The 23 October 2011 MW7.0 Van (Eastern Turkey) Earthquake: Interpretations of Recorded Strong Ground Motions and Post-Earthquake Conditions of Nearby Structures

2014 ◽  
Vol 30 (2) ◽  
pp. 657-682 ◽  
Author(s):  
V. Akansel ◽  
G. Ameri ◽  
A. Askan ◽  
A. Caner ◽  
B. Erdil ◽  
...  
Keyword(s):  
Fault Plane ◽  
Ground Motions ◽  
Hanging Wall ◽  
Strong Motion ◽  
Thrust Fault ◽  
Building Structures ◽  
Epicentral Area ◽  
Historical Structures ◽  
Strict Compliance ◽  
Strong Ground

A major thrust-fault earthquake of MW = 7.0 occurred on 23 October 2011 at 10:41:21 UTC in the eastern Anatolian region of Turkey, severely affecting the nearby towns of Van and Erciş. In this study, a few strong-motion records from the epicentral area are analyzed in order to investigate the characteristics of the ground motions. Also reported are the post-earthquake field observations for various types of structures, such as buildings, bridges, historical structures, tunnels, and dams within the vicinity of the fault plane. The spatial distribution of damage indicates a noticeable hanging-wall effect. The special-type structures are observed to experience far less damage, as opposed to the building structures in the region pointing to the need for strict compliance to seismic building code and the corresponding construction requirements.

The island of Hawaii earthquakes of November 29, 1975: Strong-motion data and damage reconnaissance report

1977 ◽  
Vol 67 (2) ◽  
pp. 493-515
Author(s):  
Christopher Rojahn ◽  
B. J. Morrill
Keyword(s):  
Local Time ◽  
Structural Damage ◽  
Strong Motion ◽  
Maximum Acceleration ◽  
Epicentral Area ◽  
Ground Shaking ◽  
Motion Data ◽  
Large Sector ◽  
Threshold Duration ◽  
Strong Ground

Abstract Two earthquakes occurred on the island of Hawaii on November 29, 1975, a magnitude (Ms) 5.7 event at 0335 (local time) and a magnitude (Ms) 7.2 event at 0447. During the larger event, a maximum acceleration of 0.22 g was recorded in the southern part of Hilo, 43 km north of the epicenter. A 0.05 g threshold duration of 13.7 sec was measured for the same component. Smaller amplitude accelerograph records were obtained at two other locations on the island along with four seismoscope records. During or subsequent to the larger event, a large sector of the southeastern coastline subsided by as much as 3.5 meters. A tsunami generated by the larger event caused at least one death (one person also missing), injury to 28 persons, and significant structural and nonstructural damage. Only scattered evidence of strong ground shaking was observed in the epicentral area, and most of the several dozen nearby structures sustained little or no structural damage from ground shaking. In Hilo, 45 km north of the Ms = 7.2 epicenter, structural and nonstructural damage was slight to moderate but more extensive than elsewhere on the island.

Seismology and Strong Ground Motions in the 2004 Niigata Ken Chuetsu, Japan, Earthquake

2006 ◽  
Vol 22 (1_suppl) ◽  
pp. 9-21 ◽  
Author(s):  
Jim Mori ◽  
Paul Somerville
Keyword(s):  
Main Shock ◽  
Ground Motions ◽  
Moment Tensor ◽  
Hanging Wall ◽  
Active Faults ◽  
Field Investigation ◽  
Extensive Field ◽  
Reverse Faulting ◽  
Significant Region ◽  
Strong Ground

The Niigata Ken Chuetsu earthquake was a shallow, moderate-sized event producing strong shaking and considerable land failure damage across a significant region of Niigata Prefecture in central Japan. Moment tensor solutions indicate the main shock as being pure reverse faulting on a fault striking 30° east of north, roughly parallel to the mapped active faults and to the structural trends of the region, with nodal planes that dip down to the west at about 50° and down to the east at about 40°. The main shock was followed by an unusual number of large aftershocks. An extensive field investigation identified only minor surface faulting. Hanging wall effects accompanied by unusually high accelerations were observed, with peak horizontal accelerations of 1.75 g recorded at Tohkamachi and 1.33 g recorded at Ojiya.

The Analysis of Thrust Fault in the Tensional Environment

2010 ◽  
Vol 29-32 ◽  
pp. 1506-1511
Author(s):  
Hui Hao ◽  
Jia Fu Qi ◽  
Jian Li Cheng
Keyword(s):  
Oil And Gas ◽  
Fault Plane ◽  
Hanging Wall ◽  
Thrust Fault ◽  
Small Displacement ◽  
Late Period ◽  
Hydrocarbon Migration ◽  
Growth Coefficient ◽  
Oil And Gas Exploration ◽  
Structure Research

Gravity glide thrust fault is always a significant type of thrust fault in the extensional basin. The research on it is of great significance for its playing an important role in hydrocarbon migration and accumulation, being one of the major targets of oil and gas exploration. Through finely analyzing Paleogene structure of Wangguantun region in Huanghua sag, specially re-analyzing the particular fault, utilizing kinematic equilibrium rule and analyzing the thrust fault developing process, I found there were discrepancies in predecessors′ interpretation to the thrust fault in the area: this fault did not form during the late period. It formed from a slump fault with small growth rate whose fault section dip changed mild, even level because of depocenter migration. The fault was pushed by the force of gravity so that the hanging wall slid along the fault plane, and makes the scan finally in the late revealed the nature of a thrust fault. Although the shape of these faults is very similar with the thrust fault formed late in previous view (early growth coefficient is small, displacement had little change), there are huge differences on origin of these two faults whose petroleum geological significance is quite different. This study is very significant to the structure research of the region and the other similar regions, providing the new theory for oil exploration.

scholarly journals The Quaternary Active El Arrayan Fault, Santiago, Chile

2021 ◽  
Vol 48 (3) ◽  
Author(s):  
Jose Araya ◽  
Gregory P. De Pascale ◽  
Sergio Sepúlveda
Keyword(s):  
Active Fault ◽  
Ground Motions ◽  
Hanging Wall ◽  
Local Source ◽  
Fault Rupture ◽  
Fault Rocks ◽  
Strong Ground Motions ◽  
The North ◽  
The City ◽  
Strong Ground

Understanding the location and nature of Quaternary active crustal faults is critical to the reduction of both fault rupture and strong ground motions hazards in the built environment. Recent work along the San Ramon Fault in Santiago, Chile demonstrates that crustal seismic sources are important hazards. We present the results of a second likely Quaternary active fault (the El Arrayan Fault, EAF) that runs through the City of Santiago. The EAF was discovered at an outcrop in El Arrayan (Lo Barnechea) with up to the North reverse motion and sinistral (left-lateral) motion clearly visible and coincident with fault rocks (gouge, cataclasite, and breccia) and higher topography (i.e. uplift) in the hanging wall. The EAF is at least 12 km long, strikes North-Northwest to South-Southeast, and is steeply dipping (mean dip 77º NE). Clear geomorphic expression with sinistral displaced streams (up to ~210 m) suggest that this fault is Quaternary active and an important local source of fault rupture and crustal strong ground motions. Because no fault zone avoidance criteria in Chile, there is need for enhanced fault mapping, legislation, implementation of active fault rupture avoidance areas in Chile to reduce the risk posed by active crustal structures.

NESS2.0: An Updated Version of the Worldwide Dataset for Calibrating and Adjusting Ground-Motion Models in Near Source

2021 ◽  
Author(s):  
Sara Sgobba ◽  
Chiara Felicetta ◽  
Giovanni Lanzano ◽  
Fadel Ramadan ◽  
Maria D’Amico ◽  
...  
Keyword(s):  
Ground Motion ◽  
Reference Model ◽  
Hanging Wall ◽  
Strong Motion ◽  
Flat File ◽  
Intensity Measures ◽  
Processing Scheme ◽  
Epicentral Area ◽  
Motion Models ◽  
Ground Motion Model

ABSTRACT We present an extended and updated version of the worldwide NEar-Source Strong-motion (NESS) flat file, which includes an increased number of moderate-to-strong earthquakes recorded in epicentral area, new source metadata and intensity measures, comprising spectral displacements and fling-step amplitudes retrieved from the extended baseline correction processing of velocity time series. The resulting dataset consists of 81 events with moment magnitude≥5.5 and hypocentral depth shallower than 40 km, corresponding to 1189 three-component waveforms, which are selected to have a maximum source-to-site distance within one fault length. Details on the flat files, metadata, and ground-motion parameters, processing scheme, and statistical findings are presented and discussed. The analysis of these data allows recognizing the presence of distinctive features (such as pulse-like waveforms, large vertical components, and hanging-wall effects) that can be exploited to assess their impact on near-source seismic motion. As an example, we use the NESS2.0 dataset for calibrating an empirical correction factor of a regional ground-motion model (GMM) mainly based on far-field records. In this way, we can adjust the median predictions to account for near-source effects not fully captured by the reference model. The final goal of this work is to promote the use of the NESS2 flat file as a tool to disseminate qualified and referenced near-source data and metadata in the light of improving the constraints of GMMs (both empirical and physics-based) close to the source.

scholarly journals The calculation of horizontal accelerations from seismoscope records

1973 ◽  
Vol 63 (5) ◽  
pp. 1637-1661
Author(s):  
Ronald F. Scott
Keyword(s):  
Vibration Mode ◽  
Ground Motions ◽  
Strong Motion ◽  
Shaking Table ◽  
Watch Glass ◽  
San Fernando ◽  
Input Acceleration ◽  
Earthquake Vibration ◽  
Two Degree Of Freedom ◽  
Strong Ground

abstract The seismoscope is a simple instrument designed originally to give a largely qualitative indication of the strong ground motions produced by an earthquake. It consists of a smoked watch glass attached to a two-degree-of-freedom pendulum with a period of 34 sec and damping about 10 per cent of critical; a pen records the pendulum motions on the watch glass. One point on the displacement spectrum of the recorded ground motion at this period and damping is obtained from the measurement of the maximum pendulum excursion. An examination of the seismoscope record obtained on the east abutment of the failed Lower San Fernando dam during the 1971 San Fernando earthquake showed a high-frequency vibration superimposed on the general oscillations. It did not seem likely that this was solely an earthquake vibration component, and shaking table tests of seismoscopes revealed the presence of a seismoscope vibration mode at frequencies of 15 to 18 Hz depending on the instrument. The oscillations due to this mode on the abutment seismocope record have, therefore, been used as timing marks, to enable the seismoscope equation to be solved for the input acceleration components. The results of the calculations are presented along with analyses of the seismoscope response to indicate the range of applicability. One other record, obtained on a seismoscope alongside a strong-motion accelerograph, was also analyzed for comparison with the recorded accelerations, to demonstrate the validity of the technique. The timing vibration appears on a number of seismoscope records.

Earthquake Ground Motions: Implications for Designing Structures and Reconciling Structural Damage

1985 ◽  
Vol 1 (2) ◽  
pp. 239-270 ◽  
Author(s):  
Jogeshwar P. Singh
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Ground Motions ◽  
Strong Motion ◽  
Soil Condition ◽  
Dominant Factor ◽  
Soil Conditions ◽  
Earthquake Ground Motions ◽  
Geological Conditions ◽  
Strong Ground

Until recently, characteristics of strong ground motion resulting from different soil conditions were considered the dominant factor in developing design ground motions and reconciling observed damage. Interpretation of recent recordings of earthquakes by strong motion instrument arrays installed in California and Taiwan show that basic characteristics of strong motion are greatly influenced by the seismological and geological conditions. For a given soil condition, the characteristics of strong ground motion (peak ground acceleration, peak ground velocity, peak ground displacement, duration, spectral content, and time histories) can vary significantly whether the site is near or far from the seismic source. As local soil conditions only modify the ground motions produced by a given source, variability in ground motion due to seismologic and geologic conditions (for a given soil condition) must be considered in estimating earthquake ground motions for structural design or for estimating structural vulnerabilities to reconcile earthquake-related damage.

The Whittier Narrows, California Earthquake of October 1, 1987—Early Results of Isoseismal Studies and Damage Surveys

1988 ◽  
Vol 4 (1) ◽  
pp. 1-10 ◽  
Author(s):  
E. V. Leyendecker ◽  
L. M. Highland ◽  
M. Hopper ◽  
E. P. Arnold ◽  
P. Thenhaus ◽  
...  
Keyword(s):  
Los Angeles ◽  
Field Survey ◽  
Ground Motions ◽  
Geographical Area ◽  
Mail Survey ◽  
Strong Motion ◽  
Peak Acceleration ◽  
Early Results ◽  
Acceleration Data ◽  
Strong Ground

Preliminary isoseismals for Modified Mercalli intensities are presented for the Whittier Narrows Earthquake. Isoseismals for intensities VI and lower are based on responses to a mail survey. Intensity VII and larger are based on a field survey of damage described in this paper. The maximum observed intensity of VIII was confined to Whittier. The shapes of the intensity contours compare favorably with the distribution of average peak acceleration data from the strong motion array in the greater Los Angeles area. The damage assessments appeared consistent with earthquake magnitude. However, the accelerations were higher than expected for the magnitude. The building classification and survey strategies developed were tested and found usable and adequate for describing damage. With further refinement this system can be used to describe damage within a limited geographical area and in a format useful for correlations with strong ground motions and the Modified Mercalli Intensity scale.

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