Embedded Files
Layers of the Earth
intro video http://video.mit.edu/watch/layers-of-the-earth-12670/
The crust of the earth is similar to the skin of an apple. It makes up about 2 percent of the total mass. The thinner denser ocean crust is about 5-6 KM thick. The continental crust is 35-70 km thick, depending on where you are standing. It is made of mostly granite and basalt.
The mantle makes up about 2/3 of the Earth’s mass. It is the biggest layer. The top part of the mantle and the crust are called the lithosphere. Right below that is a plastic like layer called the asthenosphere. This is the layer that the plates float on. It is made mostly of silicon, iron and magnesium.
The outer core it the only liquid layer. It is approximately 2900 miles and is made of melted iron and nickel.
The inner core is a solid ball made of iron. It spins at a different rate then the Earth. Scientists believe that this motion creates our magnetic field that surrounds the planet. It is about ¾ the size of the moon and hotter than the sun.
Brain Pop
https://www.brainpop.com/science/earthsystem/earthsstructure/
Additional reading: http://volcano.oregonstate.edu/earths-layers-lesson-1
Plates: Great song https://www.youtube.com/watch?v=T1-cES1Ekto
Activity 1: Read the following passage and answer the following questions.
Who was Alfred Wegener and what was his theory?
What was the name of his super continent?
Write two questions of your own from the passage.
The similarity between jigsaw puzzles and maps is undeniable. Straight lines, wavy lines, jagged lines, and often arbitrary lines delineate political borders just as they define the edges of puzzle pieces. Continents appear to be cut from the same piece of Earth's crust. At least that's the picture the earliest mapmakers saw as they created the first images of our world.
As early as 1596, the Dutch mapmaker Abraham Ortelius wrote in his work Thesaurus Geographicus that the Americas must have been "torn away from Europe and Africa." He suggested that catastrophic earthquakes and floods must have been responsible for rearranging the continents. By the early 20th century, geologists still believed that such forces were responsible for many of the major changes to Earth's surface since its formation 4.6 billion years ago. However, the suggestion that these forces actually split and moved continents had been widely dismissed.
A few scientists, however, were convinced that the continents had once been connected and had then broken apart and moved to their present positions. One such scientist, Alfred Wegener, an astronomer and meteorologist by training, set out to find evidence to support this notion. Wegener applied his wide-ranging interests and scientific knowledge to support what he would ultimately call his theory of "continental drift". In addition to detailing the similarity between the coastlines of continents on opposite sides of the Atlantic, Wegener compared assemblages of fossilized plants and animals, as well as similar rock types found oceans apart. The patterns he saw helped support his theory that all continents were once connected and formed a single supercontinent, which has since split up and drifted apart.
How the supercontinent Pangaea broke apart and how the individual continents moved to their present locations were questions Wegener couldn't answer before he died. Despite an impressive collection of data on similarities among Earth's continents, Wegener had no knowledge of mid-ocean ridges, patterns of magnetic polarity, and many other pieces of evidence that led geologists to the current theory of plate tectonics.
Activity 2: Read the following passage. What plant and animal fossils support Continental Drift theory?
Fossil Evidence in Support of the Theory
Eduard Suess was an Austrian geologist who first realized that there had once been a land bridge connecting South America, Africa, India, Australia, and Antarctica. He named this large land mass Gondwanaland (named after a district in India where the fossil plant Glossopteris was found). This was the southern supercontinent formed after Pangaea broke up during the Jurassic period. Suess based his deductions on the fossil plant Glossopteris, which is found throughout India, South America, southern Africa, Australia, and Antarctica.
Fossils of Mesosaurus (one of the first marine reptiles, even older than the dinosaurs) were found in both South America and South Africa. These finds, plus the study of sedimentation and the fossil plant Glossopteris in these southern continents led Alexander duToit, a South African scientist, to bolster the idea of the past existence of a supercontinent in the southern hemisphere, Eduard Suess's Gondwanaland. This lent further support to A. Wegener's Continental Drift Theory
Day 3
Activity 3
The Earth is broken into pieces called plates. They are in constant motion ,shifting and changing the landscape of our planet. The movement of the mantle is as it rises and sinks is called convection current. There are twelve main pieces. Go to the following site and label the plates on your handout.
http://www.learner.org/interactives/dynamicearth/plate.html
Activity 4
complete the boundaries challenge after studying the map
plate interactions
http://www.learner.org/interactives/dynamicearth/slip2.html
Activity 5 quiz
http://www.learner.org/interactives/dynamicearth/testskills.html
Plate interactions
There are three types of plate interactions.Plates can move towards each other ( convergent), or apart ( divergent) or slide past each other. ( transform) Each one results in a change on the Earth's surface.
Plate Interactions
Transform
This occurs when two plates slide past each other.
This kind of boundary results in a fault — a crack or fracture in the earth's crust.
EX: San Andreas Fault
Plates are locked together without moving, a lot of stress builds up at the fault line. Earthquakes will occur to release the pressure.
Divergent
At divergent boundaries, tectonic plates are moving away from each other and magma fills in the space. A valley like rift develops when it is continental and continental plates diverge.
Ex: Great Rift Valley
Sea floor spreading occurs when oceanic plates diverge.
Ex: Mid Atlantic Ridge
Convergent
At convergent boundaries, tectonic plates collide with each other. The events that occur at these boundaries are linked to the types of plates — oceanic or continental — that are interacting.
Continental-continental – makes mountains
Ex: Indian plate into Eurasian plate= Himalayas
Ocean to continental= subduction zone where one plate ducts under the other
Ex: Nazca late into South American plate. Volcanoes will form
Ocean to ocean= subduction
Ex: Marianas trench
Creates a trench where they meet
Avctivity 6:Locate the following places on your map: Himalayas, Mid Atlantic Ridge, Iceland, Great Rift Valley, Hawaii, San Andrea Fault
Hot spots
A third tectonic setting where volcanism occurs is called intraplate- or hot-spot-volcanism, which describes volcanic activity that occurs within tectonic plates and is generally NOT related to plate boundaries and plate movements.
Most volcanic activity occurs at plate boundaries, but there are also a large number of volcanoes located with a plate, some of which are exceptionally active. These areas of so-called intraplate volcanism are called hot spots.
Ring of Fire
The "Ring of Fire", also called the Circum-Pacific belt, is the zone of earthquakes surrounding the Pacific Ocean- about 90% of the world's earthquakes occur there. The next most seismic region (5-6% of earthquakes) is the Alpide belt (extends from Mediterranean region, eastward through Turkey, Iran, and northern India.
Map of Volcanoes
Map of Volcanoes
Here's a map of where Earth's volcanoes occur. Compare this to your tectonic plates map. Do you notice anything?
Map of earthquakes from 1975 -1997
Map of earthquakes from 1975 -1997
Did you hypothesize that earthquakes occur at ALL tectonic plate boundaries? You are right- mostly! Think about it.....tectonic plates are always on the move. This causes earthquakes. Earthquakes are happening all the time, but sometimes they are so minor that you cannot feel them. When pressure builds up between two tectonic plates as they move apart (divergence) or collide (subduction and collision) or transform (slide past each other), it eventually breaks the crust. When the pressure is very high, it can break rocks and create an earthquake.
Volcanoes and earthquakes: When pressure builds up before a volcanic eruption, this, too, can cause an earthquake. Many times earthquakes and tremors will happen before the volcano actually erupts.
vocabulary: continental drift, Alfred Wegener, convection current, convergent, divergent, transform, seafloor spreading, hot spot, asthenosphere, lithosphere, epicenter, Richter scale, glossopteris,
Are you confused? Go to the following site for more information about Earthquakes or open the power point in the "add files" section<
https://ees.as.uky.edu/sites/default/files/elearning/module06swf.swf
Extra Files:
Earthquake practice sheet.doc (33k)Kathy Dougherty, Jan 25, 2015, 12:35 PM
Earthquakes 8.1.ppt (3803k)Kathy Dougherty, Jan 26, 2015, 8:15 PM
Plate Interactions notes 1.docx (13k)Kathy Dougherty, Jan 22, 2017, 11:33 AM
Plate tectonics Website worksheet.doc (118k)Kathy Dougherty, Jan 19, 2016, 9:36 PM
plate map.docx (123k)Kathy Dougherty, Feb 8, 2018, 7:11 AM
plates quiz.docx (12k)Kathy Dougherty, Jan 24, 2017, 10:08 PM
plates sheet.docx (202k)Kathy Dougherty, Jan 22, 2017, 11:34 AM
plates test 2.pdf (269k)
Report abuse