{"id":22574,"date":"2026-03-06T04:05:23","date_gmt":"2026-03-06T04:05:23","guid":{"rendered":"https:\/\/readtrends.com\/en\/antarctica-ice-loss-los-angeles\/"},"modified":"2026-03-06T04:05:23","modified_gmt":"2026-03-06T04:05:23","slug":"antarctica-ice-loss-los-angeles","status":"publish","type":"post","link":"https:\/\/readtrends.com\/en\/antarctica-ice-loss-los-angeles\/","title":{"rendered":"Antarctica lost ice equal to 10\u00d7 the area of Los Angeles in 30 years, scientists say"},"content":{"rendered":"
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Lead:<\/strong> New research mapping Antarctica\u2019s grounding line finds the continent lost nearly 5,000 square miles of grounded ice since 1996\u2014an area equivalent to about ten times the City of Los Angeles. The study, published in the Proceedings of the National Academy of Sciences, used three decades of satellite imagery to quantify where ice sheets have retreated and where they remain stable. While roughly 77% of Antarctica\u2019s coastline shows no grounding-line migration, about 23% of ocean-reaching glaciers are in rapid retreat, concentrated in West Antarctica, the Antarctic Peninsula and select sectors of East Antarctica. Researchers warn that sustained loss in vulnerable regions is driving measurable contributions to global sea level rise.<\/p>\n

Key Takeaways<\/h2>\n
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  • Nearly 5,000 square miles of grounded Antarctic ice have been lost since 1996, based on 30 years of satellite mapping.<\/li>\n
  • About 77% of Antarctica\u2019s coastline shows no grounding-line migration; 23% of ocean-facing glaciers are retreating rapidly.<\/li>\n
  • Vulnerable regions are retreating from the grounding line at a rate exceeding 170 square miles per year in recent periods.<\/li>\n
  • Most dramatic retreats occurred in the Amundsen Sea and Getz sectors of West Antarctica; some glaciers have pulled back up to 25 miles.<\/li>\n
  • Pine Island Glacier retreated over 20 miles, Thwaites Glacier more than 16 miles, and Smith Glacier about 26 miles since 1996.<\/li>\n
  • Thwaites Glacier already contributes roughly 4% of observed global sea level rise; a full collapse of the West Antarctic Ice Sheet could add up to 9 feet.<\/li>\n
  • The intrusion of warm ocean water beneath ice explains much of the West Antarctic retreat; the cause of rapid migration along the Antarctic Peninsula remains unclear.<\/li>\n<\/ul>\n

    Background<\/h2>\n

    For decades glaciologists have tracked the position of Antarctica\u2019s grounding line\u2014the boundary where ice detaches from bedrock and begins to float\u2014because its migration is a primary indicator of ice-sheet stability. Previous regional studies flagged West Antarctica, notably the Amundsen Sea sector, as highly vulnerable to ocean-driven melt; this new work provides a comprehensive, continent-wide grounding-line time series over 30 years. The grounding line is described as a “gold standard” for documenting where ice sheets have lost contact with bedrock and become afloat, a shift that can accelerate mass loss. The combination of long-term satellite observations and consistent mapping methods allows researchers to distinguish stable coastlines from rapidly changing sectors with greater confidence than earlier snapshots.<\/p>\n

    Stakeholders span climate scientists, coastal planners, and governments preparing for sea level impacts. West Antarctica has been a focal point because its marine-based basins sit below sea level and are susceptible to warm, deep ocean currents that undercut ice shelves. The Antarctic Peninsula, by contrast, sits farther north and has different bathymetry and atmospheric exposure, making some of its grounding-line changes harder to attribute to the same ocean mechanisms. Understanding these spatial differences is central to projecting future mass loss and the timing of related sea level rise.<\/p>\n

    Main Event<\/h2>\n

    The study applied three decades of satellite imagery to produce the first long-duration map of grounding-line migration across the entire Antarctic coastline. Researchers quantified nearly 5,000 square miles of grounded ice loss since 1996 and identified fast-retreating sectors concentrated in West Antarctica, the Antarctic Peninsula and parts of East Antarctica. Mapping shows no grounding-line movement for 77% of the coastline, while the most vulnerable regions are losing grounded ice at rates exceeding 170 square miles per year during recent intervals.<\/p>\n

    In West Antarctica, the Amundsen Sea and the Getz sector registered the most dramatic changes, with several glaciers retreating up to about 25 miles from their grounding lines. Pine Island Glacier has retreated more than 20 miles and is noted as Antarctica\u2019s fastest-melting glacier; Thwaites Glacier has retreated over 16 miles and already contributes about 4% of observed global sea level rise. Smith Glacier also exhibited large retreat, roughly 26 miles, underscoring the scale of landscape change in some basins.<\/p>\n

    Authors link most of the West Antarctic retreat to intrusions of relatively warm ocean water that reach glacier fronts and melt floating ice from below, thinning ice shelves and destabilizing grounding lines. By contrast, grounding-line migration along parts of the Antarctic Peninsula shows significant change without clear evidence of warm-water intrusion in available datasets, leaving open alternative explanations such as atmospheric warming, changes in local circulation, or bedrock geometry. The paper emphasizes that the new multi-decade grounding-line record improves detection of where and how fast Antarctic sectors are changing.<\/p>\n

    Analysis & Implications<\/h2>\n

    The continent-wide grounding-line time series sharpens our ability to separate stable and unstable sectors, which matters for sea level projections. If the observed patterns in West Antarctica\u2014driven largely by ocean warming\u2014continue, dynamic discharge from marine-based basins could accelerate, raising contributions to global mean sea level beyond current central estimates. The fact that roughly three-quarters of the coastline remain stable reduces near-term worst-case exposure, but it does not preclude future destabilization if subsurface ocean conditions or ice dynamics evolve.<\/p>\n

    Thwaites Glacier’s ongoing retreat is particularly concerning because it buttresses neighboring ice; continued thinning and grounding-line retreat there can increase ice flux from upstream basins. Researchers note that a complete collapse of the West Antarctic Ice Sheet would raise global sea levels by as much as about 9 feet\u2014an outcome with profound implications for coastal communities worldwide. Current contributions from these glaciers are measurable: Thwaites is responsible for approximately 4% of observed sea level rise today, meaning present-day dynamics already affect coastlines.<\/p>\n

    Uncertainties remain that affect projections: the timing and magnitude of possible basin-wide collapses depend on subsurface ocean temperature evolution, feedbacks between ice thinning and grounding-line retreat, and bedrock topography beneath grounded ice. The Antarctic Peninsula\u2019s large grounding-line migrations without clear warm-water signals indicate that multiple processes\u2014atmospheric warming, surface melt, or local oceanographic shifts\u2014may also be important in some regions. Policymakers should treat the new grounding-line record as evidence that targeted observations and model improvements are essential to narrow remaining uncertainties.<\/p>\n

    Comparison & Data<\/h2>\n
    \n\n\n\n\n\n\n\n\n\n\n\n
    Metric<\/th>\nValue<\/th>\n<\/tr>\n<\/thead>\n
    Grounded ice lost since 1996<\/td>\n~5,000 sq miles<\/td>\n<\/tr>\n
    Coastline with no grounding-line migration<\/td>\n77%<\/td>\n<\/tr>\n
    Ocean-reaching glaciers in rapid retreat<\/td>\n23%<\/td>\n<\/tr>\n
    Retreat rate in vulnerable regions (recent)<\/td>\n>170 sq miles per year<\/td>\n<\/tr>\n
    Notable glacier retreats<\/td>\nPine Island >20 mi; Thwaites >16 mi; Smith ~26 mi<\/td>\n<\/tr>\n
    Thwaites contribution to sea level rise<\/td>\n~4%<\/td>\n<\/tr>\n
    Potential West Antarctic collapse impact<\/td>\nUp to ~9 ft global sea level<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n

    The table summarizes core metrics from the study to place the continent-wide mapping into context. Comparing a roughly 5,000-square-mile grounded-ice loss to local analogies\u2014about ten times the area of Los Angeles\u2014helps convey scale to non-specialists. The spatial pattern\u2014most loss focused in a minority of sectors\u2014means that basin-specific processes, not uniform continental warming, dominate current change. That spatial heterogeneity is why both regional field campaigns and continued satellite monitoring are needed to refine model projections of future mass loss.<\/p>\n

    Reactions & Quotes<\/h2>\n

    Lead author Eric Rignot highlighted the mapping advance and the role of ocean forcing in West Antarctica, framing the results in terms of observed patterns and unanswered questions.<\/p>\n

    \n

    “Where warm ocean water is pushed by winds to reach glaciers, that\u2019s where we see the big wounds in Antarctica.”<\/p>\n

    Eric Rignot, UC Irvine<\/cite><\/p><\/blockquote>\n

    Rignot emphasized the mixed nature of the continent’s response\u2014some sectors remain stable while others are rapidly changing\u2014underscoring both relief and risk.<\/p>\n

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    “The flip side is that we should perhaps feel fortunate that all of Antarctica isn\u2019t reacting right now, because we would be in far more trouble.”<\/p>\n

    Eric Rignot, UC Irvine<\/cite><\/p><\/blockquote>\n

    On unresolved mechanisms, Rignot noted that not all rapid migrations have a clear warm-ocean fingerprint, leaving active research questions for the community.<\/p>\n

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    “Something else is acting — it\u2019s still a question mark.”<\/p>\n

    Eric Rignot, UC Irvine<\/cite><\/p><\/blockquote>\n

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