The document discusses earthquakes, including their causes, effects, and notable examples. It explains that earthquakes occur when built-up pressure causes rocks underground to break along faults, releasing energy. Effects can include shaking, tsunamis, landslides, fires, and damage to buildings and infrastructure. The largest recorded earthquakes include the 2004 Sumatra quake and 2005 Kashmir quake. Recent major earthquakes in India are also listed. The ongoing 2015 Nepal earthquake that has caused thousands of deaths is described.

1. EARTH – THE
EARTHQUAKESby
K. BHANU PRAKASH REDDY – 14BCE1236

2. EARTHQUAKE
 An earthquake (also known as a quake, tremor or temblor) is the result of a
sudden release of energy in the Earth's crust that creates seismic waves.
 Earthquakes are measured using observations from seismometers.
 The moment magnitude is the most common scale on which earthquakes
larger than approximately 5 are reported for the entire globe. Generally it
is traditionally measured by using Richter magnitude scale.
 Magnitude 3 or lower earthquakes are mostly almost imperceptible or weak
and magnitude 7 and over potentially cause serious damage over larger
areas, depending on their depth.
 The largest earthquakes in historic times have been of magnitude slightly
over 9. The most recent large earthquake was 9.0 magnitude earthquake
in Japan in 2011 (as of March 2014), and it was the largest Japanese
earthquake since records began. Intensity of shaking is measured on the
modified Mercalli scale.

3. Why Do Earthquakes Happen?
The rocks are still pushing against each other, but not moving. After a while, the rocks break
because of all the pressure that's built up. When the rocks break, the earthquake occurs.
During the earthquake and afterward, the plates or blocks of rock start moving, and they
continue to move until they get stuck again. The spot underground where the rock breaks is
called the focus of the earthquake. The place right above the focus (on top of the ground) is
called the epicenter of the earthquake.
Earthquakes are usually caused when rock
underground suddenly breaks along a fault.
This sudden release of energy causes the seismic
waves that make the ground shake.
 When two blocks of rock or two plates are rubbing
against each other, they stick a little. They don't just
slide smoothly, the rocks catch on each other.

4. TRY THIS MINI EXPERIMENT…
 Break a block of foam rubber in half.
 Put the pieces on a smooth table.
 Put the rough edges of the foam rubber pieces
together.
 While pushing the two pieces together lightly, push one
piece away from you along the table top while pulling the
other piece toward you. See how they stick?
 Keep pushing and pulling smoothly.
 Soon a little bit of foam rubber along the crack (the
fault) will break and the two pieces will suddenly slip
past each other.
 That sudden breaking of the foam rubber is the
earthquake. That's just what happens along a strike-slip
fault.

5. EFFECTS OF EARTHQUAKES
Shaking and ground rupture :
 Shaking and ground rupture are the main effects created by
earthquakes, principally resulting in more or less severe damage to
buildings and other rigid structures.
 The severity of the local effects depends on the complex combination
of the earthquake magnitude, the distance from the epicenter, and the
local geological and geomorphological conditions, which may amplify or
reduce wave propagation. The ground-shaking is measured by ground
acceleration.
Damaged buildings in
Port-au-Prince, Haiti,
January 2010.
Specific local geological, geomorphological, and geostructural features can induce high levels
of shaking on the ground surface even from low-intensity earthquakes. This effect is called
site or local amplification.
It is principally due to the transfer of the seismic motion from hard deep soils to soft
superficial soils and to effects of seismic energy focalization owing to typical geometrical
setting of the deposits.

6.  TSUNAMI:
 Tsunamis are long-wavelength, long-period sea waves
produced by the sudden or abrupt movement of large
volumes of water.
 In the open ocean the distance between wave crests can
surpass 100 kilometers (62 mi), and the wave periods can
vary from five minutes to one hour. Such tsunamis travel
600-800 kilometers per hour (373–497 miles per hour),
depending on water depth.
Large waves produced by an earthquake or a submarine
landslide can overrun nearby coastal areas in a matter of
minutes. Tsunamis can also travel thousands of kilometers across
open ocean and wreak destruction on far shores hours after the
earthquake that generated them.
Ordinarily, subduction earthquakes under magnitude 7.5 on the
Richter scale do not cause tsunamis, although some instances of
this have been recorded. Most destructive tsunamis are caused
by earthquakes of magnitude 7.5 or more.

7. FLOODS :
 A flood is an overflow of any amount of water that reaches land.
 Floods occur usually when the volume of water within a body of
water, such as a river or lake, exceeds the total capacity of the
formation, and as a result some of the water flows or sits
outside of the normal perimeter of the body.
 However, floods may be secondary effects of earthquakes, if
dams are damaged. Earthquakes may cause landslips to dam
rivers, which collapse and cause floods.
 The terrain below the Sarez Lake in Tajikistan is in
danger of catastrophic flood if the landslide dam
formed by the earthquake, known as the Usoi Dam,
were to fail during a future earthquake.
 Impact projections suggest the flood could affect
roughly 5 million people.

8.  Human impacts :
 An earthquake may cause injury and loss of life, road
and bridge damage, general property damage, and
collapse or destabilization (potentially leading to
future collapse) of buildings.
 The aftermath may bring disease, lack of basic
necessities, and higher insurance premiums.
LANDSLIDES :
 Landslides became a symbol of the devastation the 2001 El
Salvador earthquakes left, killing hundreds in its wake.
 Earthquakes, along with severe storms, volcanic activity,
coastal wave attack, and wildfires, can produce slope
instability leading to landslides, a major geological hazard.
Landslide danger may persist while emergency personnel
are attempting rescue.

9. FIRES :
 Earthquakes can cause fires by damaging electrical
power or gas lines. In the event of water mains
rupturing and a loss of pressure.
 It may also become difficult to stop the spread of a
fire once it has started. For example, more deaths in
the 1906 San Francisco earthquake were caused by
fire than by the earthquake itself.
Soil liquefaction :
 Soil liquefaction occurs when, because of the shaking,
water-saturated granular material (such as sand)
temporarily loses its strength and transforms from a
solid to a liquid.
 Soil liquefaction may cause rigid structures, like
buildings and bridges, to tilt or sink into the liquefied
deposits. For example, in the 1964 Alaska earthquake,
soil liquefaction caused many buildings to sink into the
ground, eventually collapsing upon themselves

10. Measures against earthquakes
Personal measures :
 Seek shelter under stable tables or under door frames.
 If outside, stay away from buildings, bridges and electricity pylons and move to open
areas.
 Avoid areas at risk from secondary processes, such as landslides, rockfall and soil
liquefaction.
 After an earthquake, check gas, water and electricity pipes and lines for damage.
 Listen to the radio and follow the instructions issued by the authorities.

11. What are the most powerful earthquakes of India?
Sr. No. Place Epicenter Date, Time, and Year Magnitude Deaths
1 Indian Ocean
West coast of
Sumatra,
Indonesia
08:50, December 26,
2004
9.1–9.3 > 283,106
2 Kashmir
Muzaffarabad,
Pakistan-
administered
Kashmir
08:50:38, October 8,
2005
7.6 130,000
3 Bihar and Nepal
South of Mount
Everest
14 :13, January 15,
1934
8.7 > 30,000
4 Gujarat Kutch, Gujarat
08:50:00, January 26,
2001
7.7 20,000
5 Kangra Himalayas 06:10, April 4, 1905 7.8 > 20,000
6 Latur
Killari, Latur,
Maharashtra
22:25, September 30,
1993
6.4 > 9,748

12. Sr. No. Place Epicenter Date, Time, and
Year
Magnitude Deaths
7 Assam Rima, Tibet
19:39, August 15,
1950
8.6 1,526
8 Assam
Place name not
known
17 :11, June 12,
1897
8.1 1,500
9 Uttarkashi
Garhwal,
Uttarakhand
Unknown time,
October 20, 1991
6.8 >1,000
10 Koynanagar
Koyna dam,
Maharastra
04:21, December
11, 1967
6.5 180

13. EARTHQUAKE IN NEPAL
 From few days ago Nepal is being suffering with
earthquake effect. It has been identified that it is of 7.8
magnitude with a lot of destruction and loss of lives.
 At least 3,617 people are now known to have died in a
massive earthquake which hit Nepal on Saturday, police say.
 More than 6,500 people have been injured, according to the
National Emergency Operation Centre.
 More than 200 climbers have been rescued around Mount
Everest, which was struck by deadly avalanches
 Officials have warned that the number of casualties could
rise as rescue teams reach remote mountainous areas of
western Nepal.
 Villages like this are routinely affected by landslides, and
it's not uncommon for entire villages of 200, 300, up to
1,000 people to be completely buried by rock falls.

14. Dead or missing foreigners
 Australia: 549 Australians registered as travelling in Nepal, 200 confirmed safe
 Bangladesh: 50 nationals, including members of the country's under-14 girls'
football team, evacuated. No information on exact number of nationals in Nepal.
 China: Four nationals dead in Kathmandu, Xinhua news agency reports
 Colombia: Seven nationals missing
 France: French authorities have located 1,098 nationals, but another 674 are still
not in touch.
 UK: Several hundred Britons believed to be in Nepal. No reports of deaths or
injuries.
 US: Three Americans killed

15. CONCLUSION
 Finally, it must be understood that this presentation does not exclude the existence (in
the future) of any other methodologies, with even better accuracy than the one,
which has been achieved with the present work.
 I hope that some other eager and younger researcher will either improve it or invent a
better one, in the near future.
 What is only required, is to believe that a problem shouldn’t be considered
unsolvable, just because it was not solved for a long period of time, in the past.