冰山是什么颜色的？
Most people would say that icebergs are white, and most of them are. But did you know that icebergs can also be stunning shades of blue and green?
An iceberg looks white because the packed snow on its surface is full of tiny air bubbles and the edges of ice crystals. Together, these reflect all the colors of visible light equally, so we see white.
As more and more snow piles up on top of an iceberg, the air bubbles are squeezed, and small ice crystals grow together into larger grains. Underwater, the air bubbles are squeezed out completely. When light hits this dense, compressed ice, much of it travels deep inside. The ice absorbs colors with longer wavelengths, such as red and yellow, while colors with shorter wavelengths, like green and blue, are reflected back. This "leftover" blue-green light is what gives some icebergs their remarkable colors.
Algae also often grow on the underwater sides of icebergs, leaving beautiful green stripes in the ice. These are easy to see when an iceberg rolls over and parts that used to be underwater come to the surface.
大多数人都会说冰山是白色的，大部分冰山也确实如此。可你知道吗？冰山也会呈现出令人惊叹的蓝色和绿色。
冰山看起来是白色的，是因为它表面压实的积雪里充满了细小的气泡和冰晶的棱角。它们对所有颜色的可见光反射得一样多，所以我们看到的是白色。
随着冰山顶上积的雪越来越多，气泡被挤压，小冰晶也会长到一起，形成更大的颗粒。到了水下，气泡会被完全挤出去。当光照到这种致密、压实的冰上时，大部分光会深深地透进冰里。冰会吸收波长较长的颜色，比如红色和黄色，而波长较短的颜色，比如绿色和蓝色，则被反射回来。正是这些“剩下来”的蓝绿色光，让有些冰山呈现出非常美丽的颜色。
另外，冰山浸在水下的那一面上常常长着藻类，在冰里留下漂亮的绿色条纹。当冰山翻转过来，原本在水下的部分露出水面时，就很容易看到这些条纹。