When talking of icebergs, the first thing that pops into mind is a triangular structure. But NASA piqued worldwide interest recently after it released images of an iceberg that appears rectangular, with perfectly sharp corners.
The square iceberg
“We get two types of icebergs: We get the type that everyone can envision in their head that sank the Titanic, and they look like prisms or triangles at the surface and you know they have a crazy subsurface. And then you have what are called ‘tabular icebergs’,” Kelly Brunt, an ice scientist with NASA, said to Live Science.
The tabular icebergs tend to be flat, long, wide, and sheet-like. Their rectangular form is the result of a process similar to how a fingernail cleanly splits after growing too long. According to estimates, the iceberg is about a mile long. And like all other icebergs, the visible part only reveals about 10 percent of its total mass.
The agency also discovered that the iceberg had split from the Larsen C ice shelf in Antarctica, located behind a curved iceberg named A-68. “The berg cruised all the way north and through a narrow passage between the A-68’s northern tip and a rocky outcrop near the ice shelf known as Bawden Ice Rise… NASA/UMBC glaciologist Chris Shuman likens this zone to a nutcracker. A-68 has repeatedly smashed against the rise and caused pieces of ice to splinter into clean-cut geometric shapes,” NASA said in a statement (Live Science).
Over a period of time, the iceberg lost some of its clean-cut edges because of exposure to wind and waves. The agency predicts the iceberg will make its way to the north before it melts. The images of the iceberg were captured on October 16 by researchers working on the NASA mission “Operation IceBridge,” which monitors the effects of climate change on polar regions.
A melting Antarctica
“Humans are warming the climate… Globally, we see very clear increases in air temperature that can only be explained through human-caused carbon emissions. In Antarctica, the specifics are more murky,” Timothy Bartholomaus, a glaciologist with the University of Idaho, said to NBC News.
It is estimated that the Antarctic ice sheet lost roughly 3 trillion metric tons of ice in a 25 year period between 1992 and 2017. This directly caused the global sea level to increase by approximately 7.6 millimeters. The loss of ice has also been accelerating significantly with each passing decade.
Between 1992 and 1997, an average of 49 billion metric tons of ice was lost. But in 2002-2007, the average annual ice loss rose to 73 billion metric tons. And in 2012-2017, the loss of ice nearly tripled to 219 billion metric tons per year.
“That leap in ice loss is concentrated in West Antarctica, where losses jumped from 53 billion metric tons of ice in 1992 to 159 billion metric tons in 2017. Scientists have long been eyeing the West Antarctic ice sheet as the least stable region of the continent, and a NASA-led study confirmed that ice losses were accelerating there earlier this year. East Antarctica appears to be losing ice more steadily,” according to QZ.