Icicle

An icicle is ice in the form of a cone or column that has formed from freezing drops. The lower end may be pointed or rounded, depending on the action of the wind and the flow velocity of the drops that make up the icicles.

Formation

At the beginning there is the Icicle, who has not yet assumed its typical shape at this time, from a single drop. It grows by dropwise water runs down and freezes him side or at the top. Icicles arise at points where the one liquid (melt ) water accumulates (eg, at the edge of a sunlit, snowy roof ) and on the other temperatures prevail below freezing (eg, below the roof edge where additional wind evaporative cooling arises ). The water must therefore freeze in layers, so that the icicles can take a mature form.

A small, young icicles usually has a conical shape, often some bubbles are still visible inside.

If an icicle grows, vertical ridges and horizontal ribs may form, thereby growing the icicles both downward ( in the length ) and to the side ( in width ), but finds the growth at a different rate rather than (length growth is faster ).

Horizontal rings and vertical ridges

If an icicle is in a later stage of growth, and the ribs are already more pronounced. The ribs are, however, towards the tip more narrow and smaller. The rings are separated by a groove. The ridges are formed mostly after already over a longer period no water is coagulated on the icicles. After a period of such new meltwater flow down begins in narrow lanes icicles if this then freezes, there are thin ridges that can be up to one centimeter thick form.

The tip

The tip of a growing icicle consists of liquid water, which can hang several meters down to see this. It is held together by the outside of a very thin skin of ice crystals. At the extreme lower end of an icicle mostly depends a drop of water.

The shape of an icicle

The shape varies continuously, for example by evaporation of ice can occur a change in shape. Generally, icicles can be several meters long. After a certain length of the point, however, is reached when the pin due to its own weight and can not be maintained, and terminates. Since falling icicles can certainly kill a man, it is important to remove icicles on paths and roads before they can become a danger.