The document provides an overview of the Earth as a planet. It describes how the Earth was formed from the solar nebula according to the Nebula Theory. It also describes the Earth seen from space as a small blue planet with white clouds and liquid water. The document then discusses the different layers and boundaries within the Earth, including the continental and oceanic crusts, and the Lehman discontinuity between the liquid outer core and solid inner core. Finally, it provides details on seismic waves and how they help map the interior of the Earth, including the two types of body waves (P and S waves) and two types of surface waves (Love and Rayleigh waves).

1. OVERVIEW
OF
EARTH
AS A PLANET

2. THE EARTH AS A PLANET
According to the
Nebula Theory, Earth
was formed at the
same time as the
other members of the
solar system by
accretion from the
solar nebula . As the
nebula collapsed due
to its gravity, it spin
faster and flattened
into disk.

3. THE EARTH AS A PLANET
When we see the outer
space, Earth is a small
blue planet bathing in a
film of white clouds and
liquid water. Earth is
composed of different
spheres or layers. Life
on Earth is possible
because all of the major
parts of Earth namely,
the Atmosphere,
hydrosphere, and
geosphere work
together as a complex
system.

4. • What are the different layers and
boundaries in the outer and inner
Earth?

7. 2 types of crust

8. 1. Continental Crust
• The solid ground where you stand upon is
called continental crust. It is lighter than the
oceanic crust as it is composed of lower-
density material such as granitic rock.
continental crusts are formed through
volcanic eruption.

9. 2. Oceanic Crust
• It is made up of heavier basalt and gabbro
rocks. Oceanic crusts measures only around
7km thick while the continental crusts ranges
from 10-70 km thick. Oceanic crusts formed
by magma, when volcanic eruption occurs
underwater.

15. Lehman
Discontinuity
Is located between
the liquid outer core
and solid inner core

17. • What are the models that explain
the possible causes of plate
movements?

18. Mapping the Inner Earth
• Seismic Wave help map and
characterized the layers of Earth.
• Seismic wave travel trough the planet
when an earthquake occurs, when block
of rocks break, when a volcano erupts or
when tectonic plates move, and it is
detected by a highly instruments called
seismometer and recorded by
seismograph.

19. 2 types of seismic wave
• Body waves and surface waves.
Body waves travel through the
inner layers of the planet, while
surface waves do so only on the
surface.

20. 2 types of Body Waves

21. • P-waves or primary waves are first to be
felt on Earth’s surface, they travel at
speed between 1.5 and 8 km per second.
P- waves are compressional wave. They
shake the ground back and forth in the
same and in opposite direction through
which they move. P-waves pass through
solids sections of earth but are refracted
when they travel through liquids.

22. • Secondary or S-waves are transverse
wave, which are felt in an up-side-down
motion perpendicular to the direction of
the wave. S waves do not travel on
liquids. It is for this reason that the
outercore was found to be liquid, it move
slowly than P-waves.

23. 2 types of surface waves

24. • Love waves are the fastest types of
surface waves and move the ground
from side to side, they named it after
the british geologist, Augustus
Edward H. Love.
• Rayleigh waves moves in a circular
manner, similar to rolling on the
ground, and cause building to heave
up and down, side to side.