A note on the duration of earthquake and nuclear-explosion ground motions

1975 ◽  
Vol 65 (4) ◽  
pp. 875-883
Author(s):  
Walter W. Hays
Keyword(s):  
Nuclear Explosion ◽  
Site Amplification ◽  
High Yield ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Motion Data ◽  
Nuclear Explosions ◽  
San Fernando ◽  
The Difference ◽  
Earthquake Accelerograms

Abstract The duration of ground acceleration, an important engineering seismology parameter, was determined for a subset of nuclear explosion and earthquake accelerograms. The nuclear-explosion, ground-motion data sample consisted of accelerograms derived from velocity recordings of high-yield events, MILROW and CANNIKIN, which have been assigned surface-wave magnitudes of 5.3 and 5.7, respectively. The earthquake-data sample consisted primarily of the Richter magnitude 6.6 San Fernando earthquake accelerograms. The criterion used to define duration of ground acceleration was the amount of time that the absolute acceleration is ≧ 5 per cent g, an approximate index of the strong phase of ground shaking. On the basis of this criterion and the data subset used, the duration of earthquake ground acceleration differs from that of nuclear explosions. The difference, which is not as great as has generally been thought in the past, is small inside 20 km. Earthquake durations are greater beyond 20 km. The scatter in the duration data was analyzed and found to be sensitive to local site amplification phenomena. These preliminary conclusions need to be validated by further research.

Duration of nuclear explosion ground motion

1978 ◽  
Vol 68 (4) ◽  
pp. 1133-1145
Author(s):  
Walter W. Hays ◽  
Kenneth W. King ◽  
Robert B. Park
Keyword(s):  
Epicentral Distance ◽  
Ground Motions ◽  
Broad Band ◽  
Time History ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Distance Range ◽  
Nuclear Explosions ◽  
Dependent Site ◽  
Strong Ground

abstract This paper evaluates the duration of strong ground shaking that results from nuclear explosions and identifies some of the problems associated with its determination. Knowledge of the duration of horizontal ground shaking is important out to epicentral distances of about 44 km and 135 km, the approximate distances at which the ground shaking level falls to 0.01 g for nuclear explosions having yields of about 100 kt and 1,000 kt, respectively. Evaluation of the strong ground motions recorded from the event STRAIT (ML = 5.6) on a linear array of five, broad-band velocity seismographs deployed in the distance range 3.2 to 19.5 km provides information about the characteristics of the duration of ground shaking. The STRAIT data show that: (1) the definition that is used for defining duration is very important; (2) the duration of ground acceleration, as defined in terms of 90 per cent of the integral of the squared time history (Trifunac and Brady, 1975), increased from about 4 to 26 sec over the approximately 20-km distance range; and (3) the duration of ground velocity and displacement were slightly greater because of the effect of the alluvium layer on the propagating surface waves. Data from other events (e.g., MILROW, CANNIKIN, HANDLEY, PURSE) augment the STRAIT data and show that: (1) duration of shaking is increased by frequency-dependent site effects and (2) duration of shaking, as defined by the integral of the squared time history, does not increase as rapidly with increase in yield as is indicated by other definitions of duration that are stated in terms of an amplitude threshold (e.g., bracketed duration, response envelopes). The available data suggest that the duration of ground acceleration, based on the integral definition, varies from about 4 to 40 sec for a 100-kt range explosion and from about 4 to 105 sec for a megaton range explosion in the epicentral distance range of 0 to 44 km and 0 to 135 km, respectively.

Special Issue on Selected Papers from 9th CUEE

2012 ◽  
Vol 7 (6) ◽  
pp. 671-671
Author(s):  
Kazuhiko Kasai ◽  
Kohji Tokimatsu ◽  
Saburoh Midorikawa
Keyword(s):  
Earthquake Engineering ◽  
Ground Improvement ◽  
Site Amplification ◽  
Board Members ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Research Technology ◽  
Piled Raft Foundation ◽  
Research Activities ◽  
Institute Of Technology

The 9th International Conference on Urban Earthquake Engineering (9th CUEE) and the 4th Asia Conference on Earthquake Engineering (4th ACEE) were jointly held on March 6-8, 2012 in Tokyo, as a part of the research activities of the Center for Urban Earthquake Engineering (CUEE), Tokyo Institute of Technology, Japan. The conference featured state-of-the-art technical presentations on various themes relevant to urban earthquake engineering, followed by special sessions addressing the 11th March 2011 Great East Japan Earthquake and Tsunami that resulted in catastrophic damage and an estimated death toll of 20,000. The conference attracted 465 participants from 31 countries, and disseminated 283 papers. The board members of the Journal of Disaster Research (JDR) decided to publish special issues of JDR, selecting papers from the above joint conference, for the purpose of mainly updating status of Japan’s research/technology. The present issue is on the fields of engineering seismology and geotechnical engineering, including extraordinary ground shaking and liquefactions that affected wide areas during the March 11 incident. Other issues such as those on buildings and infrastructures are also planned. The 8 manuscripts selected and managed by the JDR Guest Editors address the following topics: - Array observations of ground shaking - Large peak ground acceleration and site amplification - Attenuation of the seismic wave - Impact against the water-supply outages - Liquefaction in a river levee on soft cohesive ground - Spread foundation performance affecting superstructure - Performance of piled raft foundation with grid-form ground improvement - Liquefaction of levee body and seepage control The Guest Editors as well as JDR board members thank the authors for their contributions and revisions. They also acknowledge gratefully the reviewers for their invaluable comments on the manuscripts.

Response Spectra at Liquefaction Sites during Shallow Crustal Earthquakes

2015 ◽  
Vol 31 (4) ◽  
pp. 2325-2349 ◽  
Author(s):  
James R. Gingery ◽  
Ahmed Elgamal ◽  
Jonathan D. Bray
Keyword(s):  
Response Spectra ◽  
Site Amplification ◽  
Soil Liquefaction ◽  
Positive Bias ◽  
Acceleration Response ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Crustal Earthquakes ◽  
Proposed Model ◽  
A Site

Site amplification studies and building code provisions recognize that soil liquefaction can alter the characteristics of ground shaking at a site. However, guidance as to how the amplitudes of spectral accelerations are modified is lacking. In this paper, available recorded ground motions from shallow crustal earthquakes at sites that exhibited evidence of liquefaction are investigated. Analysis of residuals computed relative to Next Generation Attenuation (NGA) estimates reveal positive bias at longer periods, slight negative bias at intermediate periods, and slight positive bias at short periods. Trends with V S30, NGA-estimated peak ground acceleration (PGA), and moment magnitude are also observed. A model is developed that removes the initially observed residual bias and reduces uncertainty. The proposed model can be used to adjust NGA-estimated acceleration response spectra to account for the effects of liquefaction on ground shaking.

scholarly journals Seismic hazard analysis for Sutami Dam using probabilistic method

2019 ◽  
Vol 276 ◽  
pp. 05012
Author(s):  
Yusep Muslih Purwana ◽  
Raden Harya D.H.I ◽  
Bambang Setiawan ◽  
Ni’am Aulawi
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Return Period ◽  
Hazard Analysis ◽  
Probabilistic Method ◽  
Northridge Earthquake ◽  
Ground Acceleration ◽  
Motion Data ◽  
San Fernando ◽  
Over 40 Years

One of the largest structures in Malang is Sutami dam. It was built in 1964 to 1973 and began to be operated in 1977. Considering the age of the dam which is over 40 years and the high risk of earthquake in this area, it is necessary to analyze its seismic hazard using an updated data. The probablilistic seismic hazard analyses (PSHA) was employed to obtain peak ground acceleration (PGA). The deagregation was conducted to obtain the most influencing magnitudes (M) and and distance (R) values affecting the dam. The result indicates that the area of the dam has the PGA of 0.261 for 500 years return period, 0.41 for 2500 years return period and 0.586 for 10,000 years return period of eartquakes. The magnitude of 5.93-6.17 for the distance of 22-44 km are considered as the most influencing earthquake for the dam. Due to the lack of ground motion data for Sutami dam, the ground motion from other earthquake might be utilised such as Morgan Hill earthquake 1984, Whittier Narrow earthquake 1987, Chalfant Valley earthquake 1986, Georgia USSR earthquake 1991, Northridge earthquake 1994, or San Fernando earthquake 1971.

Ground motion models for shallow crustal and deep earthquakes in Hawaii and analyses of the 2018 M 6.9 Kalapana sequence

2021 ◽  
pp. 875529302110445
Author(s):  
Ivan Wong ◽  
Robert Darragh ◽  
Sarah Smith ◽  
Qimin Wu ◽  
Walter Silva ◽  
...  
Keyword(s):  
Ground Motion ◽  
Epicentral Distance ◽  
Strong Motion ◽  
Earthquake Hazards ◽  
Ground Acceleration ◽  
Strong Motion Data ◽  
Ground Shaking ◽  
Motion Data ◽  
Crustal Earthquake ◽  
Deep Earthquakes

The damaging 4 May 2018 M 6.9 Kalapana earthquake and its aftershocks have provided the largest suite of strong motion records ever produced for an earthquake sequence in Hawaii exceeding the number of records obtained in the deep 2006 M 6.7 Kiholo Bay earthquake. These records provided the best opportunity to understand the processes of strong ground shaking in Hawaii from shallow crustal (< 20 km) earthquakes. There were four foreshocks and more than 100 aftershocks of M 4.0 and greater recorded by the seismic stations. The mainshock produced only a modest horizontal peak ground acceleration (PGA) of 0.24 g at an epicentral distance of 21.5 km. In this study, we evaluated the 2018 strong motion data as well as previously recorded shallow crustal earthquakes on the Big Island. There are still insufficient strong motion data to develop an empirical ground motion model (GMM) and so we developed a GMM using the stochastic numerical modeling approach similar to what we had done for deep Hawaiian (>20 km) earthquakes. To provide inputs into the stochastic model, we performed an inversion to estimate kappa, stress drops, Ro, and Q(f) using the shallow crustal earthquake database. The GMM is valid from M 4.0 to 8.0 and at Joyner–Boore (RJB) distances up to 400 km. Models were developed for eight VS30 (time-averaged shear-wave velocity in the top 30 m) values corresponding to the National Earthquake Hazards Reduction Program (NEHRP) site bins: A (1500 m/s), B (1080 m/s), B/C (760 m/s), C (530 m/s), C/D (365 m/s), D (260 m/s), D/E (185 m/s), and E (150 m/s). The GMM is for PGA, peak horizontal ground velocity (PGV), and 5%-damped pseudo-spectral acceleration (SA) at 26 periods from 0.01 to 10 s. In addition, we updated our GMM for deep earthquakes (>20 km) to include the same NEHRP site bins using the same approach for the crustal earthquake GMM.

Source dynamics of the 1979 Imperial Valley earthquake from near-source observations (of ground acceleration and velocity)

1982 ◽  
Vol 72 (6A) ◽  
pp. 1957-1968
Author(s):  
Mansour Niazi
Keyword(s):  
Particle Acceleration ◽  
Particle Velocity ◽  
High Frequency ◽  
Observation Point ◽  
P Wave ◽  
Imperial Valley ◽  
Ground Acceleration ◽  
Data Set ◽  
Ground Shaking ◽  
Fault Surface

abstract Two sets of observations obtained during the 15 October 1979 Imperial Valley earthquake, MS 6.9, are presented. The data suggest different dynamic characteristics of the source when viewed in different frequency bands. The first data set consists of the observed residuals of the horizontal peak ground accelerations and particle velocity from predicted values within 50 km of the fault surface. The residuals are calculated from a nonlinear regression analysis of the data (Campbell, 1981) to the following empirical relationships, PGA = A 1 ( R + C 1 ) − d 1 , PGV = A 2 ( R + C 2 ) − d 2 in which R is the closest distance to the plane of rupture. The so-calculated residuals are correlated with a positive scalar factor signifying the focusing potential at each observation point. The focusing potential is determined on the basis of the geometrical relation of the station relative to the rupture front on the fault plane. The second data set consists of the acceleration directions derived from the windowed-time histories of the horizontal ground acceleration across the El Centro Differential Array (ECDA). The horizontal peak velocity residuals and the low-pass particle acceleration directions across ECDA require the fault rupture to propagate northwestward. The horizontal peak ground acceleration residuals and the high-frequency particle acceleration directions, however, are either inconclusive or suggest an opposite direction for rupture propagation. The inconsistency can best be explained to have resulted from the incoherence of the high-frequency radiation which contributes most effectively to the registration of PGA. A test for the sensitivity of the correlation procedure to the souce location is conducted by ascribing the observed strong ground shaking to a single asperity located 12 km northwest of the hypocenter. The resulting inconsistency between the peak acceleration and velocity observations in relation to the focusing potential is accentuated. The particle velocity of Delta Station, Mexico, in either case appears abnormally high and disagrees with other observations near the southeastern end of the fault trace. From the observation of a nearly continuous counterclockwise rotation of the plane of P-wave particle motion at ECDA, the average rupture velocity during the first several seconds of source activation is estimated to be 2.0 to 3.0 km/sec. A 3 km upper bound estimate of barrier dimensions is tentatively made on the basis of the observed quasiperiodic variation of the polarization angles.

scholarly journals Earthquakes on the surface: earthquake location and area based on more than 14 500 ShakeMaps

2018 ◽  
Vol 18 (6) ◽  
pp. 1665-1679
Author(s):  
Stephanie Lackner
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Earthquake Location ◽  
Primary Concern ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Geographic Context ◽  
The Social ◽  
Strong Ground

Abstract. Earthquake impact is an inherently interdisciplinary topic that receives attention from many disciplines. The natural hazard of strong ground motion is the reason why earthquakes are of interest to more than just seismologists. However, earthquake shaking data often receive too little attention by the general public and impact research in the social sciences. The vocabulary used to discuss earthquakes has mostly evolved within and for the discipline of seismology. Discussions on earthquakes outside of seismology thus often use suboptimal concepts that are not of primary concern. This study provides new theoretic concepts as well as novel quantitative data analysis based on shaking data. A dataset of relevant global earthquake ground shaking from 1960 to 2016 based on USGS ShakeMap data has been constructed and applied to the determination of past ground shaking worldwide. Two new definitions of earthquake location (the shaking center and the shaking centroid) based on ground motion parameters are introduced and compared to the epicenter. These definitions are intended to facilitate a translation of the concept of earthquake location from a seismology context to a geographic context. Furthermore, the first global quantitative analysis on the size of the area that is on average exposed to strong ground motion – measured by peak ground acceleration (PGA) – is provided.

Seismic Response of Embankment Dams Based on Recorded Strong-Motion Data in Japan

2019 ◽  
Vol 35 (2) ◽  
pp. 955-976 ◽  
Author(s):  
DongSoon Park ◽  
Tadahiro Kishida
Keyword(s):  
Time Series ◽  
Seismic Response ◽  
Prediction Models ◽  
Strong Motion ◽  
Dynamic Responses ◽  
Design Stage ◽  
Ground Acceleration ◽  
Motion Data ◽  
Embankment Dams ◽  
Strong Motion Database

It is important to investigate strong-motion time series recorded at dams to understand their complex seismic responses. This paper develops a strong-motion database recorded at existing embankment dams and analyzes correlations between dam dynamic responses and ground-motion parameters. The Japan Commission on Large Dams database used here includes 190 recordings at the crests and foundations of 60 dams during 54 earthquakes from 1978 to 2012. Seismic amplifications and fundamental periods from recorded time series were computed and examined by correlation with shaking intensities and dam geometries. The peak ground acceleration (PGA) at the dam crest increases as the PGA at the foundation bedrock increases, but their ratio gradually decreases. The fundamental period broadly increases with the dam height and PGA at the foundation bedrock. The nonlinear dam response becomes more apparent as the PGA at the foundation bedrock becomes >0.2 g. The prediction models of these correlations are proposed for estimating the seismic response of embankment dams, which can inform the preliminary design stage.

scholarly journals ShakeMaps during the Emilia sequence

2012 ◽  
Vol 55 (4) ◽  
Author(s):  
Valentino Lauciani ◽  
Licia Faenza ◽  
Alberto Michelini
Keyword(s):  
Software Package ◽  
Civil Defense ◽  
Peak Ground Velocity ◽  
Accurate Information ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Peak Ground Motion ◽  
Emilia Romagna Region ◽  
Fully Automatic ◽  
Definition Of

<p>ShakeMap is a software package that can be used to generate maps of ground shaking for various peak ground motion (PGM) parameters, including peak ground acceleration (PGA), peak ground velocity, and spectral acceleration response at 0.3 s, 1.0 s and 3.0 s, and instrumentally derived intensities. ShakeMap has been implemented in Italy at the Istituto Nazionale di Geofisica e Vulcanologia (INGV; National Institute of Geophysics and Volcanology) since 2006 (http://shakemap.rm.ingv.it), with the primary aim being to help the Dipartimento della Protezione Civile (DPC; Civil Protection Department) civil defense agency in the definition of rapid and accurate information on where earthquake damage is located, to correctly direct rescue teams and to organize emergency responses. Based on the ShakeMap software package [Wald et al. 1999, Worden et al. 2010], which was developed by the U.S. Geological Survey (USGS), the INGV is constructing shake maps for Ml ≥3.0, with the adoption of a fully automatic procedure based on manually revised locations and magnitudes [Michelini et al. 2008]. The focus of this study is the description of the progressive generation of these shake maps for the sequence that struck the Emilia-Romagna Region in May 2012. […]</p><br />

scholarly journals On site inspection for nuclear test ban verirication

1994 ◽  
Vol 37 (3) ◽  
Author(s):  
P. D. Marschall
Keyword(s):  
Nuclear Explosion ◽  
Nuclear Test ◽  
The Political ◽  
Chemical Weapon ◽  
Nuclear Explosions ◽  
Chemical Weapon Convention ◽  
On Site Inspection ◽  
Test Ban ◽  
Nuclear Test Ban ◽  
Test Ban Treaty

The problem of verifying compliance with a nuclear test ban treaty is mainly a technical one. However the problem of detecting, locating and identifying nuclear explosions has, since the late 1950s, been intimately involved with the political problems associated with negotiating a treaty. In fact there are few other areas in which policy, diplomacy and science have been so interwoven. This paper attempts to illustrate how technology can. be applied to solve some of the political problems which arise when considering the role of an On Site Inspection (OSI) to determine whether or not a nuclear explosion, in violation of a treaty, has occurred or not. It is hoped that the reader, with a scientific background, but with little or no experience of treaty negotiations, will gain an. insight as to how technical matters can interact with political requirements. The demands made on scientists to provide technical support for negotiating and rnonitoring compliance of a treaty have increased significanfly over the last 40 years. This is a period in which a number of major treaties have contained a significant technical component e.g. the Limited Test Ban Treaty (Threshold Treaty) and the Chemical Weapon Convention. This paper gives an indication of some of the political decisions which will have to be made and suggests some of the technical methods which are of value in the identification of a clandestine nuclear explosion.

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