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Layers of the Earth
Question | Answer |
---|---|
The Earth is made of three layers | crust, the mantle and the core |
Earth's top layer | The Crust |
The Crust | as thin as 5 miles thick underocean |
The Crust | Average thickness about 22 miles |
The upper crust is made primarily of | Sedimentary Rocks |
These rocks are formed when materials on Earth's surface are worn away or broken up | Sedimentary Rocks |
These rocks are made when magma, molten rock, cools within Earth's surface or near it. These rocks come from volcanoes | Igneous |
These rocks are made when igneous or sedimentary rocks undergo change from heat and pressure.(requires temperature) | Metamorphic |
The Rock Cycle | When 1 type of rock changes to another type of rock |
The Mantle | middle layer |
when sediments are washed away with the water and harden over many years as the water evaporates. Because these types of rocks require water, often pieces of plants and animals get pressed in the sediments and form | fossils |
80% of Earth's total volume and 68% of the mass, making it the heaviest part of Earth. | The Mantle |
The Mantle is believed to be harder due to | iron |
The first 62 miles of this layer of earth is very rigid rock | The Mantle |
The remaining 155 miles of this layer of earth is close to a melting point | The Mantle |
This layer of earth is not a true liquid or solid (Plastic like rock flowing like syrup) | The Mantle |
The Core actually has two sections | The Outer Core and the Inner Core |
The Outer core is believed to be | liquid |
The Outer core is believed to influence the earth's | magnetic pull |
The Inner core is believed to be | solid iron and nickel |
the Earth is how deep | 3,958/miles deep |
This theory of how deep the earth is based on | recordings of seismic waves, or shock waves, created by earthquake activity |
The Crust | is made up of solid rocks, soil,and minerals |
The Crust | has temperatures reaching 1,600F — hot enough to melt rocks |
The Crust | ranges in thickness from 5 to 25 miles |
The Mantle | contains a layer of very hot sometimes molten rock |
The Mantle | is about 1,800 miles thick with temps reaching 8,oooF |
The Mantle | supports the crust |
Inner Core | is ball shaped and made up mostly of solid iron |
Inner Core | is 4,000 miles below the surface of the earth |
Inner Core | has temps as high as 13,000F |
The Outer Core | is made up mostly of melted iron |
The Outer Core | has temperatures<reaching up to 11,000F |
The Outer Core | is about 1,400 miles thick |
The Mantle | reaches 8,000F |
Scientists call the earth's crust | lithosphere (litho means rock or stone) |
The Earth's lithosphere changes continuously name the 4 main forces that make theses changes to Earth's surface | 1. Changes in the Earth's Crust from tectonic(volcanic/eathquakes) plates 2.Weathering - wearing away of the lithosphere by wind/rain 3. Mass movement- slippage of large areas of rock and soil from landslides 4. Erosion - eating away or slow destruction |
Alfred Wegener early 1900's | came up with the Continental Drift Theory |
The Continental Drift Theory says | 200 million years ago the Earth was one large landmass called PANGAE meaning "all earth" |
What did Wegener's theory state | that the large continents split up and pices drifted apart from each other forming the continents we know today. |
PANGAEA is divided into 2 parts | northern break (Laurasia) southern break (Gondwanaland) |
In 1960 scientist uncovered evidence of Wegener's theory, what was that evidence? | Fossils of a dinosaur were discovered in Africa and South America and it's teeth were discovered in Antarctica. This animal does not swim so the land mass must have been connected. |
What mountains match up to prove Wegeners theory | Cape Mountains of South Africa match up with folded mountains near Bueno Aires, Argentina. |
When were the Himalaya Mountains formed | when India collided with Asia |
In the 1950s, scientists were able to study the ocean floor, what did they discover | underwater mountains |
name the longest mountain chain in the world | mid ocean ridges |
Explain why the ocean floor is expanding | when exploring the ocean ridge areas, they learned that rocks found near the ridges were younger than those that were further away. This was because magma from deep inside the Earth's mantle was able to rise through vents or cracks to create ridges. As th |
Plate Tectonic Theory | Alfred Wegener's theory of Continental Drift was |
updated and refined This new version, called Plate Tectonics | (blank) |
Plate Tectonics | explains moving continents, as well as volcanoes, |
earthquakes and mountains. The Earth's crust, or lithosphere, makes up our plate system | (blank) |
7 major plates | (Pacific, North American, South American, Eurasian, African, Australian, and Antarctic) and several smaller ones |
All of these plates, with the exception of_______, contain both continental and ocean crust. | The Pacific plate |
the largest plate that contains almost 20% of the Earth's crust | Pacific plate |
Geologists believe that the plates move about on the | asthenosphere because of convection currents, or movements of gases or liquids caused by differences in temperatures, deep within the Earth. |
Plate Boundaries | The places where the plates meet |
list the 3 types of plate movement (Plate Boundaries) | 1.Divergent Boundaries or SPREADING ZONE: Here, the plates spread away from each other (ocean floor, along the mid-ocean ridges)2.Convergent Boundaries or CONVERGING ZONE: Here, two plates come together - One plate slides over the other plate forcing it d |
One of the best known transform boundaries | San Andreas Fault in California |
Which Boundary creates the most intense earthquakes | Transform Boundaries |
Beneath the Earth's surface, changes are occurring as well, list 3 types of INTERNAL changes | mountain formation, earthquakes, and volcanoes |
3 TYPES OF MOUNTAINS | volcanic,Folded mountains,A dome mountain |
volcanic eruptions. | The Hawaiian Islands are mountains formed BY |
Folded mountains | are the most common mountains |
The Alps, Himalayas, Rockies and the Appalachians are examples of | folded mountains |
two lithospheric plates push together over time until these are formed | folded mountains |
dome mountain | Magma is trapped in a pocket beneath the rock layers of the |
earth and is unable to work its way to the surface. | (blank) |
a dome mountain | The Black Hills of South Dakota |
fault block mountains | like the Sierra Nevadas in Utan and Nevada. |
Geologists believe the Earth's crust bends in as it floats on the fluid-like mantle. It continues bending until the pressure becomes too great, and then the rocks that form the crust split. | fault block mountains |
earthquake | trembling or shaking of the Earth that occurs because of a sudden movement of the crust. more than one million earthquakes each year. |
What is the most common cause of earthquakes is | faulting. |
Describe Earthquake | When the lithospheric plates slide along, the sliding plates break loose,and stored energy is released,The energy travels through the surrounding rocks until the energy is used up. When energy is released through the rocks, it can 1.MOVE THE ROCKS 2. OR V |
the vibration of rocks during an earthquake | seismic waves |
Used to measure waves(Vibration) | seismograph |
How is the the magnitude, (or strength)of an earthquake determined | Richter Scale, which is numbered from 1 to 10. |
Any earthquake measuring what or more is considered a major quake with the potential for much destruction | 6.0 |
a passage and an opening in the Earth's surface through which hot, molten rock is forced out | A volcano |
liquid rock, called | magma |
When magma reaches the surface, it is called | lava(igneous rock) |
Magma rises through what | chambers |
What forms a volcanic mountain | the cooling of lava build up |
At the top of the volcano a steep-sided hole is known as a | crater |
The volcano's opening, which allows the magma to flow to the Earth's surface is called the | vent. |
Between eruptions, active volcanoes are/said to be | dormant |
An extinct volcano | volcano that has stopped erupting |
Where Most of the world's 850 active volcanoes lie | the Ring of Fire, a belt that edges the Pacific Ocean. |