Worlds biggest Ice cubes! (Icebergs)

Today we take a look at the largest ice cubes of all the Icebergs. How do icebergs form? What's the biggest? How do they help or hinder wildlife? Find out now!


Artic Iceberg

How do icebergs form?

They are freshwater, not salt. They start as a glacier, which forms by snowfall, landing, compressing and moving then breaking into the sea.  The national snow and ice centre has a great guide on how glaciers form. When an iceberg brakes from a glacier it is known as calving.

Calving can occur due to wave oscillation (moving up and down) which can have originated miles away in the oceans, being hit by another iceberg, or frost wedging. Frost wedging is when melted water on the surface runs down into the cracks and refreezes.  The expanded water creates a wedge and prises the glacier apart. Its this action that could increase with climate change. The warmer it gets the more melting water there will be.

If you want to know how they float it's best to refer to the lover of baths, Archimedes's and his Principle of buoyancy. It's due to this principle that the vast majority of an iceberg remains underwater and is where the phrase “tip of the iceberg” originates from.

International Ice Patrol

International Ice Patrol badge

Infamous Icebergs and threat to life

Perhaps the most famous iceberg of all time sank the Titanic on her maiden voyage in 1912.

This led governments to form the Safety of Life at Sea (SOLAS) in 1914. Following on from this organisation's conference the International Ice patrol was formed.  Its mission is to monitor all Icebergs and to prevent any maritime collisions.

How big are Icebergs?

Firstly before we take this question, we have to applaud the International Ice Patrol for having the greatest sizing scheme we have ever seen.

Description Height (m) Length (m) Scale (Above Water)
Growler < 1 >< 5 small sedan
Bergy Bit 1 to < 5   5 to < 15  small, one story  cottage
Small Iceberg 5 to 15 15 to 60 small office building
Medium Iceberg 16 to 45 61 to 120 mid‐size  business district  hotel
Large Iceberg 46 to 76 121 to  200 New Orleans  Superdome 
Very Large  Iceberg > 75  > 200 large  hotel/convention   center complex 


The largest on record was B 15, which was a huge 11,000 km square. It was discovered in March 2000.  It has slowly melted and broken up in time but one piece (over 70 km square) still remained tracked in 2021!  The current largest is A-76.

Whale on a mobile phone

This Whale is on their mobile phone,
to let their friends know bout some lovely krill!

Where do icebergs go?

They eventually melt, especially as they head into warmer waters. It is estimated that from snowfall to melting in the ocean takes around 3,000 years! One recent study believes that icebergs heading north, due to the currents, are the cause of ice ages.

Icebergs and wildlife

As Icebergs melt they produce nutrient rich water, this in turn attracts plankton, krill, then fish, then the predators of fish, such as penguins and other marine life including whales. Large Icebergs can reduce the amount of sunlight to the ocean floor which can reduce the amount of life. Scientists say with climate change and an increased amount of Icebergs damaging the sebeds (they can drag along the sea floor) and restricting light sealife could be reduced.

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