Q. Consider the following statements:
1.Icebergs are formed by calving, or splitting glaciers and are made of fresh water.
2.The unseen portion of an iceberg, submerged below the waterline, is typically smaller and less dense than the above-water portion.
3.To qualify as an iceberg, the ice must have a height exceeding 16 feet above sea level, a thickness between 98-164 feet, and cover an area of at least 5,382 square feet.
4.The salinity (salt content) of an iceberg is lower than seawater.
How many of the statements given above are correct?
Explanation –
Statements 1, 3 and 4 are correct. Icebergs are formed by calving, or splitting, glaciers and are made of fresh water They are formed when large chunks of ice break off from glaciers or ice shelves and float freely in the ocean. Since they originate from freshwater sources, icebergs themselves are composed of freshwater. To qualify as an iceberg, the ice must have a height exceeding 16 feet above sea level, a thickness between 98-164 feet, and cover an area of at least 5,382 square feet. The salinity (salt content) of an iceberg is lower than seawater because the freshwater ice freezes out the salt.
Statement 2 is incorrect. Due to Archimedes’ principle, only about 10% of an iceberg’s volume is visible above the waterline. The submerged portion, which is much larger and denser due to the ice being less buoyant underwater, accounts for the remaining 90% of its mass.
Source: Forum IAS
