Buildings Setbacks Research From Surface-Fault-Rupture Statistical Analysis

2012 ◽  
Vol 204-208 ◽  
pp. 2410-2418 ◽  
Author(s):  
Jian Yi Zhang ◽  
Jing Shan Bo ◽  
Guo Dong Xu ◽  
Jing Yi Huang
Keyword(s):  
Fault Location ◽  
Active Fault ◽  
Active Faults ◽  
Damage Index ◽  
Earthquake Hazard ◽  
Hazard Evaluation ◽  
Fault Rupture ◽  
Surface Rupture ◽  
Wenchuan Ms8.0 Earthquake ◽  
Evaluation Project

With the author and others scientific investigation on China Wenchuan Ms8.0 earthquake, China Yushu Ms7.1 earthquake and "China's active fault surveying and earthquake hazard evaluation project" relevant data results and the world requirements about project setback of active faults, etc., this paper concluded that: (1) width of Surface-Fault-Rupture is about 40m by statistics, or from the main surface rupture trace about 20m; (2) width of Surface-Fault-Rupture S and the fault vertical offset V, statistical diagrams and formulas S=8.72+9.01V; (3) Setback of the main surface trace D and buildings from damage index I, statistical diagrams and formulas I=0.7969-0.00231D; (4) based on the first three results and by the actual statistics of accuracy, we get three active fault location accuracy level of the standard i, ii, iii, respectively, the error is ± 5m, ± 25m, ± 60m, also, can give this level of standards of Surface-Fault-Rupture width to the actual engineering applications.

scholarly journals Preliminary paleoearthquake investigations of active faults on Awaji Island, Japan,
 in relation to the 1995 Great Hanshin (Kobe) earthquake

1996 ◽  
Vol 29 (3) ◽  
pp. 172-177
Author(s):  
R. Van Dissen ◽  
J. Begg ◽  
Y. Awata
Keyword(s):  
New Zealand ◽  
Active Fault ◽  
Active Faults ◽  
Geological Survey ◽  
Historical Records ◽  
Surface Rupture ◽  
Kobe Earthquake ◽  
Nojima Fault ◽  
One Year ◽  
Hanshin Earthquake

Approximately one year after the Great Hanshin (Kobe) Earthquake, two New Zealand geologists were invited to help with the Geological Survey of Japan's paleoearthquake/active fault studies in the Kobe/Awaji area. Trenches excavated across the Nojima fault, which ruptured during the Great Hanshin Earthquake, showed evidence of past surface rupture earthquakes, with the age of the penultimate earthquake estimated at approximately 2000 years. A trench across the Higashiura fault, located 3-4 km southeast of the Nojima fault, revealed at least two past surface rupture earthquakes. The timing of the older earthquakes is not yet known, but pottery fragments found in the trench constrain the timing of the most recent earthquake at less than 500-600 years. Historical records for this part of Japan suggest that within the last 700 years there has been only one regionally felt earthquake prior to the 1995 Great Hanshin Earthquake, and this was the AD 1596 Keicho Earthquake. It thus seems reasonable to suggest that the Higashiura fault was, at least in part, the source of the AD 1596 Keicho Earthquake.

scholarly journals Earthquake Risk Assessment for Tehran, Iran

2020 ◽  
Vol 9 (7) ◽  
pp. 430
Author(s):  
Farnaz Kamranzad ◽  
Hossein Memarian ◽  
Mehdi Zare
Keyword(s):  
Population Distribution ◽  
Probabilistic Approach ◽  
Active Faults ◽  
Earthquake Hazard ◽  
Earthquake Risk ◽  
Vulnerability Factors ◽  
Surface Rupture ◽  
Hazard Exposure ◽  
Vulnerability Maps ◽  
Earthquake Risk Assessment

The megacity of Tehran, the capital of Iran, is subjected to a high earthquake risk. Located at the central part of the Alpine–Himalayan seismic belt, Tehran is surrounded by several active faults that show some M7+ historical earthquake records. The high seismic hazard in combination with a dense population distribution and several vulnerability factors mean Tehran is one of the top 20 worldwide megacities at a high earthquake risk. This article aims to prepare an assessment of the present-day earthquake risk in Tehran. First, the earthquake risk components including hazard, exposure, and vulnerability are evaluated based on some accessible GIS-based datasets (e.g., seismicity, geology, active faults, population distribution, land use, urban fabric, buildings’ height and occupancy, structure types, and ages, as well as the vicinity to some critical infrastructures). Then, earthquake hazard maps in terms of PGA are prepared using a probabilistic approach as well as a surface rupture width map. Exposure and vulnerability maps are also provided deterministically in terms of population density and hybrid physical vulnerability, respectively. Finally, all these components are combined in a spatial framework and an earthquake risk map is provided for Tehran.

Evidence of Previous Faulting along the 2019 Ridgecrest, California, Earthquake Ruptures

2020 ◽  
Vol 110 (4) ◽  
pp. 1427-1456 ◽  
Author(s):  
Jessica Ann Thompson Jobe ◽  
Belle Philibosian ◽  
Colin Chupik ◽  
Timothy Dawson ◽  
Scott E. K. Bennett ◽  
...  
Keyword(s):  
Active Fault ◽  
Active Faults ◽  
Ground Surface ◽  
Vertical Motion ◽  
Fault System ◽  
Field Observations ◽  
Surface Rupture ◽  
Earthquake Ruptures ◽  
Slip Displacement ◽  
Surface Ruptures

ABSTRACT The July 2019 Ridgecrest earthquakes in southeastern California were characterized as surprising by some, because only ∼35% of the rupture occurred on previously mapped faults. Employing more detailed inspection of pre-event high-resolution topography and imagery in combination with field observations, we document evidence of active faulting in the landscape along the entire fault system. Scarps, deflected drainages, and lineaments and contrasts in topography, vegetation, and ground color demonstrate previous slip on a dense network of orthogonal faults, consistent with patterns of ground surface rupture observed in 2019. Not all of these newly mapped fault strands ruptured in 2019. Outcrop-scale field observations additionally reveal tufa lineaments and sheared Quaternary deposits. Neotectonic features are commonly short (<2  km), discontinuous, and display en echelon patterns along both the M 6.4 and M 7.1 ruptures. These features are generally more prominent and better preserved outside the late Pleistocene lake basins. Fault expression may also be related to deformation style: scarps and topographic lineaments are more prevalent in areas where substantial vertical motion occurred in 2019. Where strike-slip displacement dominated in 2019, the faults are mainly expressed by less prominent tonal and vegetation features. Both the northeast- and northwest-trending active-fault systems are subparallel to regional bedrock fabrics that were established as early as ∼150  Ma, and may be reactivating these older structures. Overall, we estimate that 50%–70% (i.e., an additional 15%–35%) of the 2019 surface ruptures could have been recognized as active faults with detailed inspection of pre-earthquake data. Similar detailed mapping of potential neotectonic features could help improve seismic hazard analyses in other regions of eastern California and elsewhere that likely have distributed faulting or incompletely mapped faults. In areas where faults cannot be resolved as single throughgoing structures, we recommend a zone of potential faulting should be used as a hazard model input.

Criteria for Surface Rupture Microzonation of Active Faults for Earthquake Hazards in Urban Areas

2018 ◽  
pp. 187-230
Author(s):  
Hasan Sözbilir ◽  
Çağlar Özkaymak ◽  
Bora Uzel ◽  
Ökmen Sümer
Keyword(s):  
Land Use Planning ◽  
Urban Areas ◽  
Active Faults ◽  
Earthquake Hazard ◽  
Disaster Mitigation ◽  
Rupture Zone ◽  
Earthquake Hazards ◽  
Surface Rupture ◽  
Earthquake Hazard Assessment ◽  
Earthquake Effects

Formation of surface rupture zone along active faults buried directly beneath major cities create devastating earthquakes that seriously threaten the safety of human lives. Surface rupture microzonation (SRM) is the generic name for subdividing a region into individual areas having different potentials hazardous earthquake effects, defining their specific seismic behavior for engineering design and land-use planning in case a large devastating earthquake strikes the region. The basis of SRM is to model the rupture zone at the epicenter of an earthquake, and thus develop a hazard-avoid map indicating the vulnerability of the area to potential seismic hazard. Earthquake hazard assessment of active faults in urban areas are thus an important systematic engineering for disaster mitigation in major cities.

scholarly journals Performance Evaluation of Different SAR-Based Techniques on the 2019 Ridgecrest Sequence

2021 ◽  
Vol 13 (4) ◽  
pp. 685
Author(s):  
Marco Polcari ◽  
Mimmo Palano ◽  
Marco Moro
Keyword(s):  
Performance Evaluation ◽  
Strike Slip ◽  
Seismic Sequence ◽  
Fault Rupture ◽  
Coseismic Displacement ◽  
Surface Rupture ◽  
Eastern California Shear Zone ◽  
Tectonic Framework ◽  
Gnss Network ◽  
The One

We evaluated the performances of different SAR-based techniques by analyzing the surface coseismic displacement related to the 2019 Ridgecrest seismic sequence (an Mw 6.4 foreshock on July 4th and an Mw 7.1 mainshock on July 6th) in the tectonic framework of the eastern California shear zone (Southern California, USA). To this end, we compared and validated the retrieved SAR-based coseismic displacement with the one estimated by a dense GNSS network, extensively covering the study area. All the SAR-based techniques constrained the surface fault rupture well; however, in comparison with the GNSS-based coseismic displacement, some significant differences were observed. InSAR data showed better performance than MAI and POT data by factors of about two and three, respectively, therefore confirming that InSAR is the most consolidated technique to map surface coseismic displacements. However, MAI and POT data made it possible to better constrain the azimuth displacement and to retrieve the surface rupture trace. Therefore, for cases of strike-slip earthquakes, all the techniques should be exploited to achieve a full synoptic view of the coseismic displacement field.

scholarly journals Surface-Rupturing Historical Earthquakes in Australia and Their Environmental Effects: New Insights from Re-Analyses of Observational Data

Geosciences ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 408 ◽  
Author(s):  
King ◽  
Quigley ◽  
Clark
Keyword(s):  
Observational Data ◽  
Environmental Effects ◽  
Active Faults ◽  
Magnetic Data ◽  
Future Research ◽  
Surface Rupture ◽  
Secondary Fracture ◽  
Geological Evidence ◽  
Surface Ruptures ◽  
Strong Control

We digitize surface rupture maps and compile observational data from 67 publications on ten of eleven historical, surface-rupturing earthquakes in Australia in order to analyze the prevailing characteristics of surface ruptures and other environmental effects in this crystalline basement-dominated intraplate environment. The studied earthquakes occurred between 1968 and 2018, and range in moment magnitude (Mw) from 4.7 to 6.6. All earthquakes involved co-seismic reverse faulting (with varying amounts of strike-slip) on single or multiple (1–6) discrete faults of ≥ 1 km length that are distinguished by orientation and kinematic criteria. Nine of ten earthquakes have surface-rupturing fault orientations that align with prevailing linear anomalies in geophysical (gravity and magnetic) data and bedrock structure (foliations and/or quartz veins and/or intrusive boundaries and/or pre-existing faults), indicating strong control of inherited crustal structure on contemporary faulting. Rupture kinematics are consistent with horizontal shortening driven by regional trajectories of horizontal compressive stress. The lack of precision in seismological data prohibits the assessment of whether surface ruptures project to hypocentral locations via contiguous, planar principal slip zones or whether rupture segmentation occurs between seismogenic depths and the surface. Rupture centroids of 1–4 km in depth indicate predominantly shallow seismic moment release. No studied earthquakes have unambiguous geological evidence for preceding surface-rupturing earthquakes on the same faults and five earthquakes contain evidence of absence of preceding ruptures since the late Pleistocene, collectively highlighting the challenge of using mapped active faults to predict future seismic hazards. Estimated maximum fault slip rates are 0.2–9.1 m Myr-1 with at least one order of uncertainty. New estimates for rupture length, fault dip, and coseismic net slip can be used to improve future iterations of earthquake magnitude—source size—displacement scaling equations. Observed environmental effects include primary surface rupture, secondary fracture/cracks, fissures, rock falls, ground-water anomalies, vegetation damage, sand-blows / liquefaction, displaced rock fragments, and holes from collapsible soil failure, at maximum estimated epicentral distances ranging from 0 to ~250 km. ESI-07 intensity-scale estimates range by ± 3 classes in each earthquake, depending on the effect considered. Comparing Mw-ESI relationships across geologically diverse environments is a fruitful avenue for future research.

scholarly journals Active Fault Systems in the Inner Northwest Apennines, Italy: A Reappraisal One Century after the 1920 Mw ~6.5 Fivizzano Earthquake

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 139
Author(s):  
Giancarlo Molli ◽  
Isabelle Manighetti ◽  
Rick Bennett ◽  
Jacques Malavieille ◽  
Enrico Serpelloni ◽  
...  
Keyword(s):  
Large Scale ◽  
Active Fault ◽  
Active Faults ◽  
Dense Network ◽  
Earthquake Fault ◽  
Slip Rates ◽  
Fault Systems ◽  
Seismological Data ◽  
Seismogenic Faults

Based on the review of the available stratigraphic, tectonic, morphological, geodetic, and seismological data, along with new structural observations, we present a reappraisal of the potential seismogenic faults and fault systems in the inner northwest Apennines, Italy, which was the site, one century ago, of the devastating Mw ~6.5, 1920 Fivizzano earthquake. Our updated fault catalog provides the fault locations, as well as the description of their architecture, large-scale segmentation, cumulative displacements, evidence for recent to present activity, and long-term slip rates. Our work documents that a dense network of active faults, and thus potential earthquake fault sources, exists in the region. We discuss the seismogenic potential of these faults, and propose a general tectonic scenario that might account for their development.

scholarly journals Application of the Environmental Seismic Intensity scale (ESI 2007) and the European Macroseismic Scale (EMS-98) to the Kalamata (SW Peloponnese, Greece) earthquake (Ms=6.2, September 13, 1986) and correlation with neotectonic structures and active faults

2014 ◽  
Vol 56 (6) ◽  
Author(s):  
Ioannis G. Fountoulis ◽  
Spyridon D. Mavroulis
Keyword(s):  
Structural Damage ◽  
Active Fault ◽  
Main Shock ◽  
Active Faults ◽  
Seismic Hazard Assessment ◽  
Seismic Intensity ◽  
Fault Zones ◽  
Earthquake Sequence ◽  
Ground Subsidence ◽  
Earthquake Scenario

On September 13, 1986, a shallow earthquake (Ms=6.2) struck the city of Kalamata and the surrounding areas (SW Peloponnese, Greece) resulting in 20 fatalities, over 300 injuries, extensive structural damage and many earthquake environmental effects (EEE). The main shock was followed by several aftershocks, the strongest of which occurred two days later (Ms=5.4). The EEE induced by the 1986 Kalamata earthquake sequence include ground subsidence, seismic faults, seismic fractures, rockfalls and hydrological anomalies. The maximum ESI 2007 intensity for the main shock has been evaluated as IX<sub>ESI 2007</sub>, strongly related to the active fault zones and the reactivated faults observed in the area as well as to the intense morphology of the activated Dimiova-Perivolakia graben, which is a 2nd order neotectonic structure located in the SE margin of the Kalamata-Kyparissia mega-graben and bounded by active fault zones. The major structural damage of the main shock was selective and limited to villages founded on the activated Dimiova-Perivolakia graben (IX<sub>EMS-98</sub>) and to the Kalamata city (IX<sub>EMS-98</sub>) and its eastern suburbs (IX<sub>EMS-98</sub>) located at the crossing of the prolongation of two major active fault zones of the affected area. On the contrary, damage of this size was not observed in the surrounding neotectonic structures, which were not activated during this earthquake sequence. It is concluded that both intensity scales fit in with the neotectonic regime of the area. The ESI 2007 scale complemented the EMS-98 seismic intensities and provided a completed picture of the strength and the effects of the September 13, 1986, Kalamata earthquake on the natural and the manmade environment. Moreover, it contributed to a better picture of the earthquake scenario and represents a useful and reliable tool for seismic hazard assessment.

Do active faults’ clay mineral compositions affect whether earthquake ruptures they host will displace the surface?

2021 ◽  
Author(s):  
Selina S. Fenske ◽  
Virginia G. Toy ◽  
Bernhard Schuck ◽  
Anja M. Schleicher ◽  
Klaus Reicherter
Keyword(s):  
Fault Zone ◽  
Clay Mineral ◽  
Active Faults ◽  
Surface Displacement ◽  
Surface Rupture ◽  
Near Surface ◽  
Ground Shaking ◽  
Physical Measurements ◽  
Surface Displacements ◽  
Earthquake Ruptures

&lt;p&gt;The tectonophysical paradigm that earthquake ruptures should not start, or easily propagate into, the shallowest few kilometers of Earth&amp;#8217;s crust makes it difficult to understand why damaging surface displacements have occurred during historic events. The paradigm is supported by decades of analyses demonstrating that near the surface, most major fault zones are composed of clay minerals &amp;#8211; particularly extraordinarily weak smectites &amp;#8211; which most laboratory physical measurements suggest should prevent surface rupture if present. Recent studies of New Zealand&amp;#8217;s Alpine Fault Zone (AFZ) demonstrate smectites are absent from some near surface fault outcrops, which may explain why this fault was able to offset the surface locally in past events. The absence of smectites in places within the AFZ can be attributed to locally exceptionally high geothermal gradients related to circulation of meteoric (surface-derived) water into the fault zone, driven by significant topographic gradients. The record of surface rupture of the AFZ is heterogeneous, and no one has yet systematically examined the distribution of segments devoid of evidence for recent displacement. There are significant implications for seismic hazard, which comprises both surface displacements and ground shaking with intensity related to the area of fault plane that ruptures (which will be reduced if ruptures do not reach the surface). &amp;#160;We will present results of new rigorous XRD clay mineral analyses of AFZ principal slip zone gouges that indicate where smectites are present, and consider if these display systematic relationships to surface displacement records. We also plan to apply the same methodology to the Carboneras Fault Zone in Spain, and the infrequent Holocene-active faults in Western Germany.&lt;/p&gt;

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