Static stress changes and earthquake triggering during the 1954 Fairview Peak and Dixie Valley earthquakes, central Nevada

1997 ◽  
Vol 87 (3) ◽  
pp. 521-527
Author(s):  
S. J. Caskey ◽  
S. G. Wesnousky
Keyword(s):  
Three Dimensional ◽  
Field Studies ◽  
Static Stress ◽  
Earthquake Triggering ◽  
Three Dimensional Model ◽  
Surface Displacements ◽  
Stress Changes ◽  
Northward Propagation ◽  
Dixie Valley ◽  
Element Approach

Abstract The 16 December 1954 Dixie Valley (MS 6.8) earthquake followed the Fairview Peak (MS 7.2) earthquake by only 4 min and 20 sec. A three-dimensional model of the two dip-slip fault systems based on recent detailed field studies shows the ruptures were separated by a 6-km step in surface trace. A boundary-element approach shows that the static stress changes imposed by rupture of the Fairview Peak earthquake are in the correct sense to explain the northward propagation of faulting along four distinct faults that comprise the Fairview Peak earthquake and the subsequent triggering of the Dixie Valley earthquake. The location of rupture end points at sites where static stresses change sign is also used to suggest that static stress changes may play a role in controlling the extent of fault ruptures. We also observe that the largest coseismic surface displacements tend to correlate with those sections of the faults showing the largest positive stress change from preceding ruptures.

scholarly journals Modern Geodetic Measurement Techniques in Gravimetric Studies on the Example of Gypsum Karst in the Siesławice Region

2018 ◽  
Vol 35 ◽  
pp. 03002 ◽  
Author(s):  
Sławomir Porzucek ◽  
Monika Łój ◽  
Karolina Matwij ◽  
Wojciech Matwij
Keyword(s):  
Laser Scanning ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Digital Terrain Model ◽  
Field Studies ◽  
Surface Zone ◽  
Three Dimensional Model ◽  
Geodetic Measurement ◽  
Near Surface ◽  
Gypsum Karst

In the region of Siesławice (near Busko-Zdrój, Poland) there are unique phenomena of gypsum karst. Atmospheric factors caused numerous gypsum outcrops, canals and underground voids. The article presents the possibility of using non-invasive gravimetric surveys supplemented with geodetic measurements to illustrate karst changes occurring around the void. The use of modern geodetic measurement techniques including terrestrial and airborne laser scanning enables to generate a digital terrain model and a three-dimensional model of voids. Gravimetric field studies allowed to map the anomalies of the gravitational field of the near-surface zone. Geodetic measurement results have made it possible to accurately determine the terrain correction that supplemented the gravimetric anomaly information. Geophysical interpretation indicate the presence of weathered rocks in the near surface zone and fractures and loosened zones located surround the karst cave.

A New Technique to Calculate Earthquake Stress Transfer and to Probe the Physics of Aftershocks

2020 ◽  
Vol 110 (2) ◽  
pp. 863-873 ◽  
Author(s):  
Margarita Segou ◽  
Tom Parsons
Keyword(s):  
Stress Reduction ◽  
Regional Scale ◽  
Stress Transfer ◽  
The United States ◽  
Physical Principle ◽  
Static Stress ◽  
Stress Change ◽  
Earthquake Triggering ◽  
Triggered Earthquakes ◽  
Stress Changes

ABSTRACT Coseismic stress changes have been the primary physical principle used to explain aftershocks and triggered earthquakes. However, this method does not adequately forecast earthquake rates and diverse rupture populations when subjected to formal testing. We show that earthquake forecasts can be impaired by assumptions made in physics-based models such as the existence of hypothetical optimal faults and regional scale invariability of the stress field. We compare calculations made under these assumptions along with different realizations of a new conceptual triggering model that features a complete assay of all possible ruptures. In this concept, there always exists a set of theoretical planes that has positive failure stress conditions under a combination of background and coseismic static stress change. In the Earth, all of these theoretical planes may not exist, and if they do, they may not be ready to fail. Thus, the actual aftershock plane may not correspond to the plane with the maximum stress change value. This is consistent with observations that mainshocks commonly activate faults with exotic orientations and rakes. Our testing ground is the M 7.2, 2010 El Mayor–Cucapah earthquake sequence that activated multiple diverse fault populations across the United States–Mexico border in California and Baja California. We carry out a retrospective test involving 748 M≥3.0 triggered earthquakes that occurred during a 3 yr period after the mainshock. We find that a probabilistic expression of possible aftershock planes constrained by premainshock rupture patterns is strongly favored (89% of aftershocks consistent with static stress triggering) versus an optimal fault implementation (35% consistent). Results show that coseismic stress change magnitudes do not necessarily control earthquake triggering, instead we find that the summed background stress and coseismic stress change promotes diverse ruptures. Our model can thus explain earthquake triggering in regions where optimal plane mapping shows coseismic stress reduction.

Finite Element Analysis of Load Capacity on Coupling Clamps for Pipe

2012 ◽  
Vol 201-202 ◽  
pp. 741-744 ◽  
Author(s):  
Zhen Ning Hou ◽  
Jun Wu ◽  
Qing Wang ◽  
Hong Gen Tian ◽  
Nan Chao ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Optimization Design ◽  
Load Capacity ◽  
Three Dimensional ◽  
Process Conditions ◽  
Fe Model ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Element Approach

A finite element approach based on Ansys is developed to simulate stress intensity distribution in a three dimensional model of coupling clamp joint, which includes ferrules, pipe caps and bolts. The characteristics of stress intensity distributions of coupling clamp joint under strength pressure loading have been studied by means of the non-linear finite element method. The FE model can also predict the clamp quality and tolerances to be expected under different process conditions and define the most effective process parameters to influence the tolerances. The study could give us a better understanding on the mechanism and basis for optimization design of the coupling clamp joint.

Investigation of Dynamic and Static Effects on Earthquake Triggering Using Different Rate and State Friction Laws and Marmara Simulation

2020 ◽  
Author(s):  
Eyup Sopaci ◽  
Atilla Arda Özacar
Keyword(s):  
Onset Time ◽  
Static Stress ◽  
Fault System ◽  
Dynamic Effects ◽  
Earthquake Triggering ◽  
Dynamic Changes ◽  
System Parameters ◽  
Fault Segment ◽  
Stress Changes ◽  
Rate And State Friction

<p>The clock of an earthquake can be advanced due to dynamic and static changes when a triggering signal is applied to a stress-loading fault. While static effects decrease rapidly with distance, dynamic effects can reach thousands of kilometers away. Therefore, earthquake triggering is traditionally associated to static stress changes at local distances and to dynamic effects at greater scales. However, static and dynamic effects near the triggering signal are often nested, thus identifying which effect dominates, becomes unclear. So far, earthquake triggering has been tested using different rate-and-state friction (RSF) laws utilizing alternative views of friction without much comparison. In this study, the analogy of an earthquake is simulated using single degree of freedom spring-block systems governed with three different RSF laws, namely “Dieterich”, “Ruina” and “Perrin”. First, the fault systems are evolved until they reach a stable limit cycle and then static, dynamic and their combination are applied as triggering signals. During synthetic simulations, effects of the triggering signal parameters (onset time, size, duration and frequency) and the fault system parameters (fault stiffness, characteristic slip distance, direct velocity and time dependent state effects) are tested separately. Our results indicate that earthquake triggering is controlled mainly by the onset time, size and duration of the triggering signal but not much sensitive to the signal frequency. In terms of fault system parameters, the fault stiffness and the direct velocity effect are the critical parameters in triggering processes. Among the tested RSF laws, “Ruina” law is more sensitive than “Dieterich” law to both static and dynamic changes and “Perrin” is apparently the most sensitive law to dynamic changes. Especially, when the triggering onset time is close to an unperturbed failure time (future earthquake), dynamic changes result the largest clock advancement, otherwise, static stress changes are substantially more effective. In the next step, realistic models will be established to simulate the effect of the recent (26 September 2019) Marmara earthquake with Mw=5.7 on the locked Kumburgaz fault segment of the North Anatolian Fault Zone. The triggering earthquake will be simulated by combining the static stress change computed via Coulomb law and the dynamic effects using ground motions recorded at broadband seismic stations within similar distances. Outcomes will help us to better understand the effects of static and dynamic changes on the seismic cycle of the Kumburgaz fault segment, which is expected to break soon with a possibly big earthquake causing damage at the metropolitan area of Istanbul in Turkey.</p>

scholarly journals Impact of Density Gradients on Net Sediment Transport into the Wadden Sea

2008 ◽  
Vol 38 (3) ◽  
pp. 566-587 ◽  
Author(s):  
Hans Burchard ◽  
Götz Flöser ◽  
Joanna V. Staneva ◽  
Thomas H. Badewien ◽  
Rolf Riethmüller
Keyword(s):  
Wadden Sea ◽  
Sea Water ◽  
Model Simulation ◽  
Three Dimensional ◽  
Field Studies ◽  
Tidal Mixing ◽  
Density Gradients ◽  
Three Dimensional Model ◽  
Model Simulations ◽  
The North

Abstract This study tests the hypothesis that horizontal density gradients have the potential to significantly contribute to the accumulation of suspended particulate matter (SPM) in the Wadden Sea. It is shown by means of long-term observations at various positions in the Wadden Sea of the German Bight that the water in the inner regions of the Wadden Sea is typically about 0.5–1.0 kg m−3 less dense than the North Sea water. During winter this occurs mostly because of freshwater runoff and net precipitation; during summer it occurs mostly because of differential heating. It is demonstrated with idealized one-dimensional water column model simulations that the interaction of such small horizontal density gradients with tidal currents generates net onshore SPM fluxes. Major mechanisms for this are tidal straining, estuarine circulation, and tidal mixing asymmetries. Three-dimensional model simulations in a semienclosed Wadden Sea embayment with periodic tidal forcing show that SPM with sufficiently high settling velocity (ws = 10−3 m s−1) is accumulating in the Wadden Sea Bight because of density gradients. This is proven through a comparative model simulation in which the dynamic effects of the density gradients are switched off, with the consequence of no SPM accumulation. These numerical model results motivate future targeted field studies in different Wadden Sea regions with the aim to further support the hypothesis.

Numerical simulation of circulation in Gulf St Vincent due to an idealized storm.

1977 ◽  
Vol 28 (6) ◽  
pp. 775 ◽  
Author(s):  
AH Sharobeam ◽  
TG Sag
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Equation Of Motion ◽  
Vertical Surface ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Primitive Equation ◽  
Surface Displacements ◽  
Complete Reversal ◽  
Vertical Grid

A three-dimensional model was developed using the primitive equation of motion and continuity equation and allowing for vertical surface displacements to occur. Actual depths were used and observed values for the temperature and salinity were used to calculate the density. Four vertical grid layers were used in the numerical simulation of the circulation. The wind speed and directions were based on a theoretical form for the wind stream function. This form was similar to that for observed storm patterns in the gulf area. The simulation was carried out over a period of about 60 h and displays of mass transports, horizontal velocities at each layer and surface elevations were produced at regular intervals throughout the simulation. In the wake of the storm there was a complete reversal of the directions of the flow after the first 6 h followed by a return to the original directions after the next 6 h and then a return to the initial steady state during the next 12 h. The elevations were found to increase rapidly with the increase in the wind velocity in the shallow parts of the gulf and the lines of constant elevations settled to a direction perpendicular to the wind direction.

Static Stress Distribution in Microvessel Wall with a Layered Model

2013 ◽  
Vol 772 ◽  
pp. 258-263
Author(s):  
Fa Rong Gao ◽  
Xu Gang Xi ◽  
Yun Yuan Gao ◽  
Qi Zhong Zhang
Keyword(s):  
Stress Distribution ◽  
Outer Layer ◽  
Current Model ◽  
Circumferential Stress ◽  
Three Dimensional ◽  
Static Stress ◽  
Stress Changes ◽  
Elastic Vessel ◽  
Microvessel Wall ◽  
Initial Blood Pressure

Based on the vascular membrane stress model and the pseudo-elastic vessel model, the combination constitutive model with a layered structure in microvessel is presented in this paper. By using obtained constitutive equations of the current model, the circumferential stress of the membrane intimal (inner) layer and the three-dimensional stress distribution of the structural outer layer are analyzed. Under the initial blood pressure state, the vascular static stress changes with the inner stiffness increase are also discussed. The results show that with inner stiffness increasing, the stress of outer layer is less affected but the circumferential stress of the intimal layer is increased significantly, which may be one potential risk factor for the vascular injury. These analysis methods and its conclusions have some theoretical significance for studying the problems of arteriosclerosis and other diseases, and preventing the occurrence of related diseases.

scholarly journals Numerical Simulations Using Various Models for Tsunamis Due to a Fluid or Rigid Bodies Falling Down a Uniform Slope

2021 ◽  
Vol 16 (7) ◽  
pp. 994-1004
Author(s):  
Taro Kakinuma ◽  
Mitsuru Yanagihara ◽  
Tsunakiyo Iribe ◽  
Kuninori Nagai ◽  
Chisato Hara ◽  
...  
Keyword(s):  
Water Level ◽  
Numerical Models ◽  
Three Dimensional ◽  
Wave Model ◽  
Rigid Bodies ◽  
Type Model ◽  
Three Dimensional Model ◽  
Long Wave ◽  
Surface Displacements ◽  
Level Model

Tsunami generation due to a landslide has been simulated using various numerical models, and the resulting water surface displacements from the models, as well as the corresponding experimental data, are compared. The numerical models used in this study are a two-layer long-wave model, a two-level non-hydrostatic model, a three-dimensional model, a lattice-Boltzmann-type model, an SPH-type model, and an MPS-type model. Tsunamis generated by a fluid falling down a uniform slope are accurately reproduced by the models, especially when the wave height of the tsunami is not large. When using the two-layer long-wave model, in which the two layers of a falling fluid and seawater are assumed not to mix, the parameters including the seabed friction coefficient, adjusted in one case, are not appropriate for other mixing conditions. The two-level model with non-hydrostatic pressure exhibits wave disintegration owing to the effects of both nonlinearity and dispersion, although the second wave generated by the reflection of a wave traveling towards the shore is not simulated accurately. Tsunamis caused by a group of rigid cylinders falling down a uniform slope have also been simulated using two Lagrangian models, namely the SPH- and MPS-type models. Although the first peak at the water level is accurately reproduced by both models, the water level at the trough between the first and second crests is overestimated.

scholarly journals Earthquake triggering model based on normal-stress-dependent Nagata law: application to the 2016 Mie offshore earthquake

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Shingo Yoshida ◽  
Takuto Maeda ◽  
Naoyuki Kato
Keyword(s):  
Shear Stress ◽  
Normal Stress ◽  
Static Stress ◽  
Stress Dependence ◽  
Slow Slip ◽  
Earthquake Triggering ◽  
Slow Slip Events ◽  
Stress Changes ◽  
Stress Dependent ◽  
Offshore Earthquake

Abstract We propose a normal-stress-dependent Nagata law. Nagata et al. (J Geophys Res 117:B02314, 2012) revised the rate- and state-dependent friction law by introducing the shear stress dependence. We further extended the Nagata law by incorporating the normal stress dependence obtained by Linker and Dieterich (J Geophys Res 97:4923–4940, 1992). We performed numerical simulations of earthquake triggering by assuming the extended Nagata law. In the case of repeated earthquakes, we applied dynamic Coulomb failure function (CFF) perturbation due to normal or shear stress changes. CFF perturbation increased the slip velocity after the cessation of perturbation, relative to that of the repeated events without triggering. This leads to dynamic earthquake triggering for certain perturbation amplitudes with time to instability of 0 to several tens of days. In addition, triggering potential of the static CFF jump (ΔCFFs) was investigated. Static stress perturbation has a higher triggering potential than dynamic stress perturbation for the same magnitude of CFF. The equivalent ΔCFFeq is evaluated for dynamic perturbation that results in a triggering potential approximately the same as in the case of static stress perturbation if ΔCFFs = ΔCFFeq. We calculated ΔCFFeq on the interface of the Philippine Sea plate for the Mie offshore earthquake, which occurred around the Nankai Trough on April 1, 2016, using OpenSWPC. The results shows that ΔCFFeq is large around the trough, where slow slip events followed the Mie earthquake, suggesting that a large ΔCFFeq may have triggered slow slip events.

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