"Changes of Sea and Land" Land and Ocean PPT Courseware 8

Description

"Changes of Sea and Land" Land and Ocean PPT Courseware 8

learning target

Understand the causes of changes in sea and land

Understand the founders, content and evidence of the continental drift theory

Understand the main contents of the plate tectonics theory, the direction of plate movement and the volcanic and seismic zones on the earth.

Read pages 32-40 independently to find out the above questions.

Evidence of changes in sea and land: changes in sea and land

What fossils of marine life found in rocks in the Himalayas tell us

The impact of human activities on land and sea changes

On the earth, the sea turns into mulberry fields, and the mulberry fields turn into seas. There are many examples of this change. Modern scientific research shows that changes in the earth's crust and rise and fall of sea levels are the main causes of changes in the sea and land. Human activities also cause changes in the sea and land.

The earth beneath our feet is in motion, and the seven continents and four oceans are constantly changing.

How were the outlines of the Earth's landmasses formed? Is the distribution of the seven continents and four oceans fixed? This has been debated for a long time in the past.

Someone noticed an interesting phenomenon a long time ago: on the world map, the outlines of both sides of the Atlantic, especially the west coast of Africa and the east coast of South America, are very similar. The convex part of the South American continent almost coincides with the concave part of the African continent. If these two continents were cut out from the map, they would fit together into one whole.

Activity

Pictured above: This is like a torn piece of paper. After being pieced together, the text and rows that should be printed also correspond one-to-one;

Picture on the right: Ostriches cannot fly, and manatees live in shallow tropical seas. Logically speaking, they do not have the ability to travel far across the ocean. Why...?

Upper right: What lessons can we learn from Wegener’s story about continental drift?

Wegener and the theory of continental drift

After painstaking investigation, Wegener finally presented three pieces of evidence: first, many organisms on the west coast of the Atlantic are related; second, the rocks, strata and folds on both sides of the Atlantic are also consistent; third, in terms of paleoclimate, the two poles are The area shows signs of tropical deserts, and ice caps are found in equatorial forests.

Wegener also conducted rigorous demonstrations from the aspects of geophysics and geodesy. Finally, an acceptable "continental drift hypothesis" was proposed. The hypothesis is that the rocks that make up the ocean floor are heavier than the rocks that make up the continents. Therefore, the crust that makes up the continents drifts on the ocean floor rocks like "icebergs." This had a huge impact on the development of modern geology, and people still use the basic idea of ​​this hypothesis as one of the basis for discussing crustal movement.

Evidence 1 – Similarity of animals

I can only live in shallow tropical seas. Why do I exist in South America and Africa?

I can’t fly, so why do I exist in South America and Africa?

Evidence 2 – Similarity of ancient strata

This is like a torn newspaper. After being pieced together, the printed words and rows correspond one to one.

plate movement

Relative motion (collision)

① Continental plates and continental plates: fold mountains and plateaus:

(Himalayas, Alps, Qinghai-Tibet Plateau)

② Oceanic plates and continental plates: ocean trenches, island arcs, coastal mountains (such as the Andes Mountains, Taiwan Mountains, island arcs in eastern Asia, etc.)

Departure movement (rift): rift valley or ocean, such as the East African Rift Valley, Atlantic Ocean, etc.

Plate movement and surface morphology

The formation and distribution of the earth's oceans and continents, as well as the landforms of large-scale mountain systems, plateaus and plains, are all the result of plate movement.

(1) Collision and extrusion between continental plates: tall mountains and huge plateaus; such as the Himalayas, Alps, Qinghai-Tibet Plateau, etc.

(2) Collision between oceanic plates and continental plates: often forming trenches, island arcs, and coastal mountains; such as the Andes Mountains, Taiwan Mountains, and island arcs in eastern Asia, etc.

(3) Two major plates split: rift valley or ocean, such as the East African Rift Valley, Atlantic Ocean, etc.

1. Name the plates to which the Arabian Peninsula, Indian Peninsula, Japanese Islands, and Madagascar belong.

2. Analyze the future change trends of the Tibetan Plateau and the Atlantic Ocean.

1: The earth's crust ( ) and sea level ( ) are the main causes of changes in the sea and land, and ( ) can also cause changes in the sea and land.

2: Continental drift is caused by ( ). The earth ( ), which is composed of rocks, is not one piece, but is made up of ( ). The world can be divided into ( ) sectors.

3: The Arabian Peninsula and the Indian Peninsula belong to the ( ) plate, and the Indochina Peninsula belongs to the ( ) plate.

4: The East Siberian mountains belong to the ( ) plate.

5: The western part of South America is connected with the ( ) plate.

6: Generally speaking, the crust of plate ( ) is relatively stable, and the crust at the junction of plate ( ) and ( ) is relatively stable ( ). ( ) and ( ) in the world are also concentrated in the ( ) zone.

7: The directions of plate motion are mutual ( ) and mutual ( ).

8: According to prediction: the area of ​​the Red Sea will be ( ), the area of ​​the Mediterranean Sea will be ( ), the area of ​​the Pacific Ocean will be ( ), and the area of ​​the Atlantic Ocean will be ( ).

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For more information about the PPT courseware "Changes of Land and Sea" PPT courseware, please click on the "Changes of Sea and Land ppt Land and Ocean ppt" tab.

"Changes of Sea and Land" PPT download:

"Changes of Sea and Land" PPT download Part 1: Content objectives of this section: Give examples to illustrate that the land and sea on the earth's surface are in constant movement and change. Know the theory of continental drift and be able to use this theory to solve some problems. Changes in the sea. Changes in the sea, which can be referred to as...

"Changes of Sea and Land" PPT courseware:

"Changes of Sea and Land" PPT Courseware Part One: Teaching Objectives 1. Use examples to illustrate the changes of sea and land, and establish the scientific viewpoint of dialectical materialism that the sea and land are constantly moving and changing. 2. Understand the basic concepts of continental drift and plate tectonics, and be able to explain the world's main...

"Changes of Sea and Land" PPT:

"Changes of Sea and Land" PPT Part One Content: Course Questions Ask the question: What was the land like hundreds of millions of years ago? Establishing a hypothesis: Continental drift theory 200-300 million years ago, there was only one continent on the earth. Later, this supercontinent split into several continents, and...

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Update Time: 2024-10-20

This template belongs to Geography courseware People's Education Edition Geography for Grade 7 Volume 1 industry PPT template

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