The location of the crack is near where past rifts have appeared in the ice shelf, according to Bindschadler. He estimated that a new, rather large iceberg will probably form in the coming months, if not weeks.
“I hope that our field team will have enough time to get onto the ice shelf and set up GPS receivers before the calving event,” Bindschadler said. “We’d like to measure if the ice shelf notices the loss.”
Ted Scambos, lead scientist at the Boulder, Colo.-based National Snow and Ice Data Center, agreed that it’s likely that the crack is part of a natural cycle.
“These are cyclical, occurring every few years, very similar in size and even shape,” said Scambos via e-mail. “As a cyclical process, they are not part of the real climate-change/ice-shelf disintegration story.”
In 2002, the Larsen B Ice Shelf on the eastern side of the Antarctic Peninsula disintegrated in spectacular fashion, losing about 3,250 square kilometers of ice in a single season. More recently, the Wilkins Ice Shelf on the western side of the peninsula has started to collapse. Scientists believe both events are linked to climate change, though some researchers have suggested that wave action from distant storms could have helped break up the Wilkins Ice Shelf.
“If something different happened this time; for example, the pace of calvings changed, or this one was farther upstream from the past ones, then it might signal some major change in the Pine Island system,” said Scambos, adding that the area is changing in other ways, but the rate of calving has been steady over the last few decades.
