49 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?

Freshwater ice: a berg is a piece of a glacier or ice sheet that formed on land, so it holds no salt even though it floats in the sea; frozen seawater is sea ice, a different thing.

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

About one tenth: ice is only slightly less dense than seawater, so roughly nine-tenths of a berg floats out of sight, which gave English the phrase 'tip of the iceberg'.

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

Dutch: ijsberg literally means 'ice mountain', and English translated the 'ice' half but left 'berg' alone, which is why it counts as only a partial loan translation.

What do mariners call chunks of glacier ice that rise less than a metre above the sea, smaller than bergy bits?

Growlers, about the size of a grand piano, ride so low that lookouts lose them among the whitecaps, so a ship steering round a big berg can be in more danger from the small pieces beside it.

Operation Iceberg was the Allied codename for the 1945 invasion of which Pacific island?

Okinawa: the landing on 1 April 1945 was the biggest amphibious assault of the Pacific war, and the island was meant to be the springboard for an invasion of Japan that never had to happen.

What are the huge icebergs that break off Antarctica's ice shelves called, after their shape?

Tabular bergs break off Antarctica's floating ice shelves as flat slabs that can be tens of kilometres wide; Greenland's glaciers tend to shed irregular, jagged ones instead.

Which Antarctic ice shelf, the world's largest, shed the biggest iceberg ever measured?

Ross: the shelf released B-15 in March 2000, and the berg's biggest fragment then sat across the entrance to McMurdo Sound for years, stopping the sea ice from clearing and hampering supply ships.

Iceberg B-15, which broke off Antarctica in 2000 as the biggest berg ever measured, was about the size of which island?

Jamaica: B-15 measured roughly 295 by 37 km, about 11,000 square kilometres, and it was so big that its last fragments were still being tracked 18 years later.

An iceberg reported by the USS Glacier in 1956, some 335 km long, was said to be larger than which country?

Belgium covers a little over 30,000 square kilometres and the berg was put at about 31,000, but the ship's estimate was never confirmed, so satellite-measured bergs hold the verified records.

In late 2020 the giant iceberg A-68a drifted towards which British territory, raising fears for its penguins and seals?

South Georgia: the berg was about as big as the island itself, and scientists feared it would ground offshore and block penguins and seals from their feeding routes, but it broke up in early 2021.

Why did iceberg A23a barely move from 1986 to 2020?

It was stuck on the sea bed: soon after breaking away with a Soviet research base on its back, its deep keel dug into the mud of the Weddell Sea, and it sat there for more than 30 years.

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

The US National Ice Center, which began as a partnership between the Navy and the weather agency NOAA, names and tracks every Antarctic berg at least 10 nautical miles long, working mostly from satellite images.

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

The quadrant where it originated: Antarctica is split into four sectors lettered A to D, and the name then stays with the berg, so A23a, which broke away in 1986, was still being tracked under it almost 40 years later.

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

About 1,500 of the roughly 2,200 people aboard died, largely because the ship's lifeboats had room for only about half of those on board.

Which captain kept Titanic steaming at about 22 knots despite a string of ice warnings?

Edward Smith shifted course a little to the south after the warnings but never slowed down, was off the bridge when the berg was sighted, and went down with his ship.

Why did Titanic's lookouts have no binoculars on the night she struck the iceberg?

A mix-up at Southampton: a last-minute reshuffle of officers before sailing left the crow's nest without a pair, though in the moonless dark binoculars would reportedly have made little difference.

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

The United States Coast Guard inherited the job: the US Navy patrolled after Titanic sank but could not spare the ships in 1913, so the Revenue Cutter Service, the Coast Guard's forerunner, took over.

What does the Ice Patrol do each April where Titanic sank?

The Ice Patrol lays a wreath from a ship or aircraft over the spot each 15 April, and the crew read out a dedication to Titanic and those who died with her.

Which treaty came out of the international conference called after Titanic sank?

SOLAS, the Safety of Life at Sea convention, was adopted in 1914 as the direct response to Titanic, and its fifth version, from 1974, is generally regarded as the most important treaty on merchant-ship safety.

Jökulsárlón, a glacier lagoon full of drifting icebergs that appears in two James Bond films, is in which country?

Iceland: the lagoon formed only as the glacier behind it retreated, yet it is already the country's deepest lake, and its bergs appear in A View to a Kill and Die Another Day.

How high above the sea stood the tallest North Atlantic iceberg on record?

168 m, a 55-storey building: the berg was logged by the US icebreaker Eastwind, a height record from the Arctic, whose bergs are generally smaller than Antarctica's.

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

Jakobshavn, on Greenland's west coast, produces around 10 per cent of the island's icebergs and is often named as the likely birthplace of the berg that sank Titanic.

Greenland, whose glaciers launch most of the North Atlantic's icebergs, is a self-governing territory of which country?

Denmark: Greenland runs most of its own domestic affairs but remains part of the Danish kingdom, which is why the island's great berg-filled icefjord sits on the World Heritage list under Denmark's name.

Which 2012 documentary captured the biggest glacier break-up ever filmed, in a fjord in western Greenland?

Chasing Ice: two of photographer James Balog's crew camped for weeks above the glacier before 7.4 cubic kilometres of ice broke away in front of their cameras, which they likened to watching a city fall apart.

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

Bergie Seltzer is high-pressure air, sealed in when the ice formed thousands of years ago, bursting out bubble by bubble as the berg melts; a chip of berg ice dropped in a drink fizzes the same way.

Why do some old icebergs appear blue?

Compressed, bubble-free ice absorbs red light, so the further light travels through it the bluer it comes out; the colour belongs to the ice itself and has nothing to do with the sky.

A huge iceberg toppling back against the ice front it just broke from can set off what?

A 'glacial earthquake': as the berg topples it shoves the glacier's front backwards for several minutes, and seismometers around the world register a tremor of about magnitude 5.

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.

Nick Sloane, who refloated the Costa Concordia, proposed in 2019 to tow an Antarctic iceberg to which drought-hit country?

South Africa: after Cape Town's 2018 'Day Zero' water scare, the salvage master planned to catch a berg near Gough Island and let ocean currents do most of the towing to the city, for about $200 million.

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

Manhattan is the press's favourite yardstick: the ice island that broke off Greenland's Petermann Glacier in 2010 was reported as four times its size, and a piece that followed in 2012 as twice its size.

Which Antarctic ice shelf saw its "B" section collapse in 2002?

Larsen: the whaler Carl Anton Larsen sailed along its front in 1893, and in 2002 its B section shattered when summer meltwater ran down into its crevasses and wedged the ice apart.

The 1841 expedition that found Antarctica's largest ice shelf sailed in HMS Erebus and which other ship, later lost with Franklin?

HMS Terror: both ships later vanished with Franklin's Arctic expedition, and her wreck was found only in 2016, lying in the aptly named Terror Bay; an Antarctic volcano also carries her name.

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

The grounding line is where ice flowing off the land begins to float, and it is not fixed: as warm water thins a shelf from below, the line migrates inland.

When a floating ice shelf collapses, what do the glaciers that fed it do next?

They speed up: a shelf works as a brake on the ice behind it, so although its own break-up adds nothing to sea level, because it was already afloat, the glaciers it held back then pour into the sea faster.

Whose model of the mind is commonly pictured as an iceberg, with the unconscious hidden below the waterline?

Sigmund Freud's model is drawn with the conscious mind as the small tip above the water and the unconscious as the far larger mass beneath it, out of sight but driving much of what we do.

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

Pykrete, a mix of wood pulp and ice, melted so slowly that Lord Mountbatten, by his own account, dropped a block of it into Winston Churchill's hot bath to win the prime minister over.

Project Habakkuk's secret prototype was built on a lake in Jasper National Park, in which country?

Canada: the 1,000-ton model floated on Patricia Lake in the Rockies, kept frozen by a one-horsepower motor, and once it was abandoned it outlasted the whole summer.

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

Ernest Hemingway set the idea out in Death in the Afternoon, his 1932 book on bullfighting: a writer who truly knows a subject can leave most of it unsaid, and the reader will still feel its weight.

How is iceberg lettuce said to have got its name?

It was shipped packed on crushed ice, growers say, so the pale heads looked like little bergs; dictionaries are warier, saying only that the name was apparently a trade name of the 1890s.

American artist Frederic Church first showed The Icebergs under the title The North, days after which war began?

The American Civil War had just begun, so Church called his Arctic scene The North and gave the ticket money to a fund for Union soldiers' families; he renamed it The Icebergs before showing it in London.

Which technology lets ships and satellites pick out icebergs through cloud and darkness?

Radar still has a blind spot: smooth, wet ice gives a weak echo, so small chunks riding low in a rough sea can slip past a ship's set even when the big berg beside them shows up clearly.

What is the term for chunks of ice breaking off an iceberg, a process that pounding waves speed up?

Calving: waves carve a notch at the waterline until the ice hanging over it collapses into the sea, and a berg left lopsided this way can roll over without warning.

What is the term for a drifting iceberg scraping along the sea floor in shallow water?

Seabed gouging leaves furrows that can run for kilometres, and some lie far deeper than any modern iceberg reaches: they are thought to be scars from the ice age, when sea level was lower.

Icebergs drifting south from Greenland, their cores as cold as −20 °C, finally melt on meeting which warm ocean current?

Gulf Stream water is the end of the line: bergs that survive the long drift melt where it meets the cold current carrying them, the same clash that wraps the area in thick fog.

Which Jules Verne novel has an overturning iceberg trap its heroes beneath the ice?

Twenty Thousand Leagues Under the Sea: on the way back from the South Pole a capsizing berg seals the submarine Nautilus in a tunnel of ice, and the crew hack their way out with pickaxes as the air runs out.

Iron released by melting icebergs can act as a fertiliser in polar seas, feeding blooms of what?

Phytoplankton in polar seas are held back by a shortage of iron, so a drifting berg works like a slow-release fertiliser: satellite surveys find the water around icebergs measurably more productive.

In 2006 Antarctic icebergs drifted so close to which country that a celebrity sheep was shorn on one?

New Zealand: the bergs drifted past its South Island, and Shrek, a merino famous for dodging the shearers for six years, reportedly by hiding in a cave, was shorn on one floating off Dunedin.

The giant iceberg B-15A broke into pieces in October 2005 after doing what off Cape Adare?

Running aground set it up, and instruments left on the ice point to a final shove: swell from a storm off Alaska, 13,500 km away, which may have helped to break the berg apart.

A steward who photographed an iceberg hours after Titanic sank noted a smear of what on its side?

Red paint was 'plainly visible', he wrote, like the scrape of a ship's hull, and he noted it before news of the sinking had reached his liner; the photo later hung for decades in the office of the White Star Line's lawyers.