Very Large Ice Crack (upclose)

A Really Big Crack In An Antarctic Ice Shelf Just Got Bigger

From a News Report of WAMU,  Rae Ellen Bichell, National Public Radio, January 6, 2017

Right now, a big chunk of Antarctic ice is hanging on by a frozen thread. British researchers monitoring the crack in the Larsen C ice shelf say that only about 12 miles now connect the chunk of ice to the rest of the continent.

“After a few months of steady, incremental advance since the last event, the rift grew suddenly by a further 18 km [11 miles] during the second half of December 2016,” wrote Adrian Luckman in a statement Thursday by the MIDAS Project, which is monitoring changes in the area.

The crack in question has been growing for years and is now a total of roughly 70 miles long. When the fissure reaches the far side of the shelf, an iceberg the size of Delaware will float off, leaving the Larsen C 10 percent smaller.

A NASA scientist  (John Sonntag) with project IceBridge took this photo of the crack in November.

“This event will fundamentally change the landscape of the Antarctic Peninsula,” Luckman wrote. Ice shelves are important because they provide a buffer between the sea and the ice that sits on land, in this case on the Antarctic Peninsula. Without a healthy ice shelf, water from melting glaciers can flow straight to the sea, raising the sea level.

It’s normal for the front of an ice shelf to crack and break off, known as calving. But it’s unusual for that to happen faster than the ice shelf can refreeze.

Some scientists worry that the missing piece will destabilize the whole ice shelf. A smaller ice shelf, Larsen B, completely splintered in a little over a month in 2002, a process that started with a similar crack. Another ice shelf, Larsen A, had disintegrated a few years before.

“Larsen C may eventually follow the example of its neighbour Larsen B,” wrote Luckman. Larsen C is Antarctica’s fourth-largest ice shelf.

Crack at Larsen C Ice Sheet

“If it doesn’t go in the next few months, I’ll be amazed,” he told BBC News.

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Nearly all coral reefs will be ruined by climate change

From an Article by Katie Herzog, The Grist, January 6, 2017

According to a study in the journal Nature Scientific Reports, 99 percent of the world’s reefs will be affected by coral bleaching by the end of this century if climate change continues apace.

When water is above ideal temperatures, coral expels the symbiotic algae that reside in its tissue and provide it with nutrients. This turns the reefs a ghostly white, and while the coral is not exactly dead at that point, it is more susceptible to disease — and death. A bleaching event on Australia’s Great Barrier Reef last year, for instance, left 67 percent of its shallow-water coral dead.

This isn’t just bad for the reefs themselves; it’s bad for the vast, biodiverse ecosystems that depend on them. That includes the humans who fish these reefs and who cater to reef-loving tourists. The National Marine Fisheries Service estimates that the commercial value of fisheries near coral reefs is over $100 million in the U.S. alone, and reef-related tourism generates billions of dollars a year.

Even if aggressive actions are taken to combat climate change, such as those pledged during the Paris climate talks, it could be too late to prevent mass bleaching events at many reefs, according to the study. Divers, you might want to book those trips sooner rather than later.