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South Africa is situated in the centre of a ground-plate; therefore we may not necessarily experience very serious earthquakes. But the stirrings in the mantle of the earth’s crust are noticeable in South Africa, as we have experienced in 1969 when an earthquake in the Boland caused much damage in Ceres.

In the next learning unit the map will show that earthquakes and volcanoes occur at the same place s.

(See figure 8)

Activity 2:

To indicate on a map of the world in which areas earthquakes occur

[lo 2.1, 2.2]

2. The effect (consequences) of earthquakes on the lives of people and socio-economic activities

Read the magazine article that follows.

You are simply strolling down the street in the city or town where you live. Suddenly the ground around you starts to buckle and form waves like those that form in a dam into which a stone is hurled.

An awful droning, almost like a lamentation, rises from the earth. Around you buildings collapse like houses built of cards and the street in front of you is bursting open as if made of strips of soft, torn cardboard.

Railway girders bend and tear, bridges collapse, dam walls break. People and cars tumble into the enormous gaping cracks in the earth. The cracks close up again and everything disappears forever. Everywhere bricks, concrete blocks, beams and pillars fall down on people who scramble left and right for a place of shelter that cannot be found.

Fires break out because electric cables and gas pipes are broken. Water rushes from burst pipes. Windowpanes lie shivered into razor-sharp splinters among the rubble, adding to the horror. A most dreadful natural disaster. Horror as humankind has known it since the earliest times. Earthquake!

Huisgenoot, Jongspan , 21 May 1987.

Such an earthquake is rated as a very serious disaster, but all earthquakes fortunately are not equally severe. There may be a tremor of the earth’s crust every thirty minutes, but only about 500 of them are actually felt in any year. Fortunately those that do great damage and claim thousands of lives are few and far between.

Trace the world map from figure 8 and indicate only the areas where earthquakes occur. Then colour it in red.

Activity 3:

To discuss the consequences of earthquakes

[lo 2.1, 2.2]

1. Read the magazine article attentively. Form groups for discussing the effects of earthquakes on:

a) People

b) Nature

2. Collect photographs, pictures and newspapers or magazine cuttings dealing with earthquakes. Bring it along to the class for a discussion session and use it to supplement the information in your notes.

3. Read the following paragraph dealing with Tsunamis and try to find pictures and additional information dealing with this natural phenomenon.

Tsunami – another result of earthquakes!

When rock on the ocean floor shifts unexpectedly, the overlying seawater is also affected and a gulf that can move at 800 km per hour develops. When the gulf reaches the shallower bays of coastal areas it is dammed up higher. It can reach heights of between 30 and 60 metres and can cause serious destruction by flooding and destroying harbours and towns along the coast.

Questions & Answers

Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Geography grade 7. OpenStax CNX. Sep 09, 2009 Download for free at http://cnx.org/content/col11021/1.1
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