Vertical Displacement Rates Research Articles

Modeling of temperature deformations on the Dnister HPP dam (Ukraine)

Abstract The extended operation of Ukrainian hydroelectric power plants has caused spatial deformations and aging of hydrostructures. This can lead to man-made disasters, especially after explosions resulting from missile attacks. As a result, various defects can appear in the concrete structures of the dam. Continuous structural monitoring of hydropower plants is essential to prevent man-made accidents. The research paper also demonstrates that changes in water temperature can affect the dam’s vertical and horizontal displacements. A model was developed and analysed to determine the spatial deformations of the Dnister HPP based on water temperature and distance from the dam’s edge. It was determined that horizontal displacement rates range from −2.2 to 2.7 mm/month, and vertical displacement rates range from −2 to 1.3 mm/month. They are also seasonal in nature. The studies conducted enable the prediction and identification of seasonal spatial deformations of the Dnister HPP dam. The research also helps to find their variations due to water temperature at the definite depth. If the temperature deformation model deviates from the measurement results, the structure in those areas should be more thoroughly inspected and analysed. This may indicate the structure’s weakening due to natural aging processes or construction-related deficiencies. Deformations in the dam’s structure can lead to cracks, compromising its stability and watertightness. Dams can vary in shape, design features, depth, volume, and water temperature. So, it is important to customize the displacement model for each dam. Any deviation from the specified model may suggest defects due to abnormal temperature distribution and spatial displacements.

Intraplate active deformation: Lake Salt fault zone and source of the Obruk (Bor-Niğde) earthquakes, Cappadocia-central Anatolia, Türkiye

Intraplate strike slip deformation structures play a crucial role in understanding how the earthquake are triggered, and respond to long-term deformation in plate interiors. One of the examples for intraplate structure is the Lake Salt Fault Zone (LSFZ) in Türkiye, located at the Central Anatolia region which has hosted a few moderate magnitude earthquakes. The LSFZ extends in NW-SE direction along the eastern border of the Lake Salt basin. In the western and central sections, it exhibits a rather linear trace, and it marks the west-northwestern boundary of the Cappadocian plateau. Along its strike, two big cities, namely, Aksaray and Niğde, and some significant eruption centers (the Hasan, Keçibuyduran and Melendiz Mountain stratovolcanoes) are located, and there is a 12 km right lateral offset. LSFZ has four main segments, namely, Karacaören, Keçikalesi, Obruk and Büyükkaraoğlan fault segments, and they have hosted two moderate-sized (Mw = 5.1 to 5.2) earthquakes (on September 20, 2020 and February 25, 2023) at the localities approximately 5 km ENE and SSW of Obruk Town (Niğde). Their focal mechanisms revealed that the LSFZ exhibits dominantly dextral strike-slip faulting with normal component. The vertical and horizontal displacement rates along the LSFZ are 0.14 mm/yr and 4.6 mm/yr, respectively. The recurrence interval of earthquakes of Mw ≥ 6.7 on the LSFZ is more than one thousand years, owing to the low slip rate. We propose that the LSFZ is in a seismic gap having potential to host a large earthquake.

Analysis of Progressive Collapse Resistance in Precast Concrete Frame with a Novel Connection Method

The configuration of beam–column joints in precast concrete (PC) building structures varies widely, and different connection methods significantly affect the progressive collapse resistance of the structure. This study investigates the progressive collapse resistance of an innovative beam–column connection node frame. Finite element models of four-story, two-span space frame structures made of reinforced concrete (RC) and PC were developed using ANSYS 14.0/LS-DYNA R5.x software, employing nonlinear dynamic and static analysis to examine structural collapse behavior under bottom middle or corner column damage. Numerical results indicate that following the failure of the middle or corner column due to explosion loading, the vertical displacement and collapse rate of the PC structure with the novel connection method are less than those of the RC structure during collapse progression. Furthermore, upon removal of the middle or corner column, the residual load-carrying capacity of the PC structure with the innovative connection increased by 7% and 3.7%, respectively, compared to the RC structure. This suggests that PC structures with this type of connection demonstrate superior performance in resisting progressive collapse, offering valuable insights for future engineering applications.

Structural Evolution of the Northern Agrio Fold and Trust Belt (∼37°30′S), Neuquén Basin, Argentina, Derived From Low‐Temperature Multi‐Thermochronometry

AbstractThe Agrio Fold and Thrust Belt (FTB), situated in the Southern Central Andes at 37–39°S, underwent two phases of contractional deformation: Late Cretaceous‐Eocene and middle‐late Miocene. Despite advances in understanding its tectonic history, many questions persist regarding the timing and activity of specific structures during these deformation phases. By combining low‐temperature multi‐thermochronometry, inverse thermal models and field structural data, we present a new thermal‐structural history for the northern Agrio FTB. Our findings unveil an initial cooling event between approximately 85–75 Ma and 55–50 Ma, involving cooling rates of 1.1–2°C/Ma and vertical displacement rates from 0.07 to 0.12 km/Ma. This slow event, confined to the inner zone, is associated with the growth of the basement‐cored Manzano anticline. Additionally, still in the inner zone of the Agrio FTB, a second and faster cooling event from ∼15–10 Ma to 0 Ma, marked by a cooling rate of 7°C/Ma and a vertical displacement rate ranging from 0.11 to 0.17 km/Ma, results from in‐sequence thick‐skinned thrusting at depth. In the outer zone of the FTB, only the younger cooling event from 15–10 Ma to 0 Ma is evident, with a cooling rate of 8.8°C/Ma and a vertical displacement rate ranging from ∼0.14 to 0.26 km/Ma, attributed to displacement along the basement‐involved Las Yeseras thrust. Furthermore, Apatite Fission Track (AFT) ages of detrital grains in the Tralalhué conglomerates support the maximum depositional age for these synorogenic strata to be between 14.1 and 9.2 Ma.

Моніторинг сезонних вертикальних зміщень греблі Дніпровської ГЕС

The relationship Methods. A program developed for this purpose processed a time series of GNSS measurements, which allows for determining vertical seasonal displacements and their dependence on seasonal changes in ambient air temperature. Results. A review of scientific works on the temperature field impact on the deformation of hydraulic structures is presented. Based on the studies performed, it was found that in the absence of sharp drops in the water level in the upper reservoir, seasonal changes in ambient temperature have a significant impact on the vertical displacements of dams (in the example of the Dnipro HPP). The magnitude of extreme displacements and the epochs of their manifestation will depend on the dam design and technical parameters. Based on the processed data, a linear relationship was established between the average ambient temperature and the vertical displacements of GNSS control points located at the Dnipro HPP dam, which makes it possible to predict the value of vertical displacements of control points based on the measured temperature value. Accordingly, monitoring these displacements and their changes over time is one of the criteria for assessing the overall condition of the dam. We noticed that during the study period, the extremely positive average rate of the vertical displacements of the control points was in the first half of 2018, +1.03 mm per month, and the extremely negative average rate of 0.83 mm/month was in the second half of 2019. It explained the correlation between the vertical displacement rate of the control point and the depth of the reservoir near it. Scientific novelty and practical significance. The regularities of the relationship between temperature changes and GNSS point displacements revealed in the study can be useful for further research on the processing and analysis of monitoring data for hydraulic structures.

Seismotectonic aspects of the Ms 7.3 1948 October 5 Aşgabat (Ashgabat) earthquake, Türkmenistan: right-lateral rupture across multiple fault segments, and continuing urban hazard

SUMMARY The Ms 7.3 1948 Aşgabat earthquake was one of the most devastating earthquakes of the 20th century, yet little is known about its location, style and causative fault. In this study, we bring together new seismic and geomorphic observations with previously published descriptions of surface rupture and damage distributions to determine the likely source of the earthquake. We determine the epicentre and focal mechanism of this earthquake from digitized historical seismograms and the relocation of regional seismicity to show that the earthquake most likely nucleated close to the city of Aşgabat. The earthquake ruptured a right-lateral strike-slip fault to the southeast of the city, which has a clear long-term expression in the landscape, and also likely reactivated a subparallel concealed thrust along the Gyaursdag anticline east of the city. The earthquake potentially also ruptured a right-lateral segment northwest of Aşgabat, which does not have an identifiable expression in the landscape. Using high-resolution satellite imagery and digital elevation models we investigate the geomorphology of active faulting around Aşgabat and adjacent parts of the Köpetdag (Kopeh Dagh) mountain range front, showing that there are significant strike-slip and oblique strike-slip segments adjacent to the city that apparently did not rupture in 1948, and yet show clear geomorphic expression and potential right-lateral displacement of Parthian-era (∼2000 yr) and post-Sassanian era (∼1500 yr) archaeological remains. Luminescence dating of displaced fluvial terraces west of Aşgabat yields a vertical displacement rate of 0.6 mm yr−1, though the strike-slip rate remains undetermined.

A Statistical Approach for the Integration of Multi-Temporal InSAR and GNSS-PPP Ground Deformation Measurements.

Determining and monitoring ground deformations is critical for hazard management studies, especially in megacities, and these studies might help prevent future disaster conditions and save many lives. In recent years, the Golden Horn, located in the southeast of the European part of Istanbul within a UNESCO-protected region, has experienced significant changes and regional deformations linked to rapid population growth, infrastructure work, and tramway construction. In this study, we used Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite System (GNSS) techniques to investigate the ground deformations along the Golden Horn coastlines. The investigated periods are between 2015 and 2020 and 2017 and 2020 for InSAR and GNSS, respectively. For the InSAR analyses, we used sequences of multi-temporal synthetic aperture radar (SAR) images collected by the Sentinel-1 and ALOS-2 satellites. The ground displacement products (i.e., time series and velocity maps) were then cross-compared with those achievable using the Precise Point Positioning (PPP) technique for the GNSS solutions, which can provide precise positions with a single receiver. In the proposed analysis, we compared the ground displacement velocities obtained by both methods by computing the standard deviations of the difference between the relevant observations considering a weighted least square estimation procedure. Additionally, we identified five circle buffers with different radii ranging between 50 m and 250 m for selecting the most appropriate coherent points to conduct the cross-comparison analysis. Moreover, a vertical displacement rate map was produced. The comparison of the vertical ground velocities derived from PPP and InSAR demonstrates that the PPP technique is valuable. For the coherent stations, the vertical displacement rates vary between -4.86 mm/yr and -23.58 mm/yr and -9.50 and -27.77 mm/yr for InSAR and GNSS, respectively.

Insights into post-emplacement lava flow dynamics at Mt. Etna volcano from 2016 to 2021 by synthetic aperture radar and multispectral satellite data

Insights into post-emplacement lava flow dynamics at Mt. Etna volcano from 2016 to 2021 by synthetic aperture radar and multispectral satellite data

A commercial finite element approach to modelling Glacial Isostatic Adjustment on spherical self-gravitating compressible earth models

SUMMARYThis paper presents a method that modifies commercial engineering-oriented finite element packages for the modelling of Glacial Isostatic Adjustment (GIA) on a self-gravitating, compressible and spherical Earth with 3-D structures. The approach, called the iterative finite element body and surface force (FEMIBSF) approach, solves the equilibrium equation for deformation using the ABAQUS finite element package and calculates potential perturbation consistently with finite element theory, avoiding the use of spherical harmonics. The key to this approach lies in computing the mean external body forces for each finite element within the Earth and pressure on Earth's surface and core–mantle boundary (CMB). These quantities, which drive the deformation and stress perturbation of GIA but are not included in the equation of motion of commercial finite element packages, are implemented therein. The method also demonstrates how to calculate degree-1 deformation directly in the spatial domain and Earth-load system for GIA models. To validate the FEMIBSF method, loading Love numbers (LLNs) for homogeneous and layered earth models are calculated and compared with three independent GIA methodologies: the normal-mode method, the iterative body force method and the spectral-finite element method. Results show that the FEMIBSF method can accurately reproduce the unstable modes for the homogeneous compressible model and agree reasonably well with the Love number results from other methods. It is found that the accuracy of the FEMIBSF method increases with higher resolution, but a non-conformal mesh should be avoided due to creating the so-called hanging nodes. The role of a potential force at the CMB is also studied and found to only affect the long-wavelength surface potential perturbation and deformation in the viscous time regime. In conclusion, the FEMIBSF method is ready for use in realistic GIA studies, with modelled vertical and horizontal displacement rates in a disc load case showing agreement with other two GIA methods within the uncertainty level of GNSS measurements.

Factors of Subsidence in Katy, Texas, USA

Coastal communities are susceptible to the damaging effects of land subsidence caused by both natural and anthropogenic processes. The Greater Houston area, situated along the Gulf Coast of Texas, has experienced some of the highest rates of subsidence in the United States. Previous work has extensively analyzed the role of groundwater levels and oil and gas extraction in land subsidence of the Greater Houston area, but has failed to adequately incorporate other significant contributing factors. In this research, we aim to fill that information gap by analyzing the individual effects of subsidence from multiple different processes including groundwater and hydrocarbon extraction rates with the addition of population growth, total annual precipitation, and total developed area in terms of impervious surfaces. We perform a full resolution InSAR analysis of the Katy area using Sentinel-1 data from 2017 to 2022 and compare contributors of subsidence to vertical displacement rates calculated by GNSS stations through a generalized linear regression analysis. The InSAR results show up to 1.4 cm/yr of subsidence in multiple areas of Katy, and the generalized linear regression results suggest that population growth and total developed area are two of the highest contributors to subsidence in the area.

Simulating horizontal crustal motions of glacial isostatic adjustment using compressible Cartesian models

SUMMARY Significant land uplift and horizontal motions have been recorded with Global Navigation Satellite Systems (GNSS) in areas such as Alaska, Iceland and the Northern Antarctic Peninsula (NAP) as a result of Glacial Isostatic Adjustment (GIA) due to ice melt after the Little Ice Age. Here, analysis of horizontal displacement rates can be of extra importance, as they are more sensitive to Earth properties in shallower layers than vertical displacement rates. Proper modelling of horizontal displacement rates with dedicated GIA models requires a spherical Earth with compressible rheology. However, in these small areas, the used GIA models are often incompressible using a Cartesian geometry to ease computation and in some cases allow for lateral viscosity changes or more complex rheology. We investigate the validity of modelled horizontal displacement rates using different approximations, that is using spherical or Cartesian Earth structures, and incompressible, material compressible or compressible rheology. Although the lack of self-gravity and sphericity compensate each other in the vertical, this is less the case for the horizontal. For a disc ice sheet with a radius just over 200 km and a thickness of 1000 m, differences due to sphericity are minimal and the modelled horizontal displacement rates of compressible Cartesian models differ from those simulated by a compressible spherical model by 0.63 mm a−1. Thus, compressible Cartesian GIA models can be applied for modelling horizontal displacement rates of small ice sheets like those in Alaska, Iceland and NAP. Unfortunately, the implementation of compressibility in Abaqus that we use here cannot be extended to spherical models as gravity can not be specified for a spherical body. Other modelling approaches are recommended in such cases.

Stability of a Compacted Sand Slope Model Subject to Crest Load

Studying the stability of slopes is of great interest since it is associated to various geotechnical applications, e.g., access embankments and landslide mitigation. This paper describes the research conducted to determine the failure load applied at the top of excavations in sandy soils during the construction of deep digs without the use of retaining systems. An experimental program was performed to measure the failure load of ten laboratory-compacted sand slope models that were constructed using different slope angle values and different locations for the applied loading, which consisted of an imposed uniform rate of vertical displacement at the top of the slope. Then, a three-dimensional (3D) numerical model of the laboratory tests was developed to simulate the observed behavior during the experiments by the Plaxis 3D code. The Mohr–Coulomb (MC) and hardening soil (HS) models were used to describe the behavior of the compacted sand. The results showed that the 3D numerical simulations based on the MC model were able to predict the measured failure load within a relative difference of less than 11% for nine tested slope models, while the HS model was better in predicting the measured failure load (a relative difference of 3.5%) for only one experimental setup when the slope angle was equal to 35°. Furthermore, analytical prediction of the failure load using the yield design theory (YDT) permitted the validation of the log-spiral curve describing the observed failure surface for the tested sand slope models.

Present-Day Surface Deformation in North-East Italy Using InSAR and GNSS Data

Geodetic data can detect and estimate deformation signals and rates due to natural and anthropogenic phenomena. In the present study, we focus on northeastern Italy, an area characterized by ~1.5–3 mm/yr of convergence rates due to the collision of Adria-Eurasia plates and active subsidence along the coasts. To define the rates and trends of tectonic and subsidence signals, we use a Multi-Temporal InSAR (MT-InSAR) approach called the Stanford Method for Persistent Scatterers (StaMPS), which is based on the detection of coherent and temporally stable pixels in a stack of single-master differential interferograms. We use Sentinel-1 SAR images along ascending and descending orbits spanning the 2015–2019 temporal interval as inputs for Persistent Scatterers InSAR (PSI) processing. We apply spatial-temporal filters and post-processing steps to reduce unrealistic results. Finally, we calibrate InSAR measurements using GNSS velocities derived from permanent stations available in the study area. Our results consist of mean ground velocity maps showing the displacement rates along the radar Line-Of-Sight for each satellite track, from which we estimate the east–west and vertical velocity components. Our results provide a detailed and original view of active vertical and horizontal displacement rates over the whole region, allowing the detection of spatial velocity gradients, which are particularly relevant to a better understanding of the seismogenic potential of the area. As regards the subsidence along the coasts, our measurements confirm the correlation between subsidence and the geological setting of the study area, with rates of ~2–4 mm/yr between the Venezia and Marano lagoons, and lower than 1 mm/yr near Grado.

Glacial isostatic adjustment in the northern adriatic region: estimates of the contribution from the Alpine ice sheet

SUMMARY The present-day sea-level variations and vertical movements in the northern Adriatic Sea and in the highly vulnerable Venetian Lagoon result from a number of simultaneously operating contributions. These include Glacial Isostatic Adjustment (GIA), the global, long-term process arising from interactions between the cryosphere, the solid Earth and the oceans in response to the melting of continental ice sheets. Although the GIA contribution in northern Adriatic Sea has been the subject of various investigations so far, significant uncertainties still exist, especially related to the extent and chronology of the Würm Alpine ice sheet and to the rheological profile of the mantle. Here, taking advantage of the recent publication of updated deglaciation chronologies for the far field late-Pleistocene ice sheets and for the near-field alpine ice complex, we produce up-to-date estimates of the present-day rates of GIA-induced relative sea-level variations and vertical displacements in the Venetian Lagoon and in the northern Adriatic Sea, which are compared with GNSS and tide-gauge observations. From high-resolution numerical simulations, we find that GIA is responsible for a complex pattern of geodetic signals across the Po plain and the northern Adriatic Sea. The modeled GIA rates are of the order of fractions of mm yr−1, generally small – but not negligible – compared to the signals observed at local tide gauges and at GNSS sites in the Po plain and facing the Venetian Lagoon. Our results indicate that, while GIA represents a relatively small component among those responsible for present-day land movements and relative sea-level variations in the northern Adriatic Sea, its contribution needs to be taken into account for a correct interpretation of the observed geodetic variations.

Classifying marine faults for hazard assessment offshore Israel: a new approach based on fault size and vertical displacement

Abstract. For many countries, the methodology for offshore geohazard mitigation lags far behind the well-established onshore methodology. Particularly complicated is the assessment of fault hazard in the marine environment. The determination of whether a fault is active or not requires ultra-high-resolution seismic surveys and multiple coring and, unfortunately, frequently ends with uncertain results. Moreover, if a pipeline must cross a fault, it is not enough to determine whether the fault is active; slip rates are needed for resistant planning. Here we suggest a new approach for fault hazard assessment for the master planning of infrastructure. We provide planners a way to choose a route that will cross the least hazardous faults; these faults will then be investigated in site-specific surveys for slip rates that will allow seismic design. Instead of following the onshore practice that is hard to implement in the marine environment, we suggest taking advantage of the marine environment where seismic data are commonly better in quantity and quality. Based on existing industrial 3D seismic surveys, we measure for each fault in the study area the amount of its recent (in our specific case, 350 ka) vertical displacement and the size of its plane. According to these two independently measured quantities, we classify the faults into three hazard levels. This allows planners to choose infrastructure routes that cross the least hazardous faults at an early stage of planning and direct them to sites that need further investigation. Our case study is the Israeli continental slope, where numerous salt-related, thin-skinned, normal faults dissect the seabed, forming tens of meters high scarps. A particular hazardous zone is the upper slope south of the Dor disturbance, where a series of big listric faults rupture the seabed in an area where the sedimentation rate is 4 times faster than the vertical displacement rate. We suggest that this indicates exceptionally fast creep, seismic rupture, or rapid tremor and slip episodes.

Combined analysis of PS-InSAR and hypsometry integral (HI) for comparing seismic vulnerability and assessment of various regions of Pakistan

InSAR-based deformation analysis and the geomorphic hypsometric integral (HI) technique are powerful tools for assessing the susceptibility and comparison of seismic sites to earthquakes. Therefore, this paper mainly focuses on surface deformation analysis associated with the Mw 5.0 earthquake (2019) in Mach and Quetta, Balochistan, Pakistan. Sentinel-1 IW data was used to perform PS-InSAR time series analysis. SRTM DEM of 30 m spatial resolution was utilized for the geomorphic Hypsometry Integral (HI) method. The obtained results of the Interferogram indicate the changes in velocity and vertical displacement during pre-seismic, co-seismic, and post-seismic activity. Integral values were calculated using Hypsometry curves delineating the future probability and comparison of vulnerable seismological sites in Mach, Quetta, Ghazaband, Chamman and surroundings of Balochistan region. The combined results of HI and PS-InSAR revealed that Mach and Quetta regions are in between two lines known as the mature stages. Class 1_moderate (0.35 ≤ HI ≤ 0.52); with an integral value of HIMach = 0.398 and HIQuetta = 0.435 with a modest seismic forthcoming rate in future and susceptible to both erosion/uplifting with a vertical displacement rate more than existing ± 55 mm/year. Class 2_high (HI ˃ 0.53) with the younger and more tectonically active region surrounded by Chaman fault, which possesses a future susceptible tendency towards subsidence more than an existing velocity rate ~ 8 mm/year and Ghazaband fault towards uplifting more than 5–6 mm/year. No region of the study area was found at Monadnock: class 3_Low (HI ˂ 0.35) stabilized condition, all sites are unstable and tectonically active. Therefore, obtained results through combined PS-InSAR and HI techniques can be used for the identification of most vulnerable seismic sites and can ascertain future safe metropolitan planning.

Long-term ion hydration process and lithosphere-atmosphere coupling following the 2021 Fagradalsfjall volcanic eruption using remotely sensed data

After a series of earthquakes, the Reykjanes peninsula in Iceland faced a volcanic eruption for the first time in 800 years. This volcanism of the 2021 Fagradalsfjall started on March 19, 2021, and lasted until September 18, 2021. In this study, the vestiges of the mutual interplay of Earth’s different geophysical shells due to the local lithospheric changes around the Fagradalsfjall were extensively investigated with the help of satellite-based remotely sensed datasets. Firstly, the regional surface deformations caused by the pre-eruption seismic activity are determined using interferometric image pairs, and horizontal and vertical displacement rates are analyzed. Secondly, the satellite observations revealed that the land surface temperature of the entire area increased to a maximum of 40 °C during the maximum phase of lava discharge by the end of May 2021. Moreover, we observed that the surface mass concentrations of SO2 and CO trace gases started to ascend in parallel with the lava discharge after the initial eruption, where their concentrations were doubled in April before reaching their maximum phases (three to four times more than the initial eruption) in May 2021. The cumulative concentrations of the trace gases in the atmosphere emitted from the Fagradalsfjall volcano pushed the regional atmospheric balance into a non-equilibrium state by creating air ionization through various chemical reactions with other atmospheric gases. These ion clusters underwent an ion hydration process that changed the electric conductivity of the atmospheric boundary layer, which covers the first two kilometers of the atmosphere. Finally, our observations showed a sharp decrease in the atmospheric relative humidity that led to an increase in the atmospheric air temperature due to this ion hydration process. The large ion clusters in the atmospheric boundary layer produced a vertical electric field that penetrated over the affected region and brought long-term changes in the ionosphere layer. This unique phenomenon of the simultaneous interaction of different geophysical layers was specifically observed during the maximum phase of the lava discharge and increased ion concentrations in the atmosphere. The used data sets cover the first three months of the volcanism, and this interval seemed to be sufficient to reveal the atmospheric traces. Our comprehensive study provides an important contribution to the theory of the coupling of volcanism and the Earth's atmospheric dynamics.

An Ergonomic Design Process of the Functional Clothing for Yoga Sports

Abstract Reports attribute many physical, psychological and mental benefits to yoga sports. However, when it comes to actual research, yoga clothing has not attracted the same level of attention. The aim of this study, which involved a questionnaire survey, clothing development and clothing performance evaluation, is to propose an ergonomic design process for the design of yoga functional clothing. Results showed that textile material was rated as the most important factor for yoga clothing. The shoulder and the waist-belly regions were considered as the most important areas for yoga clothing. The newly designed clothing prototype was observed to subject significantly lower pressure to the waist under the forward bending pose (p<0.05), but with significantly higher pressure on the buttocks at the posture of the deep knee bending pose (p<0.05). It also resulted in a lower change rate of clothing vertical displacement, especially at the shoulder and waist regions. The newly designed prototype was rated with a significantly lower tightening sensation and pulling sensation during the deep knee bending posture (p<0.05). Results indicate that proper design of yoga clothing structure and selection of fabric material could reduce clothing deformation, pressure on the skin and improve subjective wearing sensations.

Extreme rainfall-related accelerations in landslides in Danba County, Sichuan Province, as detected by InSAR

Landslides are frequent mountainous geohazards induced by multiple factors, such as extreme rainfall, river erosion, and intense anthropogenic activities. On 17 June 2020, a rainstorm hit Danba County, Sichuan Province, and triggered the catastrophic Aniangzhai landslide. The impact of this rainstorm on landslide kinematics in this region has seldom been investigated. We used a time-series interferometric synthetic aperture radar (InSAR) analysis to map the active slopes in Danba County using one ascending (2015–2021) and one descending (2018–2021) Sentinel-1 dataset. A total of 36 landslides (63.1 km2) were detected along riverbanks. The time series of eastward and vertical displacements during 2018–2021 were retrieved by integrating the ascending and descending Sentinel-1 datasets. The maximum eastward and vertical displacement rates obtained are 229 and −75 mm/yr, respectively. Seasonal accelerations are correlated with concentrated rainfall. We suggest that the 2020 rainstorm and the abundant precipitation during the water year 2020 altered the long-term displacement trends of active landslides. We further constrained the volumes of the Niela and Gaoding landslides in the order 3.6–6.9 × 107 m3 and 5.4–6.0 × 108 m3, respectively, using 2D displacement rates and mass conservation equations. Our results demonstrate that multi-temporal and multi-orbit InSAR measurements can provide insights into the evolution and mechanism of landslides.

The geodynamic and limnological evolution of Balkan Lake Ohrid, possibly the oldest extant lake in Europe

Studies of the upper 447 m of the DEEP site sediment succession from central Lake Ohrid, Balkan Peninsula, North Macedonia and Albania provided important insights into the regional climate history and evolutionary dynamics since permanent lacustrine conditions established at 1.36 million years ago (Ma). This paper focuses on the entire 584‐m‐long DEEP sediment succession and a comparison to a 197‐m‐long sediment succession from the Pestani site ~5 km to the east in the lake, where drilling ended close to the bedrock, to unravel the earliest history of Lake Ohrid and its basin development. 26Al/10Be dating of clasts from the base of the DEEP sediment succession implies that the sedimentation in the modern basin started at c. 2 Ma. Geophysical, sedimentological and micropalaeontological data allow for chronological information to be transposed from the DEEP to the Pestani succession. Fluvial conditions, slack water conditions, peat formation and/or complete desiccation prevailed at the DEEP and Pestani sites until 1.36 and 1.21 Ma, respectively, before a larger lake extended over both sites. Activation of karst aquifers to the east probably by tectonic activity and a potential existence of neighbouring Lake Prespa supported filling of Lake Ohrid. The lake deepened gradually, with a relatively constant vertical displacement rate of ~0.2 mm a−1 between the central and the eastern lateral basin and with greater water depth presumably during interglacial periods. Although the dynamic environment characterized by local processes and the fragmentary chronology of the basal sediment successions from both sites hamper palaeoclimatic significance prior to the existence of a larger lake, the new data provide an unprecedented and detailed picture of the geodynamic evolution of the basin and lake that is Europe’s presumed oldest extant freshwater lake.