Natural disasters.ppt types of natural disasters

Natural disasters

1. Types of Natural Disasters

6. 1.Avalanches

7. •Avalanches is defined as any large mass of
tumbling, sliding, or flowing snow.
•Avalanches can be thought of as a type of
landslide, particularly since they can also
include boulders and other debris.
•However, avalanches primarily consist of
snow, and they have different innate
characteristics from other types of landslides.
•Since avalanches require snow in order to
occur, they are really only a threat to locations
that receive a decent amount of snowfall each
year.

8. 2. Blizzards

9. •Winter-related hazard,blizzardsare defined as
storms that last more than three hours and
that feature:
a) Winds greater than 35 mph (15.7 m/s)
b) Visibility of less than 0.25 miles (400 m)
c) Large amounts of snowfall or blowing snow
•Blizzards are only really a threat in locations
that have cold enough temperatures to
experience large amounts of snowfall.

10. •blizzards can pose a hazard for hikers,
especially if they lead to white-out conditions
that can make navigation next to impossible.
•Blizzards are also a hazard for drivers as they
can also lead to slick roads and near-zero
visibility.
•blowing snow associated with blizzards can
also increase avalanche risk in the days
following the storm.

11. 3. Cold Waves

12. •acold waveis a type of natural disaster where
the temperature drops rapidly over the course
of 24 hours.
•While cold weather in itself isn’t necessarily
enough to cause a natural disaster, a rapid
dropping of the temperature could lead to
widespread problems for communities in a
region.
•

13. •There are many reasons why a cold wave
might occur.
•One of the most common causes of a cold
wave is the arrival of a very strong high
pressure system from the polar regions.
•Alternatively, movement in the jet streams can
also drive very cold weather southward in just
a matter of hours.

14. •The primary danger of a cold wave is, indeed,
the cold weather itself.
•This can lead to a higher risk of hypothermia
and other cold-related injuries.
•Cold weather can cause ice and frost to build
up quickly, damaging infrastructure.
•Cold waves are also particularly dangerous for
aircraft and other machinery.
•Extreme cold can drain vehicle batteries or
cause diesel to gel. So, caution is needed
whenever extreme cold is in the forecast.

15. 4. Droughts

16. •Adroughtis technically defined as an
extended period of time where drier-than-
normal conditions lead to a lack of water or
other water-related issues.
•While it’s unclear how long the ground will
last, humanitarian organizations already
predict that tens of millions of people in the
region will face food insecurity as a result.
•So, while droughts can be difficult to predict
and identify, their human impacts are very
real.

17. 5. Earthquakes

18. •most unpredictable natural
disasters,earthquakesoccur whenever there’s a
sudden and violent slippage of the Earth’s
tectonic plates.
•the Earth’s crust consists of many plates that slip,
slide, collide, and move past each other on a
regular basis.
•When these plates suddenly slip past each other,
that movement can lead to very real shaking on
the Earth’s surface.
•While small earthquakes happen dozens, if not
hundreds of times a day, without issue, major
earthquakes can cause catastrophic damage and
loss of life.

19. 6. Floods

20. •Floodsare any instances where water temporarily
overflows onto land that is usually dry.
•The reason for floods might form, is heavy rainfall
is usually a culprit.
•The general rule with floods is that you should
never try to travel through a flooded area,
regardless of how minor the situation might
appear.
•Trying to walk, drive, or swim through a flood is
almost always a bad idea as rapidly changing
currents can drag you into a dangerous situation.

21. 7. Flash Floods

22. •In a weather forecasting context, flash floods are
defined as any type of flooding that begins within
6 hours of a period of heavy rain or other water-
related cause.
•Like regular floods, flash floods are normally
associated with major storms. Indeed, hurricanes
and other meteorological events can cause rapid
flooding of an area in a short period of time.
•This type of flash flooding is normally associated
with a thunderstorm upstream, but it may also be
caused by a dam break or malfunction.

23. 8. Hailstorms

24. •particularly supercells, very strong updrafts
(upward flows of air) can lead to the
formation of hail.
•the reality is that hail can be particularly
dangerous for humans and it can lead to
widespread damage.
•Although most hailstones are somewhat
small, large hailstones can injure unsuspecting
passers-by on the ground.

25. 9. Heat Waves

26. •aheat waveis a prolonged period of
exceptionally high temperatures.
•any period of two or more days where the
temperature is higher than the historical
average for an area is a heat wave.
•the danger of a heat wave is the risk of severe
dehydration that can lead to a life-threatening
condition known asheat stroke.

27. 10. Ice Storms

28. •ice stormsoccur whenever there are
substantial collections of freezing rain.
•ice storms happen when there’s a thin layer of
warm air located a few hundred feet above
the ground during a snowstorm.
•As the snow falls from the sky, it hits this layer
of warm air and melts, but then refreezes
when it enters the layer of colder air right
along the surface of the Earth, leading to the
formation of freezing rain.

29. 11. Impact Event

30. •One of the few natural disasters on our list
that’s caused by objects that don’t come from
our planet Earth,impact events, or “asteroid
impacts,” are collisions between astronomical
objects.
•The most recent major meteor event was that
of theChelyabinsk meteor in 2013. The
Chelyabinsk meteor entered the Earth’s
atmosphere over Chelyabinsk Oblast in Russia
and exploded about 14 miles (23 km) above
the ground.

31. 12. Landslides

32. •Landslides can be defined as any large-scale
movement of a mass of debris or rock down a
slope.
•landslides to be a form of something called
“mass wasting,” which is effectively the sliding
of soil or rock as a result of gravity.

33. •Landslides can be caused by a wide range of
events, includingvolcanic eruptions,
earthquakes, and heavy rains.
•Scientists can sometimes predict landslide-
prone slopes, but forecasting the exact time of
a landslide isn’t always easy due to the many
factors involved in landslide formation.

34. 13. LimnicEruptions

35. •Limnic eruptions, “exploding lakes,” are a very
rare type of natural disaster where carbon
dioxide very suddenly and violently erupts
from the bottom of a freshwater lake.
•these lakes will simply keep absorbing carbon
dioxide until they reach their saturation point.
•if something major happens in the nearby
landscape, such as a landslide, this can cause
the release of all that pressure in the lake

36. 14. Mudslides

37. •Mudslidesare technically a type of landslide
that includes mostly mud and other similar
fast-moving debris.
•mudslides have a whole host of different
causes, including heavy rain and earthquakes.

38. 15. Pea Soup Fog

39. •Pea soup fogis essentially a popular term for
yellowish-black smog that sets in over major
urban areas. It’s basically a poisonous mix of
fog, soot particulates, and sulfur dioxide that
can settle down over a given area for hours,
days, or even weeks at a time.
•places with lots of air pollution and frequent
temperature inversions are still at risk for this
type of natural disaster.

40. 16. Sinkholes

41. •Sinkholes are defined as any hole that forms
below the land surface without an external
draining. They can vary quite a bit in size, from
just a few feet wide to more than 100 feet (60 m)
in diameter.
•the bedrock in an area is made of some sort of
soluble material, like limestone, salt beds, or
carbonate rock.
•As groundwater seeps through the bedrock, it
slowly dissolves the rock, causing a hole to form
underground.
•When enough pressure is applied over the
growing hole, the ground will collapse, leaving
behind a massive sinkhole in its wake.

42. 17. Solar Flares

43. •A solar flare is effectively a major explosion
that happens on the surface of the sun. While
our sun might be very far away, these solar
flares can cause massive disruptions to our
planet’s magnetic field.
•Solar flares and their associated geomagnetic
storms can cause issues with electrical power
outages and communications satellites due to
the energy that they emit. These flares can
also affect radio communications on Earth

44. 18.Subsidence

45. •subsidence happens when large amounts of
groundwater are depleted from the bedrock.
•This sort of water loss is common in areas that
use large amounts of water for irrigation.
•land subsidence affects such a large area that
you might not even know that it’s happening.

46. 19. Thunderstorms

47. •a thunderstorm is a type of storm that results
from deep, moist convection in the
troposphere.
•These storms are labeled as thunderstorms
when they produce lightning, which then
produces thunder.

48. 20.Tornadoes

49. •A tornado can be defined as a violently
rotating column of air.
•A dedicated storm shelter underground is
ideal, but any interior room with no windows
on the lowest floor of the building is better
than nothing.

50. 21. Tsunamis

51. •tsunamisare massive waves that are caused by
geologic activity. These waves are usually
instigated by earthquakes or undersea volcanic
eruptions, both of which can cause the
propagation of seismic waves through the ocean.
•Many tsunami-prone places have early warning
detection systems and sirens in place to alert
people to the possibility of danger.
•If you hear a siren or receive a warning about a
tsunami, immediately stop what you are doing
and seek out higher ground until the threat
passes, and encourage others around you to do
the same.

52. 22. Tropical cyclone

53. •A tropical cyclone is defined as a rapidly rotating
storm that forms over tropical areas where there
is plenty of warm water and moist air. These
storms develop into massive low pressure
systems that can bring fierce winds, heavy rains,
and spectacular storm surge to coastal and inland
areas.
•tropical storms can bring high winds, heavy
rainfall, and storm surge. They often bring down
power grids and cause widespread flooding,
which can be disastrous in low-lying coastal
regions.

54. 23. Volcanic Eruptions

55. •Volcanoes are openings along the crust of the
Earth where lava, gases, and ash can escape.
When these materials escape from the
opening on the planet’s surface, we call this
avolcanic eruption.
•a volcano is at threat of an eruption, but
predicting the exact time of a volcanic event is
still beyond our current capabilities.

56. 24. Wildfires

57. •Wildfires, which are unplanned and uncontrolled
fires that burn in forests, bushlands, prairies, or
grasslands, are an increasingly common threat in
our lives.
•In very dry parts of the world, like Australia and
California, wildfires happen naturally as part of
standard ecological processes.
•wildfires can be both natural and human-caused.
•Lightning strikes are one of the most common
natural causes of wildfires while uncontrolled
campfires, downed power lines, and arson are
often the impetus behind human-caused
wildfires.