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

2020 ◽  
Author(s):  
Eszter Szűcs ◽  
Sándor Gönczy ◽  
István Bozsó ◽  
László Bányai ◽  
Alexandru Szakacs ◽  
...  
Keyword(s):  
Disaster Response ◽  
Surface Deformation ◽  
Characteristic Size ◽  
Interferometric Synthetic Aperture Radar ◽  
Mining Operations ◽  
Data Set ◽  
Linear Feature ◽  
Repetition Time ◽  
Response And Recovery ◽  
Radar Measurements

Abstract. Rocksalt has remarkable mechanical properties and a high economic importance, however, this strength of salt compared to other rocks makes it a rather vulnerable material. Human activities could lead to acceleration of the dissolution of soluble rocksalt and collapse of subsurface caverns. Although sinkhole development can be considered 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 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 even though the enormous risk managing 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 dominant in the area. With the 6-day 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.

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

2021 ◽  
Vol 21 (3) ◽  
pp. 977-993
Author(s):  
Eszter Szűcs ◽  
Sándor Gönczy ◽  
István Bozsó ◽  
László Bányai ◽  
Alexandru Szakacs ◽  
...  
Keyword(s):  
Rock Salt ◽  
Disaster Response ◽  
Surface Deformation ◽  
Characteristic Size ◽  
Radar Interferometry ◽  
Deformation Pattern ◽  
Source Modeling ◽  
Mining Operations ◽  
Complex Deformation ◽  
Data Set

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.

The ambiguous fault geometry derived from InSAR measurements of buried thrust earthquakes: a synthetic data based study

2021 ◽  
Vol 225 (3) ◽  
pp. 1799-1811
Author(s):  
Yingfeng Zhang ◽  
Xinjian Shan ◽  
Wenyu Gong ◽  
Guohong Zhang
Keyword(s):  
Surface Deformation ◽  
Fault Plane ◽  
Synthetic Data ◽  
Deformation Pattern ◽  
Interferometric Synthetic Aperture Radar ◽  
Fault Geometry ◽  
Noise Levels ◽  
Data Set ◽  
Mountain Belts ◽  
Deformation Patterns

SUMMARY The challenge of ruling out potential rupture nodal planes with opposite dip orientations during interferometric synthetic aperture radar (InSAR)-based kinematic inversions has been widely reported. Typically, slip on two or more different fault planes can match the surface deformation measurements equally well. The ambiguous choice of the nodal plane for the InSAR-based models was thought to be caused by InSAR's 1-D measurement and polar orbiting direction, leading to its poor sensitivity to north–south crustal motion. Through synthetic experiments and simulations, this paper quantitatively demonstrates the main reason of the ambiguous InSAR-based models, which confuse researchers in the small-to-moderate thrust earthquake cases investigation. We propose the inherent 1-D measurement is not the principle cause of the fault plane ambiguity, since models derived from the same InSAR data predict similar, but not identical, 3-D deformation patterns. They key to differentiating between these different models is to be able to resolve the small asymmetry in the surface deformation pattern, which may be smaller in amplitude than the typical noise levels in InSAR measurements. We investigate the fault geometry resolvability when using InSAR data with different noise levels through ‘R’ value. We find that the resolvability does not only rely on the InSAR noise, but also on the fault geometry itself (i.e. depth, dips angle and strike). Our result shows that it is impossible to uniquely determine the dip orientation of thrust earthquakes with Mw < 6.0 and depth > 5.0 km with InSAR data at a noise level that is typical for mountain belts. This inference is independent from the specific data set (i.e. interferogram or time-series) and allows one to assess if one can expect to be able to resolve the correct fault plane at all.

scholarly journals Atmospheric Ice Particle Shape Estimates from Polarimetric Radar Measurements and In Situ Observations

2017 ◽  
Vol 34 (12) ◽  
pp. 2569-2587 ◽  
Author(s):  
Sergey Y. Matrosov ◽  
Carl G. Schmitt ◽  
Maximilian Maahn ◽  
Gijs de Boer
Keyword(s):  
Aspect Ratio ◽  
Particle Shape ◽  
Characteristic Size ◽  
In Situ Measurements ◽  
Department Of Energy ◽  
Depolarization Ratio ◽  
Suggested Approach ◽  
Aspect Ratios ◽  
Radar Measurements

AbstractA remote sensing approach to retrieve the degree of nonsphericity of ice hydrometeors using scanning polarimetric Ka-band radar measurements from a U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Program cloud radar operated in an alternate transmission–simultaneous reception mode is introduced. Nonsphericity is characterized by aspect ratios representing the ratios of particle minor-to-major dimensions. The approach is based on the use of a circular depolarization ratio (CDR) proxy reconstructed from differential reflectivity ZDR and copolar correlation coefficient ρhυ linear polarization measurements. Essentially combining information contained in ZDR and ρhυ, CDR-based retrievals of aspect ratios are fairly insensitive to hydrometeor orientation if measurements are performed at elevation angles of around 40°–50°. The suggested approach is applied to data collected using the third ARM Mobile Facility (AMF3), deployed to Oliktok Point, Alaska. Aspect ratio retrievals were also performed using ZDR measurements that are more strongly (compared to CDR) influenced by hydrometeor orientation. The results of radar-based retrievals are compared with in situ measurements from the tethered balloon system (TBS)-based video ice particle sampler and the ground-based multiangle snowflake camera. The observed ice hydrometeors were predominantly irregular-shaped ice crystals and aggregates, with aspect ratios varying between approximately 0.3 and 0.8. The retrievals assume that particle bulk density influencing (besides the particle shape) observed polarimetric variables can be deduced from the estimates of particle characteristic size. Uncertainties of CDR-based aspect ratio retrievals are estimated at about 0.1–0.15. Given these uncertainties, radar-based retrievals generally agreed with in situ measurements. The advantages of using the CDR proxy compared to the linear depolarization ratio are discussed.

scholarly journals Assimilation of HF radar surface currents to optimize forcing in the northwestern Mediterranean Sea

2014 ◽  
Vol 21 (3) ◽  
pp. 659-675 ◽  
Author(s):  
J. Marmain ◽  
A. Molcard ◽  
P. Forget ◽  
A. Barth ◽  
Y. Ourmières
Keyword(s):  
Surface Wind ◽  
Circulation Model ◽  
Radar Data ◽  
Hf Radar ◽  
Open Boundary ◽  
Coastal Current ◽  
Surface Currents ◽  
Data Set ◽  
Radar Measurements ◽  
Northwestern Mediterranean

Abstract. HF radar measurements are used to optimize surface wind forcing and baroclinic open boundary condition forcing in order to constrain model coastal surface currents. This method is applied to a northwestern Mediterranean (NWM) regional primitive equation model configuration. A new radar data set, provided by two radars deployed in the Toulon area (France), is used. To our knowledge, this is the first time that radar measurements of the NWM Sea are assimilated into a circulation model. Special attention has been paid to the improvement of the model coastal current in terms of speed and position. The data assimilation method uses an ensemble Kalman smoother to optimize forcing in order to improve the model trajectory. Twin experiments are initially performed to evaluate the method skills. Real measurements are then fed into the circulation model and significant improvements to the modeled surface currents, when compared to observations, are obtained.

scholarly journals NLC and the background atmosphere above ALOMAR

2011 ◽  
Vol 11 (12) ◽  
pp. 5701-5717 ◽  
Author(s):  
J. Fiedler ◽  
G. Baumgarten ◽  
U. Berger ◽  
P. Hoffmann ◽  
N. Kaifler ◽  
...  
Keyword(s):  
Diurnal Cycle ◽  
Middle Atmosphere ◽  
Thermal State ◽  
Atmospheric Tides ◽  
Data Set ◽  
Ice Particles ◽  
Cloud Water Content ◽  
Radar Measurements ◽  
Mf Radar

Abstract. Noctilucent clouds (NLC) have been measured by the Rayleigh/Mie/Raman-lidar at the ALOMAR research facility in Northern Norway (69° N, 16° E). From 1997 to 2010 NLC were detected during more than 1850 h on 440 different days. Colocated MF-radar measurements and calculations with the Leibniz-Institute Middle Atmosphere (LIMA-) model are used to characterize the background atmosphere. Temperatures as well as horizontal winds at 83 km altitude show distinct differences during NLC observations compared to when NLC are absent. The seasonally averaged temperature is lower and the winds are stronger westward when NLC are detected. The wind separation is a robust feature as it shows up in measurements as well as in model results and it is consistent with the current understanding that lower temperatures support the existence of ice particles. For the whole 14-year data set there is no statistically significant relation between NLC occurrence and solar Lyman-α radiation. On the other hand NLC occurrence and temperatures at 83 km show a significant anti-correlation, which suggests that the thermal state plays a major role for the existence of ice particles and dominates the pure Lyman-α influence on water vapor during certain years. We find the seasonal mean NLC altitudes to be correlated to both Lyman-α radiation and temperature. NLC above ALOMAR are strongly influenced by atmospheric tides. The cloud water content varies by a factor of 2.8 over the diurnal cycle. Diurnal and semidiurnal amplitudes and phases show some pronounced year-to-year variations. In general, amplitudes as well as phases vary in a different manner. Amplitudes change by a factor of more than 3 and phases vary by up to 7 h. Such variability could impact long-term NLC observations which do not cover the full diurnal cycle.

scholarly journals Team Activity of Robot Competition of Simulated Robot in World Robot Summit 2020

2021 ◽  
Vol 102 ◽  
pp. 04016
Author(s):  
Daichi Shima ◽  
Tomoyuki Furukawa ◽  
Ryuma Aoba ◽  
Ayato Ohashi ◽  
Kota Tsuruno ◽  
...  
Keyword(s):  
Disaster Response ◽  
Project Based Learning ◽  
Response Category ◽  
Robot System ◽  
Tunnel Fire ◽  
Autonomous Operation ◽  
Team Activity ◽  
Response And Recovery ◽  
Disaster Response And Recovery

World Robot Summit (WRS) has several robot competitions, and we will participate it in the infrastructure and disaster response category. Participating teams develop their robot system by teleoperation and/or autonomous operation and run it in a set of courses modelling and simplifying disaster responding situations. The authors will attend the challenge of the tunnel disaster response and recovery, in which we are requested to achieve an investigation and rescue scenario of a tunnel fire with simulated robots. As preparation, we develop simulated robot models and corresponding software as a team. In this article, we report out activity to the robot competition and student’s project-based learning by joining it.

scholarly journals Co-creating value: Student contributions to smart cities

2014 ◽  
pp. 392-409
Keyword(s):  
Action Research ◽  
Disaster Response ◽  
Information Technologies ◽  
Smart Cities ◽  
Participatory Action ◽  
Action Research Project ◽  
Research Project ◽  
Geospatial Information ◽  
Public And Private ◽  
Response And Recovery

Given the interdependence of the public and private sectors and simultaneous and massive impact of widespread disasters on the entire community, this paper investigates the use of information technologies, specifically geospatial information systems, within the multi-organizational community to effectively co-create value during disaster response and recovery efforts. We present and examine in depth a participatory action research project in a disaster-experienced coastal community conducted during the 2006-2014 time period. The results of the action research project and analysis of a survey completed by stakeholders leads to a list of findings, in particular those related to developing a model of next generation learning design where students are co-creators of value to the smart cities.

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