Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Post-glacial rebound wikipedia , lookup
Age of the Earth wikipedia , lookup
Abyssal plain wikipedia , lookup
History of geology wikipedia , lookup
Tectonic–climatic interaction wikipedia , lookup
Oceanic trench wikipedia , lookup
Mantle plume wikipedia , lookup
The Structure of the Earth and Plate Tectonics Warm Up –Give as much information as you can about the following. This may include a diagram What are the layers (structure) of the Earth? Give as much detail as you can. Structure of the Earth • The Earth is made up of 4 main layers: – Inner Core – Outer Core – Mantle – Crust inner core Outer core Mantle crust The Crust • This is where we live! • It is thin, very hard and brittle • The Earth’s crust is divided into two types. Continental Crust - Forms the land -thick (10-70km) - buoyant (less dense than oceanic crust) - mostly old Oceanic Crust - Ocean floor -thin (~7 km) - dense (sinks under continental crust) - young Label This Continental Crust Oceanic Crust Sublevels Lithosphere – the crust and the very top of the mantle makes this zone of rigid, brittle rock Asthenosphere – a layer of hot soft semi-rigid rock in the middle mantle thatflows Label This Lithosphere Upper Mantle Convection Currents Lower Mantle Asthenosphere Middle Mantle Vocab words • • • • • • • Sedimentary Rock Metamorphic Rock Igneous Rock Inner core Outer core Mid-ocean ridge Rock cycle •Divergent boundary •Convergent boundary •Transform boundary •Mantle •Crust •Hot spot • Theory of plate tectonic •Pangaea •Continental Drift Theory • asthenosphere • lithosphere • Convection currents Faults • Tectonic plate Vocab p. 38A Name: 4 Square Definition Sentence using Word Example Characteristics Inner Core A hot solid ball of metal that is the Inner most part of the Earth. The inner core is the most dense layer of the Earth Example Outer surface Liquid cold Warm Up • Get a Textbook and turn to page 15A • Looking at the picture, what do you think the shaded area on the outline maps of South America and Africa represent? • Read Evidence for Continental Drift on pg.15A and answer the following: 1. List the 3 pieces of evidence used to prove continental drift? 2. Which evidence do you think is the most convincing and explain your answer? Continental Drift Theory • Proposed by Alfred Wegener in 1912 • 250 million years ago, all of the continents were combined into one super-continent called “Pangaea” • The continents gradually drifted apart to where they are today “Puzzle Pieces” • Continents look like they could be part of a giant jigsaw puzzle Distribution of Fossils • Plant and animal fossils found on the coastlines of different continents Sequence of Rocks • Same rock patterns found in South America, India, Africa, Antarctica and Australia Ancient Climates • Tropical plant remains (coal deposits) found in Antarctica • Glaciation in Africa, South America, India, and Australia during the same time Problems With The Theory • No mechanism for movement of continents • Wind and currents could possibly move fossils • Theory was not accepted by scientists Warm Up • Need Glue stick today • Get warm up off book shelf and copy to tectonic plate map. • Warm up is the half sheet with layers of the earth. DO NOT WRITE ON IT What is The Theory of Plate Tectonics? Generally Speaking The theory of plate tectonics explains how the Earth’s surface has changed over geologic time. The Earth’s outer crust is made of plates of rock that continues to shift and collide resulting in earthquakes and volcanoes, mountain ranges, rift valleys, etc… What are the specifics of Plate Tectonics? • The Earth’s crust is divided into 9 major plates which move in various directions. Which consist of seven major continents. • This plate motion causes them to collide, pull apart, or scrape against each other. • Each type of interaction causes a characteristic set of Earth structures or “tectonic” features. • The word, tectonic, refers to the deformation of the crust as a consequence of plate interaction. What causes the plates to move? How and Why do Tectonic Plates move around? What is the Mantle? • Located between the core (inner surface) and the crust (on its outer). • The thickest layer. It is more than two thousand miles thick and accounts for more than three-quarters of the volume of the Earth. • Has a soupy or slouchy consistency (magma…liquid rock). Mantle Convection currents The middle mantle "flows" because of convection currents. Convection currents are caused by the very hot material at the deepest part of the mantle rising, then cooling and sinking again --repeating this cycle over and over. Plate Movement • “Plates” of lithosphere are moved around by convection cells in hot mantle. Hot magma rises and cools then fall back toward the core. What are tectonic plates made of? What lies beneath the tectonic plates? What are tectonic plates made of? • Plates are made of rigid lithosphere. The lithosphere is made up of the crust and the upper part of the mantle. What lies beneath the tectonic plates? • Below the lithosphere (which makes up the tectonic plates) is the asthenosphere. Where are the World Plates located? • If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle. World Plates Copy and answer the following questions: • How many major tectonic plates are there on earth? • What causes these plates to move? • Look at the diagram on page 19A, are more plates moving apart or pushing together? • Look at the diagram on page 18A to answer the following questions: • In what direction do convection currents move on each side of a spreading center? • In what direction would the plates move? Plate Movement • “Plates” of lithosphere are moved around by convection cells in hot mantle. Hot magma rises and cools then fall back toward the core. • Use Rock cycle powerpoint Rock Poster 1.Title: Name of rock 2.Definition (what it is) 3.How it’s formed 4.How it fits in the rock cycle 5.Examples 6. Visual Rock Cycle (Only) 1.Definition 2.The processes that occurs to form each rock 3. Where each rock goes 4. A visual representation of the cycle Practical Exercise 1 Supercontinents! Copy and answer the following questions: • What are supercontinents? • How do they form and how do they break apart? What are supercontinents? a landmass comprising more than one continental core, or craton (Pangea) How do they form and how do they break apart? Through continental collision fewer and larger continents are formed while rifting makes more and smaller continents. How was Pangea made? What happens at tectonic plate boundaries? https://www.youtube.com/watch?v=Kg_UBLFUpYQ 1. What might have made this huge crack? 2. How could this crack (over time ) change the landscape of the Earth’s surface? Copy this chart on next notes page TYPES OF PLATE BOUNDARIES Type of Boundary Sketch of Boundary Direction of Movement Description/Features of Plate Boundary Examples Ocean-Ocean Ocean-Ocean Ocean-Ocean Ocean-Ocean OceanContinent Ocean-Continent Ocean-Continent OceanContinent Divergent Plate Boundary Transform Boundary Convergent Boundary ***continentcontinentCollision Collision Boundary *** Subduction Divergent Boundaries Divergent Boundaries • Spreading ridges – As plates move apart new material is erupted to fill the gap Divergent Boundaries • Spreading ridges ex. Mid-ocean ridge, rift valley – As plates move apart new material is erupted to fill the gap Three types of plate boundary Divergent boundaries are where plates move away from each other Iceland: An example of continental rifting • Iceland has a divergent plate boundary running through its middle Age of Oceanic Crust Youngest Crust Oldest Crust Courtesy of www.ngdc.noaa.gov Warm Up Draw the figure below then answer the following questions. 1.What type of boundary is this and how do you know? 2.What type of crust is this activity occurring in? 3.Identify A, B, C and D then explain what is occurring at each site. D B A C Warm Up 1.This is a Divergent boundary because the plates are moving apart 2.Because it is under water this is the oceanic crust which is located in the lithosphere 3.A, B, C and D then explain what is occurring at each site. D rifts B A Middle Mantle Asthenosphere C Convection currents –magma rises and falls as it heats and cools Transform Boundaries Transform Boundaries The San Andreas fault, adjacent to which the US city of San Francisco is built is an example of a transform boundary between the Pacific plate and the North American plate. (Earthquake zones) Transform Boundaries • Where plates slide past each other Above: View of the San Andreas transform fault Convergent Boundaries the plates move towards each other Convergent Boundaries • There are three styles of convergent plate boundaries – Continent-continent collision – Continent-oceanic crust collision – Ocean-ocean collision Continent-Continent Crust Collision Continent-Continent Crust Collision • Forms mountains, e.g. European Alps, Himalayas Continent-Oceanic Crust Collision SUBDUCTION Zones Occurs along Continent-Oceanic collision and Ocean-ocean collision • Subduction • Oceanic lithosphere subducts underneath the continental lithosphere • Oceanic lithosphere heats and dehydrates as it subsides • The melt rises forming volcanism • E.g. The Andes Ocean-Ocean Plate Collision • When two oceanic plates collide, one runs over the other which causes it to sink into the mantle forming a subduction zone. • The subducting plate is bent downward to form a very deep depression in the ocean floor called a trench. • The worlds deepest parts of the ocean are found along trenches. – E.g. The Mariana Trench is 11 km deep! Ocean-ocean collision Type of Boundary Direction of Description/Features Examples Sketch of OF TYPES PLATE BOUNDARIES Movement Boundary of Plate Boundary Diverging Plate Boundary plates move away from each other Mid-Ocean Ridge Transform Boundary plates slide past each other The San Andreas fault Conversion Boundary *** Collision plates move towards each other Collision Boundary *** Subduction Ocean-Ocean OceanContinent Ocean-Ocean Ocean-Continent Ocean-Ocean two oceanic plates collide one rolls on top while pushing the other into the mantel Ocean-Continent Continent plate collides with Oceanic plate. CP rolls on top of the more dense OP Ocean-Ocean Mariana Trench Ocean-Continent many volcanoes Andes mountain Three types of plate boundary • Divergent • Convergent • Transform Need Chromebook today. Answer questions in complete sentences. 1. What might have made this huge crack? 2. How could this crack (over time ) change the landscape of the Earth’s surface? Volcanoes and Plate Tectonics… How can hot-spot volcano be used to track plate movement? Pacific Ring of Fire An area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur Volcanism is mostly focused at plate margins Pacific Ring of Fire Hotspot volcanoes What are Hotspot Volcanoes? • Hot mantle plumes (coming from core – mantle boundary) rises to the surface in the middle of a tectonic plate. The Hawaiian island chain are examples of hotspot volcanoes. Photo: Tom Pfeiffer / www.volcanodiscovery.com The tectonic plate moves over a fixed hotspot forming a chain of volcanoes. The volcanoes get younger from one end to the other. Mantle Hot plumes occur Due to lower pressure this layer consist of liquid metal that surrounds the inner core Outer Core Inner Core Hottest, densest layer but because of extreme it remains a ball of hot solid metal What are hot spots? • Not all volcanoes come from hot spots. Volcanoes are formed by: - Subduction - Rifting - Hotspots Through rifting pates pull apart magma rises Himalayas Practical Exercise 2 Where will the UK be in: 1,000 years? 1,000,000 years? 1,000,000,000 years? Warm Up • Turn to page 41A in your textbook. • Complete questions 1-9. You only need to write the letter of the correct answer. Take out notebook, turn to vocab http://www.youtube.com/watch?v=Kg_UBLFUpYQ • As with volcanoes, earthquakes are not randomly distributed over the globe Figure showing the distribution of earthquakes around the globe • At the boundaries between plates, friction causes them to stick together. When built up energy causes them to break, earthquakes occur. Where do earthquakes form? Figure showing the tectonic setting of earthquakes Plate Tectonics Summary • The Earth is made up of 3 main layers (core, mantle, crust) • On the surface of the Earth are tectonic plates that slowly move around the globe • Plates are made of crust and upper mantle (lithosphere) • There are 2 types of plate • There are 3 types of plate boundaries • Volcanoes and Earthquakes are closely linked to the margins of the tectonic plates Structure of the Earth asthenosphere • The Earth is made up of 4 main layers: Mantle Outer core – Inner Core – Outer Core – Mantle – Crust Inner core Crust Volcanoes are formed by: - Subduction - Rifting - Hotspots