50 Fun Facts About Icebergs

An iceberg is a piece of what kind of ice, over 15 metres long, broken off a glacier or ice shelf?

Frozen seawater is sea ice, a different thing; icebergs are born on land.

Roughly what fraction of an iceberg's volume sits above the water?

Pure ice has a density of about 920 kg per cubic metre against seawater's 1,025, so Archimedes does the rest.

The word 'iceberg' is a partial loan translation from which language?

Ijsberg literally means 'ice mountain', with cognates in Danish, German and Swedish.

Bergy bits are floating ice under 5 metres high. What are pieces under 1 metre called?

Both are hard to spot on radar and dangerous to small boats.

What is the technical term for a mass of ice breaking away from a glacier or ice shelf?

It is often preceded by a loud crack or boom, and blocks up to 60 metres high can crash into the water.

Large flat-topped icebergs with steep sides and a length-to-height ratio over 5:1 are called what?

They typically break off Antarctic ice shelves such as the Ross and Filchner-Ronne; Greenland's bergs are usually irregular.

Which Antarctic ice shelf has calved the largest icebergs on record?

It is about the size of France and was discovered by James Clark Ross in 1841.

Iceberg B-15, the largest on record, calved from the Ross Ice Shelf in 2000. It was about the size of which island?

It measured roughly 295 by 37 km, about 11,000 square kilometres, and its fragments were still being tracked in 2018.

A flat-topped iceberg seen by the USS Glacier in 1956, 335 by 97 km, was larger than which country?

It was seen 240 km west of Scott Island in the South Pacific and remains the largest ever recorded.

Iceberg A-68, which broke away in July 2017, came from which ice shelf?

At 5,800 square kilometres it was twice the size of Luxembourg; no significant fragments remained by April 2021.

Iceberg A23a calved in 1986 but did not begin moving until 2020. Why?

By early 2025 it was the world's largest iceberg and had run aground off South Georgia.

Which organisation is the only one that names and tracks all Antarctic icebergs?

Every berg over 10 nautical miles along one axis gets a letter for its quadrant of origin plus a running number.

In Antarctic iceberg names such as A-68 or B-15, what does the letter stand for?

The number is simply a running count within that quadrant.

Titanic's collision with an iceberg in April 1912 killed roughly how many people?

The German liner Kronprinz Wilhelm had rammed a berg in 1907, crushed her bow, and still finished her voyage.

How fast was Titanic travelling when her lookouts sighted the iceberg?

Her wireless operators had received seven ice warnings, and the North Atlantic ice that April was the worst in 50 years.

Titanic's lookouts Fleet and Lee had no binoculars that night. Why?

Reportedly they would have made little difference in the starlit dark, and the calm sea meant no waves broke against the ice.

The International Ice Patrol, formed in 1914, is operated by which body?

It is funded by 13 nations with an interest in trans-Atlantic shipping and watches the Grand Banks of Newfoundland.

What does the Ice Patrol do every 15 April at the site of the Titanic disaster?

A dedication statement to the ship and her dead is read by the crew.

The 1913 conference in London that led to the Ice Patrol also produced which international treaty?

Wireless rules were also harmonised so that rival radio companies had to handle each other's calls.

Canada's RADARSAT-1, launched in 1995, was the first satellite to track icebergs using what?

It sends microwaves to the sea surface and records the reflections, working through cloud and darkness.

How high above the sea was the tallest North Atlantic iceberg on record, seen by the Eastwind in 1958?

That is the height of a 55-storey building; such bergs come from western Greenland's glaciers.

Which fast-moving Greenland glacier, whose fjord is a UNESCO site, is a prolific iceberg producer?

Its bergs can be a kilometre tall and get stuck on the fjord floor for years; it flows more than 45 metres a day.

Icebergs from Greenland's fastest-declining glacier caused what share of 20th-century sea-level rise?

It is one of the fastest-declining glaciers on Earth.

Ilulissat Icefjord in Greenland was made a UNESCO World Heritage Site in which year?

The listing cited its beauty and the glacier's role in understanding climate change.

What is the fizzing sound made by a melting iceberg popularly called?

Icebergs can be up to 10 percent air by volume; the noise comes from compressed bubbles bursting as the ice melts.

Why do some old icebergs appear blue?

Centuries of pressure squeeze out the air, so the light that comes back through the ice is blue or blue-green.

What gives some icebergs a dirty black colour?

Others are green, yellow, striped or even rainbow-coloured thanks to seawater, algae or a lack of air bubbles.

When a huge iceberg calves and flips against a glacier front it can produce what?

These events can release as much energy as an atomic bomb and momentarily shove the whole glacier backwards.

Which Canadian province taxed iceberg harvesting in 2016 and capped berg water exports?

Its annual iceberg supply exceeds the entire freshwater consumption of the United States; the water goes into bottled water, ice cubes and beer.

In 2019 Nick Sloane proposed towing an Antarctic iceberg to which country for about $200 million?

A UAE company had announced a similar Middle East plan in 2017.

Icebergs are often measured in multiples of which island's area, about 59 square kilometres?

Newspaper comparisons also reach for Luxembourg, Wales, Delaware and Jamaica.

Which Antarctic ice shelf, named for a Norwegian whaling captain, saw its "B" section collapse in 2002?

Carl Anton Larsen sailed along its front in the whaler Jason in December 1893.

The Ross Ice Shelf, about the size of France, was discovered by James Clark Ross in which year?

Early sailors called it 'The Barrier' or 'Great Ice Barrier' because it stopped them going further south.

What is the name for the boundary where a floating ice shelf meets ice resting on bedrock?

The other edge, where shelf meets open ocean, is the ice front or calving front.

Ice shelves range in thickness from about 100 metres up to how much?

They are fed by tributary glaciers and found in Antarctica, Greenland, northern Canada and the Russian Arctic.

The ice island that broke off Petermann Glacier in 2010 was the largest Arctic berg since which year?

About a month later it split in two after crashing into Joe Island in the Nares Strait.

Project Habakkuk was a British Second World War plan to build an aircraft carrier out of what?

Geoffrey Pyke's idea got as far as a prototype on Patricia Lake in Alberta before longer-range aircraft made it pointless.

Where was the Project Habakkuk prototype built?

Lord Mountbatten backed the scheme; rising costs and escort carriers killed it.

Which American writer coined the 'iceberg theory', or theory of omission, in fiction?

He believed the deeper meaning of a story should stay below the surface, like the seven-eighths of a berg under water.

How did iceberg lettuce get its name?

Burpee introduced the crisphead variety in 1894 with the slogan 'there is no handsomer or more solid cabbage lettuce in cultivation'.

Who painted The Icebergs (1861), based on sketches from a boat trip off eastern Canada?

The Hudson River School painter had taken a boat trip north specifically to see the bergs.

What did tests in 1945 first evaluate as a way of spotting icebergs?

Side-looking airborne radar later made it possible to image ice regardless of weather.

Besides melting, icebergs lose mass through what process, which is enhanced by waves hitting them?

Ocean heat, not sunlight, does most of the melting.

What is it called when a drifting iceberg scrapes along the sea floor in shallow water?

Bergs can also be frozen into pack ice when winds and currents push them towards the coast.

Interior temperatures of icebergs from western Greenland can be as low as what?

That cold core is one reason big bergs survive so far south.

Icebergs contain up to what proportion of air bubbles by volume?

The bubbles' acoustic signature lets scientists study how fast a berg is melting.

Fresh meltwater released from an iceberg at depth does what?

It is lighter than the surrounding seawater; bergs also act as floating breakwaters and release iron and other nutrients.

The Ross Ice Shelf mostly lies within a territory claimed by which country?

Its ice front to the sea is more than 600 km long and 15 to 50 metres high, with 90 percent of the ice below the water.

Iceberg B-15A, the largest surviving piece of B-15, split apart in October 2005 after what?

Seismographs on the berg and across Antarctica recorded it; a swell from an Alaskan storm 13,500 km away may have helped.

The Danish Meteorological Institute tracks Greenland icebergs using which satellites' radar?

Their synthetic aperture radar sees through cloud and polar night.