A history of iceberg production
28th August, 2015
If we asked you to pinpoint the Jakobshavn Glacier on a map, the majority of you would struggle to find it. It is in fact located in west Greenland and over recent weeks has been fascinating scientists. It is believed that at some point between the 13th and 19th August a large mass of ice broke away from the glacier. Measuring approximately 12.4 square kilometres in size, it would make the iceberg the largest ever witnessed to break away from the glacier.
It is estimated that Jakobshavn produces around 10 percent of the 30,000 to 40,000 icebergs calved annually in western Greenland. Once they break away they will slowly drift into the Davis Strait before heading out into the Arctic Ocean.
Types of Iceberg
Icebergs can generally be separated into two categories - tabular and non-tabular. Tabular icebergs are generally formed by ice that has broken away from a large ice shelf and can be identified as having steep sides and a flat top.
Irregular shaped icebergs come under the category of non-tabular and are sub-divided into categories including:
- Domed: As the name suggests, domed icebergs feature a curved or rounded top.
- Pinnacle: These icebergs will feature one or multiple spires.
- Wedge: Like a block of cheese. One side of a wedge iceberg will be steep and vertical, with the berg sloping down to the water on the other side.
- Drydock: Over time seawater can erode the ice and create a channel through the middle at close to sea level. On either side of this channel you will commonly find pinnacles of ice.
- Blocky: Similar to tabular icebergs, they feature steep and vertical sides with a flat top.
The Iceberg Responsible For Sinking The Titanic
One of the most famous icebergs ever produced is that which sank The Titanic in 1912. Over the years it has been widely speculated that this iceberg would have originally broken away from the Jakobshavn ice shelf.
Of course, the details of how that iceberg would have come into being are pure guesswork. However, it is likely that it would have formed some 3,000 years ago as a result of snowfall over western Greenland. Over time, with the weight of fresh snow falling on top of it, this snow would have gradually compacted and become compressed into dense ice.
Eventually the frozen glacial waters would force the ice towards the Arctic Ocean, where open water would eventually cause large chunks of ice to break away and drift out into the Arctic Ocean. As icebergs move into warmer waters, the majority will melt quickly - on average only one percent make it as far as the Atlantic Ocean. Unfortunately for those on board the liner, they encountered the one percent on that evening.