The bottom of a cut-out block of 2 m thick ice covered with ice algae, placed atop the sea ice of McMurdo Sound, Antarctica. The disappearance of sea ice in polar regions due to global warming not ...

You're by the water's edge, observing a turquoise lagoon, then a little further away, you see an almost black sea at the foot of a cliff. Why does the ocean take on such different hues, from deep dark ...