Melting Antarctic ‘Megaberg’ Released 152 Billion Tons of Water: What It Means

by Victoria Santiago

A ‘megaberg’ that broke off of Antarctica in July 2017 has been releasing billions of tons of freshwater into the ocean. Scientists kept a close eye on the berg, mostly by using a satellite monitoring system. During the last three months of the megaberg’s life, it released 152 billion tons of freshwater. All of the water has been released around the remote island of South Georgia. How much water is that, exactly? Well, it’s hard to imagine, but 152 billion tons of water would fill 61 million Olympic-sized swimming pools.

Of course, that much water being released into the ocean is concerning. Scientists are unsure how that much water has affected the local ecosystem. There are two big main worries right now: how the freshwater will affect the food chain, and how it will affect ocean circulation.

When icebergs drift, they can damage the ocean in many different ways. For starters, they can damage the seafloor by dragging across it. When this happens, it leaves plow marks on the ocean floor. Thankfully, this megaberg broke up before it caused any serious harm in that way. Drifting icebergs can also block migration or hunting routes used by marine animals, and can change the ocean patterns. Since this megaberg has already melted, the only potential issue is with the amount of water it released.

“This is a huge amount of meltwater, and the next thing we want to learn is whether it had a positive or negative impact on the ecosystem around South Georgia,” says Anne Braakmann-Folgmann, a glaciologist from the University of Leeds. She was also at the head of the study done on this megaberg.

Megaberg’s Melting Process Was ‘Fascinating’

The megaberg, called A68a, took a common iceberg route through the Drake Passage. This will allow scientists to learn more general information about the behavior of icebergs. It took three and a half years to melt down into nothing. During that time, it traveled 2,485 miles. Along the way, pieces of it broke off to form smaller icebergs, which were named A68b, A68c, and so on.

ScienceAlert reports that at the beginning of its journey, the megaberg was the sixth-largest iceberg ever recorded. It had a surface area of 2,208 square miles. When it broke off of the Larsen C ice shelf, it reduced the size of the ice shelf by 12%.

Over time, the iceberg was damaged by the elements. Wind and the impact of waves slowly eroded it. Scientists were able to closely study this, and now have a better idea of how icebergs behave in the open ocean. One specialist had this to say about the heavily-documented megaberg: “A68a was an absolutely fascinating iceberg to track all the way from its creation to its end.”