The Dynamic Earth Chapter 3

The Dynamic Earth An integrated system containing four interacting parts: The Geosphere (rock) The Atmosphere (air) The Hydrosphere (water) The Biosphere (living things)

Discovering Earth’s Interior Scientists have gathered evidence from earthquakes and volcanoes to form a model of Earth’s interior.

The Earth’s Structure CAN YOU THINK WHAT THIS IMAGE HAS TO DO WITH THE EARTH’S STRUCTURE?

The Earth’s Structure ALTHOUGH IT MAY SOUND STRANGE A GOOD WAY OF UNDERSTANDING THE STRUCTURE OF THE EARTH IS TO THINK OF IT AS AN EGG. THE THIN SHELL IS THE ‘CRUST’ THE WHITE SOFT PART IS THE ‘MANTLE’. THE YELLOW YOLK IS KNOWN AS THE ‘CORE

Earth’s Crust Mantle Outer Core Tectonic Plates Inner Core Understanding Earth's "Layers" Earth is made of several distinct layers similar to an egg:

Geosphere solid and rocky (contains all rock, soils and sediments) different layers and compositions based on density three main layers - the crust, the mantle, and the core

1. Crust outermost layer – where we live cool temp. hard, solid rock thinnest layer

2. Mantle largest layer outer mantle is solid rock inner mantle made of “gummy” rocks - the rocks are extremely hot and bendable (like gum)

3 & 4. Core the center of the earth hottest layer made mostly of iron and nickel the outer core (3 rd layer) is liquid metal the inner core (4 th layer) is solid metal

The earth heats up with depth The earth gets warmer towards the core because it contains so many radioactive isotopes. These unstable isotopes are constantly breaking down, releasing huge amounts of energy, which in turn heat the earth. Why do you think the inner core is solid?

Plate Tectonics A theory that explains how forces deep within Earth can cause the ocean floors to move. 7 major tectonic plates (and many smaller ones) fit together like puzzle pieces made of lithosphere – the crust and rigid upper portion of mantle

Plate Tectonics

Earth’s Layers

Plate Tectonics move around on the asthenosphere like ice on water plates move towards, away or alongside each other - causes mountains to form, earthquakes to shake the crust, and volcanoes to erupt move 1 to 16 cm per year moving for hundreds of millions of years – moved a large distance

Oceanic plates Continental plates Two Types of Plates

The Pangea Puzzle 20 th century, Alfred Wegener noticed that eastern South America fits into western Africa also noticed that several of the other continents fit together like puzzle pieces.

fossil evidence showed that several of the same organisms are found on continents now separated by oceans Continental drift theory million years ago all the continents combined to form the giant land mass he named Pangea

Earth Now

Earth in a 100 million years?

How the plates formed…. ocutif0cQYhttps:// ocutif0cQY BN Pangaea and Plate Tectonics Clip from BBC documentary film "Earth The Power Of The Planet “Clip from BBC documentary film "Earth The Power Of The Planet “ The Early Earth and Plate Tectonics

Fault A break or crack in the Earth’s crust where movements take place.

Divergent   Plate Boundaries plates move away from each other. When this occurs, hot liquid rock called magma rises and cools, forming new rock.

Convergent   Plate Boundaries Subduction - two plates meet, the more dense plate (oceanic), dives beneath the less dense plate (continental) rock goes down into the mantle, heats up and melts magma rises and pushes up the crust forming volcanic mountains

Transform Fault Boundaries areas where plates move along side one another as plates move, they can cause faults moving plates cause a great deal of force and create earthquakes

Earthquakes vibrations of the earth’s crust caused by plates sliding along a fault small earthquakes occur all the time measured by the Richter scale - magnitude 2=smallest to be felt, 9.5=largest recorded.

Volcanoes mountain built from magma (melted rock) The Ring of Fire – most of the world’s active volcanoes are located around the Pacific Ocean Volcanoes

Erosion the removal and transport of surface material Earth’s surface worn away by wind, water, rock debris, ice or gravity formation of Grand Canyon Grand Canyon

Let’s Review 1.The geosphere describes the _____________ part of earth. 2.Which layer of the earth do we live on? _________________ 3.True or False. The layers of Earth differ in thickness, composition, and temperature. _____________ 4.The _______________ is made of “gummy” rocks. 5.True or False. The outer core is made of solid metals and the inner core is made of liquid metals. rock crust true mantle false – the other way around

6.Which layer of the earth is the hottest? ______________ 7.What are the large pieces of the Earth’s crust called? Tectonic plates 8.Most geologic activity takes place where? _plate boundaries___ 9.How are earthquakes caused? Plates sliding past each other Review Inner core

Review 10.Most volcanoes are located around which ocean? 11.What does erosion do to the Earth’s surface? 12.Label the type of boundary: Transform Boundary Divergent Boundary Pacific Ocean wears it down

Convergent Boundary