Why does water look blue in a lake, but clear in a glass? (Even if it’s still lake water in the glass)

Question

Why does water look blue in a lake, but clear in a glass? (Even if it’s still lake water in the glass)

In: Earth Science

Answer 1

Much the same as the sky being blue, light passes through water and most of the light is blocked with only the bluer wavelengths able to escape.
A glass of water is small and doesn’t block a lot of the spectrum in such a small space.

Some lakes are VERY blue though, through natural minerals colouring it, like the Blue Lake at Jenolan Caves in the Blue Mountains, west of Sydney, Australia [Jenolan Caves Blue Lake](https://images.app.goo.gl/G2iHLABBPSKfUjcS6)