冰川侵蚀
Section outline
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Lesson
::经验教训In what ways is this glacier creating distinctive landforms?
::冰川以什么方式产生独特的地貌形态?This is modifying the landscape it's flowing through. Glaciers erode and deposit telltale landforms . They show the direction a glacier flowed and how far it advanced. They create fantastic and unique features in mountain areas. Did glaciers leave clues where you live? If you live in the northern part of the United States, you might be able to find some. Would you know what to look for?
::冰川正在改变其流经的地貌。 冰川侵蚀和沉积, 揭示了地貌。 它们展示了冰川流动的方向及其进展程度。 它们创造了山区的奇妙和独特的特征。 冰川是否留下了你住的地方的线索? 如果你住在美国北部, 你也许能找到一些线索。 你知道要寻找什么吗 ?Erosion by Glaciers
::冰川侵蚀Like flowing water , flowing ice erodes the land and deposits the material elsewhere. Glaciers cause erosion in two main ways: plucking and abrasion .
::像流水一样,流冰侵蚀土地,将物质存放在别处。 冰川以两种主要方式造成侵蚀:采掘和磨损。- Plucking is the process by which and other sediments are picked up by a glacier. They freeze to the bottom of the glacier and are carried away by the flowing ice.
::幸运是冰川和其他沉积物被冰川吸收的过程,它们冻在冰川底部,被流冰冲走。
- Abrasion is the process in which a glacier scrapes underlying rock. The sediments and rocks frozen in the ice at the bottom and sides of a glacier act like sandpaper. They wear away rock. They may also leave scratches and grooves that show the direction the glacier moved. These grooves are called glacial striations .
::冰川磨损是冰川刮碎岩床的过程。 冰层底部和冰层两侧的沉积和岩石就像砂纸一样。 它们磨损岩石。 它们还可能留下表明冰川移动方向的划痕和沟槽。 这些沟槽被称为冰川碎裂。
Valley Glaciers
::河谷冰川Valley glaciers create several unique features through erosion.
::河谷冰川通过侵蚀产生若干独特的特征。- As a valley glacier flows through a V-shaped river valley , it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls ( Figure ).
::河谷冰川穿过V形河谷,将河谷的两侧划开,将U形的河谷切成几乎垂直的墙壁(图)。
The glacier on the left is carving out the sides of a valley. The U-shaped valley on the right is what will be left when the glacier melts away. - A hanging valley was cut off from the main valley by a larger glacier ( Figure ).
::一个悬吊谷被更大的冰川切断了与主谷的距离(图)。
The waterfall on the right flows through a glacial valley. A larger glacier carved the valley the water falls into. There is a waterfall because this is a hanging valley. - A cirque is a rounded hollow carved near the top of a mountain by a glacier ( Figure ). This is where the glacier begins. The highest cliff of a cirque is called the headwall.
::圆环是一个圆形空洞,由冰川(图)在山顶附近被冰川(图)雕刻。这是冰川开始的地方。圆环的最大悬崖叫做头墙。
On the left, there are several cirques where glaciers are originating. A glacier melted and left behind the large cirque in the mountains on the right. - An arête is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arête is called a col.
::山脊是山顶对面形成岩浆时留下的山脊。山脊中的低点被称为山丘。
- A horn , like the one pictured below ( Figure ), is a sharp peak that is left behind when glaciers erode all sides of a mountain.
::一个角,像下面的角(图)一样,是冰川侵蚀山的两侧时留下的尖尖峰。
The Matterhorn in Switzerland is the classic glacial horn. Further Reading
::继续阅读Deposition by
::交存Landforms from Erosion and Deposition by Gravity
::重力侵蚀和沉降产生的土地形态Summary
::摘要- Glaciers are incredibly powerful agents of erosion.
::冰川是侵蚀的威力极强的诱因
- Valley glaciers create very distinctive landforms like horns, cirques, and hanging valleys.
::峡谷冰川创造出非常独特的陆地形态,如角、螺旋和悬吊谷。
- Glaciers pluck rocks from valley walls. This turns a V-shaped river valley into a U-shaped glacial valley.
::冰川从山谷墙上挖出岩石,将V形河谷变成U型冰川谷。
Review
::回顾- Why do glacial striations show the direction a glacier moved?
::为什么冰川磨擦会显示冰川移动的方向?
- Describe how these erosional features form: hanging valley, cirque, arete, and horn.
::描述这些侵蚀特征是如何形成的:吊吊谷、螺旋、石灰和角。
- How does plucking create a U-shaped valley?
::采掘如何创造出一个U形的山谷?
- Plucking is the process by which and other sediments are picked up by a glacier. They freeze to the bottom of the glacier and are carried away by the flowing ice.
