A-level地理——冰层活动知识点详解

在A-level所有考试中，A-level地理是不少人常选的热门考试科目之一，在备考的时候，有很多细碎的知识点需要提前了解，今天，锦秋小编将为大家介绍一下A-level地理中冰层活动相关知识点。

Revision: Action of Ice

Definitions

Coast: The strip of land where it meets the sea

Coastline: The margin of land. The limit to which wave action takes place.

Shore: The strip of land lying between the high and low water levels.

Shoreline: The limit of the shore. The line where the shore and the water meet.

Beach: A shore covered by a deposit of sand and/or pebbles.

Factors Determining the Nature of Coasts

Wave action

Tidal currents

Nature of the rocks forming the coast

Height of the coast

Nature of the climate

Formation of Waves

Wind blows over the sea surface.

The surface of the sea exerts frictional drag on the lower layer of the wind.

The top layer (with the least drag) moves faster than the lower layer and hence tumbles over it.

This causes a circular motion of wind energy that acts on the sea to create waves.

Wave Erosion

Wave erosion like river erosion involves 4 processes:

Abrasion/Corrosion: The wearing away of the sides and the bed of a river by the impact of the load.

Hydraulic Action: Erosion by the force of moving water.

Attrition: The breaking down of the load by particles hitting against each other.

Solution/Corrosion: When minerals dissolve in water.

Features Produced by Wave Erosion

A notch is cut by waves at high tide level and developed further.

As this notch is developed, a cliff is formed.

The cliff steepens as weathering attacks the base further.

As the cliff retreats, the rock debris is swept by the backwash creating a wave-cut platform.

Some of the debris collects along the seaward edge of the wave-cut platform forming and off-shore terrace.

Caves, Geos, Arches and Stacks

Holes in the cliff face are enlarged by wave action

A tunnel like opening called a cave is formed.

The cave may develop further forming a long narrow inlet known as a geo.

译文：

修正：冰的作用

定义

海岸：陆地上与大海相接的地带

海岸线：陆地的边缘。波浪作用发生的极限。

海岸：位于高水位和低水位之间的地带。

海岸线：海岸的界限。岸边与水相交的线。

海滩：被沙子和卵石覆盖的海岸。

海岸性质的决定因素

波浪作用

潮流

形成海岸的岩石的性质

海岸高度

气候的本质

波浪的形成

风吹过海面。

海面对风的下层产生摩擦阻力。

顶层(阻力最小)比下层移动得快，因此翻滚下来。

这导致了在海洋上产生波浪的风能的圆周运动。

波浪侵蚀

波浪侵蚀如河流侵蚀涉及4个过程：

磨损/腐蚀：受载荷影响的河床和河床的磨损。

水力作用：运动水的侵蚀作用。

磨损：粒子撞击对方而造成的负载分解。

溶液/腐蚀：当矿物溶解在水中时。

波浪侵蚀特征

一个缺口被波浪在高潮位切割并进一步发展。

随着这一缺口的发展，形成了一个悬崖。

悬崖陡峭作为风化进一步攻击基地。

当悬崖撤退时，岩石碎片被反冲冲刷，形成波浪切割平台。

一些碎片沿着波浪切割平台形成的海岸边缘和离岸阶地收集。

洞穴、地质、拱门和Stacks

悬崖面上的孔洞被波浪作用放大。

形成了一个称为洞穴的隧道状开口。

洞穴可能进一步发展形成一个狭长的入口称为地质。

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