Seismic waves are caused by earthquakes and volcanic eruptions and travel through the Earth, imparting acoustic energy. There are two main types of seismic waves - body waves that travel beneath the surface and surface waves that travel along the surface. Body waves include primary P-waves and secondary S-waves that travel faster and slower respectively. Surface waves include Rayleigh and Love waves that cause the most destruction and travel the slowest. Earthquakes are usually caused by a sudden release of built-up pressure when rocks underground break along a fault.

1. PROJECT IN
SCIENCE
Submitted by:
Zareena Cunanan
Kenji Delmoro

2. PROJECT IN
SCIENCE
Submitted by:
Zareena Cunanan
Kenji Delmoro

3. TOPIC: EARTHQUAKE WAVES AND
TYPHOONS
SUBTOPIC: SEISMIC WAVES
SUBTOPIC: EFFECT OF EARTHQUAKES TO
TYPHOONS
Seismic waves are not earthquakes themselves, but therefore are the
cause of earthquakes AND volcanic eruptions, or waves of energy that
travel through the Earth's layers that impart low-frequency acoustic
energy. Acoustic energy is found in sound, and are mechanical waves
in gases, liquids, and solids including vibration, ultrasound, and
infrasound. Seismic waves can also be made by volcanic eruptions
themselves.
Earthquakes create various types of waves with different velocities;
when reaching seismic observatories, their different travel time help
scientists to locate the source of the earthquake hypocenter. In
geophysics the refraction or reflection of seismic waves is used for
research into the structure of the Earth's interior, and man made
vibrations are often generated to investigate shallow, subsurface

4. WAIT!
TYPES OF SEISMIC
WAVES
FACT ABOUT
EARTHQUAKES Did you know? “Earthquakes” happen in stars, too? The study of
this is called Asteroseismology (from Greek ἀστήρ, astēr, "star";
σεισμός, seismos, "earthquake"; and -λογία, -logia) also known as
stellar seismology. It is the science that studies the internal
structure of pulsating stars by the interpretation of their
frequency spectra. This study helps discover more of not only
how earthquakes happen on stars, but on earth, too.

5. TYPES OF SEISMIC WAVES
There are 2 types of
seismic waves. These are
body waves and surface
waves. Body waves happen
under the surface of the
earth. Surface waves
happen on the surface of
the earth.

6. TYPES OF SEISMIC WAVES
BODY WAVES
There are 2 types of
Body waves are seismic waves
that seismic ONLY waves. occur under These the
are
ground. body waves They are and the surface
cause of
surface waves. waves, Body waves and are happen
sensed
first under in seismic the surface observatories.
of the
They earth. also Surface vary in waves
the
temperature happen on and the composition
surface of
of the the earth.
elements underground.

7. TYPES OF SEISMIC WAVES
BODY WAVES
BoPdRy IwMaAveRsY a rWe AseVisEmSic waves
that ONLY occur under the
ground. They are the cause of
surface waves, and are sensed
first in seismic observatories.
They also vary in the
temperature and composition
of the elements underground.
Primary waves (P-waves) are compressional waves that
are longitudinal in nature. P waves are pressure waves that travel faster
than other waves through the earth to arrive at seismograph stations
first, hence the name "Primary". These waves can travel through any
type of material, including fluids.In air, they take the form of sound
waves, hence they travel at the speed of sound. Typical speeds are
330 m/s in air, 1450 m/s in water and about 5000 m/s in granite.

8. TYPES OF SEISMIC WAVES
BODY WAVES
SECODARY PRIMARY WAVES
WAVES
Primary waves (P-waves) are compressional waves that
are longitudinal in nature. P waves are pressure waves that travel faster
than other waves through the earth to arrive at seismograph stations
first, hence the name "Primary". These waves can travel through any
type of material, including fluids.In air, they take the form of sound
waves, hence they travel at the speed of sound. Typical speeds are
330 m/s in air, 1450 m/s in water and about 5000 m/s in granite.
Secondary waves (S-waves) are shear waves that
are transverse in nature. S waves follow after Primary
waves. S-waves can travel only through solids. S-waves
are slower than P-waves, and speeds are
typically around 60% of that of P-waves in any given
material.

9. TYPES OF SEISMIC WAVES
SURFACE WAVES
Surface waves travel along the
Earth's surface. They are
called surface waves because
they weaken as they get
further from the surface.
Because of the long duration
and large amplitude of the
surface waves, they can be the
most destructive type of
seismic wave. Surface waves
travel more slowly than the
other type of seismic waves.

10. TYPES OF SEISMIC WAVES
SURFACE WAVES
Surface waves travel along the
Earth's surface. They are
called surface waves because
they weaken as they get
further from the surface.
Because of the long duration
and large amplitude of the
surface waves, they can be the
most destructive type of
seismic wave. Surface waves
travel more slowly than the
other type of seismic waves.
RAYLEIGHT WAVES
Rayleigh waves, also called ground roll, are
surface waves that travel like ripples of
water. The existence of these waves was
predicted by John William Strutt, Lord
Rayleigh, in 1885. They are slower than
body waves, roughly 90% of the speed of S
waves for typical homogeneous elastic
materials.

11. TYPES OF SEISMIC WAVES
SURFACE WAVES
RAYLEIGHT WAVES
Rayleigh waves, also called ground roll, are
surface waves that travel like ripples of
water. The existence of these waves was
predicted by John William Strutt, Lord
Rayleigh, in 1885. They are slower than
body waves, roughly 90% of the speed of S
waves for typical homogeneous elastic
materials.
LOVE WAVES
Love waves are horizontally polarized shear
waves (SH waves), existing only in the
presence of a semi-infinite medium overlain
by an upper layer of finite thickness. They are
named after A.E.H. Love, a British
mathematician who created a mathematical
model of the waves in 1911. They usually
travel slightly faster than Rayleigh waves,
about 90% of the S wave speed.

12. CAUSES OF
EARTHQUAKES
Earthquakes are usually caused
when rock underground suddenly
breaks along a fault. This sudden
release of energy causes the
seismic waves that make the
ground shake. When two blocks
of rock or two plates are rubbing
against each other, they stick a
little. They don't just slide
smoothly; the rocks catch on
each other. The rocks are still
pushing against each other, but
not moving.

13. CAUSES OF
EARTHQUAKES
After a while, the rocks break
because of all the pressure that's
built up. When the rocks break,
the earthquake occurs. During
the earthquake and afterward,
the plates or blocks of rock start
moving, and they continue to
move until they get stuck again.
The spot underground where the
rock breaks is called the focus of
the earthquake. The place right
above the focus (on top of the
ground) is called the epicenter of
the earthquake.

14. SEE THE
DAMAGE?

15. THANK YOU!!!