Evolution Of Surface Deformation Research Articles

Time‐series InSAR monitoring of surface deformation in Yakutsk, a city located on continuous permafrost

AbstractPermafrost, known for its high sensitivity to climate change and human activities, plays a crucial role in comprehending the environmental sustainability of Arctic cities. Yakutsk, being the largest city situated in continuous permafrost, has suffered irreversible damage to surface buildings due to the widespread permafrost thaw. Therefore, it is imperative to conduct detailed monitoring and assessment of surface deformation to ensure the stable operation of building facilities and to plan urban development situated above the permafrost. This study utilized 138 scenes of Sentinel‐1B images captured between 2017 and 2021 to process the surface deformation variations of Yakutsk using the Persistent Scatterer Interferometric Synthetic Aperture Radar (PS‐InSAR) method. The surface deformation rate map reflects that the study area is undergoing extensive surface subsidence. The cumulative deformation time series maps effectively trace the temporal and spatial evolution of surface deformation, with the highest surface subsidence rates exceeding 40 mm/year and maximum cumulative subsidence exceeding 250 mm. In‐depth analysis of the obtained results indicated that the permafrost in Yakutsk is undergoing degradation, and the primary reason for surface subsidence is the thawing of foundation soils and the degradation of ice‐bearing permafrost. This study provides basic data for the investigation of geohazards caused by surface subsidence in Yakutsk.

Monitoring and analysis of surface deformation in alpine valley areas based on multidimensional InSAR technology

Joshimath has received much attention for its massive ground subsidence at the beginning of the year. Rapid urbanization and its unique geographical location may have been one of the factors contributing to the occurrence of this geological disaster. In high mountain valley areas, the complex occurrence mechanism and diverse disaster patterns of geological hazards highlight the inadequacy of manual monitoring. To address this problem, the inversion of deformation of the Joshimath surface in multiple directions can be achieved by multidimensional InSAR techniques. Therefore, in this paper, the multidimensional SBAS-InSAR technique was used to process the lift-track Sentinel-1 data from 2020 to 2023 to obtain the two-dimensional vertical and horizontal deformation rates and time series characteristics of the Joshimath ground surface. To discover the causes of deformation and its correlation with anthropogenic activities and natural disasters by analyzing the spatial and temporal evolution of surface deformation. The results show that the area with the largest cumulative deformation is located in the northeastern part of the town, with a maximum cumulative subsidence of 271.2 mm and a cumulative horizontal movement of 336.5 mm. The spatial distribution of surface deformation is based on the lower part of the hill and develops towards the upper part of the hill, showing a trend of expansion from the bottom to the top. The temporal evolution is divided into two phases: gentle to rapid, and it is tentatively concluded that the decisive factor that caused the significant change in the rate of surface deformation and the early onset of the geological subsidence hazard was triggered by the 4.7 magnitude earthquake that struck near the town on 11 September 2021.

The influence of groundwater levels on land subsidence in Karaman (Turkey) using the PS-InSAR technique

Population growth and increased agricultural activities in Karaman and its surrounding region, located in the southwest of the Konya Closed Basin, have led to increasing water demand in recent years. Karaman's drinking and irrigation water needs are also almost entirely met from groundwater. Accordingly, excessive groundwater extraction deepens the water level inside the aquifers, resulting in land subsidence. In this study, the spatio-temporal evolution of surface deformation in and around the city of Karaman was investigated using Sentinel-1/A SAR data, Global Navigation Satellite System (GNSS), and groundwater levels over a period from 2016 to 2021. Sentinel-1 images obtained from ascending satellite orbits were evaluated using the persistent scatter interferometry (PS-InSAR) approach. Mean velocity maps and line-of-sight displacement time series were obtained and compared with GNSS data and groundwater levels. In all three datasets, a significant level of subsidence was obtained in the study region. The land subsidence values were found to be 25 mm/yr in the city center of Karaman and reached values of 50 mm/yr toward the northern part of the province. According to the results, there is a strong correlation between subsidence rates and groundwater levels over the analyzed period, indicating that subsidence in the area is most likely driven by excessive groundwater withdrawal.

Tectonic evolution of the Liupan Shan fold-and-thrust belt, NE Tibetan Plateau during the late Cenozoic: numerical simulations

SUMMARY The propagation of Tibetan Plateau high-elevation towards the Asian interior remains poorly understood. We conduct a series of 2-D viscoelastic plastic finite element models addressing the development of the Liupan Shan fold-and-thrust belt with multiple detachments in the NE Tibetan Plateau. We focus on the spatio–temporal relations of the Liupan Shan fold-and-thrust belt and dynamic mechanisms of growth in the NE margin of Tibetan Plateau during the late Cenozoic. Our models, consisting of a seismically-constrained two-layer-crust (of variable thicknesses) plus lithospheric mantle consider tectonic horizontal contraction and the influence of elastoplastic materials, including Model 1 (only the upper crust is elastoplastic), Model 2 (both the upper crust and the middle part of the lower crust are elastoplastic) and Model 3 (the whole lithosphere is elastoplastic). The results show that Model 1 can only reflect the properties of shallow detachment layer. Models 2 and 3 can better reflect the properties of multidetachment layers and approximately represent the process of fold-and-thrust belt formation and evolution; thus suggesting the importance of plastic rheology in the deep crust. In addition, Model 3 suggests that the pre-existing fault near the Moho below Liupan Shan is activated during the evolution process of ∼8 Ma. In summary, the results embody that the initiation and evolution of the fold-and-thrust belt depend on detachment structures: the deep and shallow detachments control the evolution of surface deformation and fold-and-thrust belt altogether. The simulated surface deformation is generally consistent with actual surface elevation distribution. Moreover, the growth of the Liupan Shan range may represent an expansion of the NE Tibetan Plateau toward the Ordos basin vicinity. Additionally, the tectonically driven uplift of Liupan Shan area supports the general crustal shortening tectonic mechanism of the Tibetan Plateau.

Analysis of the flexural properties of ultra-high-performance concrete consisting of hybrid straight steel fibers

Three combinations of single fibers and nine combinations of hybrid fibers were tested to analyze the mechanical properties and crack propagation behavior of ultra-high-performance concrete (UHPC) by digital image correlation. It was found that in comparison to single fibers, the long fibers had a more pronounced effect than short fibers. The hybrid combination of medium length fiber (Vf = 0.5%) and long fiber (Vf = 1.5%) generated a better flexural behavior in terms of post-crack strength, deflection, toughness, than the other hybridization series. A digital image correlation (DIC) technique was applied to record the evolution of surface deformation. The hybrid use of longer fiber replaced the shorter fiber, long fiber replaced medium length fiber and short fiber, medium length fiber replaced short at lower replacement ratios (0.5% and 1.0%), the crack shapes were presented linear variation and showed an abrupt change and did not have a constant increment at higher replacement ratios (1.5% and 2.0%).

Long-term spatiotemporal evolution of land subsidence in Konya metropolitan area (Turkey) based on multisensor SAR data

We have studied the spatiotemporal evolution of surface deformation in Konya city and its vicinity using advanced multitemporal synthetic aperture radar techniques with SAR data acquired by Envisat, ALOS-1, and Sentinel-1 A/B satellites between 2004 and 2020. Velocity maps and time series show that the city has been subsiding with varying rates in space and time since 2004. The pattern of deformation shows two main lobes of subsidence centered in the western and eastern sides of the city with a nondeforming north-south trending narrow zone in between. Subsidence rate increases from a few cm/yr to 11 cm/yr between 2014 and 2019. As of 2019, subsidence has slowed down dramatically, giving rise to uplift in some places. Spatiotemporal variation of subsidence and its strong correlation with change in water table level confirm the inferences that subsidence in the metropolitan area of Konya is due to over drafting of the ground water for urban needs. The decrease in subsidence rate over the last two years appears to be due to the city?s residents supplying their water from recently built dams instead of aquifers beneath the city. Initial excessive groundwater extraction in agricultural areas caused ~4 m drops every year in the water table level, which, in turn, gave rise to 8 cm subsidence every year. Modeling of the subsidence shows 7.7 x 106 m3/yr volume loss due to compaction of the aquifer in the Konya metropolitan area and its vicinity between 2014 and 2018.

Crack propagation behavior of ultra-high-performance concrete (UHPC) reinforced with hybrid steel fibers under flexural loading

This study investigates the crack propagation behavior of UHPC blended with straight steel fibers of different lengths (6, 13, and 20 mm), at varying replacement ratios (0.5%, 1.0%, and 1.5%) and a constant total fiber volume fraction (Vf = 2.0%), under flexural loading. The results indicate that blending with 0.5% medium length fibers and 1.5% long fibers yields the best flexural behavior compared to other investigated specimens. Using digital image correlation (DIC) technique, the evolution of surface deformation and strain field was analyzed. Based on the recorded images and corresponding analyses, the full debonding strain between the fibers and the matrix was determined to be about 0.32%. Moreover, the maximum strain for generating cracks was approximately 3.25%, irrespective of the fiber length. When longer fibers were replaced with shorter fibers at 0.5% or 1.0% replacement ratios, Crack opening displacement (COD) variations along the beam presented a linear shape. However, at higher replacement ratios (1.5% and 2.0%), the profile showed an abrupt change, and COD variations were non-constant. The samples comprising hybrid fibers presented a faster decline in the crack initiation strain rate at higher replacement ratios of the longer fibers. In the initial stage of cracking, the crack propagated rapidly; however, the crack propagation speed dropped dramatically during crack evolution before it stabilizes.

Experimental and numerical study of deposition mechanisms for cold spray additive manufacturing process

Cold spray is an attractive and rapidly developing process for additive manufacturing with high efficiency and precision, repairing and coating, especially in aircraft and aerospace applications. Cold spray additive manufacturing deposits micro-particles with large plastic deformation below their melting point, eliminating heat effect zone which could deteriorate the quality of repairing zone. The particle deposition in cold spray is a complex process which involves high strain rate, high contact pressure and high temperature. Here we develop, utilize and validate a thermo-mechanical model to provide a definitive way to predict deposition mechanics and surface deformation evolution for particle deposition process in cold spray additive manufacturing. Both a single particle and dual particles models were developed to investigate the contact interaction between particle/substrate and particle/particle. Different combinations of particle/substrate materials (Cu/Cu, Al/Al, steel/steel, and nickel/nickel) and process parameters were considered in this study. The experimental study was conducted to validate simulation results, providing useful information for understanding the limitations and challenges associated with cold spray additive manufacturing. The framework provides insights into improving the quality and precision of stress/strain formation, particle interactions and particle deposition in cold spray additive manufacturing process.

Evolution of surface deformation related to salt-extraction-caused sinkholes in Solotvyno (Ukraine) revealed by Sentinel-1 radar interferometry

Abstract. Rock salt has remarkable mechanical properties and high economic importance; however, the strength of salt compared to other rocks makes it a rather vulnerable material. Human activities could lead to acceleration of the dissolution of soluble rock salt and collapse of subsurface caverns. Although sinkhole development can be considered a local geological disaster regarding the characteristic size of surface depressions, the deformations can result in catastrophic events. In this study we report the spatiotemporal evolution of surface deformation in the Solotvyno salt mine area in Ukraine based on Sentinel-1 interferometric synthetic aperture radar measurements. Although the mining operations were finished in 2010, several sinkholes have been opened up since then. Our results show that despite the enormous risk management efforts, the sinkholes continue to expand with a maximum line-of-sight deformation rate of 5 cm/yr. The deformation time series show a rather linear feature, and unfortunately no slowdown of the processes can be recognized based on the investigated 4.5-year-long data set. We utilized both ascending and descending satellite passes to discriminate the horizontal and vertical deformations, and our results revealed that vertical deformation is much more pronounced in the area. Analytical source modeling confirmed that the complex deformation pattern observed by Sentinel-1 radar interferometry has a direct connection to the former mining activity and is confined to the mining territory. With the 6 d repetition time of Sentinel-1 observations, the evolution of surface changes can be detected in quasi real time, which can facilitate disaster response and recovery.

Long-Term Continuously Updated Deformation Time Series From Multisensor InSAR in Xi'an, China From 2007 to 2021

According to historical records, land subsidence has been occurring in Xi'an, China, since the 1960s, characterized by complex land subsidence patterns. This subsidence has the potential to cause serious societal and economic problems during the process of urbanization. Long-term, large-scale monitoring and dynamic high precision tracking of the evolution of surface deformation associated with geohazards is a prerequisite for effective prevention or advance warning of geological disasters. Synthetic aperture radar interferometry (InSAR), a satellite remote sensing technology, can facilitate such monitoring. Both currently operating and planned SAR satellites would provide extensive amounts of SAR data. In this article, we describe an approach for continuously updating long-term multisensor InSAR deformation time series using robust sequential least squares. It is successfully applied to near-real-time monitoring of the long-term evolution of surface deformation in Xi'an, China, from January 3, 2007 to February 12, 2021, using four SAR satellites: ALOS/PALSAR-1, TerraSAR-X, ALOS/PALSAR-2, and Sentinel-1A. In order to analyze deformation evolution, temporal independent component analysis was used to interpret deformation patterns. We found that land subsidence in Xi'an has slowed and even halted in some areas. However, large areas are uplifting, which presents a potential for geohazards. We conclude that the proposed approach using continuously updated deformation time series from multisensor InSAR can provide near-real-time deformation measurements, which are necessary for an early warning system.

Surface deformation evolution in the Pearl River Delta between 2006 and 2011 derived from the ALOS1/PALSAR images

This study monitors the land subsidence of the whole Pearl River Delta (PRD) (area: ~ 40,000 km2) in China using the ALOS1/PALSAR data (2006–2011) through the SBAS-InSAR method. We also analyze the relationship between the subsidence and the coastline change, river distribution, geological structure as well as the local terrain. The results show that (1) the land subsidence with the average velocity of 50 mm/year occurred in the low elevation area in the front part of the delta and the coastal area, and the area of the regions subsiding faster than 30 mm/year between 2006 and 2011 is larger than 122 km2; (2) the subsidence order and area estimated in this study are both much larger than that measured in previous studies; (3) the areas along rivers suffered from surface subsidence, due to the thick soft soil layer and frequent human interference; (4) the geological evolution is the intrinsic factor of the surface subsidence in the PRD, but human interference (reclamation, ground water extraction and urban construction) extends the subsiding area and increases the subsiding rate.

Additive manufactured 3Y‐TZP ceramics: Study of micromechanical behavior by nanoindentation and microscratch method

AbstractThe mechanical property of advanced ceramics by additive manufacturing through layer‐by‐layer processing and subsequent sintering has been employed as a key basis for optimizing the processing and developing future application. 3Y‐TZP ceramic was fabricated by stereolithography‐based additive manufacturing, and the mechanical properties were investigated by nanoindentation and microscratch testing. The microscopic mechanism and evolution of surface deformation and damage induced by scratching were revealed by scanning electron microscopy and surface interferometer. Results showed that the nanoindentation hardness and elastic modulus were comparable to those of conventional process. With the increase in the applied normal load, the scratch‐induced damage followed three sequential stages, that is, plastic plowing, microcracking and surface spalling. The magnitude of the microcracks nucleated during scratching depended on the applied normal load. Concerning the homogeneity and integrity with the sintered parts without delaminated cracks and pores, the evolution of surface damage was discussed in different stages. It was concluded that the layer‐by‐layer process did not affect the characteristic of microcracking evolution.

The characteristics and evolution of surface deformation induced by agricultural irrigation in the Junggar Basin from the perspective of InSAR

The characteristics and evolution of surface deformation induced by agricultural irrigation in the Junggar Basin from the perspective of InSAR

Evolution of Secondary Deformations Captured by Satellite Radar Interferometry: Case Study of an Abandoned Coal Basin in SW Poland

The issue of monitoring surface motions in post-mining areas in Europe is important due to the fact that a significant number of post-mining areas lie in highly-urbanized and densely-populated regions. Examples can be found in: Belgium, the Czech Republic, France, Germany, the Netherlands, Spain, the United Kingdom, as well as the subject of this study, the Polish Walbrzych Hard Coal Basin. Studies of abandoned coal fields show that surface deformations in post-mining areas occur even several dozen years after the end of underground coal extraction, posing a threat to new development of these areas. In the case of the Walbrzych area, fragmentary, geodetic measurements indicate activity of the surface in the post-mining period (from 1995 onward). In this work, we aimed at determining the evolution of surface deformations in time during the first 15 years after the end of mining, i.e., the 1995–2010 period using ERS 1/2 and Envisat satellite radar data. Satellite radar data from European Space Agency missions are the only source of information on historical surface movements and provide spatial coverage of the entirety of the coal fields. In addition, we attempted to analyze the relationship of the ground deformations with hydrogeological changes and geological and mining data. Three distinct stages of ground movements were identified in the study. The ground motions (LOS (Line Of Sight)) determined with the PSInSAR (Persistent Scatterer Interferometry) method indicate uplift of the surface of up to +8 mm/a in the first period (until 2002). The extent and rate of this motion was congruent with the process of underground water table restoration in separate water basins associated with three neighboring coal fields. In the second period, after the stabilization of the underground water table, the surface remained active, as indicated by local subsidence (up to −5 mm/a) and uplift (up to +5 mm/a) zones. We hypothesize that this surface activity is the result of ground reaction disturbed by long-term shallow and deep mining. The third stage is characterized by gradual stabilization and decreasing deformations of the surface. The results accentuate the complexity of ground motion processes in post-mining areas, the advantages of the satellite radar technique for historical studies, and provide information for authorities responsible for new development of such areas, e.g., regarding potential flood zones caused by restoration of groundwater table in subsided areas.

Experimental investigation on the atomization of a spherical droplet induced by Faraday instability

Faraday instability plays an important role to realize liquid atomization which has been widely applied in various fields. The spherical Faraday instability has different characteristics from the planar one. It is of great importance to understand the fundamental mechanisms of the surface deformation evolution and atomization of a spherical droplet induced by Faraday instability. In this paper, we first experimentally recorded the deformation and fragmentation process of a spherical droplet on a vertically vibrated plate with high speed camera. The results showed that the zonal, meridional and approximately circular standing waves in proper order exist on the surface of the spherical droplet with the increase of excitation amplitude. When Bo<3.0, the modes of low (zonal) and high (meridional) order m of the spherical harmonic occur more easily, and as Bo is increased, the order m becomes closer to the intermediate value of spherical mode number l. The mechanism of droplet atomization is that a spike forms first on the droplet surface due to the impingement of the liquid flowing from the neighboring trough portions, and then a neck appears because of the velocity difference between the head and bottom of the spike, and the velocity difference determines whether the head liquid can form a sub-droplet ejected from the surface of the parent droplet. The Mathieu equation was derived by a linear theoretical analysis with inviscid and incompressible assumptions for the spherical Faraday instability, in which the parameters have different definitions from its planar counterpart. In the instability diagram, the iso-curves of larger linear growth rate deviate further from the ordinate axis and finally disappear. It is also validated that Lang’s equation is applicable to the spherical Faraday instability in low frequency.

Integration of terrestrial laser scanning and soil sensors for deformation and hydrothermal monitoring of frost mounds

In this geomorphological research, terrestrial laser scanning (TLS) and a global navigation satellite system (GNSS) were employed to monitor the evolution of surface deformation in two frost mounds located in the Qinghai-Tibet engineering corridor (QTEC). The QTEC is classified as a critical engineering and transportation corridor and is connected to both inland China and the Tibetan Plateau.The engineering infrastructures over the QTEC are distributed around two slopes. A high-accuracy FARO Focus3D X130 3D laser scanner, nine Trimble 5700 GNSS systems and a DJI Inspire 1 unmanned aerial vehicle (UAV) system were used to generate a 3D surface model for the slopes. The deployment of the GNSS datum points (GDPs), GNSS control points (GCPs), a reference sphere set and a set of rectangular white–black cardboards used as registration reference targets (RRTs) enhanced the capacity for data collection, registration and pre-processing of the TLS point cloud. The mapping changes of the slopes based on the TLS data were used to examine the 3D surface topography dynamics during different time periods. Soil temperature and moisture sensors were also adopted to monitor the water and heat exchange for one of the slopes, which can reveal the effects of the hydrothermal process on slope deformation during freeze-thaw cycles. This occurred mainly because the phase transitions initiated slope deformation due to water and heat transfer. The two slopes exhibited mainly thaw slumping during thawing periods and frost heaving during the freezing period, but the frost heaving was dominant after several freeze-thaw cycles. The implementation of TLS and hydrothermal measurement technologies allow for a better understanding and assessment of hazards related to slopes adjacent to engineering and transportation corridors, and this will provide guidance for the future of highway and high-speed railway design and construction along the QTEC.

Monitoring Surface Deformation over a Failing Rock Slope with the ESA Sentinels: Insights from Moosfluh Instability, Swiss Alps

We leverage on optical and radar remote sensing data acquired from the European Space Agency (ESA) Sentinels to monitor the surface deformation evolution on a large and very active instability located in the Swiss Alps, i.e., the Moosfluh rock slope. In the late summer 2016, a sudden acceleration was reported at this location, with surface velocity rates passing from maximum values of 0.2 cm/day to 80 cm/day. A dense pattern of uphill-facing scarps and tension cracks formed within the instability and rock fall activity started to become very pronounced. This evolution of the rock mass may suggest that the most active portion of the slope could fail catastrophically. Here we discuss advantages and limitations of the use of spaceborne methods for hazard analyses and early warning by using the ESA Sentinels, and show that in critical scenarios they are often not sufficient to reliably interpret the evolution of surface deformation. The insights obtained from this case study are relevant for similar scenarios in the Alps and elsewhere.

Contrasting catastrophic eruptions predicted by different intrusion and collapse scenarios

Catastrophic volcanic eruptions triggered by landslide collapses can jet upwards or blast sideways. Magma intrusion is related to both landslide-triggered eruptive scenarios (lateral or vertical), but it is not clear how such different responses are produced, nor if any precursor can be used for forecasting them. We approach this problem with physical analogue modelling enhanced with X-ray Multiple Detector Computed Tomography scanning, used to track evolution of internal intrusion, and its related faulting and surface deformation. We find that intrusions produce three different volcano deformation patterns, one of them involving asymmetric intrusion and deformation, with the early development of a listric slump fault producing pronounced slippage of one sector. This previously undescribed early deep potential slip surface provides a unified explanation for the two different eruptive scenarios (lateral vs. vertical). Lateral blast only occurs in flank collapse when the intrusion has risen into the sliding block. Otherwise, vertical rather than lateral expansion of magma is promoted by summit dilatation and flank buttressing. The distinctive surface deformation evolution detected opens the possibility to forecast the possible eruptive scenarios: laterally directed blast should only be expected when surface deformation begins to develop oblique to the first major fault.

Multiscale postseismic behavior on a megathrust: The 2012 Nicoya earthquake, Costa Rica

AbstractThe Nicoya Peninsula in northwest Costa Rica overlies a section of the subduction megathrust along the Middle America Trench. On 5 September 2012, a moment magnitude 7.6 megathrust earthquake occurred beneath a dense network of continuous GPS and seismic stations. Many of the GPS stations recorded the event at high rate, 1 Hz or better. We analyze the temporal and spatial evolution of surface deformation after the earthquake. Our results show that the main rupture was followed by significant afterslip within the first 3 h following the main event. The behavior of the surface displacement can be represented by relaxation processes with three characteristic times: 7, 70, and more than 400 days. We assume that the long relaxation time corresponds to viscoelastic relaxation and the intermediate relaxation time corresponds to afterslip on the main fault. The short relaxation time may represent a combination of rapid afterslip, poroelastic adjustment in the upper crust, or other processes. During the first few months that followed the earthquake, afterslip likely released a significant amount of slip deficit still present following the coseismic rupture, in particular updip of the rupture. Afterslip seems to be bounded updip by regions affected by slow slip events prior to the earthquake, suggesting that the two processes are influenced by different frictional properties.

A noise model for InSAR time series

AbstractInterferometric synthetic aperture radar (InSAR) time series methods estimate the spatiotemporal evolution of surface deformation by incorporating information from multiple SAR interferograms. While various models have been developed to describe the interferometric phase and correlation statistics in individual interferograms, efforts to model the generalized covariance matrix that is directly applicable to joint analysis of networks of interferograms have been limited in scope. In this work, we build on existing decorrelation and atmospheric phase screen models and develop a covariance model for interferometric phase noise over space and time. We present arguments to show that the exploitation of the full 3‐D covariance structure within conventional time series inversion techniques is computationally challenging. However, the presented covariance model can aid in designing new inversion techniques that can at least mitigate the impact of spatial correlated nature of InSAR observations.