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Water

Introduction

Ice and glaciers

Ice forms when water in the liquid state freezes. Freezing temperature depends on the content of salt dissolved in the water: at normal atmospheric pressure, it is 0° C for pure water, not greatly different for fresh water and it drops to -1.8°C in the case of sea water. When temperatures drop below freezing point, water turns into the solid state. This is true for water that flows freely on the Earth’s surface as also for stretches of water such as lakes, rivers, seas , and also for water trapped in wedges in rocks and in pores in the ground, where ice lenses and veins form. Running water, due to its movement, freezes more slowly than still water, for this reason it is easier in winter to see the formation of ice on the surface of small stretches of still water, while the waterways are not frozen.

Specials

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Antarctica is a continent with a very particular charm...

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Glacial surges
Some glaciers are subject to sudden “expansions” called...

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