Download The transfer of energy in an earthquake

Exemplar for internal assessment resource Science for Achievement Standard 90942
The transfer of energy in an earthquake
When an earthquake occurs energy is transferred, from where the rocks break, and travels
throughout the world. The bigger the quake the further from the epicentre the waves will
travel. There are two types of earthquake wave generated during an earth quake. They carry
energy away from the earthquake epicentre.
Body Waves:
Body waves and surface waves are the two types of seismic waves formed during great
earthquakes. P waves and S waves are called body waves because they travel through the
body of the Earth.
The p-wave:
Every earthquake creates P waves and S waves. P waves travel away from the focus of an
earthquake where the rocks first fractured by compressing and expanding the rocks as they
travel through solids, liquids and gases. P waves travel through all parts of the Earth. These
waves are the fastest moving waves at 8kms-1.
The s-wave:
S-waves travel in a motion similar to a rope held tight at one end while the other end is lifted
rapidly back and forth. S-waves only travel through solids and do not travel through the liquid
outer core of the Earth. These waves move at 5kms-1.
© NZQA 2015
Exemplar for internal assessment resource Science for Achievement Standard 90942
Surface waves:
Body waves and surface waves are the two types of seismic waves formed during great
earthquakes. When body waves reach the surface of the earth they interact to make surface
waves. There are two main surface waves, the Rayleigh-Love waves.
Rayleigh-Love Waves
Love waves move back and forth in the direction they are traveling. Take a slinky and lay it
on a table and make waves that move through the slinky as you move it back and forth. This
is similar to the action of Love waves.
These waves are highly destructive. They lift,
drop buildings, and twist buildings, and especially damage stone buildings like the cathedral.
These waves move at 4kms-1.
© NZQA 2015