Average Deformation Rate Research Articles

The long-term failure processes of a large reactivated landslide in the Xiluodu reservoir area based on InSAR technology

After the first impoundment of the reservoir, many landslides seriously threatened the safety of the reservoir. Accurate determination of the relationship between the landslide deformation characteristics and water-level fluctuations is crucial. However, with the increasing number of water-level fluctuation cycles, the deformation characteristics of the landslides were also changing, and long-term continuous monitoring to capture the failure process of reservoir landslides is necessary. A large reacted landslide in the Xiluodu reservoir was set as an example, using InSAR technology to seek its variations of deformation characteristics over nine years. The local deformation rate and annual maximum deformation area variation were analyzed by InSAR technology based on Sentinel-1 descending SAR data from October 2014 to June 2022. According to the regional deformation characteristics, the landslide was divided into three zones: Zone I above the elevation of 950 m; Zone II below it; the front edge of Zone II, where the collapse happened, was further divided into Zone III. In general, the accumulated deformation in Zone I was the largest, followed by Zone III, and Zone II was the smallest. The average deformation rate of Zone II was the smallest. Zone I of NLJL was mainly affected by the drawdown of reservoir water level, and the impacts of water-level rising and drawdown on Zone II and Zone III were similar. After analyzing a nine-year variation of the deformation area, the deformation mechanism of NLJL changed from a retrogressive type to a progressive one after the first impoundment and then changed back to a retrogressive one after 2017. The impact of reservoir impoundment on NLJL was most substantial in the first three years after the first impoundment.

Monitoring and Prediction of Glacier Deformation in the Meili Snow Mountain Based on InSAR Technology and GA-BP Neural Network Algorithm.

The morphological changes in mountain glaciers are effective in indicating the environmental climate change in the alpine ice sheet. Aiming at the problems of single monitoring index and low prediction accuracy of mountain glacier deformation at present, this study takes Meili Mountain glacier in western China as the research object and uses InSAR technology to construct the mountain glacier deformation time series and 3D deformation field from January 2020 to December 2021. The relationship between glacier deformation and elevation, slope, aspect, glacier albedo, surface organic carbon content, and rainfall was revealed by grey correlation analysis. The GA-BP neural network prediction model is established from the perspective of multiple factors to predict the deformation of Meili Mountain glacier. The results showed that: The deformation of Meili Mountain glacier has obvious characteristics of spatio-temporal differentiation; the cumulative maximum deformation quantity of glaciers in the study period is -212.16 mm. After three-dimensional decomposition, the maximum deformation quantity of glaciers in vertical direction, north-south direction and east-west direction is -125.63 mm, -77.03 mm, and 107.98 mm, respectively. The average annual deformation rate is between -94.62 and 75.96 mm/year. The deformation of Meili Mountain glacier has a gradient effect, the absolute value of deformation quantity is larger when the elevation is below 4500 m, and the absolute value of deformation quantity is smaller when it is above 4500 m. The R2, MAPE, and RMSE of the GA-BP neural network to predict the deformation of Meili glacier are 0.86, 1.12%, and 10.38 mm, respectively. Compared with the standard BP algorithm, the prediction accuracy of the GA-BP neural network is significantly improved, and it can be used to predict the deformation of mountain glaciers.

A critical analysis of turbulence dissipation in near-wall flows, based on stereo particle image velocimetry and direct numerical simulation data

An experiment was performed using stereo particle image velocimetry (SPIV) in the Laboratoire de Mécanique des Fluides de Lille boundary layer facility to determine all the derivative moments needed to estimate the average dissipation rate of the turbulence kinetic energy $\epsilon = 2 \nu \langle {\mathsf{s}}_{ij}{\mathsf{s}}_{ij} \rangle$ , where ${\mathsf{s}}_{ij}$ is the fluctuating strain rate and $\langle ~\rangle$ denotes ensemble averages. Also measured were all the moments of the full average deformation rate tensor, as well as all of the first, second and third fluctuating velocity moments except those involving pressure. The Reynolds number was $Re_\theta = 7634$ or $Re_\tau = 2598$ . The present paper gives the measured average dissipation, $\epsilon$ and the derivative moments comprising it. The results are compared with the earlier measurements of Balint, Wallace & Vukolavcevic (J. Fluid Mech., vol. 228, 1991, pp. 53–86) and Honkan & Andreopoulos (J. Fluid Mech., vol. 350, 1997, pp. 29–96) at lower Reynolds numbers and to new results from a plane channel flow DNS at comparable Reynolds number. Of special interest is the prediction by George & Castillo (Appl. Mech. Rev., vol. 50, 1997, pp. 689–729) and Wosnik, Castillo & George (J. Fluid Mech., vol. 421, 2000, pp. 115–145) that $\epsilon ^+ \propto {x_2^+}^{-1}$ for streamwise homogeneous flows and a nearly indistinguishable power law, $\epsilon \propto {x_2^+}^{\gamma -1}$ , for boundary layers. In spite of the modest Reynolds number, the predictions seem to be correct. Then the statistical character of the velocity derivatives is examined in detail, and a particular problem is identified with the breakdown of local homogeneity inside $x_2^+ = 100$ . A more general alternative for partially homogeneous turbulence flows is offered which is consistent with the observations. With the help of DNS, the spatial characteristics of the dissipation very near the wall are also examined in detail.

Slope deformation monitoring and early identification of disasters in debris flow source area of Baini River, Dongchuan District, China

Dongchuan District is one of the most densely distributed regions of geological disasters in the world. Geological disasters such as debris flows and landslides are serious threats to the lives and property safety of local people. Slope deformation monitoring and early identification of geological disasters in debris flow source areas are of great significance for disaster prevention and reduction. In this study, the time-series Synthetic Aperture Radar Interferometry (InSAR) technique was used to detect the deformation in the source area of the Baini river debris flow. The deformation rate in the middle part of the three-sided mountain is the largest, the average deformation rate is about 30 mm/year. The deformation rate of the lower and upper part of the mountain is slightly lower, but the deformation is creeping constantly, and obvious tensile cracks faced the river valley in the upper. The production and living areas of residents in 8 villages around the debris flow source area are constantly deformed, and there are different degrees of landslide risk. This study provides a scientific basis and reference for early identification, deformation analysis, disaster prevention and mitigation of geological disasters in the Xiaojiang Basin.

New Insights into Ice Avalanche-Induced Debris Flows in Southeastern Tibet Using SAR Technology

Drastic climate change has led to glacier retreat in southeastern Tibet, and the increased frequency and magnitude of heavy rainfall and intense snow melting have intensified the risk of ice avalanche-induced debris flows in this region. To prevent and mitigate such hazards, it is important to derive the pre-disaster evolutionary characteristics of glacial debris flows and understand their triggering mechanisms. However, ice avalanche-induced debris flows mostly occur in remote alpine mountainous areas that are hard for humans to reach, which makes it extremely difficult to conduct continuous ground surveys and optical remote sensing monitoring. To this end, synthetic aperture radar (SAR) images were used in this study to detect and analyze the pre-disaster deformation characteristics and spatial evolution in the Sedongpu Basin and to detect changes in the snowmelt in the basin in order to improve our understanding of the triggering mechanism of the ice avalanche-induced debris flows in this region. The results revealed that the maximum average deformation rate in the basin reached 57.3 mm/year during the monitoring period from January 2016 to October 2018. The deformation displacement in the gully where the ice avalanche source area was located was intimately correlated with the summer snowmelt and rainfall and was characterized by seasonal accumulation. Clear acceleration of the deformation was detected after both the most recent earthquake and the strong rainfall and snowmelt processes in the summer of 2018. This suggests that earthquakes, snowmelt, and rainfall were significant triggers of the Sedongpu ice avalanche-induced debris flows. The results of this study provide new insights into the genesis of the Sedongpu ice avalanche-induced debris flows, which could assist in disaster warning and prevention in alpine mountain regions.

Lightweight design and experimental investigation of codirectional corrugated steel fire bulkheads on a cruise ship

A lightweight design method based on topography optimization theory, which can adaptively determine locations, numbers and topography of the codirectional beads of sandwich bulkheads is proposed. Mathematical optimization formulations for the bead topography design of sandwich bulkheads that considering weight objective and strength and buckling constraints are established. Taking a fireproof bulkhead design in the superstructure of a cruise ship as an example, the design process based on the proposed method is demonstrated. A full-scale sandwich bulkhead specimen is selected and manufactured for comparison with the stiffened bulkhead. Then, a load-bearing fire-resisting test is carried out on the specimen. The test results show that the structure of the unexposed side of the specimen is intact and that there is no smoke emission. The average and maximum increases in temperature on the unexposed side are 80.2 °C and 104 °C, and the maximum axial deformation and the average axial deformation rates are 7.9 mm and 3.8 mm/min, respectively. The new sandwich bulkhead can be regarded as a “load-bearing fire-resisting divisions 30” class bulkhead because these results meet the requirements of the 2010 Code for Application of Fire Test Procedures. However, its weight is just 73.86% that of the stiffened bulkhead.

Theoretical Model and Experimental Study of Dynamic Hot Rolling

At present, the commonly used hot rolling model is only applicable to the static rolling process. However, to study the dynamic rolling process, a dynamic rolling model with roll vertical movement velocity parameters is required. In this study, the influence of the vertical movement velocity of the rolls on the rolling process is considered, and a dynamic rolling process model is proposed when the roll gap is reduced during the hot rolling dynamic rolling process. Mathematically, the model is based on the upper limit method. The model considers the influence of the dynamic rolling process on the length of the deformation zone, establishes a dynamic velocity field model and an average deformation rate model, and then solves the total power of the rolling process. Finally, the dynamic rolling force equation is given. Compared with the experimental results, the dynamic rolling model in this paper has high accuracy with an average error of 4%. In addition, the influence of roll vertical velocity on rolling parameters is discussed, which provides a basis for the study of the dynamic rolling process.

IGS-CMAES: A Two-Stage Optimization for Ground Deformation and DEM Error Estimation in Time Series InSAR Data

Interferometric synthetic aperture radar (InSAR) has become an increasingly recognized remote sensing technology for earth surface monitoring. Slow and subtle terrain displacements can be estimated using time-series InSAR (TSInSAR) data. However, a substantial increase in the availability of exclusive time series data necessitates the development of more efficient and effective algorithms. Research in these areas is usually carried out by solving complicated optimization problems, which is very computationally expensive and time-consuming. This work proposes a two-stage black-box optimization framework to jointly estimate the average ground deformation rate and terrain digital elevation model (DEM) error. The method performs an iterative grid search (IGS) to acquire coarse candidate solutions, and then a covariance matrix adaptive evolution strategy (CMAES) is adopted to obtain the final local results. The performance of our method is evaluated using both simulated and real datasets. Both quantitative and qualitative comparisons using different optimizers support the reliability and effectiveness of our work. The proposed IGS-CMAES achieves higher accuracy with a significantly fewer number of objective function evaluations than other established algorithms. It offers the possibility for wide-area monitoring, where high precision and real-time processing is essential.

Monitoring and Analysis of Ground Deformation in Mining Area Based on SBAS Technology

In view of the serious harm and significant economic loss caused by large-scale surface subsidence in Huangling Mining area. Firstly, the surface deformation information was obtained by using the Small Baseline technology during 2007-2009 (ALOS-1) and 2018-2019 (Sentinel-1A), and then the deformation position and magnitude changes were compared in these two different periods, finally, the time series analysis of the surface subsidence funnel in the mining area was performed. The results showed that: (1) The average annual deformation rate respectively reached 360 mm/a and 480 mm/a during 2007-2009 and 2018-2019. It was found that compared with 2007-2009, the deformation position moved up in 2018-2019, and the deformation area and magnitude increased. Combined with the analysis of the mining area data, the Huangling mining area was in the early stage of mining from 2007 to 2009. As the advance of mining working face and the passage of time, the deformation position would move up in 2018-2019. (2) From 2018 to 2019, the most serious surface subsidence in the Huangling mining area was located in the northwest of Shuanglong Town, including Huangling No. 2 Coal Mine. The maximum cumulative subsidence reached 300mm. The results of the study indicated that the main cause of subsidence in this area was underground coal mining. The analysis of the deformation law provides a decision basis for the subsequent rational mining and treatment of the mining area.

Microstructure of Vein Quartz Aggregates as an Indicator of Their Deformation History: An Example of Vein Systems from Western Transbaikalia (Russia)

We investigated the microstructural and crystallographic features of quartz from complex vein systems associated with the development of thrust and shear deformations in Western Transbaikalia using electron back scatter diffraction (EBSD) and optical microscopy. Vein quartz systems were studied to obtain insights on the mechanisms and localization of strains in quartz, in plastic and semibrittle conditions close to the brittle–ductile transition, and their relationship to the processes of regional deformations. Five types of microstructures of vein quartz were distinguished. We established that the preferred mechanisms of deformation of the studied quartz were dislocation glide and creep at average deformation rates and temperatures of 300–400 °C with subsequent heating and dynamic and static recrystallization. The formation of special boundaries of the Dauphiné twinning type and multiple boundaries with angles of misorientation of 30° and 90° were noted. The distribution of the selected types in the differently oriented veins was analyzed. The presence of three generations of vein quartz was established. Microstructural and crystallographic features of vein quartz aggregates allow us to mark the territory’s multi-stage development (with the formation of syntectonic and post-deformation quartz).

Time-Series Analysis of Subsidence in Nanning, China, Based on Sentinel-1A Data by the SBAS InSAR Method

Recent research has demonstrated that the Sentinel-1 constellation can be used for continuous tracking of ground deformation phenomena. In this study, the spatial–temporal subsidence characteristics in Nanning were investigated with 18 Sentinel-1A TOPS synthetic aperture radar (SAR) images acquired from 25 June 2015 to 16 December 2016 based on the small baseline subset interferometric SAR (SBAS InSAR) technique. The results showed that the annual average surface deformation rates in Nanning ranged from − 48 mm/year to 20 mm/year, and the maximum deformation was detected in the Langdong area. The SBAS-derived results were validated by Nanning continuously operating reference station (CORS) and levelling measurement data. The correlation coefficient and root-mean-square error (RMSE) between SBAS-derived and levelling-derived mean deformation rates were 0.79 and 2 mm/year, respectively. The maximum discrepancy and the RMSE amounted to 7 mm/year and 4 mm/year comparing the SBAS time-series with the CORS-measured displacement. The verification using levelling and CORS implied high reliability and precision of surface subsidence derived by SBAS InSAR. Our analysis revealed that surface subsidence in Nanning was mainly caused by large-scale urban construction, which should be paid enough attention to avoid further aggravation. With the help of the meteorological data, we also found that the subsidence in Nanning was closely related to climatic anomalies in 2015. This research work will provide important theoretical and practical reference value for urban planning and construction in Nanning.

A strongly objective expression for the average deformation rate with application to numerical integration algorithms

Although the Hughes-Winget rotation tensor is not strongly objective when stretching occurs during a time step it is very accurate when the incremental stretching during the time step is small, a condition that is almost always met in practice. Two types of evolution equations based on the Jaumann derivative are examined which show that the main source of error in the numerical algorithms is due to the approximation of the average deformation rate during the time step. A new strongly objective expression for the average deformation rate during a time step is developed and shown to correct the observed errors in tests of strong objectivity.

Casing Bearing Capacity with Shear Load for Shale Gas Wells

Casing radial deformation during complex fracturing process was seriously for shale gas wells in Sichuan district of China, and the average casing deformation rate in the region is of 50%. The bridge plug, perforating gun and other tools cannot successfully pass with deformed casing. Aiming at the 3-D logging morphology for deformed casing of shale gas wells, the failure modes and mechanisms were analyzed by using elasticity and theoretical mechanics. Many factors were evaluated and integrated to achieve quantitative evaluation model including geology feature, wellbore trajectory, cement property, casing material and hydrofracture process. With the aid of the self-developed unconventional oil and gas well casing simulation test equipment, the casing bearing capacity with shear load were carried out, established the relationship between shear load value and radial deformation, and further constructed the casing failure criterion with shear force. This work can provide technical support for casing design and selection in shale gas wells.

Deformation Time Series and Driving-Force Analysis of Glaciers in the Eastern Tienshan Mountains Using the SBAS InSAR Method.

Glacier melting is one of the important causes of glacier morphology change and can provide basic parameters for calculating glacier volume change and glacier mass balance, which, in turn, is important for evaluating water resources. However, it is difficult to obtain large-scale time series of glacier changes due to the cloudy and foggy conditions which are typical of mountain areas. Gravity-measuring satellites and laser altimetry satellites can monitor changes in glacier volume over a wide area, while synthetic-aperture radar satellites can monitoring glacier morphology with a high spatial and temporal resolution. In this article, an interferometric method using a short temporal baseline and a short spatial baseline, called the Small Baseline Subsets (SBAS) Interferometric Synthetic-Aperture Radar (InSAR) method, was used to study the average rate of glacier deformation on Karlik Mountain, in the Eastern Tienshan Mountains, China, by using 19 Sentinel-1A images from November 2017 to December 2018. Thus, a time series analysis of glacier deformation was conducted. It was found that the average glacier deformation in the study region was −11.77 ± 9.73 mm/year, with the observation sites generally moving away from the satellite along the Line of Sight (LOS). Taking the ridge line as the dividing line, it was found that the melting rate of southern slopes was higher than that of northern slopes. According to the perpendicular of the mountain direction, the mountain was divided into an area in the northwest with large glaciers (Area I) and an area in the southeast with small glaciers (Area II). It was found that the melting rate in the southeast area was larger than that in the northwest area. Additionally, through the analysis of temperature and precipitation data, it was found that precipitation played a leading role in glacier deformation in the study region. Through the statistical analysis of the deformation, it was concluded that the absolute value of deformation is large at elevations below 4200 m while the absolute value of the deformation is very small at elevations above 4500 m; the direction of deformation is always away from the satellite along the LOS and the absolute value of glacier deformation decreases with increasing elevation.

THE ANALYSIS OF THREE-DIMENSIONAL (3D) GROUND SURFACE DEFORMATIONS IN HEIFANGTAI PLATFORM

The loess has strong collapsibility in Heifangtai Platform, Yongjing Country, Gansu Province which belongs to a typical loess platform. Collapsible loess of thick layer caused by long-term flood irrigation has induced many loess landslides and severe ground deformations. We selected ground deformations in Heifangtai Platform as research object. The descending data of Sentinel-1 A satellite in three different orbits were processed using PS-InSAR technique between 2014 and 2017, and the deformation in different line of sight(LOS) is obtained. In addition, 3 D ground surface deformations was obtained by inversion and calculation in the area. Ground surface deformations of LOS direction, vertical and horizontal direction was analyzed, and the development trend of ground surface deformation was predicted. The results show there are differential settlements in study area. The deformation rates of LOS direction are larger in some area including closing to central area of platform and the part of area on the edge of platform. The range of settlement is 4~13 mm·a-1. A region with large vertical deformation is near the middle of platform. The average rate of deformation is-20~-6 mm·a-1. The North-South deformations are small. The average rate of deformation is-5~5 mm·a-1. However, the West-East deformations are large. The average rate of deformation is mostly more than 20 mm·a-1. Ground surface deformations are still at a slow acceleration stage in short term as a whole. With continuous development of agricultural irrigation, the rate of ground surface deformation will gradually decrease after rising a certain value.

InSAR Monitoring and Analysis of Ground Deformation Due to Fluid or Gas Injection in Fengcheng Oil Field, Xinjiang, China

Over the last decade, Fengcheng oil field rich in heavy oil geological reserves has had a broad prospect of exploration. The reservoirs are mainly composed of high porosity, high permeability sandstone and conglomerate in study area. The reservoir characteristics led to poor fluid and gas injection causing ground surface deformation with the injection of gas and fluid and threatened the safety of nearby construction facilities. Interferometric Synthetic Aperture Radar (InSAR) technology has been used to identify ground surface deformation with high precision, which is widely used in various fields. This paper adopted Small Baseline Subset InSAR (SBAS-InSAR) method to monitor oil field for the period of February 2007 to September 2010. In this study, the Fengcheng oil field in Xinjiang served as an example; we measured subsurface fluid and gas injection-induced ground surface deformation by SBAS-InSAR technique and investigated the causes of observed deformation. The results showed significant uplift over Fengcheng oil field and testified the feasibility of SBAS-InSAR method. The Phased Arrary L-band Synthetic Aperture Radar (PALSAR) datasets outcome revealed ground surface maximum cumulative uplift for 4 years was 40 cm in the line of sight (LOS) direction, and annual average deformation rates were ranging from − 80 to 120 mm/year. Further, the time series analysis based on monitoring results found that the causes of ground surface uplift were related to the increase in pore pressure under the reservoir, and the surface deformation area corresponded to the production well position of study area. Therefore, InSAR technique is an essential tool for the ground surface deformation monitoring due to fluid and gas injection in heavy oil field, ensuring the safety of personnel and property.

Multi-Temporal Loess Landslide Inventory Mapping with C-, X- and L-Band SAR Datasets—A Case Study of Heifangtai Loess Landslides, China

The Interferometric Synthetic Aperture Radar (InSAR) technique is a well-developed remote sensing tool which has been widely used in the investigation of landslides. Average deformation rates are calculated by weighted averaging (stacking) of the interferograms to detect small-scale loess landslides. Heifangtai loess terrace, Gansu province China, is taken as a test area. Aiming to generate multi-temporal landslide inventory maps and to analyze the landslide evolution features from December 2006 to November 2017, a large number of Synthetic Aperture Radar (SAR) datasets acquired by L-band ascending ALOS/PALSAR, L-band ascending and descending ALOS/PALSAR-2, X-band ascending and descending TerraSAR-X and C-band descending Sentinel-1A/B images covering different evolution stages of Heifangtai terrace are fully exploited. Firstly, the surface deformation of Heifangtai terrace is calculated for independent SAR data using the InSAR technique. Subsequently, InSAR-derived deformation maps, SAR intensity images and a DEM gradient map are jointly used to detect potential loess landslides by setting the appropriate thresholds. More than 40 active loess landslides are identified and mapped. The accuracy of the landslide identification results is verified by comparison with published literatures, the results of geological field surveys and remote sensing images. Furthermore, the spatiotemporal evolution characteristics of the landslides during the last 11 years are revealed for the first time. Finally, strengths and limitations of different wavelength SAR data, and the effects of track direction, geometric distortions of SAR images and the differences in local incidence angle between two adjacent satellite tracks in terms of small-scale loess landslides identification, are analyzed and summarized, and some suggestions are given to guide the future identification of small-scale loess landslides with the InSAR technique.

GROUND SUBSIDENCE ALONG SHANGHAI METRO LINE 6 BY PS-InSAR METHOD

Abstract. With the rapid development of urban economy, convenient, safe, and efficient urban rail transit has become the preferred method for people to travel. In order to ensure the safety and sustainable development of urban rail transit, the PS-InSAR technology with millimeter deformation measurement accuracy has been widely applied to monitor the deformation of urban rail transit. In this paper, 32 scenes of COSMO-SkyMed descending images and 23 scenes of Envisat ASAR images covering the Shanghai Metro Line 6 acquired from 2008 to 2010 are used to estimate the average deformation rate along line-of-sight (LOS) direction by PS-InSAR method. The experimental results show that there are two main subsidence areas along the Shanghai Metro Line 6, which are located between Wuzhou Avenue Station to Wulian Road Station and West Gaoke Road Station to Gaoqing Road Station. Between Wuzhou Avenue Station and Wulian Road Station, the maximum displacement rate in the vertical direction of COSMO-SkyMed images is −9.92 mm/year, and the maximum displacement rate in the vertical direction of Envisat ASAR images is −8.53 mm/year. From the West Gaoke Road Station to the Gaoqing Road Station, the maximum displacement rate in the vertical direction of COSMO-SkyMed images is −15.53 mm/year, and the maximum displacement rate in the vertical direction of Envisat ASAR images is −17.9 mm/year. The results show that the ground deformation rates obtained by two SAR platforms with different wavelengths, different sensors and different incident angles have good consistence with each other, and also that of spirit leveling.

Effects of the ‘spring structure’ on the performance of a vibrating plate of the piezoelectric inkjet print-head

One of the core components of piezoelectric inkjet print-head is the piezoelectric vibrating plate which directly affects the jet performance of a print-head. In the present paper, a simplified coupling model theory of the composite vibrating plate was studied in combination with the actual manufacturing process of the piezoelectric vibrating plate. The ‘spring structure’ is formed by releasing the long edge of Lead Zirconate Titanate (PZT) thin films to enhance the amplitude of the piezoelectric vibrating plate. The laser Doppler measurement was carried out on the piezoelectric vibrating plate, and the results were verified by using numerical simulation. The results show that the ‘spring structure’ can effectively improve the amplitude and average deformation rate of the piezoelectric vibration plate in the air while does not affect the deformation time. The amplitude of the vibrating plate with spring structure increased continuously in the dwelling stage of the drive signal when the ink was inspired. Moreover, the magnitude of residual vibration also increased.

Near-surface geometry and average vertical deformation rate of the Kamishiro fault in the Itoigawa-Shizuoka Tectonic Line active fault system, revealed from a borehole survey at Kamishiro, Hakuba village, Nagano prefecture, Japan

Near-surface geometry and average vertical deformation rate of the Kamishiro fault in the Itoigawa-Shizuoka Tectonic Line active fault system, revealed from a borehole survey at Kamishiro, Hakuba village, Nagano prefecture, Japan