Most icebergs originate from the great continental ice sheets or ice shelves in polar regions like Antarctica and the Arctic (including Greenland, Alaska, and Northern Canada).
Arctic icebergs (around 90%) form from the fast-moving glaciers of western Greenland, while Southern Hemisphere icebergs calve from the massive ice sheets and shelves of Antarctica.
The largest Antarctic icebergs usually measure several kilometers (miles) long. However, Greenland icebergs pose a greater menace, endangering ships on the busy North-Atlantic routes. One of the worst disasters at sea struck in 1912 during the ocean liner RMS Titanic’s maiden voyage.
The ship collided with an iceberg and sank with great loss of life. This prompted the establishment of the International Ice Patrol, which continues to track icebergs and warn any shipping in the area.
Why couldn’t the passengers and crew on the RMS Titanic climb the iceberg?
The passengers and crew on the RMS Titanic could not climb the iceberg as the RMS Titanic traveled several miles past the iceberg in the dark before stopping, and scaling the steep, slippery ice wall was physically impossible.
Traveling near top speed (about 22.5 to 25 knots), the massive liner required 1.5 to 2 nautical miles to come to a complete stop due to its heavy momentum. By the time it halted, the iceberg lay far away and lost in the pitch-dark night.
Maneuvering a giant ocean liner like the Titanic into a U-turn in the dark—without radar technology—would have wasted vital time needed to load the lifeboats.
The iceberg featured sheer, glass-like, and jagged walls of hard Arctic ice. Passengers lacked proper climbing gear, ropes, or spikes.
People wore heavy winter layers, wool suits, and formal dress shoes that became waterlogged, heavy, and slick, making movement or vertical climbing impossible.
Icebergs frequently shift, roll, or flip as their centers of gravity change or as they melt. Adding human weight to an unbalanced mass could have caused it to capsize.
The night remained moonless and dark. Spotting, reaching, or transferring people from the ship’s deck onto an isolated, shifting block of ice proved completely impractical.
What is an Iceberg?
An iceberg is a floating mass of ice (berg is German for mountain) that breaks off from a glacier and drifts in the world’s oceans until it melts.
Snow falls on land in cold regions year after year, building up into thick layers that compress into solid glacial ice over hundreds to thousands of years.
Driven by gravity, these massive frozen rivers or continental ice sheets slowly creep or flow downhill toward the ocean.
When the ice reaches the sea, large chunks break off into the water through a natural process called calving. This occurs due to the forward motion of the glacier, tides, waves, or melting from warm water and air.
Because they originate from land-based snow and glaciers, icebergs consist of fresh water, not salt water. About 90% of an iceberg’s mass remains hidden underwater because freshwater ice is slightly less dense than liquid ocean water, leaving only the “tip” visible on the surface.
Content for this question contributed by Harry Santillo, resident of Cleveland, Ohio, USA
