Transcript What happens in an earthquake?

Do Now!
• Watch the live update link and describe what
it is that you are seeing. Based upon what you
have studied so far can you see any links?
• http://www.iris.edu/seismon/
What happens in an earthquake?
LO I can describe what happens in an
earthquake
Skill I can reflect on how to improve my
work
Key words
Focus= the point within the earth where the seismic
waves of an earthquake start
Epicentre= the point above the focus on the earth’s
surface
Seismic waves= waves of energy in an earthquake
Friction = rub against
Tension= energy that builds up
Starter
Who can remember?
List the types of plate boundaries that
earthquakes occur on…
Activity 1 - What does it feel like
when an earthquake occurs?
Watch the following clip of an actual
earthquake…
http://www.youtube.com/watch?v=JWtATxRO7A&feature=related
What would
they be thinking
and feeling?
Activity 2 - What happens when an
earthquake occurs?
• Watch the Boardworks animation (next 5
slides). Look carefully at what happens in an
earthquake
• Take notes using the key words
• Now describe in a paragraph what happens
when an earthquake occurs…
EXTENSION - Make sure you use the following
words: Tension Focus
Epicentre
Seismic waves Friction
Epicentre and
focus
Destructive plate
boundary
Conservative plate
boundary
How are earthquakes
measured?
The Richter scale can be used
to measure the magnitude
(power) of a tremor using an
instrument called a
seismograph.
It is a logarithmic scale which
means that a size ‘6’
earthquake on the Richter
scale is 10 times larger than a
size ‘5’ and 100 times larger
than a size ‘4’.
How does a seismograph work?
The Mercalli
Scale
The Mercalli scale rates an earthquake's magnitude based on
observations of the damage it causes on a scale of 1 to 12.
Items shake from
shelves: scale 5
Buildings collapse:
scale 10
Where an earthquake happens?
(Basic diagram to draw)
How do we measure earthquakes?
Plenary
• What number on the Richter Scale would you
give the following earthquakes…
a
b
d
c
e
TRUE OR FALSE???
A) Focus is the place on the surface of the earth
directly above the epicentre
B) Seismic waves are waves of energy that travel
out of the focus
C) Epicentre is the place in the earth’s crust where
the tectonic plates move causing the earthquake
D) Tension stops the plates moving past each other
E) Friction stops the plates moving past each other