最新研究显示,被称为“末日冰川”的南极西部思韦茨冰川(Thwaites Glacier)未来可能导致的海平面上升幅度远超此前预期。研究人员发现,当前用于预测冰川融化速度的主流模型可能低估了冰川退缩过程中的关键机制,这意味着全球沿海地区未来面临的海平面上升威胁可能比科学界此前估计的更加严重。
思韦茨冰川位于南极西部,是地球上最不稳定的冰川之一,面积约相当于英国本土大小。由于其对周边冰盖系统具有重要支撑作用,一旦出现大规模崩塌,不仅会直接提高全球海平面,还可能引发邻近冰体连锁失稳,因此长期被科学界称为“末日冰川”。
研究团队利用新的计算模型和冰川动力学分析方法,对思韦茨冰川未来变化进行了更精细的模拟。结果显示,在某些气候变暖情景下,该冰川后退速度可能远快于此前预测,而由此造成的海平面上升贡献甚至可能达到现有评估结果的两倍左右。
研究人员指出,传统模型在模拟冰川与海水相互作用时,往往未能充分反映冰川底部复杂的融化过程。当较暖的海水持续侵蚀冰川底部时,冰川与海床之间的接触区域会发生变化,导致冰川失去支撑并加速向海洋滑动。新研究认为,这种反馈机制可能比过去认识得更强烈。
目前,思韦茨冰川本身若完全融化,足以使全球海平面上升约65厘米。然而更令科学家担忧的是,它还像一个天然“塞子”,部分阻挡着南极西部大规模冰盖流向海洋。如果这一冰川全面失稳,可能进一步带动整个西南极冰盖加速崩解,从而引发更大规模的海平面上升。
研究团队强调,这并不意味着相关变化将在短时间内发生。冰川系统的演变往往跨越数十年至数百年时间尺度,但当前排放路径和全球气温变化将深刻影响未来的发展方向。即便如此,今天产生的气候影响可能决定未来几代人所面对的海岸线形态。
科学家表示,沿海城市、港口基础设施以及低洼岛国未来面临的规划挑战将进一步增加。更高的海平面不仅意味着海岸侵蚀和洪水风险上升,也会增强风暴潮造成的破坏能力,对数亿沿海居民构成长期影响。
研究人员认为,此次发现再次突显了持续监测南极冰盖的重要性。随着观测技术和模拟能力不断提升,科学界正在逐步揭示极地冰川对全球气候系统的真实敏感程度。而思韦茨冰川的未来命运,也将成为决定未来海平面变化幅度的关键因素之一。
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Recent studies have shown that the Thwaites Glacier in western Antarctica, known as the “end-of-life glacier”, could lead to a much higher-than-anticipated rise in sea level in the future. Researchers have found that the current mainstream models used to predict the rate of melting of glaciers may underestimate the key mechanisms in the glacial retreat process, which means that the threat of sea-level rise to the future of global coastal areas may be more serious than previously estimated by the scientific community.
The Swazi glacier, located in the western Antarctic, is one of the most unstable glaciers on Earth, approximately the size of the British mainland. Because of its important support to the surrounding ice sheet system, a large-scale collapse would not only directly raise the global sea level, but could also cause a destabilizing chain of adjacent ice bodies, which has long been referred to by the scientific community as the “end-of-life glacier”.
Using new computational models and glacial power analysis methods, the research team carried out more sophisticated simulations of future changes in the Swets glacier. The results suggest that, in some warming scenarios, the glacier may be retreating at a much faster rate than previously predicted, and the resulting contribution to sea-level rise may even be about twice as high as the results of existing assessments.
Researchers note that traditional models often do not adequately reflect the complex process of melting the bottom of glaciers when simulating the interaction of glaciers with seawater. As warmer seawater continues to erode the base of glaciers, areas of contact between glaciers and the seabed change, leading to glaciers losing their support and accelerating their slide to the sea. According to the new study, such feedback mechanisms may be stronger than in the past.
At present, the Swazi glacier itself, if fully melted, is sufficient to rise the global sea level by about 65 centimetres. However, scientists are even more concerned that it is like a natural “plug” that partially prevents large-scale ice caps in the western Antarctic from flowing to the sea. If this glacier is completely unstable, it could further accelerate the collapse of the entire western Antarctic ice sheet, which could trigger a larger sea level rise.
The team emphasized that this did not mean that the changes would occur in a short time. The evolution of glacier systems often spans dozens to hundreds of time scales, but current emission pathways and changes in global temperature will profoundly influence future directions. Even so, today ' s climate impacts may determine the coastline patterns facing future generations.
Scientists indicated that future planning challenges for coastal cities, port infrastructure and low-lying island countries would increase. Higher sea levels not only mean an increased risk of coastal erosion and flooding, but also increase the capacity for damage caused by storm surges, with long-term impacts on hundreds of millions of coastal residents.
Researchers believe that this discovery once again highlights the importance of continuous monitoring of the Antarctic ice sheet. As observation techniques and simulation capabilities continue to improve, the scientific community is gradually revealing the true sensitivity of polar glaciers to the global climate system. The future fate of the Swazi glacier will also be one of the key factors determining the extent of future sea-level change.
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