Ice Cap Shrinks

Submitted by ub on Sun, 08/11/2019 - 14:40

On Earth, there once were about 30 million km3 of total ice mass. The average temperature of an ice mass ranges between −20 °C and −30 °C. The core of an ice cap exhibits a constant temperature that ranges between −15 °C and −20 °C

As you will see an ice cap is a glacier, a thick layer of ice and snow, that covers fewer than 50,000 square kilometers (19,000 square miles). Glacial ice covering more than 50,000 square kilometers (19,000 square miles) is called an ice sheet.

An interconnected series of ice caps and glaciers is called an ice field. Ice caps and ice fields are often punctuated by nunataks. Nunataks are areas where just the summits of mountains penetrate the ice.

Ice caps form like other glaciers. Snow accumulates year after year, then melts. The slightly melted snow gets harder and compresses. It slowly changes texture from fluffy powder to a block of hard, round ice pellets. New snowfalls and buries the grainy snow. The hard snow underneath gets even denser. It is known as firn.