A NASA Operation IceBridge scientist, Jeremy Harbeck, was flying over Antarctica in early October when he spotted an iceberg unlike any other: an incredibly sharp-angled tabular iceberg floating among the sea ice right next to the Larsen C. Ice Shelf It had an almost perfect rectangular shape. The photos, shared through social networks, quickly became media.
Despite its strangely perfect shape, this iceberg is completely natural, and in fact it is not even unusual. Ice has a crystal structure, which means that it is more likely to break in straight lines than in any other way. It happens as with minerals, which can grow and break at very precise angles.
Tabular icebergs are more common than we think
That is why we often see icebergs with geometric shapes , although it is true that a rectangle as perfect as this is clearly unusual.
The walls of this new iceberg are sharp and almost perfectly vertical, suggesting that they were formed recently. Remember that normally only 10% of an iceberg is visible on the water. As time passes, the waves will begin to erode these edges, creating large arches and sinking into their walls. Perfection will disappear.
The iceberg will also continue to break and crack, losing chunks of ice around the edge, and possibly even breaking up into smaller pieces.
Also, the iceberg will begin to move away from the area in which it formed; in that movement, the cold air and the temperature of the sea will cause it to slowly melt, although large icebergs can survive for many years.
Large icebergs
The largest iceberg ever observed, called B-15 , was released from Antarctica in 2000, and some fragments of it still exist near the island of South Georgia. Other fragments of B-15 left the Southern Ocean, appearing just 60 kilometers off the coast of New Zealand in 2006.
The path to which this type of iceberg drifts is important to scientists because, as they travel, they release fresh water and micronutrients into the ocean, changing their chemical properties and affecting both local ocean currents and biology.
The reason Iceberg B-15 has survived so long is because of its sheer size: it measures 295 by 35 kilometers. In contrast, the famous rectangular iceberg is barely 1 kilometer long, so it won’t last that long.
It is likely to move farther around the shoreline and slowly disintegrate, melting before it exits Antarctic waters and losing its perfectly straight lines.
Around Antarctica, other regions have had increasing rates of iceberg production. With so many icebergs on the move, the chances of seeing more rectangular icebergs like this in the future may increase.
Reference: NASA
