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为什么冰川冰看起来蓝色?

冰川冰中观察到的颜色,冰山和裂隙通常是蓝色的。然而,冰块和工业冰块或白色如果不是完全透明的。

所以。为什么冰川冰看起来蓝色?

我的意思的一些例子:

冰块

冰川冰

PS:冰川学家,这是我收到了很多的问题,经过搜索,我发现答案不是完全满意,所以我决定在这里分享我的问答形式。

回答

简短的答案是:* * * *,因为冰蓝色。现在我们要解释为什么似乎完全透明的冰块和工业冰块。这与大多数透明材料并不完全透明,而吸收(和/或分散)光击中他们的一部分。当透明度更适合一个特定的颜色(波长)[1],颜色的材料看起来,就像彩色玻璃给色彩如何白光穿过它。现在最重要的事实是,这个“色”效应更强更厚的材料。让我们标准玻璃为例:当透过玻璃似乎完全透明,因为厚度太小,使它的颜色明显。然而,如果你看看玻璃的边缘,它看起来绿色,这表明玻璃的确是绿色的,但通过一段厚时才明显不够。[!(玻璃)[2])[2](图片取自[peakglass.ca][3])同样,冰川冰是蓝色的,但这只能欣赏,如果你是块冰足够厚。我们可以看到这种效果在接下来的冰山的照片,在不同粗细的部分显示一个颜色梯度从透明到蓝色。 [![ice colors][4]][4] The remaining questions is: Why are glaciers not always blue? As we know, many icebergs (and snow) are white. The key here is "bubbles". The reason is that for each ice/air interface, part of the light gets reflected and only a fraction goes through. Therefore the greater the number of bubbles a piece of ice has, the less light will be able to proceed deeper into the ice. As such, when you view light from more bubbly ice, most of it will have traveled through less ice, and thus have had less distance to obtain the blue tint. I've made this figure to help understanding the idea: [![light in ice with bubbles diagram][5]][5] On the left, a piece of ice with very few bubbles allows a longer travel path through the ice, inducing a marked blue tint in the outgoing light. On the right, in contrast, if there are many bubbles the light will go bounce back right away with only a very subtle tint, or no tint at all. Snow is the extreme of this, because it is mostly air (bubbles), and only some small pieces of ice, that's why it looks so white. An interesting ramification of this: those deep blue pieces of ice started as snow. But as the snow piles up, the weight of the snow on top compacts it, squeezing air out changing it from snow to [firn][6] until you finally reach the density of being a block of ice (with bubbles). In a big glacier, hundreds or thousands of meters of ice can exert such a pressure that the bubble spaces get compacted smaller and smaller until they disappear and the air is dissolved into the ice itself. Therefore this means that the more blue (and bubble-less) a piece of ice is, the more it has come from deeper within the glacier... meaning it also has traveled from further up in the glacier basin and it is, therefore, older. So, now you can identify deep, old ice just by its color. To give a more familiar example of how adding bubbles can turn something transparent with a tint into something white, take the case of egg whites, which are transparent with a yellowish tint. But as you whip it, adding in bubbles, it begins to turn into meringue which is perfectly white. [![making meringue][7]][7] However, there is a trick that can even make the blue color of seemingly-white snow noticeable. If you let a ray of light bounce on it many times, each time it will travel through a little bit of ice, getting a bit of blue tint each time, and after enough bounces it will look unquestionably blue. That's what you see when looking at the entrance of a snow cave or a crevasse in a glacier. The light that comes from deeper in the cave has bounced many more times around the walls and becomes bluer: [![enter image description here][8]][8] (Picture taken from [outdoorlifenorway.com][9]) [1]: https://en.wikipedia.org/wiki/Visible_spectrum [2]: https://i.stack.imgur.com/3vf75.png [3]: http://www.peakglass.ca [4]: https://i.stack.imgur.com/HdHIG.jpg [5]: https://i.stack.imgur.com/arZ5v.png [6]: https://en.wikipedia.org/wiki/Firn [7]: https://i.stack.imgur.com/iPSe0.jpg [8]: https://i.stack.imgur.com/zmQrF.jpg [9]: https://outdoorlifenorway.com

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\ begingroup美元伟大的回答。我总是愚蠢地提到“不同的冰晶形状”。在有些事情肯定是有效的(为什么我们有一系列不同的雪、霰、雨夹雪/等等)。但你的答案解释更彻底,显然比我所见过的:-) \ endgroup美元
- - - - - -JeopardyTempest
2018年1月31日,在42
5

\ begingroup美元同时,那些从阅读:注意,(液体)水本身的颜色一样的玻璃厚度的想法。海洋不是蓝色的天空是蓝色的(或反之亦然)。 \ endgroup美元
- - - - - -JeopardyTempest
2018年1月31日,在47
1

\ begingroup美元很棒的回答!你自己把所有的照片/图片吗?如果被别人一些,你能提供源归属吗? \ endgroup美元
- - - - - -gerrit ♦
2018年1月31日12点
1

\ begingroup美元 @gerrit谢谢。不是所有的照片是我的,我已经添加了引用我把他们从的地方。我会经常这样做。干杯 \ endgroup美元
- - - - - -卡米洛·Rada
2018年1月31日,在十八12
1

\ begingroup美元 @gansub冰川冰的密度范围。小冰是定义最古老的积雪一样密集,约840公里/ m3。但在老冰,受到过重的压力,气泡基本上消失了,它可以达到常规bubble-less冰的密度,约为917 kg / m3 \ endgroup美元
- - - - - -卡米洛·Rada
2019年2月4日当日

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创建代码用引号”或式子~篱笆
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像这样
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def函数(foo):
打印(foo)
' ' '
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在结束linebreak添加2个空间
_italic_或* *的* *
报价将>开始的
做链接(尽量使用https)
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