All articles tagged with #ice shelves
A new study shows circumpolar deep water heat is migrating toward Antarctica, melting ice shelves from below and potentially accelerating global sea-level rise. By combining decades of ship data with Argo floats, researchers built a 40-year record of warming that also suggests deeper changes in ocean circulation, which could affect currents like the AMOC and have broad climate impacts.
A high‑resolution survey around Antarctica identified 332 submarine canyons, some deeper than 4,000 meters, with distinct eastern and western morphologies that challenge prior climate assumptions. These canyons regulate exchanges between the continental shelf and the deep Southern Ocean, channeling warm water toward ice shelves to accelerate melting while exporting freshwater that influences global ocean circulation. The dataset enables more realistic seafloor topography in climate models, though direct flow measurements are still limited and further mooring/observational campaigns are planned.
Antarctica’s ice shelves are melting from below as warming ocean water erodes their bases, a process that could accelerate inland ice loss and raise sea levels by metres. Nine-model synthesis estimates basal melting at about 843 billion tonnes per year, but data gaps leave large uncertainties about rate and regional impact, including potential effects on major ocean currents—emissions choices will largely determine future sea level rise.
Scientists warn that rapid and extreme changes in Antarctica, including collapsing ice shelves and record-low sea ice, are occurring faster than expected, posing serious risks such as accelerated global heating, sea level rise potentially over ten meters, and ecosystem threats, emphasizing the urgent need for global action and better predictive models.
Researchers drilling into the Ronne ice shelf in Antarctica discovered that strong tides significantly accelerate melting by causing friction and warming beneath the ice, which weakens the shelf's ability to hold back land ice, contributing to rising sea levels and ecological impacts. The study highlights the urgent need for reducing pollution and exploring intervention strategies to preserve ice shelves and mitigate climate change effects.
Scientists used 1966 Navy aerial photos combined with modern satellite data to study the collapse of Antarctica's Wordie Ice Shelf, revealing that ocean water melting from below, rather than surface melt, primarily drives ice shelf disintegration, which has implications for future sea level rise predictions.
Scientists have discovered an unexpected upside-down landscape beneath Antarctica's Dotson Ice Shelf, revealing peaks, valleys, and plateaus formed by meltwater. This discovery, made using an unmanned submersible, provides new insights into how ocean currents melt ice shelves and the potential impact on global sea levels. The findings highlight the rapid melting of the West Antarctic Ice Sheet, which could significantly raise sea levels, affecting coastal cities worldwide. The research also underscores the ecological changes in the Amundsen Sea, where increased meltwater is altering marine ecosystems.
A new study published in Nature Communications reveals that the interplay between meandering ocean currents and the ocean floor induces upwelling velocity, transporting warm water to shallower depths, contributing substantially to the melting of ice shelves in the Amundsen Sea of West Antarctica. The Pine Island and Thwaites ice shelves are among the fastest-changing in Antarctica and are of particular interest due to their vulnerability to warming ocean waters, posing a significant threat to coastal communities worldwide because of the resulting rise in global sea levels. The study challenges prior assumptions and underscores the significant role played by the interactions between meandering ocean currents and the ocean floor in driving the melting process, emphasizing the importance of the ocean in understanding and addressing the impacts of climate change.
Scientists have observed the fastest glacier fracture ever recorded, with a crack in Antarctica's Pine Island Glacier opening at roughly 80 mph. The finding suggests that giant ice masses can shatter like glass, providing insight into how climate change will impact ice sheets. The study, published in AGU Advances, combined satellite observations with seismic data to understand the rift's behavior. The Pine Island Glacier and its neighbor, the Thwaites Glacier, have been in retreat and melting rapidly, contributing to rising sea levels. If the Thwaites Glacier were to melt completely, it would raise sea levels by more than 2 feet, and the broader destabilization of the West Antarctic Ice Sheet could lead to a global sea level rise of approximately 11 feet.
Scientists from The University of Edinburgh have found that Antarctica's ice shelves are thinning at an accelerated rate, with the loss of pinning points indicating increased vulnerability to climate change. Rising temperatures and altered snowfall patterns are contributing to the melting, posing a significant threat to the stability of the ice shelves and potentially leading to rising sea levels. Urgent action to reduce global carbon emissions and support research is crucial in addressing this concerning trend.
Enormous city-sized holes on Antarctica's ice shelves may be linked to the formation of giant icebergs, offering a glimpse into the continent's melting process. A study focused on polynyas, large open ocean areas in the ice shelf, near the vulnerable Pine Island Glacier, using satellite data to track their changes over 22 years. The researchers found that polynyas are indicators of melting and may influence the structural integrity of the ice shelf, potentially contributing to calving. This research provides valuable insights into the complex dynamics of Antarctica's ice shelves and their response to climate change.
The melting of Antarctica's ice shelves is contributing to rising sea levels, with 68 ice shelves shrinking significantly between 1997 and 2021, resulting in the loss of about 8.3 trillion tons of ice. The melting is caused by a higher rate of icebergs breaking off, leading to faster ice flow and sea level rise. The West Antarctic ice sheet is particularly vulnerable, and if it reaches a point of no return, it could contribute to a significant rise in sea levels. Limiting global warming is crucial to mitigate the melting of Antarctica's ice and prevent further sea level rise.
Scientists have issued a warning about the alarming collapse of Greenland's ice shelves, with three out of eight already experiencing complete collapse and the remaining five in rapid retreat. The loss of these ice shelves could lead to a rise in sea levels by nearly 7 feet, with significant consequences. Rising ocean temperatures have caused the ice shelves to lose over a third of their volume since 1978, primarily due to warm water melting them from underneath. This trend of accelerated melting is not limited to Greenland but is occurring in icy regions worldwide, contributing to observed sea-level rise.
The last remaining ice shelves in Northern Greenland have lost a third of their volume in the past four decades, with three of them collapsing completely, according to a study published in Nature Communications. These ice shelves play a crucial role in regulating the flow of ice into the ocean from glaciers, which could ultimately raise sea levels by 2.1 meters (seven feet). With continued global warming, the ice shelves are at risk of further retreat and collapse, potentially leading to dramatic sea level rise. The melting of the ice shelves themselves does not contribute to sea level rise, but their collapse could cause glaciers to dump more ice into the oceans. The study highlights the urgent need to reduce greenhouse gas emissions to mitigate the impact of climate change on the polar regions and sea levels.
A new study published in Nature Communications reveals that ice shelves in North Greenland have lost over 35% of their volume since 1978 due to rising temperatures. Three of the shelves have completely collapsed, and the remaining five have experienced a widespread increase in mass loss, primarily due to warming ocean temperatures. This loss of ice shelf volume could have dramatic consequences for sea level rise, as the Greenland ice sheet is the second-largest contributor to it. The study highlights the strong oceanic control on ice shelves changes and warns that continued ocean thermal forcing could lead to unstable retreat and collapse of the remaining ice shelves, resulting in significant sea level rise.