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冰川是如何移动的?南极洲会被分离吗?

以拉森冰架为例。冰平台附着在冰川上，这样它们就可以防止周围的暖空气直接融化冰川。这是冰平台的一个重要方面。

冰川运动的机制是什么?

当我们谈论冰川运动时，我们是考虑由于融化和积雪沉积而导致的前进和后退，还是对冰川运动的研究更多地是关于冰川下面与岩石接触的流体层，这使得冰川向下坡移动?

由于第二种类型的运动，冰川可以分离。那么，南极洲有可能分离并消失吗?

回答

冰川学是一个很大的研究领域，我无法在简短的回答中涵盖所有方面。我会试着给出一些概念来帮助你们理解冰冻圈。根据定义，冰川由于重力**向低海拔移动**。也有一些例外，例如[岩石冰川][1]是移动冰川的停滞残留物。大的冰体被称为冰帽(如果小于5万公里$^2$)或冰原(如果更大)。今天，我们只有[南极冰盖][2]和[格陵兰][3]，但在更大的冰川作用时期，北半球的大部分地区被覆盖。在冰原内，快速流动的区域被称为冰川。这些区域的形成取决于许多参数，如质量平衡、基底熔化、地形等。如果冰川或冰盖到达海洋，它就会变得浮力很大。对于较大的冰川，靠近海岸的部分仍然足够大，可以与地面保持接触。 The point of extent where the ocean reaches under the ice is called the [grounding line][6] - a subglacial beach, if you like. As it's floating, tidal variations moving the ice sheets help it to break up, but in some cases, depending on thickness and topography, it can float in a rather uniform shape which we call an ice-shelf. The same way as rivers and lakes are formed as rainwater floats towards the oceans, ice sheets and ice caps are formed as snow falls in cold areas, where it doesn't get warm enough to melt during the summer. As the snow accumulates it forms [firn][7] and later ice. The ice starts moving as the gravity and shear forces make it unstable. Eventually the ice will melt, either on the surface due to warm air, e.g. during summer months, or in the oceans as it calves off into icebergs and is warmed by the ocean. Glaciers can also melt on the base due to heat flux from the Earth beneath or due to pressure. In this way, subglacial lakes are formed under the ice. Large parts of Antarctica are [situated below sea level][8]. Partly this is due to the intensive erosion of fast moving ice, but the main reason is that the weight of the ice pushes down the crust into the mantle. If the ice sheet melts, the mass decreases and the land under it will [rebound][9]. This happens almost on a human timeline. Some areas, such as Hudson Bay, Scandinavia, and the Antarctic Peninsula, have a fast uplift making sea into land. [![Quantarctica][10]][10] _Maps from [Quantarctica][11]. 1: Ice flow velocity. 2: The topography under the ice. 3: Geoid height (not so relevant for your question). 4: Snow accumulation and blue (=old, hard) ice._ As I've suggested [before][12], I recommend you to download the [Quantarctica][11] package. It's rather big but free and easy to use. You can investigate how the ice flows are forming the ice sheet and how the bed map looks under. The large chunk of Larsen C Ice Shelf that just broke off, doesn't directly reshape the Antarctic continent or cause any change in global sea level, as it was already floating. However, if the ice shelf becomes more unstable, it can affect the ice sheet left trailing it and the flow pattern of the glaciers, and that would have a large impact on most human activities - and beyond. [1]: https://en.wikipedia.org/wiki/Rock_glacier [2]: https://en.wikipedia.org/wiki/Antarctic_ice_sheet [3]: https://en.wikipedia.org/wiki/Greenland_ice_sheet [4]: https://en.wikipedia.org/wiki/List_of_glaciers_in_the_Antarctic [5]: http://web.mit.edu/slazzari/www/3.-why-does-ice-float-on-water.html [6]: http://www.antarcticglaciers.org/glaciers-and-climate/ice-ocean-interactions/grounding-lines/ [7]: https://en.wikipedia.org/wiki/Firn [8]: http://www.the-cryosphere.net/7/375/2013/tc-7-375-2013.pdf [9]: https://en.wikipedia.org/wiki/Post-glacial_rebound [10]: https://i.stack.imgur.com/7kZn9.jpg [11]: http://quantarctica.npolar.no/ [12]: //www.hoelymoley.com/questions/10761/considering-how-old-the-antarctic-ice-cover-is-why-isnt-it-much-thicker/10764#10764

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\ begingroup美元你可能想要更详细地了解导致冰川移动的力量。比如累积质量和斜率。 \ endgroup美元
- - - - - -约翰
2017年7月17日4:04

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使用反撇号'或波浪号~创建代码围栏
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像这样
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添加语言标识符以突出显示代码
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def函数(foo):
打印(foo)
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在段落之间放置返回
对于换行符，末尾加2个空格
_italic_或* *的* *
通过将>放在行开始来引用
要建立链接(尽可能使用HTTPS)
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(例子)(https://example.com)
< a href = " https://example.com " > < / >示例
MathJax方程罪\ \ ^ 2θ美元

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