Earth: A Unique Planet

1
Earth A Unique Planet
2
Earth- an oblate spheroid

• Circumference about the poles is 40,007 km
• Circumference about the equator is 40,074 km
• 71 of the Earth is covered by water
• - 97 of that water is in the oceans
• - the remaining 3 is fresh water
  found in lakes, rivers, streams, glaciers, and
  polar ice sheets

3
(No Transcript)
4
Compositional Zones of Earths Interior

• Crust
• Mantle
• Core

5
Zones of the Earththe Crust

• The crust only makes up 1 of the Earths mass
• The oceanic crust is only 5km to 10 km thick
• The continental crust ranges from 32 km to 70km
  thick

6
Zones of the Earththe Mantle

• About 2,870 km thick
• Makes up almost two thirds of Earths mass
• The mantle is divided into two parts the
  uppermost mantle and the lower mantle
• Within the uppermost mantle
• -Lithosphere solid rock that also
  contains the crust above about 65km to 100 km
  thick
• - Asthenosphere- since there is so much
  heat and pressure, rocks become weak and are able
  to slowly flow

7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
Zones of the Earththe Core

• Two zones the outer core and inner core
• The core is composed mainly of iron
• The outer core is a dense liquid layer about
  2,190 km thick
• The inner core is a dense solid about 2,680 km
  thick
• Together, they make up about one third of the
  Earths mass

12
The Moho

• The Moho is the boundary that marks the end of
  the crust and the beginning of the mantle.
• About 32-70 km below the surface
• Seismic waves speed up here because the mantle is
  more dense than the crust
• At 100km deep seismic waves slow down because
  they meet the asthenosphere

13
(No Transcript)
14
(No Transcript)
15
The Magnetosphere

• Earths magnetic field extends beyond the
  atmosphere and affects a region of space called
  the magnetosphere.
• Scientists think that motions within the liquid
  iron of Earths outer core produce electric
  currents that in turn create Earths magnetic
  field.

16
How come the ocean doesnt fall off the Earth?

• Gravity! Gravity! Well why do we have gravity?

17
Gravity is an observed phenomenom

• Basically, all masses have a force of attraction
  between them
• The bigger the mass and the closer the centers of
  the mass are to one another, the greater the
  attraction.

18
(No Transcript)
19
Sir Isaac Newton

• Considered one of the fathers of calculus
• and quite the physicist and astronomer
• Law of Gravitation force of attraction between
  any two objects depends upon their masses and the
  distance between them.
• F(force)

20
Lets think here for a moment. When an apple
falls off a tree is falls to the ground due to
gravity. The moon in in Earths orbit, but how
come it doesnt fall?
21
All this talk about mass..

• Weight vs mass
• weight is the measure of the Earths pull on
  you (gravity)
• The closer you are to the center of the Earth the
  more you weigh
• Mass in the measure of the amount of matter an
  object contains

22
Earth-System Science

• a set of particles or interacting components
  considered to be a distinct physical entity for
  the purpose of study
• All systems have boundaries, and many systems
  have matter and energy that flow though them.
• Even though each system can be described
  separately, all systems are linked. A large and
  complex system, such as the Earth system,
  operates as a result of the combination of
  smaller, interrelated systems.

23
Matter, Energy and Systems

• The operation of the Earth system is a result of
  interaction between the two most basic components
  of the universe matter and energy.
• Matter is anything that has mass and takes up
  space.
• Energy is defined as the ability to do work.
  Energy can be transferred in a variety of forms,
  including heat, light, vibrations, or
  electromagnetic waves.
• A system can be described by the way that matter
  and energy are transferred within the system or
  to and from other systems.

24
Closed vs Open Systems

• A closed system is a system in which energy, but
  not matter is exchanged with the surroundings.
• An open system is a system in which both energy
  and matter are exchanged with the surroundings.

25
The Earth System

• Technically, all systems that make up the Earth
  system are open.
• However, the Earth system is almost a closed
  system because matter exchange is limited.
• Energy enters the system in the form of sunlight
  and is released into space as heat.
• Only a small amount of dust and rock from space
  enters the system, and only a fraction of the
  hydrogen atoms in the atmosphere escape into
  space.