Probabilistic fault displacement hazard analysis of the Anghiari - Città di Castello normal fault (Italy)

2021 ◽  
Vol 140 (3) ◽  
pp. 1-20
Author(s):  
Alessio Testa ◽  
Alessandro Valentini ◽  
Paolo Boncio ◽  
Bruno Pace ◽  
Francesco Visini ◽  
...  
Keyword(s):  
Hazard Analysis ◽  
Normal Fault ◽  
Fault Displacement

A new release of the SURE database of earthquake surface ruptures suited to Fault Displacement Hazard Analysis

2021 ◽  
Author(s):  
Stéphane Baize ◽  
Anna Maria Blumetti ◽  
Paolo Boncio ◽  
Francesca Romana Cinti ◽  
Riccardo Civico ◽  
...  
Keyword(s):  
Land Use Planning ◽  
Hazard Analysis ◽  
Active Faults ◽  
Normal Fault ◽  
Surface Expression ◽  
Reverse Fault ◽  
Empirical Relationships ◽  
Global Database ◽  
Ranking Scheme ◽  
Fault Displacement

<p>Fault displacement hazard assessment is based on empirical relationships derived from data of historical surface rupturing earthquakes. This approach is used for land use planning, sizing of lifelines or major sensitive infrastructures located in the proximity of active faults. These relationships provide the probability of occurrence of surface rupture and predict the amount of displacement, both for the main ruptures (principal) and for distributed ones appearing beyond.</p><p>Following the first version of the global database SURE 1.0 (Baize et al., 2019), we are continuing the effort to compile observations from well-documented historical and recent surface faulting events in order to feed and improve empirical relationships. The new SURE2.0 global database consolidates the previous version SURE 1.0 data, rejecting some poorly constrained cases, reviewing some cases already in, and adding well-documented new ones (e.g. Ridgecrest sequence, USA, 2019). In total, the SURE 2.0 database has 46 earthquakes, including 15 normal fault cases, 16 reverse fault cases and 15 strike-slip cases from 1872 to 2019. The magnitude range is from M4.9 to 7.9, with ruptures from 5 to 300 km long.</p><p>SURE 2.0 provides the geometric location and attribute information of rupture segments in a GIS environment and a spreadsheet reports the amplitude and characteristics of deformation, including data sources and its eventual geometric refinement during analysis. In this new version, we completed an essential task to derive attenuation relationships, by classifying each rupture segment and each slip measurement point, using a ranking scheme based on the pattern and amplitude of the observed rupture traces, and considering the structural context and the long-term geomorphology. This distinguishes the principal rupture (class 1), which is the main surface expression of the source of the earthquake. Typically, in the siting study, this class is assigned to the identified active fault. Class 2 features (distributed ruptures) are characterized by shorter lengths and smaller displacements that appear randomly close and around the main rupture. We introduced the distributed main fracture category (class 1.5), which corresponds to the relatively long minor fractures recognized on cumulative structures secondary to the main fault. Class 3 represents triggered slip evidences on remote active faults, clearly not connected with the earthquake causative fault (sympathetic ruptures).</p><p>As was done with reverse fault cases (Nurminen et al., 2020), this new SURE 2.0 version will be used to derive probabilities associated with the rupture distribution  during any type of earthquake.</p>

scholarly journals The impact of earthquakes on fluids in the crust

1994 ◽  
Vol 37 (6) ◽  
Author(s):  
G. C. P. King ◽  
R. M. Wood
Keyword(s):  
Water Discharge ◽  
Normal Fault ◽  
Reverse Fault ◽  
Crustal Rocks ◽  
Decay Times ◽  
Crystalline Crust ◽  
Chemical Behaviour ◽  
Deformation Models ◽  
Fault Displacement ◽  
The Impact

The character of the hydrological changes that follow major earthquakes has been investigated and found to be critically dependent on the style of fault displacement. In areas where fracture-flow in the crystalline crust communicates uninterrupted with the surface the most significant response is found to accompany major normal fault earthquakes. Increases in spring and river discharges peak a few days after the earthquake and typically excess flow is sustained for a period of 4 12 months. Rainfall equivalent discharges, have been found to ceed 100 mm close to the fault and remain above 10 mm at distances greater than 50 km. The total volume of water released in two M 7 normal fault earthquakes in the Western U.S.A. was 0.3-0.5 km3. In contrast, hydroIogical changes accompanying reverse fault earthquakes are either undetected or else involve falls in well-levels and spring-flows. The magnitude and distribution of the water-discharge for these events is compared with deformation models calibrated from seismic and geodetic information, and found to correlate with the crustal volume strain down to a depth of at least 5 km. Such relatively rapid drainage is only possible if the fluid was formerly contained in high aspect ratio fissures interconnected throughout much of the seismogenic upper crust. The rise and decay times of the discharge are shown to be critically dependent on crack widths, for which the «characteristic» or dominant cracks cannot be wider than 0.03 mm. These results suggest that fluid-filled cracks are ubiquitous throughout the brittle continental crust, and that these cracks open and close through the earthquake cycle. Seismohydraulic fluid flows have major implications for our understanding of the mechanical and chemical behaviour of crustal rocks, of the tectonic controls of fluid flow associated with petroleum migration, hydrothermal mineralisation and a significant hazard for underground waste disposal.

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 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.

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 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.

scholarly journals Paleoseismological analysis of the Rurrand fault near Jülich, Roer Valley graben, Germany: Coseismic or aseismic faulting history?

2001 ◽  
Vol 80 (3-4) ◽  
pp. 155-169 ◽  
Author(s):  
K. Vanneste ◽  
K. Verbeeck
Keyword(s):  
Normal Fault ◽  
Historical Earthquakes ◽  
Early Pleistocene ◽  
Moderate Activity ◽  
Rhine River ◽  
Fault Creep ◽  
Vertical Movements ◽  
Roer Valley Graben ◽  
Fault Displacement ◽  
German Part

AbstractA first trench has been excavated for paleoseismological analysis in the German part of the Roer Valley graben, which has experienced several historical earthquakes with a maximum intensity up to VIII on the MSK-scale.The trench has exposed the Rurrand fault as a complex fault zone with at least five separate, SW-dipping, normal fault strands displacing an early Pleistocene terrace of the Rhine river by more than 7 m. The major part of the observed deformation was produced during or after deposition of an overlying unit of stratified loess of middle Weichselian to probably Saalian age. The faulting history is shown to be episodic, with different fault strands active at different times. Growth faulting that would be indicative of continuous, aseismic fault motion has not been observed. Our stratigraphic control is not sufficient to constrain the timing and to provide evidence of the coseismic nature for each observed fault displacement. However, two units of structureless, gravelly loess are interpreted as the result of extensive solifluction triggered by two large surface-rupturing events. This is suggested by the position of these units, which is controlled by the main faults, and by their remarkably young age (< 400 cal. BC), indicated by radiocarbon and OSL datings and by the presence of historic brick fragments. At least two faults show moderate activity that is even younger. Our interpretation is not in agreement with earlier hypotheses that ongoing vertical movements of circa 1 mm/a in the German part of the Lower Rhine graben are the result of aseismic fault creep, but is in line with the results of similar investigations on the southwestern border fault of the Roer Valley Graben in Belgium, which demonstrates the need for further paleoseismological research in this region. The Rurrand fault is presently experiencing aseismic slip on its superficial portion, induced by extensive groundwater lowering for mining purposes. This ongoing deformation seems to be expressed in the trench as diffuse bundles of anastomosing cracks extending up to, and in some cases even into the plough zone, rather than as sharp fault planes which are typical of older, tectonic fault movements.

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