Sea levels could be rising faster than predicted due to new source of Antarctic ice melting

Sea levels could be rising faster than predicted due to new source of Antarctic ice melting

SOURCE: The Independent and Science Daily DATE: April 18, 2018 SNIP: Sea level rise could be happening at a faster rate than previously thought, as scientists have identified a new source of melting ice in Antarctica. Melting glaciers can create a positive feedback loop in which the more they melt, the more they drive further melting, according to the Australian team. They predict that the processes they identified could be playing a role in accelerating both sea level rise and climate change. As glaciers melt, they produce fresh water. When this meltwater enters the ocean surrounding the glacier it makes the surface layer less salty and therefore more buoyant. This leads to a layer of water floating on the surface, and prevents the natural mixing of the ocean. The lack of mixing becomes a problem during winter, as it prevents warm water at greater depths from mixing with cooler water above. With a pool of warm water underneath them, the melting of the bottom side of the glaciers...
Underwater melting of Antarctic ice far greater than thought, study finds

Underwater melting of Antarctic ice far greater than thought, study finds

SOURCE: The Guardian DATE: April 2, 2018 SNIP: Hidden underwater melt-off in the Antarctic is doubling every 20 years and could soon overtake Greenland to become the biggest source of sea-level rise, according to the first complete underwater map of the world’s largest body of ice. Warming waters have caused the base of ice near the ocean floor around the south pole to shrink by 1,463 square kilometres – an area the size of Greater London – between 2010 and 2016. The research by the UK Centre for Polar Observation and Modelling at the University of Leeds suggests climate change is affecting the Antarctic more than previously believed and is likely to prompt global projections of sea-level rise to be revised upward. “What’s happening is that Antarctica is being melted away at its base. We can’t see it, because it’s happening below the sea surface,” said Professor Andrew Shepherd, one of the authors of the paper. “The changes mean that very soon the sea-level contribution from Antarctica could outstrip that from...
The world’s largest High Arctic lake responds rapidly to climate warming

The world’s largest High Arctic lake responds rapidly to climate warming

SOURCE: Nature Communications DATE: March 29, 2018 SNIP: In this study, we investigate how a warming climate has impacted the Lake Hazen watershed from its glacier headwaters, all the way through to the Arctic Char at the top of the aquatic foodweb, using a combination of historical, contemporary, modeled and paleoliminological datasets. We hypothesized that, due to its large size and thermal inertia, Lake Hazen would be more resilient to Arctic warming than smaller aquatic ecosystems, a number of which have already undergone significant regime shifts. However, we demonstrate that the Lake Hazen watershed was not resilient to even an ~1 °C relative increase in recent summer air temperatures. Accelerated melt in the cryosphere resulted in an ~10 times increase in delivery of glacial meltwaters, sediment, organic carbon and legacy contaminants to Lake Hazen and a reduction in summer lake ice cover. Changes to the physical and chemical components of the watershed caused an ecological reorganization of the algal (diatom) community assemblage and a decline in the physiological condition of Arctic...
Sea level fears as more of giant Antarctic glacier floating than thought

Sea level fears as more of giant Antarctic glacier floating than thought

SOURCE: Agence France Presse DATE: March 20, 2018 SNIP: More of a giant France-sized glacier in Antarctica is floating on the ocean than previously thought, scientists said Tuesday, raising fears it could melt faster as the climate warms and have a dramatic impact on rising sea-levels. The Totten Glacier is one of the fastest-flowing and largest glaciers in Antarctica with scientists keen to keep a close eye on how it melts given the enormous amount of water it could potentially unleash. Using artificially created seismic waves that help scientists see through the ice, researchers have discovered that more of the Totten Glacier floats on the ocean than initially thought. The findings are important because recent studies have shown the Totten Glacier’s underbelly is already being eroded by warm, salty sea water flowing hundreds of kilometres inland after passing through underwater “gateways”. As it does, the portion of the glacier resting on water rather than rock increases, accelerating the pace of...
Melting Glaciers Do More Than Raise Sea Levels

Melting Glaciers Do More Than Raise Sea Levels

SOURCE: Hakai Magazine DATE: March 9, 2018 SNIP: Novels and blockbuster movies that tackle climate change gravitate toward the dramatic, especially when it comes to melting ice. In these stories, mountainous glaciers crumble and cities flood as the sea rises. But a lot more happens in between the mountains and the sea, as meltwater passes through the liminal space of the coast. Here are five ways the slow, non-dramatic drip of melting ice changes our coastlines and oceans. Released Toxins Re-emerged Diseases Smothered Sea Life Flooded Rivers Changing Coastlines Read for more details:...