All About Those Gigantic Antarctic Icebergs - Owlcation - Education
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All About Those Gigantic Antarctic Icebergs

Science has always fascinated me. This includes not only the ecological sciences, which I studied in school, but other endeavors, as well.

A Crack In the Ice

This NASA photo shows the crack in the Larsen Ice Shelf C from the air

This NASA photo shows the crack in the Larsen Ice Shelf C from the air

Overview

Currently, our planet is equipped with two large polar ice caps and many glaciers that can be found amidst the more mountainous regions. Add up all the ice from these cold and forsaken places and you will end up with a lot of frozen water that could drastically change the way we live, if it would to all melt very rapidly.

This scenario does not to appear to be happening right now, but there does appear to be a reduction in the size of the glaciers that dominate these cold places. By far, the largest amount of ice and snow can be found in Antarctica and so, when a large piece of this ice mass breaks free, the event usually becomes headline news. Presented here, is some historical and scientific information about this noteworthy chain of events.


The Big Event

On July 12, 20017 a chunk of ice the size of Delaware broke free from the Larsen Ice Shelf, a long arm of ice that extends away from the main continent towards the southern tip of South America. This in itself is not an unusual event, as the "calving" (formation) of a southern iceberg is a natural event. Even though a huge chunk of ice had been set free and would eventually melt as it broke up and drifted northward, it is just as likely that an equal (or even larger) amount of snow and ice would be created elsewhere on the Antarctica continent. Basically, this is an ongoing process that occurs all the time.

Antarctica and the Antarctic Ocean

The Larsen Ice Sheet is that long arm of Antarctica that extends towards South America

The Larsen Ice Sheet is that long arm of Antarctica that extends towards South America

Ice Shelves and Icebergs

An ice shelf is created when a glacier moves out from its land mass onto the open sea. Because ice is lighter than water, this large chunk of frozen freshwater will remain on the surface of the ocean, while it is still attached to the mainland. Since glaciers are constantly on the move, the ice shelf will grow in size, as the glacier continues to push away from land. Eventually, the shelf gets so big that part of it breaks free and becomes a floating iceberg.

Strange Undersea Creatures

The icefish is just one of the many strange undersea creatures that dwell in the Antarctica Ocean.

The icefish is just one of the many strange undersea creatures that dwell in the Antarctica Ocean.

The Antarctic Ocean

The Antarctic Ocean is a body of very cold water, which surrounds the Antarctica continent. Compared to other oceans, the depth of the sea is relatively shallow. And despite the frigid temperatures, this ocean is rich in sea life. One interesting oceanographic feature of this southernmost sea is a strong current that circles around the continental ice mass.

A Chunk of B-15

This piece of B-15, named B-15A, became a floating laboratory for studying Antarctic icebergs

This piece of B-15, named B-15A, became a floating laboratory for studying Antarctic icebergs

The Largest Iceberg Ever

The iceberg that just broke free from the Larsen Ice Shelf in July 2017 is surprisingly not the largest piece of ice to come free from the South Pole. That honor belongs to a grand chunk of ice, called Iceberg B-15. In 2000, this iceberg tore away from the Ross Ice shelf. Approximately the size of Jamaica, this huge island lasted six years, eventually breaking into smaller pieces, some of which made their way as far north as New Zealand.

And then two years earlier another very large iceberg broke free from the Filchner-Ronne Ice Shelf in Antarctica. This iceberg was dubbed A-38 and at the time, it was the largest iceberg ever recorded. This massive floating island eventually broke up with some pieces making it as far north as the South Georgia Islands, some 1,500 miles away.

Scientist at Work on an Iceberg

Weather instruments and GPS recording equipment were set up on the B-15 iceberg

Weather instruments and GPS recording equipment were set up on the B-15 iceberg

Floating Research Islands

When B-15 calved from the Ross Ice Shelf back in 2000, a few inventive scientist took advantage of the situation and set up a few basic research instruments on the floating piece of ice. From the scientific data that was gathered, researchers were better able to track to exact position of the iceberg and then discover what effects this ice island had on its surrounding environment. For instance in 2005, the B-15 iceberg collided with the Drygalski Ice Tongue causing a part of the tongue to break off. This break-off piece was large enough that maps of Antartica had to be redrawn.

Antarctica Bird Life

Penguins are frequently found along the outer edge of the Antarctica continent

Penguins are frequently found along the outer edge of the Antarctica continent

Observations on Larsen Ice Sheet C

My Take

Let me say that the creation of a gigantic iceberg in the Antarctic is nothing new, the process has been going on for ages. However, the breakup of the Larsen Ice Sheet, which extends far out in the water towards the southern tip of South America could mark major changes in the ocean currents that swirl around the continent. The breakup of the Larsen Ice Sheet would have only a minute effect on sea levels, but some scientists worry that this event could be a prelude to other parts of the Antarctic ice shelf undergoing similar disintegration.

Questions & Answers

Question: Does the sea level rise when a floating iceberg melts?

Answer: This is a $64,000 question. When an iceberg melts, fresh water is added to the ocean. In general, there is not enough water released to affect sea levels. With Antarctic ice, these icebergs can be huge, like as big as a small New England state. Still, I have not found any scientist that believes that a large Antarctic iceberg meltdown would affect global sea levels. However, once the discussion turns to the possible meltdown effects from the Antarctic continental mass, then you will find opinions that suggest a possible rise in the worldwide sea level.

P.S., I have found no one discussing what would happen if the water from melting Antarctic icebergs would evaporate into the atmosphere. In that scenario, we could see a super-saturated atmosphere that produces bigger and wetter storms.