Category: Antarctica

What’s the tipping point for Antarctica’s ice sheets?

New study suggests rapid meltdown during post-ice age warming

How long will it take for Antarctica’s ice sheets to melt? @bberwyn photo.

Staff Report

After taking a close look at rocks from West Antarctica’s dramatic Ellsworth Mountains, climate researchers say there’s a chance that ice sheets in the region could melt quickly as the planet warms, potentially causing sea level to rise by  six to eight feet.

The new study, published in Nature Communications, took a close look at Antarctic climate change about 21,000 years ago during a period of warming after the coldest point of the most recent Ice Age. They found that  the West Antarctic Ice Sheet reached a tipping point, after which it thinned relatively quickly, losing 400m of thickness in 3,000 years. Continue reading “What’s the tipping point for Antarctica’s ice sheets?”

Eruption poses threat to huge penguin colony

chinstrap penguin
A chinstrap penguin on Deception Island. @bberwyn photo.

British Antarctic Survey scientists to monitor impacts of ash deposits

Staff Report

A volcanic eruption in the remote South Sandwich archipelago, near the tip of the Antarctic Peninsula, may threaten the largest known colony of chinstrap penguins, according to scientists with the British Antarctic Survey who have been monitoring the eruption.

The Mt. Curry volcano on Zavodovski Island has been erupting since March, sending ash toward the penguin enclave. The uninhabited island is part of the British Overseas Territory of South Georgia and the South Sandwich Islands. After reports of a 7.2 magnitude earthquake last month, researchers confirmed from satellite imagery that not one, but two volcanoes are erupting in the South Sandwich Islands — Mt. Curry on Zavodovski Island to the north of the archipelago and Mt. Sourabaya on Bristol Island to the south. Continue reading “Eruption poses threat to huge penguin colony”

Warming oceans to aid spread of invasive species in Antarctica

Kelp rafts seen pathways for non-native worms, snails

For now, humans are the main invasive species in Antarctica, but that could change as the surrounding ocean warms. @bberwyn photo.

Staff Report

Parts of Antarctica could soon face an invasion by exotic species floating southward on kelp rafts, Australian researchers found in a new study published in the journal Ecography.

While the Antarctic circumpolar current has long formed a barrier to invasive species, the research found that the kelp rafts often cross that Antarctic Polar Front, carrying with them crustaceans, worms, snails and other seaweeds across hundreds of kilometres of open ocean. Continue reading “Warming oceans to aid spread of invasive species in Antarctica”

Crumbling Antarctic ice sheets could speed sea level rise

Fifty feet in 500 years?

Mountains of the Antarctic Sound.
New climate modeling suggests more significant melting of the Antarctic ice sheets and ice shelves driven by atmospheric warming. @bberwyn photo.

Staff Report

The edges of Antarctic ice sheets may crumble and collapse much faster than most existing climate models suggest, potentially raising global sea level by as much as 50 feet in the next 500 years, according to researchers from Penn State and University of Massachusetts, Amherst.

The scientists added new, previously underestimated processes to their projection after studying the role of Antarctic ice melting during the warm Pliocene era, about 3 million years ago when sea level rose by as much as 30 to 60 feet. Continue reading “Crumbling Antarctic ice sheets could speed sea level rise”

Climate: New study shows how warm ocean currents affect Antarctic ice shelves

Erosion from beneath could lead to more sea-level rise

If floating Antarctic ice sheets disintegrate, land-based glaciers and ice sheets will flow much faster to the sea, speeding sea level rise. @bberwyn photo.

Staff Report

Oceans warming under a thickening blanket of greenhouse gases are licking at the edge of Antarctica and carving new channels in the bottom of ice shelves all around the frozen continent, researchers said this week in a new study led by scientists with the National Snow and Ice Data Center.

Those channels, characterized as “upside-down rivers” by the scientists, may make the ice shelves more prone to collapsing, which could speed up the flow of ice and the increase the rate of sea-level rise. Overall, some Antarctic ice sheets have thinned by about 18 percent and the rate of melting is accelerating, other research shows.

The findings, published in Nature Geoscience, are based on detailed photography and laser measurements showing that the basal channels also leave traces on the surface of the ice sheets. Continue reading “Climate: New study shows how warm ocean currents affect Antarctic ice shelves”

Study suggests Antarctic ice sheets could crumble rapidly in response to global warming

‘Once you pull the stopper out of the bottle, the glaciers move much faster …’

A new study suggests some Antarctic ice sheets could vanish quickly as global temperatures increase. @bberwyn photo.

Staff Report

An Antarctic ice sheet about the size of Colorado disintegrated suddenly and quickly at the end of the last global ice age, scientists concluded in a new study, showing what might happen in other parts of the cryosphere as Earth’s atmosphere continues to warm.

Analyzing detailed data from a 2015 research expedition, U.S. and Japanese oceanographers  showed that a 100,000-square-mile section of the Ross Ice Shelf broke apart within 1,500 years during a warming period after the last ice age.

The Ross Ice Shelf is the world’s largest ice shelf, a vast floating extension of the West Antarctic Ice Sheet that is about the size of France. But at the end of the last ice age, it extended much farther north and covered the entire Ross Sea. Continue reading “Study suggests Antarctic ice sheets could crumble rapidly in response to global warming”

Climate study says West Antarctic Ice Sheet could melt quickly

The ice fields of Antarctica
How quickly will the West Antarctic Ice Sheet melt away under global warming? @bberwyn photo.

‘All signs suggest the ice from West Antarctica could disappear relatively quickly …’

Staff Report

An in-depth survey of Antarctica’s rugged Ellsworth Mountains suggests that the West Antarctic Ice Sheet could melt quickly under the influence of global warming, potentially raising global sea level by three meters.

“It is possible that the ice sheet has passed the point of no return and, if so, the big question is how much will go and how much will sea levels rise,” said Professor John Woodward, of the University of Northumbria. Continue reading “Climate study says West Antarctic Ice Sheet could melt quickly”