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As one of the best indicators of the periglacial environment, ice-wedge polygons (IWPs) are important for arctic landscapes, hydrology, engineering, and ecosystems. Thus, a better understanding of the spatiotemporal dynamics and evolution of IWPs is key to evaluating the hydrothermal state and carbon budgets of the arctic permafrost environment. In this paper, the dynamics of ground surface deformation (GSD) in IWP zones (2018–2019) and their influencing factors over the last 20 years in Saskylakh, northwestern Yakutia, Russia were investigated using the Interferometric Synthetic Aperture Radar (InSAR) and Google Earth Engine (GEE). The results show an annual ground surface deformation rate (AGSDR) in Saskylakh at −49.73 to 45.97 mm/a during the period from 1 June 2018 to 3 May 2019. All the selected GSD regions indicate that the relationship between GSD and land surface temperature (LST) is positive (upheaving) for regions with larger AGSDR, and negative (subsidence) for regions with lower AGSDR. The most drastic deformation was observed at the Aeroport regions with GSDs rates of −37.06 mm/a at tower and 35.45 mm/a at runway. The GSDs are negatively correlated with the LST of most low-centered polygons (LCPs) and high-centered polygons (HCPs). Specifically, the higher the vegetation cover, the higher the LST and the thicker the active layer. An evident permafrost degradation has been observed in Saskylakh as reflected in higher ground temperatures, lusher vegetation, greater active layer thickness, and fluctuant numbers and areal extents of thermokarst lakes and ponds. [ABSTRACT FROM AUTHOR]

The ground surface deformation (GSD) caused by oil shale in-situ mining poses a threat to land resources and human's lives and property. This study, for the first time, conducts a full stratum simulation of the Fuyu oil shale in-situ pyrolysis pilot base, analyzing the evolution characteristics of the temperature field, stress field, and deformation field of the entire stratum profile during the heating and cooling processes of convective heating mining. Considering the changes in the pore structure, thermophysical, and mechanical properties of the stratum, the environmental geological effects of rock deformation during in-situ mining were identified. Simulation results show that after heating, the temperature within 80 cm of the heating well reaches above the initial pyrolysis temperature of 350 °C for oil shale organic matter, and there is a significant stress concentration near the heat source. In the simulation, ground displacement rises in a wave-like manner during heating, quickly subsides after cooling, and finally stabilizes. Eventually, the entire stratum exhibited subsidence, with a subsidence amount of 0.59 cm. The spatiotemporal deformation trend obtained from SBAS-InSAR real-time monitoring results is similar to the simulation results. By comparing the monitoring results with the simulation results, the synergistic deformation mechanism of underground and ground surface co-deformation during in-situ mining of geochemical reactions in the study area was analyzed. The deformation rate is determined by the thermal hysteresis phenomenon and the temperature difference between the heated fluid and the rock layer. This provides scientific support for the geological effect evaluation of oil shale in-situ mining, which helps to improve mining safety and efficiency. • First-time analysis of the entire heating and cooling process in convective mining • Simulating the whole strata change of an oil shale in-situ mining case • Analyzing deformation using microstructures and macro-physical mechanics properties • The first use of SBAS-InSAR for displacement monitoring in oil shale in-situ mining • Revealing the oil shale in-situ mining's subsurface and surface co-deformation law [ABSTRACT FROM AUTHOR]

• Multi-type data characterized the disturbance of the China–Russia Crude Oil Pipeline (CRCOP) on the permafrost environment. • Mapped the development of the talik around pipelines under the influence of multiple factors. • Permafrost thawing along the CRCOP caused topographic reshaping and the regular distribution of ponds. • Synergistic changes of underground permafrost and surface features. Engineering activities in permafrost regions have a major impact on the local permafrost environment. The construction and operation of the China-Russia Crude Oil Pipeline (CRCOP) have changed the surface conditions and the soil's thermal state. However, the response of the permafrost environment to CRCOP is less studied. This article carries out ground temperature monitoring, ground surface deformation (GSD) and pipeline deformation observations, electrical resistivity tomography (ERT) measurements, and unmanned aerial vehicle (UAV) surveys to study permafrost thawing, talik development, topographic change, and pond distribution. The results indicated that the oil temperature has increased yearly and the permafrost around the pipeline has degraded quickly. The artificial permafrost table has decreased at a rate of 0.68 m/a at a location 2 m away from the center of the pipeline, and reached −11.4 m deep by 2022. The talik around CRCOP I was larger than that around CRCOP II and the two taliks were gradually approaching each other. Permafrost-thawing-induced pipeline subsidence and surface settlement have led to thermokarst depressions and water accumulation. The sinking rates of CRCOP I and II are approximately 0.2 m/a and 0.45 m/a, respectively. The ground surface settlement rate on the right-of-way of the pipeline (on-ROW) is about 5.49 cm/a. Settlement rate in ponding areas is 8.18 cm/a, significantly larger than 4.81 cm/a in non-ponding areas. The ponding area on-ROW accounts for 67.4 % and it on CRCOP I is larger than that on CRCOP II. Pipeline construction, high oil temperature, and permafrost thawing have led to the development of geohazards, which have potential to be worsen under the influence of fires, climate warming, and human activities. Multi-type data provides ground verification for satellite images to extract deformation and ponding information along pipelines, and provides a scientific basis for assessing the thermal impact of pipelines and geohazard development. [ABSTRACT FROM AUTHOR]

As one of the best indicators of the periglacial environment, ice-wedge polygons (IWPs) are important for arctic landscapes, hydrology, engineering, and ecosystems. Thus, a better understanding of the spatiotemporal dynamics and evolution of IWPs is key to evaluating the hydrothermal state and carbon budgets of the arctic permafrost environment. In this paper, the dynamics of ground surface deformation (GSD) in IWP zones (2018–2019) and their influencing factors over the last 20 years in Saskylakh, northwestern Yakutia, Russia were investigated using the Interferometric Synthetic Aperture Radar (InSAR) and Google Earth Engine (GEE). The results show an annual ground surface deformation rate (AGSDR) in Saskylakh at −49.73 to 45.97 mm/a during the period from 1 June 2018 to 3 May 2019. All the selected GSD regions indicate that the relationship between GSD and land surface temperature (LST) is positive (upheaving) for regions with larger AGSDR, and negative (subsidence) for regions with lower AGSDR. The most drastic deformation was observed at the Aeroport regions with GSDs rates of −37.06 mm/a at tower and 35.45 mm/a at runway. The GSDs are negatively correlated with the LST of most low-centered polygons (LCPs) and high-centered polygons (HCPs). Specifically, the higher the vegetation cover, the higher the LST and the thicker the active layer. An evident permafrost degradation has been observed in Saskylakh as reflected in higher ground temperatures, lusher vegetation, greater active layer thickness, and fluctuant numbers and areal extents of thermokarst lakes and ponds.

Adequately and timely measuring and evaluating the ground surface deformation (GSD) are keys to the prudent mitigation of frost hazards of foundation soils and thus to the safe and cost-effective operation of oil pipelines in permafrost regions. Thus, it is crucial to accurately evaluate the GSD along the route of China-Russia Crude Oil Pipelines (CRCOPs) for a better understanding of frequent and substantial (differential) frost heave and thaw settlement of pipeline foundation soils in permafrost regions. In this study, GSDs along the CRCOPs from Xiufeng town to Jinsong town, northern Heilongjiang Province were monitored in discontinuous permafrost regions in the northern Da Xing'anling Mountains, Northeast China. The Sentinel-1B images from 2017 to 2021 and the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technology were used in combination with the Geographical Detector (GeoDetector) for identifying the drivers for GSDs and with ground survey data for validation analysis of GSD at chosen sites (e.g., MDX304 and others). InSAR results show that most of the annual GSD rates along the CRCOPs range from −10 to 0 mm/a, with larger deformation rates in Ta'he, Cuigang, and Jinsong. GeoDetector analysis shows that latitude and soil types are the most important contributors to GSDs along the CRCOPs, and; GSDs are closely related to elevation, ground temperature at the depth of 1 m (GT 1m), normalized difference vegetation index (NDVI), annual precipitation (AP), and slope aspects. Analyses of ground and oil-flow temperatures and survey results of electrical resistivity tomography (ERT) show that permafrost along CRCOPs has been degrading and thawing, resulting in thaw settlement, consolidation, and deformation of pipeline foundation soils and underlying/lateral permafrost layers and subsequently, the ground surface subsidence. This study provides key deformation data for the assessment and mitigation of frost hazards along the CRCOPs. • Ground surface subsidence dominates in the deformations along the CRCOPs. • Ground surface deformations are closely related to latitude and soil types along the CRCOPs. • Permafrost degrading along the CRCOPs leads to ground-surface subsidence. [ABSTRACT FROM AUTHOR]