scholarly journals Constraints on the location, depth and yield of the 2017 September 3 North Korean nuclear test from InSAR measurements and modelling

2019 ◽  
Vol 220 (1) ◽  
pp. 345-351 ◽  
Author(s):  
K M Sreejith ◽  
Ritesh Agrawal ◽  
A S Rajawat
Keyword(s):  
Large Scale ◽  
Surface Deformation ◽  
Nuclear Explosion ◽  
Source Parameters ◽  
Test Site ◽  
Nuclear Test ◽  
Interferometric Synthetic Aperture Radar ◽  
Surface Displacements ◽  
Detailed Surface ◽  
Scale Surface

SUMMARY The Democratic People's Republic of Korea (North Korea) conducted its sixth and largest affirmed underground nuclear test on 2017 September 3. Analysis of Interferometric Synthetic Aperture Radar (InSAR) data revealed detailed surface displacements associated with the nuclear explosion. The nuclear explosion produced large-scale surface deformation causing decorrelation of the InSAR data directly above the test site, Mt. Mantap, while the flanks of the Mountain experienced displacements up to 0.5 m along the Line-of-Sight of the Satellite. We determined source parameters of the explosion using the Bayesian inversion of the InSAR data. The explosive yield was estimated as 245–271 kiloton (kt) of TNT, while the previous yield estimations range from 70–400 kt. We determined the nuclear source at a depth of 542 ± 30 m below Mt. Mantap (129.0769°E, 41.0324°N). We demonstrated that the Bayesian modelling of the InSAR data reduces the uncertainties in the source parameters of the nuclear test, particularly the yield and source depth that are otherwise poorly resolved in seismic methods.

scholarly journals Refinement of MPS method for practical application to snow avalanches

2012 ◽  
Vol 53 (61) ◽  
pp. 13-22
Author(s):  
Yoshihiko Saito ◽  
Hirotaka Kato ◽  
Masaya Otsuki ◽  
Ichiro Kimura ◽  
Yasuyuki Shimizu ◽  
...  
Keyword(s):  
Large Scale ◽  
Surface Deformation ◽  
Deposition Process ◽  
Snow Avalanches ◽  
Modified Model ◽  
Mps Method ◽  
Commercial Viability ◽  
Moving Particle ◽  
Dilatant Fluid ◽  
Scale Surface

AbstractThis paper considers the possible commercial viability of applying the moving particle semi-implicit (MPS) method to avalanches. The MPS method is a powerful tool for reproducing the flow phenomenon with large-scale surface deformation. In order to apply this method to snow avalanches, we modified the original model to introduce constitutive equations of Bingham fluid, dilatant fluid and the erosion–deposition process. The modified model was applied to some cases and evaluated through comparison with experimental results and observed data.

Monitoring post-closure large scale surface deformation in mining areas

2013 ◽  
Author(s):  
Carl Banton ◽  
Luke Bateson ◽  
Harry Mccormack ◽  
Rachel Holley ◽  
Ian Watson ◽  
...  
Keyword(s):  
Large Scale ◽  
Surface Deformation ◽  
Mining Areas ◽  
Scale Surface

Using surface deformation to image reservoir dynamics

Geophysics ◽  
2000 ◽  
Vol 65 (1) ◽  
pp. 132-147 ◽  
Author(s):  
Don W. Vasco ◽  
Kenzi Karasaki ◽  
Christine Doughty
Keyword(s):  
Volume Change ◽  
Large Scale ◽  
Surface Deformation ◽  
Test Site ◽  
Oil Field ◽  
Volume Changes ◽  
Reservoir Volume ◽  
Steam Flood ◽  
Inversion Procedure ◽  
Sudden Decrease

The inversion of surface deformation data such as tilt, displacement, or strain provides a noninvasive method for monitoring subsurface volume change. Reservoir volume change is related directly to processes such as pressure variations induced by injection and withdrawal. The inversion procedure is illustrated by an application to tiltmeter data from the Hijiori test site in Japan. An inversion of surface tilt data allows us to image flow processes in a fractured granodiorite. Approximately 650 barrels of water, injected 2 km below the surface, produces a peak surface tilt of the order of 0.8 microradians. We find that the pattern of volume change in the granodiorite is very asymmetrical, elongated in a north‐northwesterly direction, and the maximum volume change is offset by more than 0.7 km to the east of the pumping well. The inversion of a suite of leveling data from the Wilmington oil field in Long Beach, California, images large‐scale reservoir volume changes in 12 one‐ to two‐year increments from 1976 to 1996. The influence of various production strategies is seen in the reservoir volume changes. In particular, a steam flood in fault block II in the northwest portion of the field produced a sudden decrease in reservoir volume.

scholarly journals The Correlation of Spatial Distribution Between Surface Deformation and Landslides by SBAS-InSAR and Spatial Analysis in Longnan Region, China

2015 ◽  
Vol 9 (1) ◽  
pp. 867-876 ◽  
Author(s):  
Xue Yating ◽  
Meng Xingmin ◽  
Guo Peng ◽  
Li Kai ◽  
Chen Guan
Keyword(s):  
Large Scale ◽  
Surface Deformation ◽  
Western China ◽  
Interferometric Synthetic Aperture Radar ◽  
Medium Thickness ◽  
Envisat Asar ◽  
Landslides Susceptibility ◽  
Distribution Features ◽  
Sbas Insar ◽  
Spot 5

We use interferometric synthetic aperture radar (InSAR) time-series analysis of Envisat ASAR data to reveal the correlation of distribution between surface deformation and landslides in western China. The results of SBAS-InSAR revealed that the velocity of surface deformation is between -18.6mm/year to 26.8mm/year. The landslides data which we extracted from SPOT 5 image and investigated in field were correlated with altitude, lithology, slope, degree, land-use, fault, NDVI and distance to river. We found that the landslides mainly distribute on 13°~41° slope degree, 1200m~2000m altitude, the strong human activity, the poor vegetation covered, near the river and fault, underlain medium thickness limestone and thin-layered siltstone and mud stone. Using the landslides distribution features, landslides will be identified from the results of surface deformation and landslides susceptibility will be assessed. This method can help local government rapidly monitor landslides and assess landslides susceptibility on large scale.

scholarly journals Fault source investigation of the 6 December 2016 MwMw 6.5 Pidie Jaya, Indonesia, earthquake based on GPS and its implications of the geological survey result

2020 ◽  
Vol 14 (4) ◽  
pp. 405-412
Author(s):  
Endra Gunawan ◽  
Takuya Nishimura ◽  
Susilo Susilo ◽  
Sri Widiyantoro ◽  
Nanang T. Puspito ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Source Parameters ◽  
Secondary Effects ◽  
Near Surface ◽  
Morphological Attributes ◽  
Ground Shaking ◽  
The North ◽  
Coulomb Failure ◽  
North And South ◽  
Fault Source

AbstractOn 6 December 2016 at 22:03 UTC, a devastating magnitude 6-class strike-slip earthquake occurred along an unidentified and unmapped fault in Pidie Jaya, northern Sumatra. We analysed the possible fault using continuous Global Positioning System (GPS) observation available in the region. In our investigation, we searched for the fault source parameters of the north- and south-dipping left-lateral faults and the west- and east-dipping right-lateral faults. We identified that the fault responsible for the earthquake was located offshore, with a southwest-northeast direction. We also computed the Coulomb failure stress and compared the result with the distribution of the aftershocks. In this study, we demonstrated that the result of the geological field survey conducted soon after the mainshock was attributed to the secondary effects of ground shaking and near-surface deformation, and not surface faulting. The newly identified offshore fault proposed by this study calls for further investigation of the corresponding submarine morphological attributes in this particular region.

scholarly journals Elucidating the Onset of Plasticity in Sliding Contacts Using Differential Computational Orientation Tomography

2021 ◽  
Vol 69 (3) ◽  
Author(s):  
S. J. Eder ◽  
P. G. Grützmacher ◽  
M. Rodríguez Ripoll ◽  
J. F. Belak
Keyword(s):  
Grain Boundary ◽  
Large Scale ◽  
Surface Deformation ◽  
Boundary Migration ◽  
Material Design ◽  
Lattice Rotation ◽  
Time Resolved ◽  
Near Surface ◽  
Color Saturation ◽  
Dynamics Simulations

Abstract Depending on the mechanical and thermal energy introduced to a dry sliding interface, the near-surface regions of the mated bodies may undergo plastic deformation. In this work, we use large-scale molecular dynamics simulations to generate “differential computational orientation tomographs” (dCOT) and thus highlight changes to the microstructure near tribological FCC alloy surfaces, allowing us to detect subtle differences in lattice orientation and small distances in grain boundary migration. The analysis approach compares computationally generated orientation tomographs with their undeformed counterparts via a simple image analysis filter. We use our visualization method to discuss the acting microstructural mechanisms in a load- and time-resolved fashion, focusing on sliding conditions that lead to twinning, partial lattice rotation, and grain boundary-dominated processes. Extracting and laterally averaging the color saturation value of the generated tomographs allows us to produce quantitative time- and depth-resolved maps that give a good overview of the progress and severity of near-surface deformation. Corresponding maps of the lateral standard deviation in the color saturation show evidence of homogenization processes occurring in the tribologically loaded microstructure, frequently leading to the formation of a well-defined separation between deformed and undeformed regions. When integrated into a computational materials engineering framework, our approach could help optimize material design for tribological and other deformation problems. Graphic Abstract .

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