14.8风的侵蚀
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Is wind the greatest erosional force in the desert?
::风是沙漠中最大的侵蚀力吗?Wind can do remarkable things. It can erode to make beautiful shapes. Wind has eroded this rock so that it looks like a rabbit. This limestone formation is in the Sahara Desert in Egypt. Water is the most important erosional force even in the desert. But wind makes its mark in many ways.
::风可以做一些了不起的事情。 它可以腐蚀以塑造美丽的形状。 风侵蚀了这块岩石, 使它看起来像兔子。 这种石灰石形成在埃及的撒哈拉沙漠。 水是沙漠中最重要的侵蚀力。 但是风在许多方面都有它的标记。Sediment Transport by Wind
::由风向运输的沉积物Like flowing water, wind picks up and transports particles. Wind carries particles of different sizes in the same ways that water carries them ( Figure ).
::风像流水一样,风能吸收并输送微粒,风能以与水一样的方式携带不同大小的微粒(图)。- Tiny particles, such as clay and silt, move by suspension . They hang in the air, sometimes for days. They may be carried great distances and rise high above the ground.
::粘土和淤泥等微小颗粒通过悬浮移动,悬浮在空气中,有时长达几天,可能长途飘移,高高飞到地面上。
- Larger particles, such as sand, move by saltation . The wind blows them in short hops. They stay close to the ground.
::大颗粒,如沙子,通过盐化运动,风在短短的跳跃中吹过它们,它们离地面很近。
- Particles larger than sand move by creep . The wind rolls or pushes them over the surface. They stay on the ground.
::比沙子大得多的粒子随爬行 风向滚动或推向表面 它们停留在地上
Wind transports particles in different ways depending on their size.
::风向传送粒子的方式不同,视其大小而定。Wind Erosion
::风侵蚀Dust storms ( Figure ) are more common in . The soil is dried out and dusty. Plants may be few and far between. Dry, bare soil is more easily blown away by the wind than wetter soil or soil held in place by plant roots.
::沙尘暴(图)在......土壤干涸和灰尘散落,植物可能很少,相距很远。干燥、裸露的土壤更容易被风吹走,比植物根部的湿润土壤或土壤更容易被风吹走。When winds whip up in the desert, they can create tremendous dust storms.
::当风在沙漠中吹起时,它们会产生巨大的沙尘暴。Deflation
::通缩Wind blows small particles away. As a result, the ground surface gets lower and rockier; this is called deflation . The rocks that are left are called desert pavement . Desert pavement is a surface covered by gravel-sized particles that are not easily moved by wind.
::风吹走小粒子。 因此, 地表会越来越低, 岩石会变大; 这被称为通缩。 剩下的岩石被称为沙漠路面。 沙漠路面是岩浆大小微粒覆盖的表面, 这些微粒不易被风移动。Abrasion
::面部Did you ever see workers sandblasting a building to clean it? Sand is blown onto the surface to scour away dirt and debris. Wind-blown sand has the same effect. It scours and polishes rocks and other surfaces. Wind-blown sand may carve rocks into interesting shapes ( Figure ). This form of erosion is called abrasion . It occurs any time rough sediments are blown or dragged over surfaces. Can you think of other ways abrasion might occur?
::你曾没有看见工人用沙子把一座建筑打扫干净吗?沙子被吹到表面以扫走泥土和瓦砾。风沙也有同样的效果。它会刮,会抛光,会岩石和其他表面。风沙会把岩石雕刻成有趣的形状(图)。这种侵蚀形式被称为擦伤。每当粗糙的沉积物被吹过或拖过表面时都会发生。你能想到其他的磨损方式吗?This incredible rock formation in Utah is the result of wind erosion.
::犹他州这种不可思议的岩层形成 是风蚀的结果Desert Varnish
::沙漠分布Exposed rocks in desert areas often develop a dark brown or black coating called desert varnish ( Figure ). Wind transports clay-sized particles that chemically react with other substances at high temperatures. The coating is formed of iron and manganese oxides .
::沙漠地区暴露的岩石往往形成一种深褐色或黑色涂层,称为沙漠清漆(图示)。风飘移的粘土尺寸微粒与其他物质在高温下发生化学反应。涂层由铁和氧化锰组成。Ancient people carved these petroglyphs into desert varnish at Sego Canyon, Utah.
::古代人把这些花纹雕刻成 犹他州塞戈峡谷的沙漠清漆Further Reading
::继续阅读Deposition by Wind
::风向沉降Summary
::摘要- Wind moves sediments by suspension, saltation, or creep.
::风向通过悬浮、盐化或爬行来移动沉积物。
- In deserts, wind picks up small particles and leaves behind larger rocks. This forms desert pavement.
::在沙漠中,风会吸收小粒子,留下更大的岩石,形成沙漠路面。
- Moving sand may sand blast rocks and other materials causing abrasion.
::移动的沙子可能沙沙爆炸岩石和其他材料,造成磨损。
Review
::回顾- How does desert varnish form?
::沙漠清漆如何形成?
- Why are dust storms more common in deserts than in wetter regions?
::为什么沙尘暴在沙漠中比在湿润地区更为常见?
- How does wind transport the smallest sediments? How does wind transport sand? How does wind transport particles somewhat larger than sand?
::风如何运输最小的沉积物?风如何运输沙子?风如何运输沙子?风运输粒子如何比沙子大一点?
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。- Why is soil erosion a problem?
::为什么土壤侵蚀是一个问题?
- How does wind erosion occur? What is the relationship between wind speed and the amount of erosion?
::风速和侵蚀程度之间的关系是什么?
- What are the three types of wind erosion?
::三种类型的风蚀是什么?
- What type of wind erosion moves 50% of the soil?
::什么样的风蚀会移动50%的土壤?
- What is creep?
::什么是变态?
- What is saltation?
::什么是盐化?
- What is suspension?
::什么是暂停?
- When is suspension easily seen?
::何时可以轻易看到暂停?
- What has accelerated erosion?
::什么是加速侵蚀?
- Tiny particles, such as clay and silt, move by suspension . They hang in the air, sometimes for days. They may be carried great distances and rise high above the ground.
