Phenomenon

NATURAL

PHEN

OMEN

A

A na

tura

l disa

ster is

the e

ffect

of a n

atura

l

haza

rd th

at aff

ects

the en

viron

ment, a

nd

leads

to fin

ancia

l, env

ironm

ental

and/o

r

human

loss

es. T

he re

sultin

g los

s dep

ends

on th

e cap

acity

of th

e pop

ulatio

n to s

uppo

rt

or re

sist th

e disa

ster, a

nd th

eir re

silien

ce

torna

do.

Torn

adoe

s are

viole

nt, r

otati

ng co

lumns

of ai

r whic

h can

blow

at sp

eeds

betw

een 5

0 and

300 m

ph, a

nd po

ssibly

high

er. To

rnad

oes c

an oc

cur o

ne

at a ti

me, or

can o

ccur

in la

rge to

rnad

o out

brea

ks al

ong s

quall

lines

or in

othe

r large

area

s of t

hund

ersto

rm de

velop

ment. W

atersp

outs

are

torn

adoe

s occ

urrin

g ove

r wate

r in lig

ht ra

in co

ndition

s.

tsuna

mi

A tsun

ami is

a se

ries o

f wav

es cr

eate

d whe

n a bo

dy of

wate

r, suc

h as a

n

ocea

n, is

rapidl

y disp

laced

. Ear

thqu

akes

, mas

s mov

emen

ts ab

ove o

r

below

wate

r, volc

anic

erup

tions a

nd ot

her u

nder

water e

xplos

ions,

lands

lides

, large

met

eorit

e impa

cts co

met im

pacts

and t

esting

with

nucle

ar w

eapo

ns at

sea a

ll hav

e the

pote

ntial

to ge

nerat

e a ts

unam

i. A

tsuna

mi is no

t the

same t

hing a

s a tida

l wav

e, whic

h will

gene

rally

have

a far

less

damag

ing eff

ect t

han a

Tsun

ami.

Earthquake

An e

arth

quak

e is

the

resu

lt of a

sudd

en re

lease

of e

nerg

y

in th

e Ea

rth's

crus

t tha

t cre

ates

seism

ic wav

es.

Earth

quak

es a

re re

cord

ed w

ith a

seism

omet

er, a

lso kn

own

as a

seism

ogra

ph. T

he m

omen

t mag

nitud

e of

an

earth

quak

e is

conv

entio

nally

repo

rted,

with

mag

nitud

e 3

or

lower

ear

thqu

akes

bein

g m

ostly

impe

rcep

tible

and

mag

nitud

e 7

caus

ing se

rious

dam

age

over

larg

e ar

eas.

Inte

nsity

of s

hakin

g is

mea

sure

d on

the

mod

ified

Met

ricall

y

scale

.

Hurricane

Hurric

anes

, tro

pical

cyclo

nes,

and t

ypho

ons a

re di

fferen

t nam

es fo

r the

same p

heno

menon

: a cy

clonic

stor

m syste

m that

form

s ove

r the

ocea

ns.

It is c

ause

d by e

vapo

rated

wate

r tha

t com

es off

of th

e oce

an an

d

beco

mes a

storm

. The

Coro

llas E

ffect c

ause

s the

stor

ms to s

pin, a

nd a

hurri

cane

is de

clare

d whe

n this

spinn

ing m

ass o

f sto

rms a

ttains a

wind

spee

d gre

ater t

han 7

4 mph

. Hur

rican

e is u

sed f

or th

ese p

heno

mena i

n

the A

tlanti

c and

easte

rn Pa

cific O

cean

s, tro

pical

cyclo

ne in

the I

ndian

,

and t

ypho

on in

the w

este

rn Pa

cific.

.

Flood

s

A flood

is an

over

flow of

an ex

pans

e of w

ater t

hat s

ubmer

ges l

and,

a

delug

e. It

is us

ually

due t

o the

volum

e of w

ater w

ithin

a bod

y of w

ater,

such

as a

river

or la

ke, e

xcee

ding t

he to

tal ca

pacit

y of t

he bo

dy, a

nd as

a

resu

lt som

e of t

he w

ater fl

ows o

r sits

outsi

de of

the n

ormal

perim

eter

of

the b

ody.

It can

also

occu

r in riv

ers,

when t

he st

reng

th of

the r

iver is

so

high i

t flow

s righ

t out

of th

e rive

r cha

nnel,

usua

lly at

corn

ers o

r

meand

ers.

AVALAN

CHES

An ava

lanch

e is a

geop

hysic

al ha

zard

invo

lving

a sli

de of

a lar

ge sn

ow or

rock

mas

s dow

n a m

ount

ainsid

e, ca

used

whe

n a bu

ildup

of m

ateria

l is

relea

sed d

own a

slop

e, it i

s one

of th

e majo

r dan

gers

faced

in th

e

mount

ains i

n wint

er. As a

valan

ches

mov

e dow

n the

slop

e the

y may

entra

in sn

ow fr

om th

e sno

wpack

and g

row in

size

. The

snow

may

also

mix with

the a

ir and

form

a po

wder c

loud.

An ava

lanch

e with

a po

wder

cloud

is kn

own a

s a po

wder s

now av

alanc

he. T

he po

wder c

loud i

s a

turb

ulent

susp

ensio

n of s

now pa

rticle

s tha

t flow

s as a

grav

ity cu

rrent

.

volca

nic er

uption

A volca

nic er

uption

is th

e poin

t in w

hich a

volca

no is

active

and r

eleas

es

lava a

nd po

isono

us ga

sses i

n to t

he ai

r. The

y ran

ge fr

om da

ily sm

all

erup

tions t

o extr

emely

infre

quen

t sup

er vo

lcano

erup

tions (

where

the

volca

no ex

pels

at lea

st 1,0

00 cu

bic ki

lomet

ers o

f mate

rial.)

Some

erup

tions f

orm flo

ws, whic

h are

high

-tempe

ratur

e clou

ds of

ash a

nd

steam

that

can t

ravel

down m

ount

ainsid

es at

spee

ds ex

ceed

ing th

at of

an ai

rline

r.

Wildfire

Wild

fires

, or f

ores

t fire

s, ar

e unc

ontro

lled fi

res b

urnin

g in w

ild la

nd

area

s. Co

mmon ca

uses

inclu

de lig

htnin

g, hu

man ca

reles

snes

s, ar

son,

volca

no er

uption

, and

clou

d fro

m active

volca

no. T

he ca

n be a

thre

at to

thos

e in r

ural

area

s and

also

to w

ildlife

. Wild

fires

can a

lso pr

oduc

e

embe

r attac

ks, w

here

floati

ng em

bers

set fi

re to

build

ings a

t a di

stanc

e

from th

e fire

itself

Drought

A drou

ght is

an ex

tend

ed pe

riod o

f mon

ths o

r yea

rs whe

n a re

gion

suffer

s a se

vere

defic

iency

in its

wate

r sup

ply. G

ener

ally,

this

occu

rs

when a

regio

n rec

eives

cons

isten

tly be

low av

erag

e rain

fall. I

t can

have

a

subs

tantial

impa

ct on

the e

cosy

stem an

d agr

icultu

re of

the a

ffecte

d

regio

n. Alth

ough

drou

ghts

can p

ersis

t for

seve

ral y

ears,

even

a sh

ort,

inten

se dr

ough

t can

caus

e sign

ifican

t dam

age a

nd ha

rm th

e loc

al

econ

omy

Landslide

A land

slide

is a

disas

ter i

nvolv

ing el

emen

ts of

the g

roun

d, inc

luding

rock

s, tre

es, p

arts

of ho

uses

, and

anyth

ing el

se w

hich m

ay ha

ppen

to be

swep

t up.

Land

slide

s can

be ca

used

by an

earth

quak

e, vo

lcanic

erup

tions,

or ge

neral

insta

bility

in th

e sur

roun

ding l

and.

Mud

slide

s or

mudflo

ws, ar

e a sp

ecial

case

of la

ndsli

des,

in whic

h hea

vy ra

infall

caus

es

loose

soil o

n ste

ep te

rrain

to co

llaps

e and

slide

downw

ards

.

Made b

y :

Siddh

arth S

ingh

Class

: 8th A

Roll n

o : 37