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  • 海浪侵蚀

    Coastal landscape showing cliff erosion and sand deposition on the beach.

     

    Is this erosion or deposition?
    ::这是侵蚀还是沉降?

    The power of the ocean modifies  landforms  by  erosion  and deposition. Landforms modified by both erosion and deposition are seen in this photo. The cliff is being eroded by incoming waves. The  beach  is being created as sand is being  deposited .
    ::海洋的力量通过侵蚀和沉降来改变陆地形态。 通过侵蚀和沉降来改变陆地形态。 通过侵蚀和沉降来改变陆地形态的陆地形态可见于这张照片中。 悬崖正在被波浪侵蚀。 海滩正在随着沙子沉积而形成。

    Wave Erosion
    ::波浪侵蚀

    Wave  energy  does the work of erosion at the shore. Waves erode  sediments  from cliffs and shorelines. The sediment in ocean  water  acts like sandpaper. Over time, they erode the shore. The bigger the waves are and the more sediment they carry, the more erosion they cause ( Figure   ).
    ::波浪能是海岸侵蚀的结果。波浪侵蚀了悬崖和海岸线的沉积物。海水中的沉积物像砂纸一样作用。随着时间的推移,它们侵蚀了海岸。波浪越大,所携带的沉积物越多,造成的侵蚀就越大(图 ) 。

    Aerial view of a sandy beach surrounded by steep cliffs in Greece.

     

    Waves erode sediment from sea cliffs. The sediment is then deposited on beaches. These sandy cliffs are in Greece.
    ::海浪侵蚀海悬崖的沉积物,然后沉积在海滩上,这些沙岩悬崖位于希腊。

    Wave  refraction  either concentrates wave energy or disperses it. In quiet water areas, such as bays, wave energy is dispersed. This allows sand to be deposited. Land that sticks out into the water is eroded by the strong wave energy. The wave energy concentrates its power on the  wave-cut cliff .
    ::波的折射要么浓缩波能,要么分散波能。在诸如海湾等静静的水区,波能被分散。这可以让沙子沉降。渗入水中的土地被强波能侵蚀。波能将其电力集中到波断悬崖上。

    Landforms From Wave Erosion
    ::来自波浪侵蚀的地面形态

    Erosion by waves can create unique landforms ( Figure   ).
    ::海浪侵蚀可产生独特的地表形态(图 )。

    • Wave-cut cliffs  form when waves erode a rocky shoreline. They create a vertical wall of exposed   layers.
      ::当波浪侵蚀岩石般的海岸线时,波断悬崖形成,它们形成一层暴露层的垂直墙壁。
    • Wave-cut platforms  are level areas formed by wave erosion. Since these platforms are above  sea level , it means that either sea level was higher relative or the rock was lower.
      ::波断平台是波侵蚀形成的海平面区域。 由于这些平台高于海平面,这意味着海平面相对较高或岩石较低。

    Eroded rocky shoreline with a wave-cut platform in Pembrokeshire, South Wales.

     

    A wave-cut platform is exposed in Pembrokeshire, South Wales.
    ::在南威尔士的彭布罗克郡,一个波切平台被暴露。

    • Sea  arches  form when waves erode both sides of a cliff. They create a hole in the cliff, like the one pictured below ( Figure   ).
      ::当海浪侵蚀悬崖两侧时海拱形形成。 它们像下图(图 ) 一样在悬崖上造成一个洞。

    A sea arch in California with waves crashing against it during sunset.

     

    A sea arch creates a natural bridge in California.
    ::海拱门在加州建造了一座天然桥

    • Sea stacks  form when waves erode the top of a sea arch. This leaves behind pillars of rock.
      ::海浪侵蚀海拱顶端时形成海堆,留下岩石的柱子。

    Sediment Transport
    ::沉积物运输

    Rivers  carry sediments from the land to the sea. Sometimes the sediments are deposited in a  delta . But if the waves are powerful, the water will transport the sediments along the coastline. Sediments eroded from cliffs near the shoreline may also be transported.
    ::河流将沉积物从陆地运到海洋,有时沉积物沉入三角洲,但如果海浪强大,水会沿海岸线运送沉积物,从海岸线附近的悬崖侵蚀的沉积物也可能被运走。

    Wave Refraction
    ::波浪折射

    Most waves approach the shore at an angle. The part of the wave that is nearer the shore reaches shallow water sooner than the part that is farther out. The shallow part of the wave "feels" the bottom first. This slows down the inshore part of the wave and makes the wave "bend." This bending is called  refraction .
    ::大多数海浪从一个角度接近海岸。 靠近海岸的那部分海浪到达浅水的时间比更远的更早。 海浪的浅部分“ feels” 首先是底部。 这减慢了海浪的近岸部分, 使海浪“ bend ” 。 这种弯曲被称为折曲 。

    Most waves strike the shore at an angle.This creates longshore currents, which move roughly parallel to the shoreline.
    ::大部分海浪从一个角度撞击海岸。 这创造了远岸洋流, 大约与海岸线平行移动。

    Further Reading
    ::继续阅读

    Summary
    ::摘要

    • Ocean waves have a tremendous amount of energy and so they may do a great deal of erosion.
      ::海洋波浪有巨大的能量 所以它们可能会造成大量的侵蚀
    • Some landforms created by erosion are platforms, arches, and sea stacks.
      ::侵蚀造成的一些陆地形态是平台、拱门和海床。
    • Longshore currents are created because water approaches the shore at an angle.
      ::由于水从一个角度向岸边靠岸,形成了长岸洋流。

    Review
    ::回顾

    1. What are the two ways an increase in wave energy will increase coastal erosion?
      ::增加海浪能源会增加海岸侵蚀的两种方式是什么?
    1. How does wave refraction work as a wave approaches a shoreline?
      ::当波浪接近海岸线时波浪的折射如何运作?
    1. Does all the sand at a beach come from currents and waves bringing it in?
      ::沙滩上所有的沙子 都来自海流和海浪吗?

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    1. What is coastal erosion?
      ::什么是海岸侵蚀?
    1. What is accretion?
      ::什么是权宜之计?
    1. What causes erosion to increase?
      ::是什么导致侵蚀增加?
    1. How does rock type affect the rate of erosion? How does this affect the appearance of the coastline?
      ::岩石类型如何影响侵蚀速度?这如何影响海岸线的外观?
    1. What are the four ways coastal erosion happens?
      ::海岸侵蚀的四种方式是什么?
    1. Why are rates of erosion expected to increase?
      ::为什么侵蚀率预期会上升?