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```					L.O.      To know the effects of the 1995 Kobe Earthquake.
Key Words.
Epicentre
Richter
Mercalli Scale
What are earthquakes and where do they occur?
Earthquakes are
DESTRUCTIVE              vibrations caused by
earth movements at plate
boundaries and at major
fault lines (cracks in the
earth’s surface).

They can occur at all 4
CONSERVATIVE
major plate boundaries
but the most severe
earthquakes are normally
found at CONSERVATIVE
and DESTRUCTIVE
boundaries.
Why do earthquakes happen?
How can we measure earthquakes?                  1
2
The Richter Scale                               3
4
This measures the magnitude of a                 5
6
tremor (how powerful it is) using an             7
instrument called a seismograph.                 8
9
10
On the Richter Scale, magnitude is
Richter
expressed in whole numbers and                Scale
decimal fractions. Although the
Richter Scale has no upper limit, the
magnitudes in the 8.8 to 8.9 range. It
is a logarithmic scale which means        The largest earthquake
ever recorded was in
that a size ‘6’ on the Richter Scale is   Chile. It measured 8.9
10 times larger than a size ’5’ and       on the Richter Scale.
100 times larger than a size ‘4’.
1
2
3
The Japanese earthquake in Kobe               4
5
(September 1995) measured 7.2 on the          6
Richter Scale.                                7
8
9
10
The Greek earthquake (June 1995)            Richter
measured 6.2 on the Richter Scale.          Scale

How many times greater was the Japanese earthquake?
Activity
Design your own cartoon based on
the Mercalli Scale descriptions below.
I     Felt by almost no one.
II    Felt by very few people.
III   Tremor noticed by many, but they often do not realise it is an
earthquake.
IV    Felt indoors by many. Feels like a truck has struck the building.
V     Felt by everyone; many people are awakened. Swaying trees and
poles may be observed.
VI    Felt by all; many people run outdoors. Furniture is moved.
VII   Everyone runs outdoors. Poorly built structures considerably
damaged. Slight damage elsewhere.
VII   Specially designed structures damaged slightly, others collapsed.
IX    All buildings considerably damaged, many shift off foundations.
Noticeable cracks in the ground.
X     Many structures destroyed. Ground badly cracked.
XI    Almost all structures fall. Bridges wrecked.
XII   Total destruction. Waves seen on ground surfaces, objects are
tumbled and tossed.
Mercalli Scale
This measures
how much
damage is
caused by the
Mercalli Scale   earthquake
based on
observations. It
is measured on a
scale between I
and XII.
Focus       Epicentre

An earthquake has occurred along this fault line.
Match the letter with the correct label.

```
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