Eideard

A yellow submarine has helped to solve a puzzle about one of Antarctica’s fastest-melting glaciers, adding to concerns about how climate change may push up world sea levels.

The robot submarine, deployed under the ice shelf floating on the sea at the end of the Pine Island Glacier, found that the ice was no longer resting on a subsea ridge that had slowed the glacier’s slide until the early 1970s.

Antarctica is key to predicting the rise in sea levels caused by global warming — it has enough ice to raise sea levels by 57 meters (187 ft) if it ever all melted. Even a tiny thaw at the fringes could swamp coasts from Bangladesh to Florida…

West Antarctica’s thaw accounts for 10 percent of a recently observed rise in sea levels, with melting of the Pine Island glacier quickening, especially in recent decades, according to the study led by the British Antarctic Survey (BAS) and published in the journal Nature Geoscience.

Loss of contact with the subsea ridge meant that ice was flowing faster and also thawing more as sea water flowed into an ever bigger cavity that now extended 30 km beyond the ridge. The water was just above freezing at 1 degree Celsius…

Adrian Jenkins, lead author at BAS, said the study raised “new questions about whether the current loss of ice from Pine Island Glacier is caused by recent climate change or is a continuation of a longer-term process that began when the glacier disconnected from the ridge.”

Research that provides more data, better directed conclusions is always welcome. Welcomed, that is, by scientists and those who would make decisions about life and politics based on scientific understanding.

Humpback whale checking out the humans in the neighborhood
Daylife/Reuters Pictures used by permission

Scientists are surprised at how extensively coastal ice in Antarctica and Greenland is thinning, according to a study that could help predict rising sea levels linked to climate change.

Analysis of millions of NASA satellite laser images showed the biggest loss of ice was caused by glaciers speeding up when they flowed into the sea, according to scientists at the British Antarctic Survey (BAS) and Bristol University.

“We were surprised to see such a strong pattern of thinning glaciers across such large areas of coastline — it’s widespread and in some cases thinning extends hundreds of kilometers inland,” said Hamish Pritchard of BAS who led the study…

Among findings, Wednesday’s study said 81 of 111 fast-moving glaciers in Greenland were thinning at twice the rate of slow-flowing ice at the same altitude.

“Dynamic thinning of Greenland and Antarctic ice-sheet margins is more sensitive, pervasive, enduring and important than previously realized,” they wrote. “Dynamic thinning” means loss of ice due to a faster flow.

There are a number of variables in the dynamism – all happening faster than anyone expected.