2. What are
CYCLONES!
In meteorology, a cyclone is a large air mass that rotates around a strong center of low
atmospheric pressure, counter clockwise in the Northern Hemisphere and clockwise in the
Southern Hemisphere as viewed from above.
Cyclones are characterized by inward-spiraling winds that rotate about a zone of low
pressure.
4. Formation of CYCLONES!
• Cyclones form only over warm
ocean waters near the equator.
• When the warm, moist air rises
upward over the ocean, it causes an
area of lower air pressure below.
• Air from surrounding areas with
higher air pressure pushes in to the
low pressure area. Then this new
“cool” air becomes warm and moist
and rises, too. And the cycle
continues…
5. Impacts of CYCLONES!
Major impact of cyclone includes heavy
rainfall, strong wind, landslides, large storm
surges at landfall, and tornadoes.
The destruction from a cyclone depends
mainly on its intensity, its size, and its location.
Some of the disaster caused by cyclones are:
▪ Wind
▪ Floods
▪ Erosion
▪ Storm churn
6. WINDS
The winds in the cyclones can travel with speed of
more than 156mph which can rip trees from the
ground and flatten buildings.
This often results in loss of animal habitats,
destroying vegetation, interrupting and changing
ecosystems.
Cyclonic winds also can damage infrastructure, such
as power lines, communication towers, bridges and
roads.
7. FLOODS
Floods caused by cyclones can drown
people and animal, and are often the
greatest killer in cyclone.
Streets can become swift moving rivers
and the underpasses can become the most
deadliest traps.
Overflowing waters can damage buildings
and can also damage the infrastructure in
coastal areas.
8. EROSION
In earth science, erosion is the action
of surface processes that removes
soil, rock, or dissolved material from
one location on the Earth's crust, and
then transports it to another location
where it is deposited.
Removal of rock or soil as clastic
sediment is referred to as physical or
mechanical erosion which contrasts
with chemical erosion, where soil or
rock material is removed from an
area by dissolution.
9. Causes of Cyclones
Damage to coastal homes
Redistribution of sand
Rise in river level
Overflow of seawater
Collapse of Trees and Buildings
Migration or Displacement of people
Outbreak of infectious disease
Lose of biodiversity
11. It is one of the deadliest natural disasters
ever recorded. The storm formed over the
Bay of Bengal in November 1970 and made
landfall on the coast of East Pakistan (now
Bangladesh) before continuing on to West
Bengal.
At its peak, the cyclone generated winds of
up to 115 mph devastating the coastal regions
it encountered. It’s estimated that between
300,000 and 500,000 people were killed
during the disaster, making it the deadliest
tropical cyclone on record.
The Bhola Cyclone 1970
12. The Bangladesh Cyclone 1991
Another deadly cyclone that formed over the
Bay of Bengal was the 1991 Bangladesh
cyclone. By the time it reached land in
Bangladesh and eastern India, winds of up to
155 mph were recorded, making it one of the
most powerful on record.
The cyclone caused a deadly storm surge
that was 20ft high. It swept over the
coastline, claiming the lives of at least
138,866 people. In the fallout of the storm,
various countries carried out one of the
largest military relief efforts on record,
Operation Sea Angel.
13. The Odisha Cyclone 1999
This storm was the most intense tropical
cyclone ever recorded in the North Indian
Ocean. It was also one of the most
destructive in the region. At the peak of the
storm, winds of up to 160 mph were
recorded, as well as a record-low
pressure.
As well as hitting the state of Odisha in
India, Thailand, Myanmar, and Bangladesh
also all felt the impact. Nearly 10,000 people
died, and it caused around $4.44 billion
worth of damage.
15. Safety Measures!!
When your area is under cyclone warning
get away from low-lying beaches or other
low-lying areas close to the coast:
• Leave early before your way to high
ground or shelter gets flooded.
• Do not delay and run the risk of being
marooned.
• If your house is securely built on high
ground take shelter in the safe part of the
house.
16. Conclusion
➢ A cyclone is a spinning storm caused
by a low-pressure area in the
atmosphere.
➢ The process of Cyclone formation
and intensification is described as
cyclogenesis.
➢ We cannot avoid natural disasters like
cyclones, but being aware of the signs
and following all the safety measures
we can mitigate the loss of life and
property.
