Earthquakes, tsunamis, volcanic eruptions, cyclones, and floods are some of the major natural hazards discussed in the document. For earthquakes, the document describes what they are, how they are measured, and their typical causes from tectonic plate movement. For tsunamis, it notes they are large sea waves caused by seismic events. Key steps outlined for preparing for tsunamis include learning about risk, developing evacuation plans, and moving quickly inland to higher ground if one occurs. Volcanic eruptions and cyclones are also briefly mentioned. Floods are described as overflowing of water beyond normal boundaries, with heavy rain, dam breaches, or tidal waves listed as common

2. 1. Earthquakes
2. Tsunamis
3. Volcanic Eruptions
4. Cyclones
5. Floods
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3. EARTHQUAKE
An earthquake (also known as a quake, tremor or temblor) is
the perceptible shaking of the surface of the Earth. They result
from the sudden release of energy in the Earth's crust that
creates seismic waves. The seismicity, seismism or seismic
activity of an area refers to the frequency, type and size of
earthquakes experienced over a period of time.
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. The more numerous earthquakes smaller than magnitude 5
reported by national seismological observatories are measured
mostly on the local magnitude scale, also referred to as the Richter
magnitude scale.
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4. Causes:-
 Earthquakes are the vibrations caused by rocks breaking under stress. The
underground surface along which the rock breaks and moves is called a fault
plane.
 Most earthquakes are causally related to compressional or tensional stresses
built up at the margins of the huge moving lithospheric plates that make up the
earth's surface.
 The immediate cause of most shallow earthquakes is the sudden release of
stress along a fault, or fracture in the earth's crust, resulting in movement of the
opposing blocks of rock past one another.
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5. Effects:-
 Shaking and ground rupture are the
main effects created by earthquakes.
 Earthquakes, along with severe
storms, volcanic activity, coastal wave
attack, and wildfires, can produce
slope instability leading to landslides,
a major geological hazard.
 Earthquakes can cause fires by
damaging electrical power or gas
lines.
 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. 5

6. Hence, in case of an earthquake, the safest place to be would be in an open ground – away
from all kinds of buildings and tall structures.
If you can not rush out of your building, you can duck under some sturdy desk etc. which
might provide protection against heavy objects falling on your body.
If even that is not possible, sit against a wall, with your back pushing the wall firmly, and,
lean forward – to take your head in between both your knees, and, put your hands at the
back of your head – to provide protection to your head and spine.
Or, you could stand directly below one of the door-frame in your house. This one appears
a bit strange to many people. In fact, there are jokes that after an earthquake – you don’t
see all those door-frames standing. So, what's the reasoning behind advising people to
stand below door-frames? In most styles of construction, doorframes are made very strong,
or, would have a “RCC beam” running right above these frames. Either way, this “strong”
structure would take the impact of objects falling from above, and, would break the impact
of the heavy objects falling on the person. If you use this posture, remember to save your
arms and fingers from swaying doors etc. If not careful, they could cause damage by
chopping off fingers etc. due to the banging of the doors against the frame.
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7. 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 kilometres (62 mi), and the
wave periods can vary from five minutes to
one hour.
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9. Step 1:- Learn about the potential for danger in advance.
It is important to consider whether or not you live somewhere that could potentially face
a tsunami. It is likely that you are at some risk if: Your home, school, or workplace is in a coastal
region, near the sea.
The elevation of your home, school or workplace is at sea level or fairly low and on flat or only
slightly undulating land. If you don't know the elevation level of your home, school or workplace,
find out. Some local authorities use elevation as a warning indicator.
There are warning signs indicating that your area is prone to tsunamis.
Your local authorities have issued information about the potential for tsunamis.
Natural sea barriers such as levees of dunes have been removed for development.
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10. Step 2:- Be aware if tsunamis have struck your coastal region in the past.
Do some library research or ask at the local government office. FEMA has a website
enabling online flood risk searches. Most tsunamis happen in what's called the "ring of fire," an
area in the Pacific ocean known for its geologic activity. Chile, the western United States, Japan, and
the Philippines are especially vulnerable.
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11. Step 3:- Prepare essential materials in an easy-to-obtain location.
If a tsunami (or other natural disaster) hits, chances are you'll need a few survival items,
and you'll need them fast. It can be helpful to have both a safety and survival pack already
assembled: Make a safety pack. Food, water, and a first aid kit are among the basics required. Keep
the safety pack somewhere obvious, well-known to everyone in the building and easy to grab in an
emergency. It can also help to leave a raincoat or other coat for each person near the safety pack.
Make a personal survival pack for each person in the family, and a family survival pack with common
items for everyone. Include a supply of necessary medications for each member of the family. Don't
forget survival items for your pets.
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12. Step 4:- Develop an evacuation plan.
An evacuation plan must be prepared in advance to be of use. In developing one,
consider your family, your workplace, your school, and your wider community. If necessary, begin
to develop a community-wide evacuation plan if nothing is being done in your community. Take
the initiative to start developing the plan, and involve local authorities and other residents. Lack of
evacuation plans and local warning systems put you, your family and your entire community at
increased risk for injury or death during and after a tsunami. These are the things that should be
part of a successful evacuation plan: Discuss with family, and colleagues the various options for
evacuation. Know, for example, where you might reunite with your loved ones should a tsunami
hit.
Conduct practice drills to ensure that all members of the community are clear about what they
need to do and where they need to go during a safety evacuation.
Include a plan that can ensure a head count of every single member of the community; ensure that
assistance for disabled or ill persons can be provided.
Ensure that warning and evacuation signals are understood by the community in advance —
distribute pamphlets or give lectures to ensure that everybody is aware. Read Understand Tsunami
Notification Terms.
Remember to provide multiple safety routes owing to the possibility of an earthquake destroying
roads and other infrastructure, preventing exit using some routes.
Consider what types of sheltered areas might exist in the evacuation zones; do such shelters need to
be built in advance?
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13. Step 5:- Abandon belongings.
If a tsunami hits, save lives, not possessions. Trying to retrieve things and belongings may
hamper your escape by causing you to lose valuable time. Grab your safety pack, something to
keep you warm, your family and leave immediately. Tsunami survivors act quickly, and usually
don't bother with trying to save possessions.
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14. Step 6:- Move inland, and to high ground.
The first thing you should try to do, if possible, is to move away from the coast, lagoons
or other bodies of water, towards higher ground and even into hills or mountains. Move until you
are either 2 miles (3,200 m) inland or 100 feet (30 m) above sea level. Expect roads to be totally
wiped out by a tsunami. If you're planning on using roads to get where you need to go, think
again. In a full-blown tsunami, many roads will be wiped out, either by the seismic activity of the
earthquake or by the tsunami itself. Have a good sense of the general direction you want to be
heading in, and consider keeping a compass in your survival pack.
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15. Step 7:- React quickly if you are caught up in the water.
If you did not manage to evacuate but find yourself caught up in the tsunami for one
reason or another, there are things that you can do to try and survive: Grab onto something that
floats. Use a floating object as a raft to keep yourself above the water. Items that float such as tree
trunks, doors, fishing equipment etc. may be in the water with you.
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16. Volcanic Eruption
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18. Cyclone
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20. Flood
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.
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21. Causes:-
 very heavy rainfall (say: due to
cyclones, typhoons etc.) in a short
span of time. It should be noted
that the amount of rainfall itself is
not a sufficient cause, the duration
within which the rainfall is receive
is equally important contributor.
 breach in levy, dams etc.
 very high tidal waves (sometimes
in the aftermath of a seismic
activity, e.g. earthquakes) etc.
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22. Effects:-
 During floods (especially flash
floods), roads, bridges, farms,
houses and automobiles are
destroyed. People become homeless.
Additionally, the government
deploys firemen, police and other
emergency apparatuses to help the
affected.
 The environment also suffers when
floods happen. Chemicals and other
hazardous substances end up in the
water and eventually contaminate
the water bodies that floods end up
in.
 Additionally, flooding causes
kills animals, and others insects
are introduced to affected areas,
distorting the natural balance of
the ecosystem. 22

23. Sea walls and tide gates have been built in some places
to prevent tidal waves from pushing the waters up
ashore. In some areas too, sand bags are made and
placed in strategic areas to retain floodwaters.
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24. In some places, retaining walls levees, lakes, dams, reservoirs or
retention ponds have been constructed to hold extra water
during times of flooding.
In some places, retaining walls levees, lakes, dams, reservoirs or
retention ponds have been constructed to hold extra water
during times of flooding.
Trees, shrubs and grass help protect the land from erosion by
moving water. People in low-lying areas must be encouraged to
use a lot of vegetation to help break the power of moving flood
water and also help reduce erosion.
These are small reservoirs built and connected to waterways.
They provide a temporary storage for floodwaters. This means in
an event of flooding, water is drained into the basin first, giving
people more time to evacuate. It can also reduce the magnitude
of downstream flooding.
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