这个是OG最后一篇阅读的第三和四段..表示看不懂- -# 各位高手能否来指点下~就当练手帮助新人了哇

zealdin

以及之后的3题和4题..尤其是3题..迷茫啊~~~

One explanation for green icebergs attributes their color to an optical illusion when blue ice is illuminated by a near-horizon red sun, but green icebergs stand out among white and blue icebergs under a great variety of light conditions. Another suggestion is that the color might be related to ice with high levels of metallic compounds, including copper and iron. Recent expeditions have taken ice samples from green icebergs and ice cores- vertical, cylindrical ice samples reaching down to great depths – from the glacial ice shelves along the Antarctic continent. Analyses of these cores and samples provide a different solution to the problem.


The ice shelf cores, with a total length of 215 meters, were long enough to penetrate through glacial ice -- which is formed from the compaction of snow and contains air bubbles -- and to continue into the clear, bubble-free ice formed from seawater that freezes onto the bottom of the glacial ice. The properties of this clear sea ice were very similar to the ice from the green iceberg. The scientists concluded that green icebergs form when a tow-layer block of shelf ice breaks away and capsizes, exposing the bubble-free shelf ice that was formed from seawater.