3. EARTHQUAKES
An earthquake is the result of a 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
8. EFFECTSOF EARTHQUAKE
Destructive effects:-
1.loss of life and
property
2.landslide and floods
3.tsunami
4.fire may breakout due
to dislocation of
electrical wiring
Constructive effects:-
1.formation of lakes and
hot springs
2.lifting of water table
3.exposure to deep
minerals and formation
of new minerals
4.may create new
coastal plains that are
very fertile
DESTRUCTIVE EFFECT
CONSTRUCTIVE EFFECT
12. As warm, moist air over the ocean
rises up from the ocean
surface, there is less air left
near the surface, and this
causes an area of lower air
pressure below. The air around
this region has higher air
pressure, and so it rushes in to
fill the low pressure area.
13. The mainsource of energyfor tropical cyclones is the warmoceans in the
tropical regions. To initiate a tropical cyclone the sea-surface
temperature generally needs to be above26.5°C. However, existing
cyclones oftenpersist as they moveovercooler waters.
The development of a tropical cyclone also relies on favorable broad-scale
windregimes and can persist for several days withmany following quite
erratic paths. They lose their sourceof energy whenthey move overland
or colder oceans causing themto dissipate. Weakening may also occur if
the cyclone moves into an unfavorable windregime which disrupts the
structure of the system. Sometimes a decaying tropical cyclone may
interact witha weather systemin higher latitudes to cause impacts far
fromthe tropics.
16. Cyclone Safety Tips
• Check construction of houses should be built to
cyclone standards.
• Trim treetops and branches well clear of your home
• Clear your property of loose material that could blow
about and possibly cause injury or damage during
extreme winds.
• In case of a storm warning or other flooding, know
your nearest safe high ground and the safest access
route to it.
• Prepare an emergency kit to take with you and keep a
list of emergency numbers on display.
17. • Listen continuously to your local radio/TV for
further warnings.
• When a cyclone watch is issued be prepared.
• When the cyclone strikes, disconnect all electrical
appliances. Listen to your battery radio for
updates.
• Stay indoors (unless you are asked to evacuate) in
the strongest part of the building, i.e. cellar,
internal hallway or bathroom. Keep evacuation and
emergency kits with you.
• Protect yourself with mattresses, rugs or blankets
under a strong table or bench if the building starts
to break up.
• Drive carefully as roads may be filled with debris.