Images taken by its Envisat remote-sensing satellite show that Wilkins Ice Shelf is “hanging by its last thread” to Charcot Island, one of the plate’s key anchors to the Antarctic peninsula, ESA said in a press release.
“Since the connection to the island... helps stabilise the ice shelf, it is likely the breakup of the bridge will put the remainder of the ice shelf at risk,” it said. Wilkins Ice Shelf had been stable for most of the last century, covering around 16,000 square kilometres, or about the size of Northern Ireland, before it began to retreat in the 1990s.
Since then several large areas have broken away, and two big breakoffs this year left only a narrow ice bridge about 2.7 kilometres wide to connect the shelf to Charcot and nearby Latady Island.
The latest images, taken by Envisat’s radar, say fractures have now opened up in this bridge and adjacent areas of the plate are disintegrating, creating large icebergs.
Scientists are puzzled and concerned by the event, ESA added. The Antarctic peninsula — the tongue of land that juts northward from the white continent towards South America — has had one of the highest rates of warming anywhere in the world in recent decades. But this latest stage of the breakup occurred during the Southern Hemisphere’s winter, when atmospheric temperatures are at their lowest.
One idea is that warmer water from the Southern Ocean is reaching the underside of the ice shelf and thinning it rapidly from underneath.
“Wilkins Ice Shelf is the most recent in a long, and growing, list of ice shelves on the Antarctic Peninsula that are responding to the rapid warming that has occurred in this area over the last fifty years,” researcher David Vaughan of the British Antarctic Survey (BAS) said. “Current events are showing that we were being too conservative, when we made the prediction in the early 1990s that Wilkins Ice Shelf would be lost within 30 years. The truth is, it is going more quickly than we guessed.” AFP
Study links global warming to higher levels of smog
US environmental regulators quietly published a draft study on Thursday that linked global warming to higher levels of smog that could harm human health, a report green groups said stood in contrast to the Bush administration’s slow movement on climate change. The draft report published by the Environmental Protection Agency in the Federal Register said, “Climate change has the potential to produce significant increases in near-surface (ozone) concentrations in many areas of the US.” It said parts of the Mid-Atlantic, Northeast and lower Midwest show some increases in ozone in study simulations, and the seasons in which ozone is a problem could last longer as a result of higher temperatures. REUTERS
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