1. History of Earth

2. Conditions conducive to support LIFE
Liquid Water on its Surface
Atmosphere with large proportion of oxygen
Size
Rotation Rate
Distance from the Sun

3. Earth Basics
Earth is the third planet from the sun in our solar system.
Earth formed about 4.6 billion years ago and is made mostly of rock.
Approximately 70% of Earth’s surface is covered by a thin layer of water known as the global ocean.

4. Earth’s Interior
Composition and Structure of Earth’s interior is known by indirect observations:
Seismic waves [natural-earthquakes or man made-explosions]
travel at different velocities through the various layers of the Earth. [different densities]

5. 3 Compositional Zones CRUST thin and solid
Rigid, rocky outer surface of the Earth
It has the tendency to fracture [most earthquakes occur within the crust]
- Two types: continental and oceanic

7. 3 Compositional Zones MANTLE rigid and semi-solid
Thickest layer, 2900km
Contains approximately 70% of the Earth’s mass
Because it is rather flexible, it has the tendency to flow instead of fracturing

8. 3 Compositional Zones CORE spherical center 3500km radius
mainly Ni and Fe
Liquid Outer and Solid inner core
Liquid out is responsible for Earth’s magnetic field

9. The continental crust will be thicker under mountains.
The continents -part of the crust- are made of lighter rock and thus literally “float” on material of higher density.
The continental crust will be thicker under mountains.
(km) 10 20 30 40 50
Oceanic crust
(3.0 g/cm3)
Continental crust
(2.8 g/cm3)
Mantle
(3.4 g/cm3)
Horizontal distance not to scale

10. How are scientists able to study the composition and size of the interior layers of Earth?
By direct observation
By analyzing surface rock samples
By using seismic waves
By deep-drilling into the interior layers

12. All of the following are parts of the compositional structure of Earth EXCEPT the
Global ocean
Core
Mantle
Crust

13. Earth’s Gravity
Newton’s Law of Gravitation describes one of the four Universal Forces
The force of ATTRACTION , the pull, between any two objects depends on:
MASS  M increases, Fg increases
DISTANCE  D increases, Fg decreases

14. G = Fg = G m1 x m2 r^2 constant of gravitation
If the mass doubles, the force will double.
m1 x m2
If the distance doubles, the force will decrease by a factor of 4.
r^2 G =
constant of gravitation
6.67 x 10^-11 N m^2/kg^2
Unit is ??

15. WEIGHT and MASS
WEIGHT is a force, a measure of the pull on an object due to gravity.
Weight changes with location depending on the distance from the Earth’s center
MASS is the amount of matter that an object contains.
Mass always remains the same.

16. The force of attraction that exists among all matter in the universe is called
Magnetism
Weight
Magnetosphere
Gravity

17. The core is mainly composed of
Si, Ni
Si, Mg, Fe
Fe, Ni
Ni, Mg

18. What is responsible for the Earth’s magnetic field?
The pressure exerted by the mantle
The flowing iron in the outer core
The magnetite concentrated in mountains
The sun’s energy

19. The inner core is ____________. Why?
Solid
Liquid
Despite a very high T, the P is such that it squeezes the atoms together, thus it remains solid.

20. EARTH AS A SYSTEM
A group of interacting components, that can be described separately.
Small and larger systems combine to form complex system such as the Earth
All those systems are linked in one way or another as the result of the interaction of the 2 main components of the Universe

21. Main components of the Universe
MATTER
Anything that has mass and takes up space [i.e. volume]
ENERGY
The ability to do work
Can be transferred [not destroyed, nor created] in various ways including
Heat
Electromagnetic waves
Light
Vibrations

22. SYSTEM
A system can be described by the way that matter and energy are transferred within the system or to and from other systems:
CLOSED  energy but not matter is exchanged with the surroundings
OPEN  both energy and matter are exchanged with the surroundings

25. Discussion / Assessment
Write a paragraph to explain the following statement:
“Technically, all systems that make up the Earth system are open; however, the Earth system is almost a closed system.”

26. The Earth system is composed of 4 spheres:

27. 78% Nitrogen, 21% Oxygen, 1% other
ATMOSPHERE
78% Nitrogen, 21% Oxygen, 1% other

28. HYDROSPHERE

29. Geosphere Continental, oceanic crusts, and all various Earth’s interior layers

30. Biosphere All life on earth, including man, and all organisms.
The life zone on our planet distinguishes our planet from the others in the solar system.

31. Interconnected Spheres
Spheres are closely connected
A change in one sphere results in changes in others - called an EVENT
Forest fire destroys plants in an area
An event can cause a chain reaction

32. Why is it important to understand those interactions?

33. Understanding Interactions
Global implications
Helps people predict outcomes
Preparation for natural disasters
Environmental impacts of human activities

34. Major Components of the Earth System

35. Earth’s Energy Budget
The transfers of energy between Earth’s spheres can be thought of as parts of an energy budget.
The first law of thermodynamics states that energy is transferred between systems, but it cannot be created nor destroyed.
The constant exchange of matter and energy between Earth’s spheres happens through chemical reactions, radioactive decay, the radiation of energy, and the growth and decay of organisms.

37. SUN Earth's primary external source of energy
Solar radiation warms Earth’s atmosphere and surface, causing air masses’ movement, generating winds and ocean currents.
Many chemical reactions on Earth also require solar energy.

38. What scientific principle states that energy can be transferred but that it cannot be created or destroyed?
First Law of Motion
Law of Gravitation
First Law of Thermodynamics
Second Law of Thermodynamics

39. Which percentage of the solar radiation reradiates in the form of longer waves?4%
25%
51%
70%

40. How much of the solar radiation is absorbed by oceans and land?4%
25%
51%
71%