Abstract InSAR time series of surface deformation from 16 yr of Envisat (2003-2011) and Sentinel-1 (2014-2019) ESA satellite radar measurements have been constructed to characterise spatial and temporal dynamics of ground deformation over an 80,000 km2 area in the permafrost of the northeastern Tibetan Plateau. The regional deformation maps encompass various types of periglacial landforms and show that seasonal thaw effects are controlled by the sediment type and local topography. High seasonal ground movements are concentrated on shallow slopes and poor-drainage areas in unconsolidated, frost-susceptible and fine-grained sediments within glacier outwash plains, braided stream plains, alluvial deposits or floodplains. Fast subsidence due to thaw settlement takes place during June/July while frost heave is intense during December/January when two-sided freezing of pore water under pressure causes prolonged ice segregation near the permafrost table. The analysis reveals pervasive subsidence of the ground of up to ∼2 cm/yr, and increasing by a factor of 2 to 5 from 2003 to today, in high-relief and well-drained areas. The findings suggest that seasonal thaw increasingly affects ice-rich layers at the permafrost table, as well as high-rates of widespread mass movements of non-consolidated sediments, the latter amplified by an increase of effects from frost heave/thaw settlement.

中文翻译：

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欧空局 16 年搜救任务所见青藏高原东北部多年冻土的冰层流失

摘要 构建了 Envisat 16 年（2003-2011）和 Sentinel-1（2014-2019）ESA 卫星雷达测量的 InSAR 地表变形时间序列，以表征永久冻土区 80,000 平方公里区域地面变形的时空动态。青藏高原东北部。区域变形图包括各种类型的冰缘地貌，并表明季节性融化效应受沉积物类型和当地地形的控制。高季节性地面运动集中在冰川外冲平原、辫状河平原、冲积沉积物或洪泛平原内松散、易受霜冻和细粒沉积物的浅坡和排水不良地区。6 月/ 7 月发生解冻沉降导致的快速沉降，而 12 月/ 1 月期间冻胀剧烈，压力作用下孔隙水的两侧冻结导致永久冻土台附近的冰分离时间延长。分析表明，在高地势和排水良好的地区，地面普遍下沉高达约 2 厘米/年，从 2003 年到现在增加了 2 到 5 倍。研究结果表明，季节性融化越来越多地影响永久冻土台上的富冰层，以及非固结沉积物的广泛大规模运动，后者因冻胀/融化沉降的影响增加而放大。从 2003 年到今天，在高地势和排水良好的地区增加了 2 到 5 倍。研究结果表明，季节性融化越来越多地影响永久冻土台上的富冰层，以及非固结沉积物的广泛大规模运动，后者因冻胀/融化沉降的影响增加而放大。从 2003 年到今天，在高地势和排水良好的地区增加了 2 到 5 倍。研究结果表明，季节性融化越来越多地影响永久冻土台上的富冰层，以及非固结沉积物的广泛大规模运动，后者因冻胀/融化沉降的影响增加而放大。