Improved Implementation of Rupture Location Uncertainty in Fault Displacement Hazard Assessment

2019 ◽  
Vol 109 (5) ◽  
pp. 2132-2137
Author(s):  
Rui Chen ◽  
Mark D. Petersen
Keyword(s):  
Hazard Assessment ◽  
Fault Location ◽  
Hazard Analysis ◽  
Short Note ◽  
Location Uncertainty ◽  
Close Proximity ◽  
Fault Trace ◽  
Fault Displacement

Abstract This short note proposes an improvement to the implementation of uncertainty associated with rupture location from future earthquakes in probabilistic fault displacement hazard analysis. Location uncertainty leads to nonzero primary fault displacement near a mapped fault. With the improved implementation of location uncertainty, estimated fault displacement hazard at a given site is affected strongly by the dimension of the area considered (or the footprint size of the structure). A larger area near a mapped fault has greater potential of exhibiting primary fault displacement than does a smaller area at the same location. In addition, fault displacement hazard is affected by fault‐map quality and fault‐trace complexity. For a more accurately mapped fault with simpler geometry, larger fault displacement is expected directly over and in close proximity of the mapped fault. If fault location is highly uncertain and fault traces are complex, expected displacement is spread out in a wider zone along the mapped fault.

scholarly journals Potential Fault Displacement Hazard Assessment Using Stochastic Source Models: A Retrospective Evaluation for the 1999 Hector Mine Earthquake

GeoHazards ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 398-414
Author(s):  
Katsuichiro Goda
Keyword(s):  
Hazard Analysis ◽  
Analysis Method ◽  
Fault Rupture ◽  
Displacement Vectors ◽  
Alternative Approach ◽  
Consistent Manner ◽  
Source Models ◽  
Fault Trace ◽  
Fault Displacement

Surface fault displacement due to an earthquake affects buildings and infrastructure in the near-fault area significantly. Although approaches for probabilistic fault displacement hazard analysis have been developed and applied in practice, there are several limitations that prevent fault displacement hazard assessments for multiple locations simultaneously in a physically consistent manner. This study proposes an alternative approach that is based on stochastic source modelling and fault displacement analysis using Okada equations. The proposed method evaluates the fault displacement hazard potential due to a fault rupture. The developed method is applied to the 1999 Hector Mine earthquake from a retrospective perspective. The stochastic-source-based fault displacement hazard analysis method successfully identifies multiple source models that predict fault displacements in close agreement with observed GPS displacement vectors and displacement offsets along the fault trace. The case study for the 1999 Hector Mine earthquake demonstrates that the proposed stochastic-source-based method is a viable option in conducting probabilistic fault displacement hazard analysis.

Probabilistic Fault Displacement Hazard Assessment (PFDHA) for Nuclear Installations According to IAEA Safety Standards

2021 ◽  
Author(s):  
Alessandro Valentini ◽  
Yoshimitsu Fukushima ◽  
Paolo Contri ◽  
Masato Ono ◽  
Toshiaki Sakai ◽  
...  
Keyword(s):  
Hazard Assessment ◽  
Hazard Analysis ◽  
Surface Displacement ◽  
Hazard Evaluation ◽  
Energy Agency ◽  
Member States ◽  
Site Specific ◽  
Safety Standards ◽  
Fault Displacement ◽  
Technical Guidance

ABSTRACT In the last 10 yr, the International Atomic Energy Agency (IAEA) revised its safety standards for site evaluations of nuclear installations in response to emerging fault displacement hazard evaluation practices developed in Member States. New amendments in the revised safety guidance (DS507) explicitly recommend fault displacement hazard assessment, including separate approaches for candidate new sites versus existing sites. If there is insufficient basis to conclusively determine that a fault is not capable of surface displacement at an existing site, then a probabilistic fault displacement hazard analysis (PFDHA) is recommended to better characterize the hazard. This new recommendation has generated the need for the IAEA to provide its Member States with guidance on performing PFDHA, including its formulation and implementation. This article provides an overview of current PFDHA state-of-practice for nuclear installations that is consistent with the new IAEA safety standards. We also summarize progress in an ongoing international PFDHA benchmark project that will ultimately provide technical guidance to Member States for conducting site-specific fault displacement hazard assessments.

The Gutenberg-Richter or characteristic earthquake distribution, which is it?

1994 ◽  
Vol 84 (6) ◽  
pp. 1940-1959 ◽  
Author(s):  
Steven G. Wesnousky
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
Slip Rate ◽  
Historical Earthquakes ◽  
Practical Implementation ◽  
Characteristic Earthquake ◽  
Earthquake Model ◽  
Earthquake Distribution ◽  
Fault Trace ◽  
Major Strike

Abstract Paleoearthquake and fault slip-rate data are combined with the CIT-USGS catalog for the period 1944 to 1992 to examine the shape of the magnitude-frequency distribution along the major strike-slip faults of southern California. The resulting distributions for the Newport-Inglewood, Elsinore, Garlock, and San Andreas faults are in accord with the characteristic earthquake model of fault behavior. The distribution observed along the San Jacinto fault satisfies the Gutenberg-Richter relationship. If attention is limited to segments of the San Jacinto that are marked by the rupture zones of large historical earthquakes or distinct steps in fault trace, the observed distribution along each segment is consistent with the characteristic earthquake model. The Gutenberg-Richter distribution observed for the entirety of the San Jacinto may reflect the sum of seismicity along a number of distinct fault segments, each of which displays a characteristic earthquake distribution. The limited period of instrumental recording is insufficient to disprove the hypothesis that all faults will display a Gutenberg-Richter distribution when averaged over the course of a complete earthquake cycle. But, given that (1) the last 5 decades of seismicity are the best indicators of the expected level of small to moderate-size earthquakes in the next 50 years, and (2) it is generally about this period of time that is of interest in seismic hazard and engineering analysis, the answer to the question posed in the title of the article, at least when concerned with practical implementation of seismic hazard analysis at sites along these major faults, appears to be the “characteristic earthquake distribution.”

Application of Probabilistic Fault Displacement Hazard Analysis in Japan

2013 ◽  
Vol 13 (1) ◽  
pp. 17-36 ◽  
Author(s):  
Makoto TAKAO ◽  
Jiro TSUCHIYAMA ◽  
Tadashi ANNAKA ◽  
Tetsushi KURITA
Keyword(s):  
Hazard Analysis ◽  
Fault Displacement

scholarly journals Probabilistic Tsunami Hazard Analysis: High Performance Computing for Massive Scale Inundation Simulations

2020 ◽  
Vol 8 ◽  
Author(s):  
Steven J. Gibbons ◽  
Stefano Lorito ◽  
Jorge Macías ◽  
Finn Løvholt ◽  
Jacopo Selva ◽  
...  
Keyword(s):  
High Performance Computing ◽  
Hazard Assessment ◽  
High Performance ◽  
Hazard Analysis ◽  
Tsunami Hazard ◽  
Site Specific ◽  
Tsunami Inundation ◽  
Inundation Modelling ◽  
Probabilistic Tsunami Hazard Analysis ◽  
Performance Computing

Probabilistic Tsunami Hazard Analysis (PTHA) quantifies the probability of exceeding a specified inundation intensity at a given location within a given time interval. PTHA provides scientific guidance for tsunami risk analysis and risk management, including coastal planning and early warning. Explicit computation of site-specific PTHA, with an adequate discretization of source scenarios combined with high-resolution numerical inundation modelling, has been out of reach with existing models and computing capabilities, with tens to hundreds of thousands of moderately intensive numerical simulations being required for exhaustive uncertainty quantification. In recent years, more efficient GPU-based High-Performance Computing (HPC) facilities, together with efficient GPU-optimized shallow water type models for simulating tsunami inundation, have now made local long-term hazard assessment feasible. A workflow has been developed with three main stages: 1) Site-specific source selection and discretization, 2) Efficient numerical inundation simulation for each scenario using the GPU-based Tsunami-HySEA numerical tsunami propagation and inundation model using a system of nested topo-bathymetric grids, and 3) Hazard aggregation. We apply this site-specific PTHA workflow here to Catania, Sicily, for tsunamigenic earthquake sources in the Mediterranean. We illustrate the workflows of the PTHA as implemented for High-Performance Computing applications, including preliminary simulations carried out on intermediate scale GPU clusters. We show how the local hazard analysis conducted here produces a more fine-grained assessment than is possible with a regional assessment. However, the new local PTHA indicates somewhat lower probabilities of exceedance for higher maximum inundation heights than the available regional PTHA. The local hazard analysis takes into account small-scale tsunami inundation features and non-linearity which the regional-scale assessment does not incorporate. However, the deterministic inundation simulations neglect some uncertainties stemming from the simplified source treatment and tsunami modelling that are embedded in the regional stochastic approach to inundation height estimation. Further research is needed to quantify the uncertainty associated with numerical inundation modelling and to properly propagate it onto the hazard results, to fully exploit the potential of site-specific hazard assessment based on massive simulations.

scholarly journals Integrated Assessment of Natural Hazards, Including Climate Change’s Influences, for Cultural Heritage Sites: The Case of the Historic Centre of Rethymno in Greece

2019 ◽  
Vol 10 (3) ◽  
pp. 343-361 ◽  
Author(s):  
Mohammad Ravankhah ◽  
Rosmarie de Wit ◽  
Athanasios V. Argyriou ◽  
Angelos Chliaoutakis ◽  
Maria João Revez ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Natural Hazards ◽  
Hazard Assessment ◽  
Climate Model ◽  
Heat Waves ◽  
Hazard Analysis ◽  
Sudden Onset ◽  
Assessment Procedure ◽  
Northern Coast ◽  
Historic Centre

Abstract Within the framework of disaster risk management, this article proposes an interdisciplinary method for the analysis of multiple natural hazards, including climate change’s influences, in the context of cultural heritage. A taxonomy of natural hazards applicable to cultural heritage was developed based on the existing theoretical and conceptual frameworks. Sudden-onset hazards, such as earthquakes and floods, and slow-onset hazards, such as wetting–drying cycles and biological contamination, were incorporated into the hazard assessment procedure. Future alteration of conditions due to climate change, such as change in heat waves’ duration, was also taken into account. The proposed hazard assessment framework was applied to the case of the Historic Centre of Rethymno, a city on the northern coast of the island of Crete in Greece, to identify, analyze, and prioritize the hazards that have the potential to cause damage to the center’s historic structures. The assessment procedure includes climate model projections, GIS spatial modeling and mapping, and finally a hazard analysis matrix to enable the sharing of a better understanding of multiple hazards with the stakeholders. The results can facilitate decision making by providing the vulnerability and risk analysis with the nature and spatial distribution of the significant hazards within the study area and its setting.

scholarly journals Probabilistic Assessment of Innovative Mitigating Measures for Buried Steel Pipeline–Fault Crossing

2015 ◽  
Author(s):  
Vasileios E. Melissianos ◽  
Dimitrios Vamvatsikos ◽  
Charis J. Gantes
Keyword(s):  
Hazard Analysis ◽  
Structural Response ◽  
Comprehensive Analysis ◽  
Effectiveness Evaluation ◽  
Second Step ◽  
Flexible Joints ◽  
Intensity Measure ◽  
Seismological Data ◽  
Fault Displacement ◽  
Probabilistic Nature

A methodology is presented on assessing the effectiveness of flexible joints in mitigating the consequences of faulting on buried steel pipelines through a comprehensive analysis that incorporates the uncertainty of fault displacement magnitude and the response of the pipeline itself. The proposed methodology is a two-step process. In the first step the probabilistic nature of the fault displacement magnitude is evaluated by applying the Probabilistic Fault Displacement Hazard Analysis, considering also all pertinent uncertainties. The second step is the “transition” from seismological data to the pipeline structural response through the fault displacement components as the adopted vector intensity measure. To mitigate the consequences of faulting on pipelines, flexible joints between pipeline parts are proposed as innovative measure for reducing the deformation of pipeline walls. Thus, the mechanical behavior of continuous pipelines and pipelines with flexible joints is numerically assessed and strains are extracted in order to develop the corresponding strain hazard curves. The latter are a useful engineering tool for pipeline – fault crossing risk assessment and for the effectiveness evaluation of flexible joints as innovative mitigating measures against the consequences of faulting on pipelines.

Changes in the location of the nucleation point of slip events on ancient normal faults

2020 ◽  
Author(s):  
Efstratios Delogkos ◽  
Conrad Childs ◽  
Tom Manzocchi ◽  
John Walsh
Keyword(s):  
Continuous Mapping ◽  
Fault Slip ◽  
Propagation Direction ◽  
Normal Faults ◽  
Northern Greece ◽  
Slip Surfaces ◽  
Local Propagation ◽  
Lignite Mine ◽  
Fault Trace ◽  
Fault Displacement

<p>The lack of an unambiguous method for determining the propagation direction of slip events on faults over significant time periods limits our understanding of the long-term stability of fault slip propagation directions. A geological means for determining the propagation direction of slip events during the growth of faults is provided by mutually cross-cutting faults and bed-parallel slip-surfaces in the Ptolemais Basin, northern Greece.</p><p>In the Kardia lignite mine, Ptolemais Basin, bed-parallel slip surfaces intermittently offset the Quaternary faults as they grew to form discontinuities on otherwise continuous fault surfaces. Subsequent fault slip increments bypassed these discontinuities to re-establish a continuous fault trace and leave an associated ‘dead’ splay. The geometry and displacement distributions at these fault/bed-parallel slip intersections record the fault displacement at the time of bed-parallel slip and whether the next fault slip increment had an upwards or downwards component to its local propagation vector.</p><p>A database (N = 88) of slip propagation directions and fault throws was derived from continuous mapping of mine faces during lignite extraction over an eight year period. The data demonstrate a clear relationship between slip propagation direction and the accumulation of fault displacement on individual faults. During the early stages of fault growth, slip events propagated almost exclusively upwards through the mined sequence, but later stages of growth are marked by slip events showing both upward and downward components of propagation. The data therefore demonstrate that the location of the point of initiation of fault slip events on these Quaternary faults varied over the fault surfaces as the faults grew.</p><p>The emergence of systematic results from our analyses suggests that cross-cutting relationships between other synchronously active structures (e.g. conjugate faults) can provide a robust means for determining the propagation directions of slip events on ancient faults at outcrop.</p>

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