I NSIDE THE EARTH Chapter 4 – Lesson 1

L ESSON OBJECTIVES : Identify the layers of the Earth by their chemical composition. Identify the layers of the Earth by their physical properties. Describe a tectonic plate. Explain how scientists know about the structure of Earth’s interior.

I CE AGE

E ARTH MODELS ✕ Examine the avocado. Make comparisons about Planet Earth.

T HE C OMPOSITION OF THE E ARTH ● The Earth is divided into 4 layers— ● the crust, the mantle, and the core (2) ● based on the compounds that make up each layer. ● The Crust is the outermost layer of the Earth. The crust is 5 to 100 km thick, and is the thinnest layer of the Earth.

✕ There are two types of crust—continental and oceanic. Oceanic crust is thinner and denser than continental crust. Temps range from -90 o C to 100 o C

*C ONTINENT ✕ Great landmasses surrounded by oceanslandmasses ✕ Made of layers of rock: ✕ Minerals...

T HE C OMPOSITION OF THE E ARTH The Mantle is the layer of the Earth between the crust and the core. Rock!!! Silicon, Oxygen, Magnesium, little iron The mantle is much thicker than the crust and contains 2/3’s of the Earth’s mass. The crust is too thick to drill through km Depth Temp of ~ 870 o C

T HE C OMPOSITION OF THE E ARTH The Core is the central part of the Earth makes up about one-third of Earth’s mass Below the mantle. It has 2 areas: The Outer core ( Liquid ~ o C) km depth Mostly of iron and smaller amounts of nickel

T HE C OMPOSITION OF THE E ARTH The Inner Core Solid ~ o C km depth Mostly of iron and smaller amounts of nickel

T HE C OMPOSITION OF THE E ARTH The Outer Core solid, spins inside the Liquid Outer Core Creates Magnetic Field around the Earth

T HE P HYSICAL S TRUCTURE OF THE E ARTH ✕ The Earth is divided into five physical layers: ✕ The lithosphere ✕ The asthenosphere ✕ The mesosphere ✕ The outer core ✕ The inner core

5 Physical Layers 1) Lithosphere “Litho”---- “Rock” ●uppermost rigid layer, made of the crust & the rigid part of upper mantle ●divided into pieces --- “Tectonic Plates”

5 Physical Layers 2) Asthenosphere “Astheno”---- “Weak” ●soft layer of upper mantle ●hot, soft rock, “plastic” ●Constant motion ●moves tectonic plates

5 Physical Layers 3) Mesosphere “Meso”---- “Middle” ●Strong, lower part of Mantle ●Dense rock, compact ●From Asthenosphere to Outer Core ●Constant motion by ???

Crusts: Are not all alike!1% of Earth’s Mass Continental (5-100 km) Thicker, granite rock lots of Silicon, Aluminum, Oxygen Oceanic (5-30 km) Thinner, denser, basalt rock more Calcium, Magnesium, Iron

5 Physical Layers 4) Outer Core 5) Inner Core

Atmosphere

Layers of Atmosphere

T ECTONIC P LATES Pieces of the lithosphere that move around on top of the asthenosphere. rigid, outermost part of the mantle. “float” on the asthenosphere. cover the surface of the asthenosphere touch one another and move around.

M APPING THE E ARTH ’ S I NTERIOR deepest parts of the planet by measuring the speeds of the seismic waves that travel through the Earth’s interior during earthquakes. By using seismographs, scientists have learned that the Earth is made of different layers.

W HAT IS THE SCIENCE OF G EOLOGY ? ✕ Geology – the study of Earth ✕ Seismic Waves – Video Seismic Waves Video when earthquakes occur geologist record the speed and paths of seismic waves to determine the layers of the Earth

C ONVECTION CURRENTS IN THE MANTLE ✕ HOT PARTICLES RISE EXPAND>MORE VOL LESS DENSE ✕ COOL PARTICLES SINK DENSE (COLLECTED) COOL PARTICLES SINK W/ GRAVITY DEVELOPS UP & DOWN CURRENTS (CONVECTION)

Dr Damon Teagle of the National Oceanography Centre in Southampton, England and Dr Benoit Ildefonse from Montpellier University in France, have announced jointly in an article in Nature that they intend to drill a hole through the Earth’s crust and into the mantle; 2018 Scientists plan to drill all the way down to the Earth's mantle! Bob Yirka

N OTES : WHAT WOULD BE FOUND ON A JOURNEY TO THE CENTER OF THE EARTH ? CENTER OF THE EARTH ✕ Draw the Earth’s interior. + Label each section + Label the depth of each section + Label the temperature of each section + Include a summary of each layer.

D RAW & L ABEL D RAW & L ABEL !!! C OLOR TOO !!! Can you explain the Lithosphere vs. Asthenosphere?

P RESSURE (atmospheres) Sea level = 1 atm 230,000 – 1.3 million atm 3 4 As the depths increase: What happens to pressure? What happens to Temp?

Read the following section summary. The Earth is made up of three layers—the crust, the mantle, and the core—based on chemical composition. Less dense compounds make up the crust and mantle. Denser compounds make up the core. The Earth is made up of five main physical layers: the lithosphere, the asthenosphere, the mesosphere, the outer core, and the inner core. Tectonic plates are large pieces of the lithosphere that move around on the Earth’s surface. The crust in some tectonic plates is mainly continental. Other plates have only oceanic crust. Still other plates include both continental and oceanic crust. Thick tectonic plates, such as those in which the crust is mainly continental, displace more asthenosphere than do thin plates, such as those in which the crust is mainly oceanic. Knowledge about the layers of the Earth comes from the study of seismic waves caused by earthquakes.

E ARTH ON THE MOVE ! MOVE ✕ Constructive Forces – shape the surface by BUILDING UP the mountains and landmasses. ✕ Destructive Forces – slowly WEAR AWAY mountains and, eventually every other feature on the surface

E ARTH ON THE MOVE E ARTH ON THE MOVE ! ✕ Examples of Constructive Forces: ✕ Examples of Destructive Forces:

W HAT DOES THIS IMAGE REPRESENT ? What type of Forces are at work here? Name 2

ENRICHMENT ✕ The inner core of the Earth is simultaneously melting and freezing due to…???