What Does the Iceberg Calving in Antarctica Mean?

19 Jul

An iceberg the size of Delaware broke off from the Larsen C ice shelf in early July. What does this mean in terms of the pace of climate change and other phenomena?

An iceberg the size of Delaware broke off from the Larsen C ice shelf in early July. Photo: Shutterstock

You’d have to be living under a rock not to know that a 1 trillion-ton iceberg calved off the Larsen C Ice Shelf of Antarctica some time between July 10 and July 12.

But what does this mean in terms of the Earth’s climate? Did the release of the iceberg mean that the threat of global warming is drastically increasing? At this point, scientists aren’t really sure whether the iceberg calving was caused by global climate change.

“We just can’t make a clear connection to this being driven by climate change at this time,” said Christopher Shuman, a NASA research scientist and professor of glaciology at the University of Maryland. However, “this is a worrisome sign for the Larsen C; you can’t lose 12 or 13 percent of your area from an ice shelf and not think, ‘Hmm. Well, that’s an awful lot that’s gone missing.’ On the other hand, there have been previous large bergs from this area.”

However, the calving did take place in the Antarctic Peninsula, an area that’s undergone a warming of 4.5 degrees Fahrenheit since 1950, probably due to warmer water deep in the ocean.

“There have been large increases in temperature in the region over the last half-century or so,” said research scientist and glaciologist Martin O’Leary of Swansea University. “Obviously we have been seeing climate change impacts, and it’s possible that this is going to put the ice shelf in a much more vulnerable position.”

“Yes, this is an unusual event. Yes, the Larsen C will have retreated farther west than we’ve ever known it to have retreated before,” Shuman said. “On the other hand, it has dropped large [bergs] before.”

O’Leary said that scientists are going to be watching the rest of the ice shelf very carefully for signs that the shelf as a whole is becoming unstable.

“In the ensuing months and years, the ice shelf could either gradually regrow, or may suffer further calving events which may eventually lead to collapse—opinions in the scientific community are divided,” added Professor Adrian Luckman of Swansea University. “Our models say it will be less stable, but any future collapse remains years or decades away.”

If there’s any good news to come from the calving, it’s that it won’t raise sea levels since the ice was already floating in the water to begin with. Also, ships will easily be able to avoid the berg because of modern satellite, radar, and sonar technology.

The new iceberg will likely take several years to disappear for good.

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