Chapter 2 | Shaping of the earth’s surface | Class 9 Social Science | Animation Video · NEW AGE Golden School Books
本视频讲解九年级地理第二章‘地球表面的塑造’，涵盖内部与外部力量、板块构造、地壳层结构等内容，适合练习地理基础知识和科学表达。
Chapter-2 Shaping of the earth’s surface Teacher : Good morning, students!
第二章：地球表面的形成 老师：同学们，早上好！
Today, we will explore Chapter 2 – “Shaping of the Earth’s Surface”.
今天，我们将学习第二章——“地球表面的形成”。
In this chapter, we will discuss internal and external forces and how they constantly shape and transform the Earth's surface.
在本章中，我们将讨论内力和外力，以及它们如何不断塑造和改变地球的表面。
Students : Good morning, Ma’am.
学生们：早上好，女士。
Teacher: Do you know what causes the constant transformation of the earth’s surface?
老师：你们知道是什么导致了地球表面的不断变化吗？
Ananya: Yes, Ma’am.
阿南雅：是的，女士。
I’ve heard that there are some powerful forces operating within and on the surface of the planet.
我听说，在这颗行星的内部以及表面，有一些强大的力量在发挥作用。
Arvind: Operating?
阿尔文德：是在运营吗？
How can solid ground even change, Ma'am?
女士，坚实的土地怎么可能发生变化呢？
Teacher: It’s all thanks to a brilliant concept called Plate Tectonics, first introduced by W.J.
老师：这一切都要归功于一个非常出色的科学理论——板块构造学说（Plate Tectonics），这一理论最初是由W.J.提出的。
Morgan.
摩根。
Ananya: What is plate tectonics, Ma’am?
阿南雅：女士，什么是板块构造学说呢？
Teacher: Oh!
老师：哦！
It is about how the Earth's crust is broken into giant puzzle pieces.
这讲的是地球的地壳是如何被分割成无数巨大的“拼图块”的。
Tectonic plates are the several small and large pieces into which the outermost layer of earth is broken.
构造板块是指地球最外层所分裂成的那些大小不一的板块。
Ananya: Are they stationary or moving?
阿南雅：它们是静止的还是在移动？
Teacher: Yes, Ananya.
老师：是的，阿南雅。
Tectonic plates are always moving slowly, and their movement of tectonic plates creates various landforms such as mountains,
构造板块总是在缓慢移动，而这种移动会形成各种地貌，比如山脉。
volcanoes, plains, and valleys.
火山、平原和山谷。
Arvind: Ma’am, please tell us more about the layers of the Earth.
阿尔文德：女士，请再向我们详细介绍一下地球的各个层次结构。
Teacher: The Earth has three main layers which are called crust, mantle, and core.
老师：地球主要由三层结构组成，分别是地壳、地幔和地核。
The crust is the outermost layer, below crust lies the thick and hot mantle, and below mantle lies the super-hot core.
地壳是最外层的结构；地壳之下是厚实且温度极高的地幔；地幔之下则是温度极高的地核。
The crust and upper mantle form the rigid lithosphere, which is broken into massive slabs called tectonic plates.
地壳和上地幔共同构成了坚硬的岩石圈（lithosphere），而岩石圈又被分割成许多巨大的板块，这些板块被称为“构造板块”（tectonic plates）。
Ananya: Wow!
阿南雅：哇！
This sounds so fascinating.
这听起来真是太有趣了。
But Ma’am, what is Asthenosphere?
但是女士，什么是软流圈（Asthenosphere）呢？
Teacher: Ananya, Asthenosphere exists below the lithosphere and is a semi-molten layer which allows the tectonic plates to move.
老师：阿南雅，软流圈位于岩石圈之下，是一层处于半熔融状态的物质，它使得地壳板块能够发生移动。
Arvind: Ma’am, how many types of tectonic plates are there?
阿尔文德：女士，地壳板块一共有多少种类型呢？
Teacher: There are three main types of tectonic plates namely continental plates, oceanic plates and mixed plates.
老师：构造板块主要有三种类型，分别是大陆板块、海洋板块和混合板块。
Continental plates carry continents.
大陆板块携带着各大洲。
Oceanic plates carry ocean floors.
海洋板块携带着海底地壳。
And mixed plates carry both continents and oceans.
这些混合拼盘既包含了来自两大洲的食材，也融入了来自不同海洋的元素。
Arvind: Ma’am, could you please explain what causes tectonic plates to move?
阿尔文德：女士，您能解释一下是什么导致地壳板块移动的吗？
Teacher: Sure.
老师：当然可以。
Convection currents present in the mantle are the cause of movement of tectonic plates.
地幔中的对流电流是导致板块运动的原因。
Intense heat from the Earth's core causes hot magma rise, cool, and sink.
来自地球地核的强烈热量使高温岩浆上升、冷却后再次下沉。
This continuous movement create convection currents that push and pull the plates by a few centimeters every year!
这种持续的运动产生了对流电流，这些电流每年会使板块发生几厘米的移动（即板块会被推动或拉动）。
Ananya: Ma’am, do tectonic plates meet during movement?
阿南雅：女士，地壳板块在运动过程中会相互碰撞吗？
Teacher: Offcourse, they meet at their edges which are called plate boundaries.
老师：当然了，它们会在各自的边缘相遇，这些边缘被称为板块边界。
Arvind: Ma’am, how many types of plate boundaries are there?
阿尔文德：女士，地壳板块边界一共有多少种类型呢？