Statistical relations among earthquake magnitude, surface rupture length, and surface fault displacement

1984 ◽  
Author(s):  
M.G. Bonilla ◽  
R.K. Mark ◽  
J.J. Lienkaemper
Keyword(s):  
Earthquake Magnitude ◽  
Surface Rupture ◽  
Rupture Length ◽  
Fault Displacement

Surface rupture of the Greendale Fault during the Darfield (Canterbury) earthquake, New Zealand

2010 ◽  
Vol 43 (4) ◽  
pp. 236-242 ◽  
Author(s):  
M. Quigley ◽  
R. Van Dissen ◽  
P. Villamor ◽  
N. Litchfield ◽  
D. Barrell ◽  
...  
Keyword(s):  
New Zealand ◽  
Ground Surface ◽  
Vertical Displacement ◽  
Fault Rupture ◽  
Surface Rupture ◽  
Framed Structures ◽  
Rupture Length ◽  
The North ◽  
Dextral Strike Slip ◽  
East West

The Mw 7.1 Darfield (Canterbury) earthquake of 4 September 2010 (NZST) was the first earthquake in New Zealand to produce ground-surface fault rupture since the 1987 Edgecumbe earthquake. Surface rupture of the previously unrecognised Greendale Fault during the Darfield earthquake extends for at least 29.5 km and comprises an en echelon series of east-west striking, left-stepping traces. Displacement is predominantly dextral strike-slip, averaging ~2.5 m, with maxima of ~5 m along the central part of the rupture. Maximum vertical displacement is ~1.5 m, but generally < 0.75 m. The south side of the fault has been uplifted relative to the north for ~80% of the rupture length, except at the eastern end where the north side is up. The zone of surface rupture deformation ranges in width from ~30 to 300 m, and comprises discrete shears, localised bulges and, primarily, horizontal dextral flexure. At least a dozen buildings were affected by surface rupture, but none collapsed, largely because most of the buildings were relatively flexible and robust timber-framed structures and because deformation was distributed over tens to hundreds of metres width. Many linear features, such as roads, fences, power lines, and irrigation ditches were offset or deformed by fault rupture, providing markers for accurate determinations of displacement.

scholarly journals Probabilistic Fault Displacement Hazard Analysis for North Tabriz Fault

2021 ◽  
Author(s):  
Mohamadreza Hosseyni ◽  
Habib Rahimi
Keyword(s):  
Return Period ◽  
Hazard Analysis ◽  
Probabilistic Approach ◽  
Surface Displacement ◽  
Return Periods ◽  
Surface Rupture ◽  
Slip Mechanism ◽  
The North ◽  
North Tabriz Fault ◽  
Fault Displacement

Abstract. The probabilistic fault displacement hazard analysis is one of the new methods in estimating the amount of possible displacement in the area at the hazard of causal fault rupture. In this study, using the probabilistic approach and earthquake method introduced by Youngs et al., 2003, the surface displacement of the North Tabriz fault has been investigated, and the possible displacement in different scenarios has been estimated. By considering the strike-slip mechanism of the North Tabriz fault and using the earthquake method, the probability of displacement due to surface ruptures caused by 1721 and 1780 North Tabriz fault earthquakes has been explored. These events were associated with 50 and 60 km of surface rupture, respectively. The 50–60 km long section of the North Tabriz fault was selected as the source of possible surface rupture. We considered two scenarios according to possible displacements, return periods, and magnitudes which are reported in paleoseismic studies of the North Tabriz fault. As the first scenario, possible displacement, return period, and magnitude was selected between zero to 4.5; 645 years and Mw~7.7, respectively. In the second scenario, possible displacement, return period and magnitude were selected between zero to 7.1, 300 years, and Mw~7.3, respectively. For both mentioned scenarios, the probabilistic displacements for the rate of exceedance 5 % in 50, 475, and 2475 years for the principle possible displacements (on fault) of the North Tabriz fault have been estimated. For the first and second scenarios, the maximum probabilistic displacement of the North Tabriz fault at a rate of 5 % in 50 years is estimated to be 186 and 230 cm. Also, mentioned displacements for 5 % exceedance in 475 years and 2475 years in both return periods of 645 and 300 years, are estimated at 469 and 655 cm.

scholarly journals Surface slip distributions and geometric complexity of intraplate reverse-faulting earthquakes

2021 ◽  
Author(s):  
Haibin Yang ◽  
Mark Quigley ◽  
Tamarah King
Keyword(s):  
Ground Surface ◽  
Mean Value ◽  
Geometric Complexity ◽  
Trajectory Data ◽  
Surface Rupture ◽  
Intraplate Earthquakes ◽  
Maximum Displacement ◽  
Rupture Length ◽  
Surface Ruptures ◽  
Strength Gradient

Earthquake ground surface ruptures provide insights into faulting mechanics and inform seismic hazard analyses. We analyze surface ruptures for 11 historical (1968−2018) moment magnitude (Mw) 4.7−6.6 reverse earthquakes in Australia using statistical techniques and compare their characteristics with magnetic, gravity, and stress trajectory data sets. Of the total combined (summative) length of all surface ruptures (∼148 km), 133 km (90%) to 145 km (98%) align with the geophysical structure in the host basement rocks. Surface rupture length (SRL), maximum displacement (MD), and probability of surface rupture at a specified Mw are high compared with equivalent Mw earthquakes globally. This is attributed to (1) a steep cratonic crustal strength gradient at shallow depths, promoting shallow hypocenters (∼1−6 km) and limiting downdip rupture widths (∼1−8.5 km), and (2) favorably aligned crustal anisotropies (e.g., bedrock foliations, faults, fault intersections) that enhanced lateral rupture propagation and/or surface displacements. Combined (modeled and observed) MDs are in the middle third of the SRL with 68% probability and either the ≤33rd or ≥66th percentiles of SRL with 16% probability. MD occurrs proximate to or directly within zones of enhanced fault geometric complexity (as evidenced from surface ruptures) in 8 of 11 earthquakes (73%). MD is approximated by 3.3 ± 1.6 (1σ) × AD (average displacement). S-transform analyses indicates that high-frequency slip maxima also coincide with fault geometric complexities, consistent with stress amplifications and enhanced slip variability due to geometric and kinematic interactions with neighboring faults. Rupture slip taper angles exhibite large variations (−90% to +380% with respect to the mean value) toward rupture termini and are steepest where ruptures terminate at obliquely oriented magnetic lineaments and/or lithology changes. Incremental slip approximates AD between the 10th and 90th percentiles of the SRL. The average static stress drop of the studied earthquakes is 4.8 ± 2.8 MPa. A surface rupture classification scheme for cratonic stable regions is presented to describe the prevailing characteristics of intraplate earthquakes across diverse crustal structural-geophysical settings. New scaling relationships and suggestions for logic tree weights are provided to enhance probabilistic fault displacement hazard analyses for bedrock-dominated intraplate continental regions.

scholarly journals Impacts of surface fault rupture on residential structures during the 2016 Mw 7.8 Kaikōura earthquake, New Zealand

2019 ◽  
Vol 52 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Russ J. Van Dissen ◽  
Timothy Stahl ◽  
Andrew King ◽  
Jarg R. Pettinga ◽  
Clark Fenton ◽  
...  
Keyword(s):  
Slope Failure ◽  
Ground Deformation ◽  
Local Strain ◽  
Fault Rupture ◽  
Surface Rupture ◽  
Ground Shaking ◽  
Lateral Offset ◽  
Permanent Ground Deformation ◽  
Fault Displacement ◽  
Kaikoura Earthquake

Areas that experience permanent ground deformation in earthquakes (e.g., surface fault rupture, slope failure, and/or liquefaction) typically sustain greater damage and loss compared to areas that experience strong ground shaking alone. The 2016 Mw 7.8 Kaikōura earthquake generated ≥220 km of surface fault rupture. The amount and style of surface rupture deformation varied considerably, ranging from centimetre-scale distributed folding to metre-scale discrete rupture. About a dozen buildings – mainly residential (or residential-type) structures comprising single-storey timber-framed houses, barns and wool sheds with lightweight roofing material – were directly impacted by surface fault rupture with the severity of damage correlating with both local discrete fault displacement and local strain. However, none of these buildings collapsed. This included a house built directly atop a discrete rupture that experienced ~10 m of lateral offset. The foundation and flooring system of this structure allowed decoupling of much of the ground deformation from the superstructure thus preventing collapse. Nevertheless, buildings directly impacted by surface faulting suffered greater damage than comparable structures immediately outside the zone of surface rupture deformation. From a life-safety standpoint, all these buildings performed satisfactorily and provide insight into construction styles that could be employed to facilitate non-collapse performance resulting from surface fault rupture and, in certain instances, even post-event functionality.

An investigation of methods for Fault Displacement Hazard Assessment for offshore studies

2020 ◽  
Author(s):  
Emilia Fiorini
Keyword(s):  
Hazard Assessment ◽  
Ground Deformation ◽  
Surface Displacement ◽  
Warning System ◽  
Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard Assessment ◽  
Surface Rupture ◽  
Permanent Ground Deformation ◽  
Fault Displacement

&lt;p&gt;The expected surface displacement in the aftermath of an earthquake is an important issue to consider, among others, for pipeline damage. While estimates of permanent ground deformation after an earthquake event is often performed nowadays through the acquisition of Interferometric Synthetic Aperture Radar (InSAR) scenes, this method is only applicable to onshore regions.&lt;/p&gt;&lt;p&gt;In this work we explore possible methodologies for fault hazard assessment to be applied in offshore regions.&lt;/p&gt;&lt;p&gt;Methods to estimate the surface rupture hazard for faults of known location and geometry are reviewed, such as the Okada equations available in the Coulomb3 software. However since fault data may be lacking or scarce in offshore areas we also explore the availability of methods to estimate a probabilistic surface rupture assessment, to be applied within the same framework of Probabilistic Seismic Hazard Assessment studies. A simple application of both methods is presented in a hypothetic case study where an early warning system for pipeline damage inspection is required.&lt;/p&gt;

PFDHA modelling based on new empirical regressions for distributed faulting on dip-slip earthquakes

2020 ◽  
Author(s):  
Fiia Nurminen ◽  
Stéphane Baize ◽  
Paolo Boncio ◽  
Bruno Pace ◽  
Oona Scotti ◽  
...  
Keyword(s):  
Decision Making ◽  
Active Fault ◽  
Numerical Estimate ◽  
Hazard Analysis ◽  
Normal Faulting ◽  
Surface Rupture ◽  
Regression Parameters ◽  
Surface Ruptures ◽  
A Site ◽  
Fault Displacement

&lt;p&gt;Probabilistic fault displacement hazard analysis (PFDHA) is needed for a numerical estimate of the displacement likely to occur at a site near an active fault in case of a surface faulting earthquake. The methodology is based on parameters describing the probability of occurrence, and the spatial distribution of the displacement on and off-fault. The methodology was created for normal faulting setting, and has been later complemented with the parameters for other slip types, especially regarding the principal fault rupturing. Based on empirical fault displacement data in the Worldwide and Unified Database of Surface Ruptures (SURE), we are presenting new regression parameters for distributed faulting for dip-slip earthquakes. The parameters are used in a computational model for assessing the surface rupture hazard near active dip-slip faults. The modelling results the probability distribution of exceeding a chosen level of displacement, and can be used in stcture design and land-use related decision making in areas where surface faulting hazard should be considered.&lt;/p&gt;

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