Download Earthquakes

EARTHQUAKES
Monday 29/03
WEEK 9 – EARTHQUAKES
DO NOW
Read the section of text below. Some of the words have been spelt
incorrectly. Identify the incorrect word and write the correct spelling for
it:
“An erthquake is the rapid movemant of the ground, usually back and
fourth and up and down in a wave motion. It is caused by the rapid relese
of energy as the tectonic plates move. The severety of an earthquake is
calcalated in several different ways. There are some comonly used scales,
such as the Richter scale and the Mercalli scale.”
WEEK 9 – DO NOW
ANSWERS
Read the section of text below. Some of the words have been spelt
incorrectly. Identify the incorrect word and write the correct spelling for
it:
“An earthquake is the rapid movement of the ground, usually back and
forth and up and down in a wave motion. It is caused by the rapid release
of energy as the tectonic plates move. The severity of an earthquake is
calculated in several different ways. There are some commonly used
scales, such as the Richter scale and the Mercalli scale.”
Monday 29/03
WEEK 9 – EARTHQUAKES
Lesson Aims:
• Describe the causes of and methods of detecting earthquakes.
• Recall different types of seismic waves and their movement through the earth
• Differentiate between focus and epicentre.
Homework:
Education Perfect Tasks.
CAUSES OF EARTHQUAKES AND DETECTION
METHODS
Detection
Causes
Rapid movement of the
ground, usually back and
forth and up and down.
Caused by rapid release of
energy as the tectonic plates
move.
Earthquakes are measured using a
seismometer.
The pen is fixed and the drum moves with
the vibrations of the Earth.
3 TYPES OF SEISMIC WAVES
Primary waves (P-waves): longitudinal (up and down) waves that travel fast
through the Earth.
Secondary waves (S-waves): transverse (back and forth) waves that travel slightly
slower than P-waves through the Earth.
Surface waves: are the slowest waves and cause the most destruction.
WHERE EARTHQUAKES OCCUR
Earthquakes occur under the ground
where the Earth slips, usually along a
fault.
The quake starts at the focus,
usually hundreds of kilometres deep
in the Earth.
The point on the Earth’s surface
directly above the focus is called the
epicentre.