About Cyclone and Earthquake

1. CYCLONES AND
EARTHQUAKES
MONISH M
2021005062
UG - 2nd YEAR

2. ⦁ Cyclones are huge revolving storms caused by
winds blowing around a central area of low
atmospheric pressure.
Wind blows anti-clockwise in the
NH and clockwise in the SH
Typhoon- termed used when it
formed in the Pacific ocean
Hurricane- termed used when it
formed in the Atlantic ocean
Cyclone- termed used when it
formed in the southern ocean and
Indian ocean
Willy-willy- termed used in Australia

3. ⦁ Classification of cyclone according to synoptic
scale
⦁ 1. Polar cyclone (polar regions, vast)
⦁ 2. Polar lows (polar regions, short)
⦁ 3. Extratropical cyclone (mid-latitude cyclone)
⦁ 4. Subtropical cyclone (between the equator
and 50o N and S)
⦁ 5. Mesocyclone (associated with tornado
formation)
⦁ 6. Tropical cyclone (tropics)

4. ⦁ Tropical cyclone is non-frontal synoptic scale low-
pressure system over tropical waters with
organized convection (i.e. Thunderstorm activity)
and cyclonic surface circulation.
This low pressure creates
violent storms that are
characterised by winds
over 100km/h and heavy
rainfall.
They have caused the
loss of life on a number of
occasions due to there
intensity.

5. ⦁ TC has synoptic scales of 100’s km

6. ⦁ The lifetime of a cyclone is
determined by how
favourable the atmospheric
environment is, movement,
sea surface temperatures.
⦁ While most cyclones
undergo a life-cycle of 3-7
days some weak ones only
briefly reach gale force
while others can be
sustained for weeks if they
remain in a favourable
environment.
⦁ The longest being
Hurricane Ginger (1971)
that lasted for 30 days.

7. ⦁ Winds of 30-60 kph is expected.
⦁ Sea condition
◦ Wave Height: 1.25-4.0 meters
⦁ Damage to structures
Very light or no damage to high risk
structures,
Light to medium and low risk structures
Slight damage to some houses of very
light materials or makeshift structures in
exposed communities.
⦁ Damage to vegetations
Some banana plants are tilted, a few
downed and leaves are generally
damaged
Twigs of small trees may be broken.
Rice crops, however, may suffer significant
damage when it is in its flowering stage.

8. ⦁ Winds of greater than 61 kph and up to
120 kph may be expected in at least 24
hours.
⦁ Sea condition
⦁ Wave Height: 4.1-14.0 m
Storm surge possible at coastal areas
Damage to structures
Light to Moderate damage to high risk
structures;
· Very light to light damage to medium-risk
structures;
·No damage to very light damage to low risk
structures
Unshielded, old dilapidated schoolhouses,
makeshift shanties, and other structures of light
materials are partially damaged or unroofed.
⦁ Damage to vegetations
Most banana plants, a few mango trees, ipil-ipil
and similar types of trees are downed or broken
Some coconut trees may be tilted with few others
broken
Rice and corn may be adversely affected
Considerable damage to shrubbery and trees with
some heavy-foliaged trees blown down.

9. ⦁ Winds of greater than 121 kph up to
170 kph may be expected in at least 18
hours.
⦁ Sea condition
⦁ Wave Height: > 14.0 meters
Storm surge possible at coastal areas
⦁ Damage to structures
Heavy damage to high–risk structures;
·Moderate damage to medium- risk
structures;
· Light damage to low-risk structures
Increasing damage to old, dilapidated
residential structures and houses of light
materials (up to 50% in a community)
⦁ Damage to vegetations
Almost all banana plants are downed, some
big trees (acacia, mango, etc.) are broken or
uprooted,
Dwarf-type or hybrid coconut trees are tilted
or downed
Considerable damage to shrubbery and trees
with heavy foliage blown off; some large trees
blown down.

10. ⦁ Very strong winds of greater than 171
kph up to 220 kph may be expected in at
least 12 hours.
⦁ Sea condition
⦁ Wave Height: more than 14.0 meters
Storm surge2-3m possible at coastal areas
⦁ Damage to structures
Very heavy damage to high –risk structures
· Heavy damage to medium risk structures;
·Moderate damageto low-risk structures
Considerable damage to structures of light
materials (up to 75% are totally and partially
destroyed); complete roof structure failures.
⦁ Damage to vegetations
There is almost total damage to banana
plantation,
Most mango trees, ipil-ipil and similar types of
large trees are downed or broken.
Coconut plantation may suffer extensive
damage.
Rice and corn plantation may suffer severe
losses.

11. ⦁ more than 220kph
Expected in12hrs on 1stissuance.
⦁ Sea condition
⦁ Wave Height: more than 14.0 m
Storm surge more than 3 meters possible at
coastal areas
⦁ Damage to structures
Widespread damage to high-risk
structures
· Very heavy damage to medium-risk
structures
·Heavy damage to low-risk structures;
Almost total damage to structures of light
materials, especially in highly exposed coastal
areas.
⦁ Damage to vegetations
Total damage to banana plantation
Most tall trees are broken, uprooted or
defoliated;
Coconut trees are stooped, broken or uprooted.
Few plants and trees survived

12. 1. Bring precipitation. Rainfall increases groundwater and the water
levels of dams that provide drinking water, irrigation water and
power generation.
2. Rains mean water for plants. About 50% of our water supply
comes from rainfall brought by tropical cyclones.
3. Decreases the level of pollutants.
4. Tropical cyclones also help maintain the global heat balance by
moving warm, moist tropical air to the middle latitudes and polar
regions.
5. The storm surge and winds of hurricanes may be destructive to
human-made structures, but they also stir up the waters of coastal
estuaries, which are typically important fish breeding locales.

13. 1. Tropical cyclones out at sea cause large waves, heavy rain, and
high winds, disrupting international shipping and, at times,
causing shipwrecks.
2. Tropical cyclones stir up water, leaving a cool wake behind them,
which causes the region to be less favourable for subsequent
tropical cyclones.
3. On land, strong winds can damage or destroy vehicles,
buildings, bridges, and other outside objects, turning loose
debris into deadly flying projectiles.
4. The storm surge, is typically the worst effect from landfalling
tropical cyclones, historically resulting in 90% of tropical cyclone
deaths
5. The broad rotation of a landfalling tropical cyclone, and vertical
wind shear at its periphery, spawns tornadoes.

14. EARTHQUAKE

15. ⦁ Earthquake also known as quake , tremor or temblor is the
phenomenon where there is a sudden release of extreme
energy from the earth crust resulting in shaking and
displacement of the ground along with the creation of sesmic
waves.
⦁ If the Epicenter of a larger earthquake is situated in the
offsore (sea/ocean) seabed may be displaced sufficiently to
cause Tsunami.
⦁ It also triggers land slides
and occassionally volcanic
eruptions.

16. ⦁ Earthquake shaking may cause loss of life and destruction
of property.
⦁ In a strong earthquake the ground shakes violently.
⦁ Buildings may fall
or sink into the soil.
Rocks and soil may
move downhill at a
rapid rate.
⦁ Such landslides can
bury houses and
people.

17. ⦁ Earthquake = Vibration of the Earth produced by
the rapid release of energy
⦁ Seismic waves = Energy moving outward from the
focus of an earthquake
⦁ Focus= location of initial slip on the fault; where
the earthquake origins
⦁ Epicenter= spot on Earth’s
surface directly above the
focus
focus
epicenter

19. ⦁ Geological Faults.
⦁ Volcanic Eruptions.
⦁ Mine Blasts.
⦁ Nuclear Tests.

20. ⦁ Based on Magnitude:
MAGNITUDE CLASSIFICATION
M ≥ 8.0 Great Earthquake
7.0 ≥ M < 8.0 Major / Large Earthquake
5.0 ≥ M < 7.0 Moderate Earthquake
3.0 ≥ M < 5.0 Small Earthquake
1.0 ≥ M < 3.0 Microearthquake
M < 1.0 Ultra Microearthquake

21. CLASSIFICATION DISTANCE
Teleseismic Earthquake > 1000 km
Regional Earthquake > 500 km
Local Earthquake < 500 km

22. Primary Earthquake Hazards: Rapid Ground Shaking
Structural
Damage
Buckled roads and rail tracks

23. Landslides Avalanches

24. Alterations to Water Courses Fire resulting from an
earthquake

26. ⦁Seismometers: instruments
that detect seismic waves.
⦁ Seismographs:Record
intensity, height and
amplitude of seismic
waves

27. 1. Magnitude: Richter Scale
a) Measures the energy released by fault movement.
b) Logarithmic-scale; quantitative measure.

28. 2) Intensity: Mercalli Scale:
What did you feel?
⦁ Assigns an intensity or rating to measure an
earthquake at a particular location (qualitative)
⦁ Measures the destructive effect
 Intensity is a function of:
⦁ Energy released by fault
⦁ Geology of the location
⦁ Surface substrate: can magnify shock waves

29. Remote Seismograph Positioning.
 Scientists consider seismic activity as it is
registered on a seismometer.
 A volcano will usually register some small
earthquakes as the magma pushes its way up through
cracks and vents in rocks.
 As a volcano gets closer to
erupting, the pressure builds
up in the earth under the
volcano and the earthquake
activity becomes more and more
frequent

30.  Analog Image:
 This is an image of an analog recording of
an earthquake. The relatively flat lines are
periods of quiescence and the large and
squiggly line is an earthquake.

31.  Digital Seismogram.
 Below is a digital seismogram. The data is
stored electronically, easy to access and
manipulate, and much more accurate and
detailed than the analog recordings.

32.  Tiltmeter:
 Tilt meters attached to the sides of a volcano
detect small changes in the slope of a volcano.
 When a volcano is about to erupt, the earth may
bulge or swell up a bit.
Installing a
tiltmeter

33.  Changes in Groundwater Levels.
 Hydro geological responses to large distant
earthquakes have important scientific implications
with regard to our earth’s intricate plumbing
system.
 Improves our insights into the
responsible mechanisms, and
may improve our frustratingly
imprecise ability to forecast
the timing, magnitude, and
impact of earthquakes.

34. Observations of Strange Behaviors in Animals.
The cause of unusual animal behavior seconds
before humans feel an earthquake can be easily
explain-ed.
 Very few humans notice the smaller P wave that
travels the fastest from the earthquake source and
arrives before the larger S wave.
 But many animals with more keen senses are able
to feel the P wave seconds before the S wave
arrives.
indeed it’s possible that some animals could sense
these signals and connect the perception with an
impending earthquake.