An iceberg is a large piece of freshwater ice that has broken off from a glacier or an ice shelf and is floating freely in open water. The majority of an iceberg’s mass is underwater, with only about 10% of it visible above the surface. Icebergs are a common sight in polar regions, particularly in the Arctic and Antarctic.

Key characteristics of icebergs include:

1. Formation: Icebergs form through a process called calving, where chunks of ice break off from the edges of glaciers or ice shelves. This can occur due to a variety of factors, including the melting of ice, the flow of glaciers, or the impact of waves.
2. Shape and Size: Icebergs come in various shapes and sizes. Some are relatively small, while others can be massive, with dimensions comparable to large buildings. The shape of an iceberg is influenced by factors such as the manner in which it breaks off from the glacier and how it subsequently weathers and erodes.
3. Visible and Submerged Parts: The visible part of an iceberg above the waterline is called the “sail,” while the larger, submerged part is referred to as the “keel.” The proportion of the iceberg beneath the waterline makes them potentially hazardous to navigation, as ships may collide with the submerged ice.
4. White Appearance: Icebergs typically appear white due to the presence of air bubbles and the scattering of sunlight by the ice crystals. The ice can take on a bluish tint in certain conditions, indicating denser ice with fewer air bubbles.
5. Drift: Icebergs can drift with ocean currents, and their movement is influenced by factors such as wind and water temperature. They can travel great distances and pose navigational challenges in shipping lanes.
6. Role in Climate: The melting of icebergs contributes to the freshwater content of the oceans and can influence ocean circulation patterns. Iceberg meltwater is also an important factor in the ecology of polar regions.
7. Titanic Disaster: One of the most famous encounters with an iceberg was the sinking of the RMS Titanic in 1912. The ship struck an iceberg in the North Atlantic, leading to one of the deadliest maritime disasters in history.

Icebergs are not only fascinating natural phenomena but also play a crucial role in shaping the polar environments and influencing global ocean dynamics. They are subjects of scientific study and are closely monitored for their potential impacts on navigation and climate.