 0.01 0.1 1 10

Clay - PI=20-40 (Sun et al.)

Mo

du

lus R

atio

Shear Strain (%)

0.0

0.2

0.4

0.6

0.8

1.0

0.00001 0.0001 0.001 0.01 0.1 1 10

2011-GE-56

Graph B/W Damping Ratio and Shear Strain (Clay):

Clay - Upper Bound (Sun et al.)

Da

mp

ing R

atio

(%

)

Shear Strain (%)

0

10

20

30

40

0.00001 0.0001 0.001 0.01 0.1 1 10

Gravel (Seed et al.)

Da

mp

ing R

atio

(%

)

Shear Strain (%)

0

5

10

15

20

25

30

0.00001 0.0001 0.001 0.01 0.1 1 10

2011-GE-56

Graph B/w Modulus Ratio and Shear Strain (Gravel):

Gravel (Seed et al.)

Mo

du

lus R

atio

Shear Strain (%)

0.0

0.2

0.4

0.6

0.8

1.0

0.00001 0.0001 0.001 0.01 0.1 1 10