Question

explain the existence and chemical composition of icebergs in the ocean.

Answer 1

Icebergs are gigantic freshwater ice that broke off from glaciers and is floating on open water.

Origin: Icebergs are formed when chunks of ice breaks off from glaciers or ice shelves or a larger iceberg. They travel along with the ocean current and often collide with each other creating a disturbance in the shallow waters.

To be classified as an iceberg a floating mass of ice need to be satisfy certain preset criterias:

Height: 16 feet or more above sea level

Thickness: 98-164 feet

Area covered: Atleast 5,382 square feet

Otherwise any other floating mass of ice can be considered as bergy bits or growlers

Bergy bits and growlers have their origin from glaciers or broken piece of ice bergs.

The word iceberg is derived from the dutch word "ijsberg" meaning ice mountain.

Existence :

As the density of pure ice(920 kg/m³) is lesser than the sea water(1025 kg/m³) , more or less about one tenth of the volume of the entire mass is above the water. The existence of the huge mass on water is governed by the Archimedes's principle of buoyancy.

Chemical composition:

They are composed of freshwater.

And are basically formed by the accumulation of snow over many centuries. As the snow congregate over subsequent layers and recryastallises it forms a firn or a permeable layer. when the firn reaches a density of 830 kg/m³; the pores close off trapping the air remains as bubbles. Sometimes the bubbles become smaller and may be incorporated within the ice sheets upon densification.

Thus icebergs majorly consists of freshwater ice , soils , rock debris , and trapped air bubbles.

Combination of snow and air bubbles refracts sunlight and give spectacular colors to the iceberg. Some shades of blue, green and white.

Colors of icebergs may also signify age. Blue icebergs are old enough while green ones contain algae and are new ones.