Regional Difference in Scaling Laws for Large Earthquakes and its Tectonic Implication

2000 ◽  
pp. 2283-2302 ◽  
Author(s):  
Yoshihiro Fujii ◽  
Mitsuhiro Matsu’ura
Keyword(s):  
Regional Difference ◽  
Scaling Laws ◽  
Tectonic Implication ◽  
Large Earthquakes

scholarly journals Tectonic Geomorphology and Paleoseismology of the Sharkhai fault: a new source of seismic hazard for Ulaanbaatar (Mongolia)

2021 ◽  
Author(s):  
Abeer Al-Ashkar ◽  
Antoine Schlupp ◽  
Matthieu Ferry ◽  
Ulziibat Munkhuu
Keyword(s):  
Seismic Hazard ◽  
Scaling Laws ◽  
Active Faults ◽  
Seismic Hazard Assessment ◽  
Capital City ◽  
Tectonic Geomorphology ◽  
Time Interval ◽  
Coseismic Slip ◽  
Slip Rates ◽  
Large Earthquakes

Abstract. We present new constraints from tectonic geomorphology and paleoseismology along the newly discovered Sharkhai fault near the capital city of Mongolia. Detailed observations from high resolution Pleiades satellite images and field investigations allowed us to map the fault in detail, describe its geometry and segmentation, characterize its kinematics, and document its recent activity and seismic behavior (cumulative displacements and paleoseismicity). The Sharkhai fault displays a surface length of ~40 km with a slightly arcuate geometry, and a strike ranging from N42° E to N72° E. It affects numerous drainages that show left-lateral cumulative displacements reaching 57 m. Paleoseismic investigations document the faulting and deposition record for the last ~3000 yr and reveal that the penultimate earthquake (PE) occurred between 1515 ± 90 BC and 945 ± 110 BC and the most recent event (MRE) occurred after 860 ± 85 AD. The resulting time interval of 2080 ± 470 years is the first constraint on the Sharkhai fault for large earthquakes. On the basis of our mapping of the surface rupture and the resulting segmentation analysis, we propose two possible scenarios for large earthquakes with likely magnitudes between 6.4 ± 0.2 and 7.1 ± 0.2. Furthermore, we apply scaling laws to infer coseismic slip values and derive preliminary estimates of long-term slip rates between 0.2 ± 0.2 and 1.0 ± 0.5 mm/y. Finally, we propose that these original observations and results from a newly discovered fault should be taken into account for the seismic hazard assessment for the city of Ulaanbaatar and help build a comprehensive model of active faults in that region.

scholarly journals The impact of earthquakes on orogen-scale exhumation

2019 ◽  
Author(s):  
Oliver R. Francis ◽  
Tristram C. Hales ◽  
Daniel E. J. Hobley ◽  
Xuanmei Fan ◽  
Alexander J. Horton ◽  
...  
Keyword(s):  
Scaling Laws ◽  
Cosmogenic Radionuclides ◽  
Surface Uplift ◽  
Bedrock Weathering ◽  
Exhumation Rates ◽  
Averaging Time ◽  
Recent Earthquakes ◽  
The Impact ◽  
Large Earthquakes

Abstract. Individual, large thrusting earthquakes can cause hundreds to thousands of years of exhumation in a geologically instantaneous moment through landslide generation. The bedrock landslides generated are important weathering agents through the conversion of bedrock into mobile sediment. Despite this, records of surface uplift and exhumation at the orogen scale contain little to no evidence of individual large earthquakes. We examine how earthquakes influence exhumation rates by exploring how stochastic earthquakes and landslides affect surface uplift and exhumation in a zero-dimensional numerical model, supported by observations from the 2008 Mw7.9 Wenchuan earthquake. Our model uses empirically constrained seismic, weathering, and landsliding scaling laws to show that large earthquakes generate the most surface uplift, despite causing exhumation of the bedrock surface. Where earthquakes, rather than aseismic processes predominantly drive rock uplift, rapid surface uplift can occur when regolith is preserved in the orogen, which limits the amount of bedrock weathering. By simulating the concentration of cosmogenic radionuclides within the model domain, we can examine the timescales over which earthquake-driven changes in exhumation can be measured. After an initial lowering in well-mixed landslide material, the concentration of 10Be returns to the long-term average within 103 years. We further demonstrate that the variability in exhumation caused by earthquakes occurs at timescales shorter than the averaging time of most thermochronometers. When combined with evidence of signal shredding response within recent earthquakes, it seems unlikely for single earthquakes to affect long-term measurements of exhumation rates. Nevertheless, short term stochastic feedbacks between weathering and exhumation produce measurable increases in cosmogenically measured exhumation rates which can be linked to earthquakes.

Siphon Flows in Stratified Coronal Loops

1994 ◽  
Vol 144 ◽  
pp. 185-187
Author(s):  
S. Orlando ◽  
G. Peres ◽  
S. Serio
Keyword(s):  
Heat Flux ◽  
Scaling Laws ◽  
Flow Model ◽  
Supersonic Flows ◽  
Coronal Loops ◽  
Characteristic Parameters

AbstractWe have developed a detailed siphon flow model for coronal loops. We find scaling laws relating the characteristic parameters of the loop, explore systematically the space of solutions and show that supersonic flows are impossible for realistic values of heat flux at the base of the upflowing leg.

Equilibrium scaling laws for layered spin glasses

1993 ◽  
Vol 3 (10) ◽  
pp. 2041-2062 ◽  
Author(s):  
M. J. Thill ◽  
H. J. Hilhorst
Keyword(s):  
Spin Glasses ◽  
Scaling Laws ◽  
Layered Spin

Analysis of shear bands in slow granular flows using a frictional Cosserat model

2000 ◽  
Vol 627 ◽  
Author(s):  
Prabhu R. Nott ◽  
K. Kesava Rao ◽  
L. Srinivasa Mohan
Keyword(s):  
Scaling Laws ◽  
Shear Bands ◽  
Shear Layers ◽  
Theoretical Description ◽  
Field Variable ◽  
Cosserat Continuum ◽  
Momentum Balance ◽  
Rigid Plastic ◽  
Independent Field ◽  
Cosserat Model

ABSTRACTThe slow flow of granular materials is often marked by the existence of narrow shear layers, adjacent to large regions that suffer little or no deformation. This behaviour, in the regime where shear stress is generated primarily by the frictional interactions between grains, has so far eluded theoretical description. In this paper, we present a rigid-plastic frictional Cosserat model that captures thin shear layers by incorporating a microscopic length scale. We treat the granular medium as a Cosserat continuum, which allows the existence of localised couple stresses and, therefore, the possibility of an asymmetric stress tensor. In addition, the local rotation is an independent field variable and is not necessarily equal to the vorticity. The angular momentum balance, which is implicitly satisfied for a classical continuum, must now be solved in conjunction with the linear momentum balances. We extend the critical state model, used in soil plasticity, for a Cosserat continuum and obtain predictions for flow in plane and cylindrical Couette devices. The velocity profile predicted by our model is in qualitative agreement with available experimental data. In addition, our model can predict scaling laws for the shear layer thickness as a function of the Couette gap, which must be verified in future experiments. Most significantly, our model can determine the velocity field in viscometric flows, which classical plasticity-based model cannot.

Scaling laws of cylindrical shells under lateral pressure

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1669-1671
Author(s):  
A. Tabiei ◽  
J. Sun ◽  
G. J. Simitses
Keyword(s):  
Scaling Laws ◽  
Lateral Pressure ◽  
Cylindrical Shells
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