Earth’s Structure: How the Earth Formed 10/7 Earth’s Structure: How the Earth Formed

Bellwork 10/7 Copy the questions and answer them on your green bellwork log. What did our Sun and planets form from? What event started the solar system’s formation? What force caused tiny particles of dust to stick together?

How did Earth form? The solar system formed when a cloud of gas, ice, and dust, called a nebula, was pulled together by gravity.

The nebula shrank, flattened into a disk, and began to rotate. The materials in the center of the disk formed the Sun. Planets began to take shape from the remaining bits of material. Earth formed as gravity pulled small particles together, that would collide, build mass, and collect more particles. Early Earth generated thermal energy in its interior, making the rocks of the planet soft enough to flow. Gravity pulled in the irregular bumps, the rock flowed, and Earth developed a relatively even spherical surface.

How did Earth develop its spherical shape? Gravity is the force that every object exerts on every other object because of their masses. All objects on or near Earth are pulled toward Earth’s center by gravity. The early Earth’s gravity pulled all material down, forcing it to have a smooth surface

The Formation of Earth’s Layers Earth developed distinct layers of different material after thermal energy melted some of the material and it began to flow. Different materials formed layers according to their densities. Density is the amount of mass in a material per unit volume and can be described as D = m/V (density is mass divided by volume). If two materials have the same volume, the denser material will have more mass. When ancient Earth started melting, the densest materials sank and formed the innermost layer.

The least dense materials stayed at the surface and formed a separate layer, and materials with intermediate densities formed layers in between.

Bellwork 10/11 Copy the questions and answer them on your green bellwork log. The layers of the Earth are arranged according to _________________________. Where is the densest material located? Where is the least dense material located?

Clues to Earth’s Interior Deep mines and wells give scientists hints about Earth’s interior. Scientists also use earthquake waves to gather information about Earth’s interior. By studying how earthquake waves move, scientists are able to infer the density and composition of the materials within Earth.

Temperature and pressure increase as depth increases inside Earth.

Earth’s 4 Layers The Earth is composed of four different layers. crust Mantle outer core inner core

The Crust The brittle, rocky, outer layer of Earth is called the crust. It is the least dense and thinnest layer

The Earth's Crust is like the skin of an apple- very thin. The crust is only about 3-5 miles (8 kilometers) thick under the oceans (oceanic crust) and about 25 miles (32 kilometers) thick under the continents (continental crust).

The crust under oceans is called oceanic crust and is made of dense rocks containing iron and magnesium. Continental crust is much thicker and less dense.

The Mantle Earth’s mantle is the thick middle layer.

Scientists group the crust and the uppermost mantle into a rigid layer called the lithosphere. The layer of rocks within the mantle, where the rock is soft enough to flow, is called the asthenosphere. The solid rock below the asthenosphere, where high pressure prevents melting, is the mantle.

Lesson 2-2

The Core The dense metallic center of Earth is the core. The outer core is liquid iron and nickel and the inner core is solid iron.

Bellwork: 10/13 Describe each layer on your green bellwork sheet: Crust: ____________________________________ Mantle: ___________________________________ Outer Core: ________________________________ Inner Core: _________________________________

Vocab Quiz over the 10 yellow terms tomorrow Vocab Quiz over the 10 yellow terms tomorrow. Quiz over white terms on Monday. Inner Core Outer core Mantle Crust Lithosphere Asthenosphere Earth layers Chemical Composition Physical Properties Density Gravity Temperature State of Matter Pressure Magnetosphere Plasticity

Earth’s Core and Geomagnetism For centuries, people have used compasses and Earth’s magnetic field to navigate. Earth’s magnetic field is a region of magnetism produced in part by the flow of molten materials in the outer core. The magnetic field acts like a giant magnet with opposite poles.

The outer part of the magnetic field that interacts with cosmic rays and charged particles from the Sun is called the magnetosphere.

Foldable: Earth Layers 10/14 Cut out circle 1, making sure to leave the flaps on either side attached. Cut out the other 4 circles.

Lay circle 5 flat on the table. Lay circle 4 on top of circle 5. Lay circle 3 on top of circle 4. Lay circle 2 on top of circle 3. Fold circles 2-5 in half down the middle. Cut circle 1 down the middle on the dotted line.

Glue circle 5 into the center page of your INB. Glue the left half of each circle to the circle below it (except for circle 1). Fold the flaps on circle 1. Place circle one on top of all circles and glue down the flaps onto the notebook paper so circle one opens like shutters.

Open the foldable. Trace the outline of circle 2 onto the right side of circle 3. Fold back circle 2. On the inside, write “The Inner Core” at the top. You will fill the rest of the space with information about the inner core.

Trace the outline of circle 3 onto the right side of circle 4. Fold back circle 3. On the inside, write “The Outer Core” at the top. You will fill the rest of the space with information about the outer core.

Fold back circle 4. On the blank left side, write “The Mantle” at the top. Draw an arrow from “The Mantle” to the second layer on the right side of the foldable. Half way down on the left side, write “The Crust”. Draw a line You will fill the rest of the space on the top of the left with information about the mantle an the bottom with information about the crust.