In permafrost areas, the active layer undergoes seasonal frost heave and thaw subsidence caused by ice formation and melting. The amplitude and timing of the ground displacement cycles depend on the climatic and ground conditions. Here we used Sentinel-1 Synthetic Aperture Radar Interferometry (InSAR) to document the seasonal displacement progression in three regions of Svalbard. We retrieved June–November 2017 time series and identified thaw subsidence maxima and their timing. InSAR measurements were compared with a composite index model based on ground surface temperature. Cyclic seasonal patterns are identified in all areas, but the timing of the displacement progression varies. The subsidence maxima occurred later on the warm western coast (Kapp Linné and Ny-Ålesund) compared to the colder interior (Adventdalen). The composite index model is generally able to explain the observed patterns. In Adventdalen, the model matches the InSAR time series at the location of the borehole. In Kapp Linné and Ny-Ålesund, larger deviations are found at the pixel-scale, but km or regional averaging improves the fit. The study highlights the potential for further development of regional InSAR products to represent the cyclic displacements in permafrost areas and infer the active layer thermal dynamics.

中文翻译：

---

季节性 InSAR 位移记录了斯瓦尔巴群岛中西部斯匹次卑尔根的活动层冻融进程

在多年冻土区，活动层会因冰的形成和融化而经历季节性冻胀和解冻沉降。地面位移周期的幅度和时间取决于气候和地面条件。在这里，我们使用 Sentinel-1 合成孔径雷达干涉测量法 (InSAR) 来记录斯瓦尔巴群岛三个地区的季节性位移进展。我们检索了 2017 年 6 月至 11 月的时间序列，并确定了解冻沉降最大值及其时间。InSAR 测量结果与基于地表温度的复合指数模型进行了比较。在所有地区都确定了周期性的季节性模式，但位移进展的时间各不相同。与较冷的内陆（Adventdalen）相比，下沉最大值出现在温暖的西海岸（Kapp Linné 和 Ny-Ålesund）较晚。综合指数模型通常能够解释观察到的模式。在 Adventdalen 中，模型匹配钻孔位置处的 InSAR 时间序列。在 Kapp Linné 和 Ny-Ålesund，在像素尺度上发现了更大的偏差，但公里或区域平均改善了拟合。该研究强调了进一步开发区域 InSAR 产品以表示永久冻土地区的循环位移和推断活动层热动力学的潜力。