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1

Moment Tensor Inversions Using Waveforms from Taiwan Strong-Motion Instrumentation Program (TSMIP): A Case Study of 22 October 1999 Taiwan Earthquake Sequence  

Microsoft Academic Search

We inverted Taiwan strong motion waveforms for the source mechanisms of the 22 October 1999 earthquake sequence to investigate seismogenic structure of Meishan fault system in Taiwan. In 1906, an earthquake of magnitude 7.1 shocked the Meishan area, and inflicted severe damages. Similar event might cause even greater damages due to the modern dense population in this region. However, detailed

K. Chang; W. Chi; Y. Gung; H. Chiu

2010-01-01

2

STRONG GROUND MOTION SOURCE SCALING AND ATTENUATION MODELS FOR EARTHQUAKES LOCATED IN DIFFERENT SOURCE ZONES IN TAIWAN  

Microsoft Academic Search

The ground-motion database collected recently in Taiwan was used for evaluation of strong ground motion models. The database contains more then 2800 acceleration records from M > 3.0 - 3.5 earthquakes occurred in 1993-2004. The records were obtained at rock (class B) sites located in the northern and eastern parts of Taiwan. Parameters of attenuation models (geometrical spreading and anelastic

Vladimir Sokolov; Chin-Hsiung Loh; Wen-Yu Jean

3

The Development of Real-time Strong-motion Observation on the Earthquake Early Warning in Taiwan  

Microsoft Academic Search

For the sake of seismic hazards mitigation, a real-time strong-motion monitoring system was implemented by the Central Weather Bureau (CWB) since 1995. After successive refinements during the past decade, the system has been utilized as the basis for the development of the early warning (EWS) application in Taiwan. In order to shorten the earthquake response time, a virtual sub-network approach

N. Hsiao; T. Shin; Y. Wu

2007-01-01

4

Moment tensor inversions using strong motion waveforms of Taiwan TSMIP data, 1993–2009  

Microsoft Academic Search

Earthquake source parameters are important for earthquake studies and seismic hazard assessment. Moment tensors are among the most important earthquake source parameters, and are now routinely derived using modern broadband seismic networks around the world. Similar waveform inversion techniques can also apply to other available data, including strong-motion seismograms. Strong-motion waveforms are also broadband, and recorded in many regions since

Kaiwen Chang; Wu-Cheng Chi; Yuancheng Gung; Douglas Dreger; William H. K. Lee; Hung-Chie Chiu

2011-01-01

5

Coseismic Fault Slip Rupture from the Joint Inversion of Teleseismic, Local Strong-Motion and CGPS Related to the 2010 Jia-Shian Earthquake in Southwestern Taiwan  

NASA Astrophysics Data System (ADS)

The Jia-Shian earthquake (Mw=6.3) occurred on 04th March 2010 in the southwestern Taiwan. We used the waveforms of teleseismics to identify the strike, dip and rake of focal mechanism are 311/33/37. Furthermore, we explored the strike, dip and rake are 316/40/44 on the first pulse of the teleseismic P wave. We also took account of the Continuous Global Positioning System (CGPS) data for the coseismic offset. The maximum horizontal and vertical (uplift) of coseismic offsets at the surface are 29.8mm± 1.0mm and 30.6mm± 5.1mm, respectively at station GS51. Moreover, the space and time distribution of slip during the coseismic rupture was modeled by the joint inversion, which includes the CGPS coseismic offset, the teleseismic, and near field seismic records. We identified the faults geometry and reconstructed the rupture process of coseismic faults slip. The initial rupture was generated on the northwest - southeast trending fault and propagated to the northeast - southwest trending structure after 5 s of main shock. Their strike, dip and rake are 311/33/37 and 020/25/108, respectively. The average slip of rupture was 20.1 cm, with the maximum slip of 50.4 cm. The rupture of the seismic moment was 4.0 × 10 ^ 25 dyne-cm in 30 s of duration time.The slip rupture constrained the synthetic data quite well, especially for the CGPS coseismic offset. We inferred the Jia-Shian earthquake took place on blind fault and the northeast - southwest trending structure was activated following the rupture on main northwest - southeast trending fault.

Lin, Kuan-Chuan; Delouis, Bertrand; Hu, Jyr-Ching; Nocquet, Jean-Mathieu; Mozziconacci, Laetitia; Bethoux, Nicole

2013-04-01

6

Tilts in Strong Ground Motion  

Microsoft Academic Search

Most instruments used in seismological practice to record ground motion are pendulum seismographs, velocigraphs or accelerographs. In most cases it is assumed that seismic instruments are only sensitive to the translational motion of the instrument's base. In this study the full equation of pendulum motion including the inputs of rotations and tilts is considered. It is shown that tilting the

Vladimir Graizer

2006-01-01

7

Towards Integrated Marmara Strong Motion Network  

Microsoft Academic Search

Istanbul has a 65% chance of having a magnitude 7 or above earthquake within the next 30 years. As part of the preparations for the future earthquake, strong motion networks have been installed in and around Istanbul. The Marmara Strong Motion Network, operated by the Department of Earthquake Engineering of Kandilli Observatory and Earthquake Research Institute, encompasses permanent systems outlined

E. Durukal; M. Erdik; E. Safak; A. Ansal; O. Ozel; H. Alcik; A. Mert; N. Kafadar; A. Korkmaz; A. Kurtulus

2009-01-01

8

Seismic switch for strong motion measurement  

DOEpatents

A seismic switching device that has an input signal from an existing microseismic station seismometer and a signal from a strong motion measuring instrument. The seismic switch monitors the signal level of the strong motion instrument and passes the seismometer signal to the station data telemetry and recording systems. When the strong motion instrument signal level exceeds a user set threshold level, the seismometer signal is switched out and the strong motion signal is passed to the telemetry system. The amount of time the strong motion signal is passed before switching back to the seismometer signal is user controlled between 1 and 15 seconds. If the threshold level is exceeded during a switch time period, the length of time is extended from that instant by one user set time period.

Harben, Philip E. (Oakley, CA); Rodgers, Peter W. (Santa Barbara, CA); Ewert, Daniel W. (Patterson, CA)

1995-01-01

9

Seismic switch for strong motion measurement  

DOEpatents

A seismic switching device is described that has an input signal from an existing microseismic station seismometer and a signal from a strong motion measuring instrument. The seismic switch monitors the signal level of the strong motion instrument and passes the seismometer signal to the station data telemetry and recording systems. When the strong motion instrument signal level exceeds a user set threshold level, the seismometer signal is switched out and the strong motion signal is passed to the telemetry system. The amount of time the strong motion signal is passed before switching back to the seismometer signal is user controlled between 1 and 15 seconds. If the threshold level is exceeded during a switch time period, the length of time is extended from that instant by one user set time period. 11 figs.

Harben, P.E.; Rodgers, P.W.; Ewert, D.W.

1995-05-30

10

Ground Motion Characteristic in the Kaohsiung Area, Taiwan  

NASA Astrophysics Data System (ADS)

Kaohsiung city is the most important harbor in Taiwan. Recently, there are many high-rise buildings and public transportation system are under construction in this area. Therefore, it is very important to know the surface geological conditions for many practical reasons especially after the strikes of 1999 Chi-Chi, Taiwan earthquake. The Central Geological Survey had spent four years to bore more than 50 wells. And now, it is very clear to know the basement depth is changing from 120 to 40 meters for the western and eastern part of the Kaohsiung city. The harbor and commercial area locate at the western part of this area, and the eastern part is small hill area. To serve the purpose of earthquake hazard mitigation, it would be better to understand the soil amplification effect of the Kaohsiung city. We then conducted a research to study the site effects of the Kaohsiung city, which includes analyze the acceleration seismogram data of TSMIP (Taiwan Strong Motion Instrumentation Program) network and two newly installed borehole seismometer arrays, and perform very dense microtremor measurements in the study area. Most microtremor measurements were done during the midnight to reduce artifacts. After carefully selection, we pick 233 records and use the H/V ratio method to get information of soil amplification. From the result, we found it correlated to the basement depth very well. For the purpose of the earthquake resistant design, earthquake engineers must consider the site response at a specific period. For example, the structure period of a ten-flour building is at about 1 second. If the input ground motion is dominate at 1 Hz, then the building will has a resonant effect. Therefore, in this study, we select 10 frequencies (0.3, 0.5, 0.7, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 Hz) to plot out the contour map for understanding the frequency responses in this area. For the 0.5 Hz, the contours show that main amplification effects occurred at the southern part of Kaohsiung area. With the frequency increasing to 2.0 Hz, the main amplification area move from the harbor and the southern part of Kaohsiung area to the hill area, which locates at the eastern part of Kaohsiung area. For the higher frequency (3.0 Hz), there are no obvious high contour areas. We pick the dominant frequency of each record and plot out the contour map. At the harbor and city area, the dominant frequency is about 0.5 ~ 0.9 Hz, and the northeastern part is about 1.3 ~ 1.7 Hz. We found that the basement structure can explain the contour very well. Yet, the H/V dominated frequency distribution map reveals more detail features.

Chiang, H.; Wen, K.; Chang, T.

2003-12-01

11

Tilts in strong-ground motion  

NASA Astrophysics Data System (ADS)

Most instruments used in seismological practice to record ground motion are pendulum seismographs, velocigraphs or accelerographs. In most cases it is assumed that seismic instruments are only sensitive to the translational motion of the instrument's base. In this study the full equation of pendulum motion including the inputs of rotations and tilts is considered. It is shown that tilting the accelerograph's base can severely impact its response to the ground motion. The method of tilt evaluation using uncorrected strong-motion accelerograms was first suggested by Graizer (1989), and later tested in a number of laboratory experiments with different strong-motion instruments. The method is based on the difference in the tilt sensitivity of the horizontal and vertical pendulums. The method was applied to a number of strongest records of the Mw 6.7 Northridge earthquake of 1994. Examples are shown when relatively large tilts of up to a few degrees occurred during strong earthquake ground motion. Residual tilt extracted from the strong-motion record at the Pacoima Dam Upper Left Abutment reached 3.1 degrees in N45E direction, and was a result of local earthquake induced tilting due to high amplitude shaking. This value is in agreement with the residual tilt measured using electronic level a few days after the earthquake. The method was applied to the building records from the Northridge earthquake. According to the estimates, residual tilt reached 2.6 degrees on the ground floor of the 12-story Hotel in Ventura. Processing of most of the strongest records of the Northridge earthquake shows that tilts, if happened, were within the error of the method, or less than about 0.5 degree.

Graizer, V.

2006-12-01

12

Strong-Motion Earthquake Records in Japan, 1983. Volume 28.  

National Technical Information Service (NTIS)

Contents: Characteristics of strong-motion earthquake accelerographs; List of earthquakes recorded by any of the strong-motion accelerographs in 1983; Hypocenters of earthquakes recorded by any of the strong-motion accelerographs in 1983; List of the site...

1985-01-01

13

Strong-Motion Earthquake Records in Japan, 1984. Volume 29.  

National Technical Information Service (NTIS)

Contents: Characteristics of strong-motion earthquake accelerographs; List of earthquakes recorded by any of the strong-motion accelerographs in 1984; Hypocenters of earthquakes recorded by any of the strong-motion accelerographs in 1984; List of the site...

1986-01-01

14

Catalog of Strong-Motion Seismograph Stations and Records.  

National Technical Information Service (NTIS)

The catalog lists all strong-motion accelerographs which are part of the National Strong-Motion Instrumentation Network managed by Seismic Engineering, USGS, for the National Science Foundation. The National Strong-Motion Instrumentation Network consists ...

R. J. Brazee

1974-01-01

15

Predictions of high-frequency ground-motion in Taiwan based on weak motion data  

NASA Astrophysics Data System (ADS)

Following a recent paper we use weak-motion waveforms to calibrate a model for the prediction of earthquake-induced ground-motion in Taiwan, in the 0.25-5.0 Hz frequency range, valid up to Mw 7.6. The excitation/attenuation model is given in terms of frequency-dependent seismic wave attenuation, Qs(f), geometrical spreading, g(r), a magnitude-dependent stress parameters ?? for the excitation terms, and a site term for each seismic station used in the study. A set of weak-motion data was gathered from about 170 aftershocks of the Chi-Chi earthquake, Mw 7.6, of 1999 September 20, (17:47 UTC), recorded by 10 broad-band seismic stations. The moment magnitudes of the registered aftershocks ranged from Mw 3.0 to 6.5, and the hypocentral distances from a few kilometres to about 250 km. A frequency-dependent crustal quality factor, Q(f) = 350f0.32, was obtained, to be coupled with the geometrical spreading function Earthquake-related excitation spectra were calibrated over our empirical results by using a magnitude-dependent Brune model with a stress drop value of ??= 8.0 ± 1.0 MPa for the largest event of Mw 6.5 in our data set and with a near surface attenuation parameter of ?= 0.05 s. Results on region-specific crustal attenuation and source scaling were used to generate stochastic simulations both for point-source and extended-fault ruptures through the computer codes: Stochastic Model SIMulation, SMSIM and Extended-Fault Model Simulation, EXSIM. The absolute peak ground accelerations (PGA), peak ground velocities (PGV) and 5 per cent-damped Spectral Accelerations (SA) at three different frequencies, 0.33 Hz, 1.0 Hz and 3.0 Hz for several magnitudes and distance ranges were predicted at large magnitudes, well beyond magnitude Mw 6.5, the upper limit for the events of our weak-motion data set. The performance of the stochastic model was then tested against the strong-motion data recorded during the Mw 7.6 Chi-Chi earthquake, and against several other empirical ground-motion models.

D'Amico, Sebastiano; Akinci, Aybige; Malagnini, Luca

2012-04-01

16

Investigation of Strong Motion Processing Procedures.  

National Technical Information Service (NTIS)

The work which is described here presents preliminary results of an on-going research relating to the accurate recording and quality processing of earthquake strong ground motions. The work is the product of a tripartite co-operation between three Europea...

D. Rinaldi X. Goula J. M. Menu

1988-01-01

17

New Brunswick strong ground motion records  

Microsoft Academic Search

Although large earthquakes including several of magnitude 7 are known to have occurred in eastern Canada since the arrival of European settlers in the 16th century, no significant strong ground motion records were available until 1982, and earthquake engineering design relies on extrapolation of results from mostly California data, modified to take into account the well-known lower attenuation of felt

Dieter H. Weichert

1985-01-01

18

A comparison of two strong motion accelerometers.  

NASA Astrophysics Data System (ADS)

New technology has been developed for mass-producing electro-mechanical systems using micro machining of silicon wafers. This technology is known as Micro-Electro-Mechanical Systems (MEMS). The geophysical equipment manufacturer, Input Output of Houston, TX, has developed an accelerometer element using MEMS. Refraction Technology (REF TEK) incorporates this accelerometer element in its strong motion recorders and packaged accelerometers. The performance of the REF TEK MEMS accelerometer is compared to the well-known Episensor accelerometer manufactured by Kinemetrics.

Passmore, P.; Zimakov, L.

2003-04-01

19

Towards Integrated Marmara Strong Motion Network  

NASA Astrophysics Data System (ADS)

Istanbul has a 65% chance of having a magnitude 7 or above earthquake within the next 30 years. As part of the preparations for the future earthquake, strong motion networks have been installed in and around Istanbul. The Marmara Strong Motion Network, operated by the Department of Earthquake Engineering of Kandilli Observatory and Earthquake Research Institute, encompasses permanent systems outlined below. It is envisaged that the networks will be run by a single entity responsible for technical management and maintanence, as well as for data management, archiving and dissemination through dedicated web-based interfaces. • Istanbul Earthquake Rapid Response and Early Warning System - IERREWS (one hundred 18-bit accelerometers for rapid response; ten 24-bit accelerometers for early warning) • IGDA? Gas Shutoff Network (100 accelerometers to be installed in 2010 and integrated with IERREWS) • Structural Monitoring Arrays - Fatih Sultan Mehmet Suspension Bridge (1200m-long suspension bridge across the Bosphorus, five 3-component accelerometers + GPS sensors) - Hagia Sophia Array (1500-year-old historical edifice, 9 accelerometers) - Süleymaniye Mosque Array (450-year-old historical edifice,9 accelerometers) - Fatih Mosque Array (237-year-old historical edifice, 9 accelerometers) - Kanyon Building Array (high-rise office building, 5 accelerometers) - Isbank Tower Array (high-rise office building, 5 accelerometers) - ENRON Array (power generation facility, 4 acelerometers) - Mihrimah Sultan Mosque Array (450-year-old historical edifice,9 accelerometers + tiltmeters, to be installed in 2009) - Sultanahmet Mosque Array, (390-year-old historical edifice, 9 accelerometers + tiltmeters, to be installed in 2009) • Special Arrays - Atakoy Vertical Array (four 3-component accelerometers at 25, 50, 75, and 150 m depths) - Marmara Tube Tunnel (1400 m long submerged tunnel, 128 ch. accelerometric data, 24 ch. strain data, to be installed in 2010) - Air-Force Academy Array (72 ch. dense accelerometric array to be installed in 2010) - Gemlik Array (a dense basin array of 8 stations, to be installed in 2010) The objectives of these systems and networks are: (1) to produce rapid earthquake intensity, damage and loss assessment information after an earthquake (in the case of IERREWS), (2) to monitor conditions of structural systems, (3) to develop real-time data processing, analysis, and damage detection and location tools (in the case of structural networks) after an extreme event, (4) to assess spatial properties of strong ground motion and ground strain, and to characterise basin response (in the case of special arrays), (5) to investigate site response and wave propagation (in the case of vertical array). Ground motion data obtained from these strong motion networks have and are being used for investigations of attenuation, spatial variation (coherence), simulation benchmarking, source modeling, site response, seismic microzonation, system identification and structural model verification and structural health control. In addition to the systems and networks outlined above there are two temporary networks: KIMNET - a dense urban noise and microtremor network consisting of 50 broadband stations expected to be operational in mid 2009, and SOSEWIN - a 20-station, self-organizing structural integrated array at Ataköy in Istanbul.

Durukal, E.; Erdik, M.; Safak, E.; Ansal, A.; Ozel, O.; Alcik, H.; Mert, A.; Kafadar, N.; Korkmaz, A.; Kurtulus, A.

2009-04-01

20

SCEC Broadband Platform Strong Ground Motion Simulations  

NASA Astrophysics Data System (ADS)

The Southern California Earthquake Center (SCEC) Broadband Platform is a collaborative software development project involving SCEC researchers, graduate students, and the SCEC Community Modeling Environment. The goal of the SCEC Broadband Simulation Platform is to generate broadband (0-10 Hz) ground motions for earthquakes using deterministic low-frequency and stochastic high-frequency simulations. SCEC developers have integrated complex scientific modules for rupture generation, low-frequency deterministic seismogram synthesis, high-frequency stochastic seismogram synthesis, and non-linear site effects calculation into a system that supports easy on-demand computation of broadband seismograms. The SCEC Broadband platform has two primary modes of operation, validation mode, and scenario mode. In validation mode, the earthquake modeling software calculates broadband seismograms for one of three earthquakes, Northridge, Loma Prieta, or Landers at sites with observed strong motion data. Then, the platform calculates goodness of fit measurements that quantify how well the model-based broadband seismograms match the observed seismograms for each event. In scenario mode, the user can specify a scenario earthquake and a list of sites and calculate ground motions at each site for the scenario event. In February 2011, SCEC released Broadband Platform 11.2 as an open-source scientific software distribution. Since that time, we have continued development of the platform by adding a new site response module and new goodness of fit measures by Mayhew and Olsen. Along with a source code distribution of the Broadband Platform, we now offer a virtual software image distribution of the platform to support its use on a variety of computing hardware and operating systems.

Kumar, S.; Callaghan, S.; Maechling, P. J.; Olsen, K. B.; Archuleta, R. J.; Somerville, P. G.; Graves, R. W.; Jordan, T. H.; Broadband Platform Working Group

2011-12-01

21

Strong-Motion Earthquake Records in Japan, 1988, Volume 33.  

National Technical Information Service (NTIS)

CONTENTS: Characteristics of SMAC-type strong-motion earthquake accelerographs; List of earthquakes recorded by any of the strong-motion accelerographs in 1988; Hypocenters of earthquakes recorded by any of the strong-motion accelerographs in 1988; List o...

1990-01-01

22

Evaluation of Turkish National Strong Ground Motion Network Database  

NASA Astrophysics Data System (ADS)

The strong ground motion records archieved in the Turkish National Strong Ground Motion Network database and Kandilli Observatory and Earthquake Research Institute Strong Ground Motion Network database have been analysed in order to extract some regional characterisitics of the records and to evaluate existing attenuation relationships. The strong ground motion data of (M2.2-M7.4) earthquakes recorded from 1976 to 2007 have been analysed and engineering parameters extracted. The engineering parameters obtained from the process include peak ground motion parameters such as PGA, PGV, PGD, spectral parameters such as Sa, Sd, ground motion duration and intensity estimations. In total 6762(2254 x 3) strong ground motion records with epicentral distance varying from 8.7km to 250km have been studied. The calculated parameters have been used in the evaluation and comparision of ground motion prediction equations which are used in the formation of real-time ground motion parameters and intensity maps.

Zulfikar, C.; Kamer, Y.; Erdik, M. O.

2011-12-01

23

Ground Motion Characteristic in the Kaohsiung & Pingtung Area, Taiwan  

NASA Astrophysics Data System (ADS)

Kaohsiung city is the most important harbor in Taiwan. Recently, there are many high-rise buildings and public transportation system are under construction in this area. Therefore, it is very important to know the surface geological conditions for many practical reasons especially after the strikes of 1999 Chi-Chi, Taiwan earthquake. To serve the purpose of earthquake hazard mitigation, it would be better to understand the soil amplification effect of the Kaohsiung-Pingtung area. We then conducted a research to study the site effects of the area, which includes analyze three newly installed borehole seismometer arrays, and perform very dense microtremor measurements in the study area. Most microtremor measurements were done during the midnight to reduce artifacts. After carefully selection, we pick 590 records and use the H/V ratio method to get information of soil amplification. From the result, we found it correlated to the basement depth very well. For the purpose of the earthquake resistant design, earthquake engineers must consider the site response at a specific period. For example, the structure period of a ten-flour building is at about 1 second. If the input ground motion is dominate at 1 Hz, then the building will has a resonant effect. Therefore, in this study, we select several frequencies to plot out the contour map for understanding the frequency responses in this area. For the 0.5 Hz, the contours show that main amplification effects occurred at the southern part of Kaohsiung area. With the frequency increasing to 2.0 Hz, the main amplification area move from the harbor and the southern part of Kaohsiung area to the hill area, which locates at the eastern part of Kaohsiung area. For the higher frequency (3.0 Hz), there are no obvious high contour areas. We pick the dominant frequency of each record and plot out the contour map. At the harbor and city area, the dominant frequency is about 0.5 ~ 0.9 Hz, and the northeastern part is about 1.3 ~ 1.7 Hz. We found that the basement structure can explain the contour very well. Yet, the H/V dominated frequency distribution map reveals more detail features.

Chiang, H.; Wen, K.; Chang, T.

2004-12-01

24

Modeling and synthesis of strong ground motion  

Microsoft Academic Search

Success of earthquake resistant design practices critically depends on how accurately the future ground motion can be determined\\u000a at a desired site. But very limited recorded data are available about ground motion in India for engineers to rely upon. To\\u000a identify the needs of engineers, under such circumstances, in estimating ground motion time histories, this article presents\\u000a a detailed review

S. T. G. Raghu Kanth

2008-01-01

25

Stochastic Finite-Fault Modeling of Ground Motions from the 1999 Chi-Chi, Taiwan, Earthquake: Application to Rock and Soil Sites with Implications for Nonlinear Site Response  

Microsoft Academic Search

The stochastic method for simulating strong ground motions from finite faults is applied to the records of the 1999 Chi-Chi, Taiwan, earthquake. The method involves discretization of the fault plane into smaller subfaults, each of which is assigned an x2 spectrum. The contributions from all subfaults are empirically atten- uated to the observation site and summed to produce the synthetic

Zafeiria Roumelioti; Igor A. Beresnev

2003-01-01

26

Strong Motion Data from Japanese Earthquakes.  

National Technical Information Service (NTIS)

This report contains plots of 177 components of uncorrected and corrected Japanese ground-motion accelerograms recorded between 1956 and 1978. Extensive information pertaining to the processing and characteristics of these records is also included.

A. W. Mori C. B. Crouse

1981-01-01

27

Next Generation Attenuation of Ground Motions in Ilan, Taiwan: Establishment and Analysis of Attenuation Relations for Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV)  

NASA Astrophysics Data System (ADS)

An evaluation of seismic hazards requires an estimate of the expected ground motion at the site of interest. The most common means of estimating this ground motion in engineering practice is the use of an attenuation relation. A number of developments have arisen recently to suggest that a new generation of attenuation relationships is warranted. The project named Next Generation Attenuation of Ground Motions (NGA) Project was developed by Pacific Earthquake Engineering Research Center (PEER) in response to a core objective: reducing uncertainty in earthquake ground motion estimation. This objective reflects recognition from industry sponsors that improvements in earthquake ground motion estimation will result in significant cost savings and will result in improved system performance in the event of a large earthquake. The Central Weather Bureau has implemented the Taiwan Strong Motion Instrumentation Program (TSMIP) to collect high-quality instrumental recordings of strong earthquake shaking.It is necessary for us to study the strong ground motion characteristics at the Ilan area of northeastern Taiwan. Further analyses using a good quality data base that includes 486 events and 4172 recordings of magnitude greater than 4.0 are required to derive the next generation attenuation of ground motion in Ilan area. In addition, Liu and Tsai (2007) used a catalog of more than 1840 shallow earthquakes with homogenized Mw magnitude ranging from 5.0 to 8.2 in 1900-2007 to estimate the seismic hazard potential in Taiwan. As a result, the PGA and PGV contour patterns of maximum ground motion show that Ilan Plain has high values of 0.2g and 80cm/sec with respect to MMI intensity VII and IX, respectively. Furthermore, from the mean ground motion and the seismic intensity rate analyses, they show that a high annul probability of MMI > VI greater than 35 percents are located at the Chianan area of western Taiwan and Ilan Plain in northeastern Taiwan. However, these results was estimated by used attenuation relationship of Taiwan which conducted by Liu and Tsai (2005). Hence, Next Generation Attenuation of Ground Motions (NGA) of Ilan Plain must be developed as soon as possible, in order to provide more important information for the site evaluation of critical facilities in those relatively high earthquake hazard potential regions and will be helpful for the plan of land-using.

Liu, K.

2009-12-01

28

MODELING STRONG-MOTION ACCELEROGRAMS BY \\  

Microsoft Academic Search

The 143 victims of the Mw=5.9 earthquake of September 7, 1999 in the capital of Greece call for an assessment of ground-motion acceleration in the near-source region, where instruments were missing. PEXT method is a new finite-source modeling tool in which source complexities are represented by stochastic perturbation and extrapolation of the low-frequency deterministic wavefield. The low-frequency exact full-wave modeling,

J. Zahradnik; G-Akis Tselentis

1999-01-01

29

Vertical Crustal Motion of Taiwan Determined from Tide Gauge and Altimeter Data  

Microsoft Academic Search

Taiwan is located at the western bordure of the convergent boundary between the Philippine Sea plate and Eurasian plate. Processings of plate collision and mountain building is obvious and occur uncountable earthquakes here. In this study, we applied the method of comparing the tide gauge (TG) and altimeter (ALT) data to resolve land vertical motion at 20 TG sites along

C. Chiang; E. T. Chang; C. Lo; B. F. Chao

2008-01-01

30

DETERMINATION OF LOCAL MAGNITUDE, ML, FROM STRONG MOTION ACCELEROGRAMS  

Microsoft Academic Search

A technique is presented for determination of local magnitude, ML, from strong-motion accelerograms. The accelerograph records are used as an accel- eration input to the equation of motion of the Wood-Anderson torsion seismo- graph to produce a synthetic seismogram which is then read in the standard manner. When applied to 14 records from the San Fernando earthquake, the resulting ML

HIROO KANAMORI; PAUL C. JENNINGS

1978-01-01

31

Common problems in automatic digitization of strong motion accelerograms  

Microsoft Academic Search

Common problems encountered in automatic digitization of strong motion accelerograms, recorded on film, are presented and discussed. These include synchronization of the time scale for the three components of motion, non-uniform film speed, trace following in case of scratches or trace crossings, distortions from high contrast preprocessing of the scanned image, and trace “rotation” resulting from rotated position of the

M. D. Trifunac; V. W. Lee; M. I. Todorovska

1999-01-01

32

Strong Ground Motion from the Michoacan, Mexico, Earthquake  

Microsoft Academic Search

The network of strong motion accelerographs in Mexico includes instruments that were installed, under an international cooperative research program, in sites selected for the high potential of a large earthquake. The 19 September 1985 earthquake (magnitude 8.1) occurred in a seismic gap where an earthquake was expected. As a result, there is an excellent description of the ground motions that

J. G. Anderson; P. Bodin; J. N. Brune; J. Prince; S. K. Singh; R. Quaas; M. Onate

1986-01-01

33

Catalog of Strong Motion Stations in Eastern North America.  

National Technical Information Service (NTIS)

The catalog contains information on all strong motion stations operating in Eastern North America known to NCEER. The location, coordinates, installation dates, type of instrument, operator, structure type and size, and site geology are listed for each st...

R. W. Busby

1990-01-01

34

Soviet strong-motion and vibration-and-blast seismographs  

Microsoft Academic Search

This report contains a description of the current state of the art of Soviet strong-motion and vibration-and-blast seismographs, taken from Soviet publications available in the United States through early 1975. It is intended primarily for U.S. seismologists working with strong-motion data, and persons interested in Soviet advances in seismic instruments. The report contains: (1) four tables listing the technical specifications

C. Shishkevish

1975-01-01

35

Taiwan.  

PubMed

Attention in this discussion of Taiwan is directed to the following: geography; the people -- education, languages, religions, and cultural background; history; administration; political conditions; the economy; defense; foreign relations; and relations between the US and Taiwan. In 1987 the population was estimated to be 19.7 million with an annual growth rate of 1.07%. The infant mortality rate in 1986 was 0.7% with a life expectancy of 70.8 for men and 75.8 for women. Taipei, which continues its claim of sovereignty over all of China in the name of the "Republic of China," exercises control only over the island of Taiwan, the Penghu Islands, and about 20 offshore islands, most near the China mainland. Most native Taiwanese speak a variant of the Amoy (Hokkien) dialect of Southern Fujian. The predominant religion is a combination of Buddhism and Taoism. Chinese sources show migration to Taiwan began as early as A.D. 500. Dutch traders 1st claimed the island in 1624 as a base for Dutch commerce with Japan and the China coast. The 1st major influx of migrants from the Chinese mainland came during the Dutch period. In 1664, a Chinese fleet led by the Ming loyalist Zheng Chenggong retreated from the mainland and occupied Taiwan. Zheng expelled the Dutch and established Taiwan as a base in his attempt to restore the Ming Dynasty. After his death in 1683, his successors submitted to Manchu control. Manchu China ruled Taiwan as a frontier district until it was declared a separate Chinese province in 1886. The authorities in Taipei claim to be the government of all China, including Taiwan. When President Chiang Ching-kuo died in 1988, he was succeeded by Vice President Lee Teng-hui, who had been elected along with Chiang by the National Assembly to a 6-year term. Until 1986, Taiwan's political system was effectively 1 party. Before elections in 1986, many "nonpartisans" grouped together to form Taiwan's 1st new political party in over 4 decades -- the Democratic Progressive Party. Friction between mainlanders and native Taiwanese continues to be a problem, but it has abated with time and the gradual melding of the 2 Chinese communities. Taiwan has changed from an agricultural to an industrialized economy over the past 30 years. During 1973-82, the gross domestic product rose at an annual average of 9.5% in real terms. President Carter signed into law on April 10, 1979, the Taiwan Relations Act, which created domestic legal authority for the conduct of unofficial relations with Taiwan. PMID:12177975

1988-03-01

36

Nonlinear attenuation and rock damage during strong seismic ground motions  

Microsoft Academic Search

Strong seismic waves cause nonlinear behavior in the shallow subsurface in fractured rocks. Seismologists use low-amplitude signals from small repeating earthquakes to measure S wave velocity decrease after strong motion. The 2004 Parkfield, California, earthquake provides examples of such velocity changes in fractured sandstone with an S wave velocity of ?300 m s?1. This nonlinear behavior occurred around the wave

Norman H. Sleep; Paul Hagin

2008-01-01

37

Nonlinear attenuation and rock damage during strong seismic ground motions  

Microsoft Academic Search

Strong seismic waves cause nonlinear behavior in the shallow subsurface in fractured rocks. Seismologists use low-amplitude signals from small repeating earthquakes to measure S wave velocity decrease after strong motion. The 2004 Parkfield, California, earthquake provides examples of such velocity changes in fractured sandstone with an S wave velocity of ~300 m s-1. This nonlinear behavior occurred around the wave

Norman H. Sleep; Paul Hagin

2008-01-01

38

Vertical Crustal Motion of Taiwan Determined from Tide Gauge and Altimeter Data  

NASA Astrophysics Data System (ADS)

Taiwan is located at the western bordure of the convergent boundary between the Philippine Sea plate and Eurasian plate. Processings of plate collision and mountain building is obvious and occur uncountable earthquakes here. In this study, we applied the method of comparing the tide gauge (TG) and altimeter (ALT) data to resolve land vertical motion at 20 TG sites along Taiwan coast. Sea surface height measured by altimetry is related to an absolute reference frame, while TG is related to the coast where they are attached on land. The difference of time series Alt(t)-TG(t) contains information about vertical crustal motion. This method has been used to many applications, such as the global image of vertical ground motion [Cazenave et al., 1999; Nerem and Mitchum, 2002], the tectonic activity around Mediterranean [Garcia et al., 2007], and glacial isostatic rebound occurred in Scandinavian Peninsula, Great Lakes region, and Alaska [Kuo, 2004], etc. In this study, the tide gauge records are adopted from the Marine database of Central Weather Bureau, and altimetry data are the Geophysical Data Record (GDR) which conducted from the tracks of TOPEX/Poseidon(1992 - 2002) and Jason-1 (2002 - Present), charging from JPL's Physical Oceanography Distributed Active Archive Center (PO.DAAC). We calculate the linear trend of the ALT-TG record for each of the TG locations. Seasonal signals, primarily periodic tides are removed from both TG and ALT data as the beforehand treatment for linear regression. We can therefore figure out a whole image of vertical motion along the Taiwan coast. The majority of these movements tend to descend in the latest decade. However, some TG stations reveal an extreme large uplift rate which may be affected by local effects. Sites in the eastern Taiwan generally have a smaller descending rate in comparison to the western sites. Furthermore, our estimations in the southwestern Taiwan show a clear land subsidence from -6.2mm/yr to -34.3mm/yr. Another focus of our study is to determine the coseismic motion in the TG sequence. Step-function with least- square method is used to measure the magnitude of transient motion probably caused by earthquakes neighboring to TG station. In terms of geometrical spreading of seismic energy, the determined coseismic transient motion should be function of hypocentral distance and earthquake size. A forward rupture modeling is also taken to predict coseismic vertical offset with the preset parameters of focal mechanism solution. Further application of the determined vertical offset from TG sequence can help to discuss the coseismic movement of historical earthquakes, which occurred in the period prior to the modern rapid response of coseismic measurement.

Chiang, C.; Chang, E. T.; Lo, C.; Chao, B. F.

2008-12-01

39

Processing of strong-motion accelerograms: Needs, options and consequences  

USGS Publications Warehouse

Recordings from strong-motion accelerographs are of fundamental importance in earthquake engineering, forming the basis for all characterizations of ground shaking employed for seismic design. The recordings, particularly those from analog instruments, invariably contain noise that can mask and distort the ground-motion signal at both high and low frequencies. For any application of recorded accelerograms in engineering seismology or earthquake engineering, it is important to identify the presence of this noise in the digitized time-history and its influence on the parameters that are to be derived from the records. If the parameters of interest are affected by noise then appropriate processing needs to be applied to the records, although it must be accepted from the outset that it is generally not possible to recover the actual ground motion over a wide range of frequencies. There are many schemes available for processing strong-motion data and it is important to be aware of the merits and pitfalls associated with each option. Equally important is to appreciate the effects of the procedures on the records in order to avoid errors in the interpretation and use of the results. Options for processing strong-motion accelerograms are presented, discussed and evaluated from the perspective of engineering application. ?? 2004 Elsevier Ltd. All rights reserved.

Boore, D. M.; Bommer, J. J.

2005-01-01

40

A simple model for strong ground motions and response spectra  

USGS Publications Warehouse

A simple model for the description of strong ground motions is introduced. The model shows that response spectra can be estimated by using only four parameters of the ground motion, the RMS acceleration, effective duration and two corner frequencies that characterize the effective frequency band of the motion. The model is windowed band-limited white noise, and is developed by studying the properties of two functions, cumulative squared acceleration in the time domain, and cumulative squared amplitude spectrum in the frequency domain. Applying the methods of random vibration theory, the model leads to a simple analytical expression for the response spectra. The accuracy of the model is checked by using the ground motion recordings from the aftershock sequences of two different earthquakes and simulated accelerograms. The results show that the model gives a satisfactory estimate of the response spectra.

Safak, Erdal; Mueller, Charles; Boatwright, John

1988-01-01

41

Evolutionary spectra for strong motion body and surface waves  

NASA Astrophysics Data System (ADS)

The nonstationary characteristic of strong motion accelerograms is one of the most important ingredients for the generation of design earthquake motion. The various influences which contribute to the nonstationarity were examined. The examination of the nonstationarity made use of the evolutionary spectrum. The evolutionary spectrum describes the accelerogram in the form of Fourier amplitude versus time and frequency. It provided a clear description of the nonstationarity of the accelerogram and it also allowed the various body and surface wave trains in the accelerogram to be identified. The identification of the wave components using the evolutionary spectrum allowed the nonstationary characteristics of the strong motion accelerogram to be directly related to the behavior of the seismic waves. The Thomson-Haskell model provided the theoretical verification for the wave components identified by the evolutionary spectrum.

Liang, G. C. C.

1980-03-01

42

Sea Level Change and Crustal Vertical Motion around Taiwan Derived by Altimetry and Tide Gauges  

NASA Astrophysics Data System (ADS)

Taiwan is an island, where 60%-70% are mountains located at the center area, and most developed cities are located within 20-30 miles of the coast. Compared with other countries, sea level rise could cause a more significant impact on economic and human societal well being in Taiwan, for example, erosion of beaches and increased flooding and storm surge damage. Recently the most common instrument used to determine global sea level changes are tide gauges and satellite altimetry; however, tide gauge records contain sea level and crustal vertical motion, and altimetry data span is too short to avoid low-frequency effect on trend determination. In order to determine sea level accurately, in this study we develop a novel technique to calculate accurate sea level change around Taiwan by combining tide gauge and altimeter data. First of all, Hilbert-Huang Transformation (HHT) method is used to decompose tide gauge records completely into few independent monotones cycles, which called Intrinsic Mode Functions (IMF). Afterwards, residual time series computed by subtracting sea level time series reconstructed using specific IMFs, which represent low frequencies and cannot be clearly detected in altimeter data, from the corresponding altimetry data is fitted to determine the sea level trend. In addition, we also calculate crustal vertical motions using tide gauge and altimeter data at gauge stations.

Wu, C.; Kuo, C.; Shum, C.; Yang, M.

2009-12-01

43

Soviet Strong-Motion and Vibration-and-Blast Seismographs.  

National Technical Information Service (NTIS)

This report contains a description of the current state of the art of Soviet strong-motion and vibration-and-blast seismographs, taken from Soviet publications available in the United States through early 1975. It is intended primarily for U.S. seismologi...

C. Shishkevish

1975-01-01

44

ANALYSIS OF ERRORS IN DIGITIZED STRONG-MOTION ACCELEROGRAMS  

Microsoft Academic Search

To devise the optimum procedures for the processing of digitized strong- motion accelerograms, detailed error analysis is required. This paper summarizes some aspects of previous error analyses (Trifunac, 1970; Trifunac et al., 1971) and adds the results of several recent investigations. The error analysis described here is divided into two main parts. The first part deals with particular sources of

M. D. TRIFUNAC; F. E. UDWADIA; A. G. BRADY

1973-01-01

45

Attenuation Characteristics of Turkey Based on Recent Strong Motion Data  

Microsoft Academic Search

This paper deals with the derivation of a consistent set of empirical attenuation relationships for predicting free-field horizontal components of peak ground acceleration (PGA) and 5 percent damped pseudo acceleration response spectra (PSA) from 47 strong ground motion records recorded in Turkey. The relationships for Turkey were derived in similar form to those previously developed by Boore et al. (1997)

P. Gülkan; E. Kalkan

2002-01-01

46

Strong ground-motion relations for Mexican interplate earthquakes  

Microsoft Academic Search

We derive strong ground-motion relations for horizontal components of pseudo-acceleration response spectra from Mexican interplate\\u000a earthquakes at rock sites (NEHRP B class) in the forearc region. The functional form is obtained from the analytical solution\\u000a of a circular finite-source model. For the regression analysis we use a recently proposed multivariate Bayesian technique.\\u000a The resulting model has similar accuracy as those

Danny Arroyo; Daniel García; Mario Ordaz; Mauricio Alexander Mora; Shri Krishna Singh

2010-01-01

47

Enhancement of the national strong-motion network in Turkey  

USGS Publications Warehouse

Two arrays comprising 20 strong-motion sensors were established in western Turkey. The 14 stations of BYTNet follow a N-S trending line about 65 km in length, normal to strands of the North Anatolian fault that runs between the cities of Bursa and Yalova. Here the dominant character of the potential fault movement is a right-lateral transform slip. The DATNet array, comprising a total of eight stations, is arranged along a 110-km-long E-W trending direction along the Menderes River valley between Denizli and Aydin. (Two stations in this array were incorporated from the existing Turkish national strong-motion network.) This is an extensional tectonic environment, and the network mornitors potential large normal-faulting earthquakes on the faults in the valley. The installation of the arrays was supported by the North Atlantic Treaty Organization (NATO) under its Science for Peace Program. Maintenance and calibration is performed by the General Directorate of Disaster Affairs (GDDA) according to a protocol between Middle East Technical University (METU) and GDDA. Many young engineers and scientists have been trained in network operation and evaluation during the course of the project, and an international workshop dealing with strong-motion instrumentation has been organized as part of the project activities.

Gulkan, P.; Ceken, U.; Colakoglu, Z.; Ugras, T.; Kuru, T.; Apak, A.; Anderson, J. G.; Sucuoglu, H.; Celebi, M.; Akkar, D. S.; Yazgan, U.; Denizlioglu, A. Z.

2007-01-01

48

On pads and filters: Processing strong-motion data  

USGS Publications Warehouse

Processing of strong-motion data in many cases can be as straightforward as filtering the acceleration time series and integrating to obtain velocity and displacement. To avoid the introduction of spurious low-frequency noise in quantities derived from the filtered accelerations, however, care must be taken to append zero pads of adequate length to the beginning and end of the segment of recorded data. These padded sections of the filtered acceleration need to be retained when deriving velocities, displacements, Fourier spectra, and response spectra. In addition, these padded and filtered sections should also be included in the time series used in the dynamic analysis of structures and soils to ensure compatibility with the filtered accelerations.

Boore, D. M.

2005-01-01

49

Non-Linear Response of High Rise Buildings to Pulse Type Strong Ground Motions  

Microsoft Academic Search

Occurrence of strong ground motions in areas near causative faults is expectative. Studies on recorded near fault strong motions indicate that there are usually some obvious effects in the acceleration, velocity and displacement time histories. Generally, the strong ground motions recorded in near fault zones contain distinct pulses in the velocity time history. These powerful velocity pulses cause that structural

Mohsen Tehranizadeh; Afshin Meshkat-Dini

50

Site response and attenuation analyses using strong motion and short-period data  

NASA Astrophysics Data System (ADS)

Site amplification and seismic attenuation are analyzed in this study using strong ground motion records and short period records. Site amplification factors at instrumented free-field sites are inferred from recorded motions using: (1) Generalized Inversion of S-waves; (2) the H/V method (i.e., the ratio of the spectral amplitudes of the horizontal and vertical components of motion); (3) Coda-wave Inversion; (4) the Standard Spectral Ratio method; and (5) the Coda Normalization method. The site amplification factors inferred from the above methods are compared to each other. The amplification factors obtained from the Generalized Inversion are validated by the other four methods. The correlation of site amplification to site condition is also analyzed and the results demonstrate that site amplification appears to be stronger for the geologically younger (and thus softer) sediments, and the site classification in conformance with UBC provisions provides smaller scatter than the classification based on geological formation. The site amplification factors for the different site classes of the NEHRP classification (i.e., site class C, D and E), which is important for engineering application, are provided and compared with the values proposed by Borcherdt (1994) and adopted in the 1997 UBC and 2003 IBC design codes. The agreement between the site amplification obtained in this study and those proposed by Borcherdt (1994) and adopted by the design codes is good. The nonlinearity of site amplification, resulting from the intensity of ground motion, is clearly identified at selected station where this is feasible. The intrinsic and scattering attenuation are analyzed at stations SML and TYC using the Multiple Lapse Time Window (MLTW) method. The total attenuation is derived from the intrinsic and scattering attenuation. The coda attenuation is analyzed for 14 stations from coda decay curves using linear regression. The S-wave attenuation is analyzed using the coda normalization method at the stations SML and TYC. The coda attenuation estimated from the coda decay curves is close to the intrinsic attenuation. The intrinsic attenuation is the dominant component in the total attenuation. The total attenuation, estimated using the MLTW method, closely agrees with the results from the Coda Normalization Method. The scattering coefficient is estimated to be 3--8 x 10 -3km-1, consistent with estimates of this parameter for other tectonically active regions (see figure 3.10 in Sato and Fehler, 1998). The data sets used in this study are collected from a strong motion network and a short period network in Taiwan province, China. The strong motion data set contains: (1) 2751 motions recorded at 407 stations from 33 aftershocks ranging from ML = 4.11--6.80 and depths from 1.05km to 21.28km, following 1999 Chi-Chi earthquake; and (2) 410 motions recorded at 410 stations from the main event of 1999 Chi-Chi earthquake. The short period data set contains 5499 records recorded by 71 stations instrumented with the Teledyne S-13 seismometers. The 108 events have a magnitude ranging from ML = 2.90--4.97, and depths from 2.21km to 30.82km; these events occurred over a period of time from 2000 to 2003.

Zhang, Fangyin

51

Another Look at Strong Ground Motion Accelerations and Stress Drop  

NASA Astrophysics Data System (ADS)

The relationship between earthquake stress drop and ground motion acceleration is central to seismic hazard analysis. We revisit measurements of root-mean-square (RMS) acceleration, arms, using KikNet accelerometer data from Japan. We directly measure RMS and peak acceleration, and estimate both apparent stress and corner frequencies using the empirical Green’s function (eGf) coda method of Baltay et al. [2010]. We predict armsfrom corner frequency and stress drop following McGuire and Hanks [1980] to compare with measurements. The theoretical relationship does a good job of predicting observed arms. We use four earthquake sequences in Japan to investigate the source parameters and accelerations: the 2008 Iwate-Miyagi earthquake; the off-Kamaishi repeating sequence; and the 2004 and 2007 Niigata events. In each data set, we choose events that are nearly co-located so that the path term to any station is constant. Small events are used as empirical Green’s functions to correct for propagation effects. For all sequences, we find that the apparent stress averages ~1 MPa for most events. Corner frequencies are consistent with Mo-1/3 scaling. We find the ratio of stress drop and apparent stress to be 5, consistent with the theoretical derivation of Singh and Ordaz [1994], using a Brune [1970] spectra. armsis theoretically proportional to stress drop and the inverse square root of the corner frequency. We show that this calculation can be used as a proxy for armsobservations from strong motion records, using recent data from the four earthquake sequences mentioned above. Even for the Iwate-Miyagi mainshock, which experienced over 4 g’s of acceleration, we find that apparent stress, stress drop and corner frequency follow expected scaling laws and support self-similarity.

Baltay, A.; Prieto, G.; Ide, S.; Hanks, T. C.; Beroza, G. C.

2010-12-01

52

Perceptual Training Strongly Improves Visual Motion Perception in Schizophrenia  

ERIC Educational Resources Information Center

|Schizophrenia patients exhibit perceptual and cognitive deficits, including in visual motion processing. Given that cognitive systems depend upon perceptual inputs, improving patients' perceptual abilities may be an effective means of cognitive intervention. In healthy people, motion perception can be enhanced through perceptual learning, but it…

Norton, Daniel J.; McBain, Ryan K.; Ongur, Dost; Chen, Yue

2011-01-01

53

Effect of tilt on strong motion data processing  

USGS Publications Warehouse

In the near-field of an earthquake the effects of the rotational components of ground motion may not be negligible compared to the effects of translational motions. Analyses of the equations of motion of horizontal and vertical pendulums show that horizontal sensors are sensitive not only to translational motion but also to tilts. Ignoring this tilt sensitivity may produce unreliable results, especially in calculations of permanent displacements and long-period calculations. In contrast to horizontal sensors, vertical sensors do not have these limitations, since they are less sensitive to tilts. In general, only six-component systems measuring rotations and accelerations, or three-component systems similar to systems used in inertial navigation assuring purely translational motion of accelerometers can be used to calculate residual displacements. ?? 2004 Elsevier Ltd. All rights reserved.

Graizer, V. M.

2005-01-01

54

Detection of soil liquefaction from strong motion records  

Microsoft Academic Search

SUMMARY During the recent earthquakes in Japan and the U.S.A. a number of records from liqueed-soil sites have been obtained. The ground motion parameters from these sites were studied and several methods for detection of liquefaction from seismic records were developed. The methods, however, focus mainly on the horizontal ground motion and may interpret as liquefaction-induced some records from soft-soil

Mladen V. Kostadinov; Fumio Yamazaki

2001-01-01

55

Strong-field ionization of diatomic molecules and companion atoms: Strong-field approximation and tunneling theory including nuclear motion  

SciTech Connect

We present a detailed comparison of strong-field ionization of diatomic molecules and their companion atoms with nearly equal ionization potentials. We perform calculations in the length and velocity gauge formulations of the molecular strong-field approximation and with the molecular tunneling theory, and in both cases we consider effects of nuclear motion. A comparison of our results with experimental data shows that the length gauge strong-field approximation gives the most reliable predictions.

Kjeldsen, Thomas Kim; Madsen, Lars Bojer [Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C (Denmark)

2005-02-01

56

Amplitudes, polarity and time of peaks of strong ground motion during the 1994 Northridge, California, earthquake  

Microsoft Academic Search

Plots of smoothed contours of peak amplitudes and of areas with the same peak sign are presented for the radial, transverse and vertical components of accelera- tion, velocity and displacement. These were drawn by hand based on strong motion recordings, and represent direct observational evidence of the nature of the attenuation of strong motion with distance at high, intermediate and

M. I. Todorovska; M. D. Trifunac

1997-01-01

57

Strong Motion Networks - Rapid Response and Early Warning Applications in Istanbul  

Microsoft Academic Search

In recent years several strong motion networks have been established in Istanbul with a preparation purpose for future probable earthquake. This study addresses the introduction of current seismic networks and presentation of some recent results recorded in these networks. Istanbul Earthquake Early Warning System Istanbul Earthquake Early Warning System has ten strong motion stations which were installed as close as

C. Zulfikar; H. Alcik; O. Ozel; M. Erdik

2009-01-01

58

Structural Time-Varying Parameter Analysis Based on Adaptive System Identification Method Using Strong Motion Records  

Microsoft Academic Search

To diagnose and predict the seismic damage of buildings under the excitation of strong earthquake, the structural time-varying parameters are identified based on the strong motion records by using on-line system identification method. As one example, the natural frequency and damping ratio of a 5-story reinforcement concrete structure are obtained from its strong motion records. The results show that the

Gong Maosheng; Sun Jing; T. Kashima; Xie Lili

2009-01-01

59

Site Characterization of Italian Strong Motion Recording Stations  

NASA Astrophysics Data System (ADS)

A dataset of site conditions at 101 Italian ground motion stations with recorded motions has been compiled that includes geologic characteristics and seismic velocities. Geologic characterization is derived principally from local geologic investigations by ENEL that include detailed mapping and cross sections. For sites lacking such detailed geologic characterization, the geology maps of the by Servizio Geologico d'Italia are used. Seismic velocities are extracted from the literature and the files of consulting engineers, geologists and public agencies for 33 sites. Data sources utilized include post earthquake site investigations (Friuli and Irpinia events), microzonation studies, and miscellaneous investigations performed by researchers or consulting engineers/geologists. Additional seismic velocities are measured by the authors using the controlled source spectral analysis of surface waves (SASW) method for 18 sites that recorded the 1997-1998 Umbria Marche earthquake sequence. The compiled velocity measurements provide data for 51 of the 101 sites. For the remaining sites, the average seismic velocity in the upper 30 m (Vs30) is estimated using a hybrid approach. For young Quaternary alluvium, Vs30 an existing empirical relationship for California sites by Wills and Clahan (2006) is used, which we justify by validating this relationship against Italian data. For Tertiary Limestone and Italian Mesozoic rocks, empirical estimates of Vs30 are developed using the available data. This work is also presented in Scasserra et al. (2008: JEE, in review).

Scasserra, Giuseppe; Stewart, Jonathan P.; Kayen, Robert E.; Lanzo, Giuseppe

2008-07-01

60

SISMA (Site of Italian Strong Motion Accelerograms): a Web-Database of Ground Motion Recordings for Engineering Applications  

NASA Astrophysics Data System (ADS)

The paper describes a new website called SISMA, i.e. Site of Italian Strong Motion Accelerograms, which is an Internet portal intended to provide natural records for use in engineering applications for dynamic analyses of structural and geotechnical systems. SISMA contains 247 three-component corrected motions recorded at 101 stations from 89 earthquakes that occurred in Italy in the period 1972-2002. The database of strong motion accelerograms was developed in the framework of a joint project between Sapienza University of Rome and University of California at Los Angeles (USA) and is described elsewhere. Acceleration histories and pseudo-acceleration response spectra (5% damping) are available for download from the website. Recordings can be located using simple search parameters related to seismic source and the recording station (e.g., magnitude, Vs30, etc) as well as ground motion characteristics (e.g. peak ground acceleration, peak ground velocity, peak ground displacement, Arias intensity, etc.).

Scasserra, Giuseppe; Lanzo, Giuseppe; Stewart, Jonathan P.; D'Elia, Beniamino

2008-07-01

61

SISMA (Site of Italian Strong Motion Accelerograms): a Web-Database of Ground Motion Recordings for Engineering Applications  

Microsoft Academic Search

The paper describes a new website called SISMA, i.e. Site of Italian Strong Motion Accelerograms, which is an Internet portal intended to provide natural records for use in engineering applications for dynamic analyses of structural and geotechnical systems. SISMA contains 247 three-component corrected motions recorded at 101 stations from 89 earthquakes that occurred in Italy in the period 1972-2002. The

Giuseppe Scasserra; Giuseppe Lanzo; Jonathan P. Stewart; Beniamino D'Elia

2008-01-01

62

Detection of moving foreground objects in videos with strong camera motion  

Microsoft Academic Search

In this paper, we propose a novel method for moving foreground object extraction in sequences taken by a wearable camera,\\u000a with strong motion. We use camera motion compensated frame differencing, enhanced with a novel kernel-based estimation of\\u000a the probability density function of background pixels. The probability density functions are used for filtering false foreground\\u000a pixels on the motion compensated difference

D. Szolgay; J. Benois-Pineau; R. Megret; Y. Gaestel; J.-F. Dartigues

2011-01-01

63

Ground Motion Simulation for a Large Active Fault System using Empirical Green's Function Method and the Strong Motion Prediction Recipe - a Case Study of the Noubi Fault Zone -  

Microsoft Academic Search

The 1995 Hyogo-ken Nambu Earthquake (1995) near Kobe, Japan, spurred research on strong motion prediction. To mitigate damage caused by large earthquakes, a highly precise method of predicting future strong motion waveforms is required. In this study, we applied empirical Green's function method to forward modeling in order to simulate strong ground motion in the Noubi Fault zone and examine

M. Kuriyama; T. Kumamoto; M. Fujita

2005-01-01

64

Predicting Strong Motions for Seismic Hazard Assessments in Seattle, Washington  

NASA Astrophysics Data System (ADS)

Much of Seattle, Washington lies atop a deep sedimentary basin. The Seattle Basin amplifies and distorts seismic waves in ways that modulate the hazard from earthquakes. Seismic hazard assessments heavily depend upon upper crustal and near-surface S-wave velocity models, which have traditionally been constructed from P-wave models using an empirical relationship between P-wave and S-wave velocity or by interpolating and extrapolating widely spaced observations of shallow geologic structures. Improving the accuracy and resolution of basin S-wave models is key to predictions for ground shaking. Tomography, with short-period Rayleigh waves extracted using noise interferometry, can refine S-wave velocity models in urban areas with dense arrays of short-period and broadband instruments. I apply this technique to the Seattle area to develop a new shallow S-wave model for use in hazard assessment. Continuous data from the Seismic Hazards in Puget Sound (SHIPS) array and local broadband stations have inter-station distances as short as a few kilometers. This spacing allows me to extract Rayleigh waves between 2-10s period that are sensitive to shallow basin structure. My results reveal greater detail in the upper 4 km than previous models. I use the new model to make predictions on the levels of ground motions for a variety of representative crustal and Benioff Zone earthquakes. My simulations reveal additional risk from earthquake shaking in some neighborhoods in north Seattle from crustal events relative to predictions made in the current seismic hazard map. The predicted amplitudes in the Seattle neighborhoods of Capital Hill and Queen Anne are twice as high as previous predictions for some events. The combined risk for all possible events will increase somewhat due to these predictions. My simulations of Benioff Zone events show similar results to the previous model used to make predictions for the seismic hazard map.

Delorey, Andrew A.

65

Simulation of strong ground motions based on recorded accelerograms and the stochastic method  

Microsoft Academic Search

Considering the strong influence of severe ground motions of shear waves on the dynamic behavior of buildings and civil structures, these shear wave motions are simulated by using the recorded accelerograms under the surface of the ground which is regarded as a base rock in Osaka, Japan, and by using the stochastic method which can easily introduce higher frequency contents

Sanshiro Suzuki; Koji Hada; Koichiro Asano

1998-01-01

66

Estimation of strong ground motions from hypothetical earthquakes on the Cascadia subduction zone, Pacific Northwest  

Microsoft Academic Search

Strong ground motions are estimated for the Pacific Northwest assuming that large shallow earthquakes, similar to those experienced in southern Chile, southwestern Japan, and Colombia, may also occur on the Cascadia subduction zone. Fifty-six strong motion recordings for twenty-five subduction earthquakes ofMs=7.0 are used to estimate the response spectra that may result from earthquakesMwMw 9.5) is the largest event that

Thomas H. Heaton; Stephen H. Hartzell

1989-01-01

67

Estimation of strong ground motions from hypothetical earthquakes on the Cascadia subduction zone, Pacific Northwest  

Microsoft Academic Search

Strong ground motions are estimated for the Pacific Northwest assuming that large shallow earthquakes, similar to those experienced in southern Chile, southwestern Japan, and Colombia, may also occur on the Cascadia subduction zone. Fifty-six strong motion recordings for twenty-five subduction earthquakes of M s>=7.0 are used to estimate the response spectra that may result from earthquakes M w<81\\/4. Large variations

Thomas H. Heaton; Stephen H. Hartzell

1989-01-01

68

The near-source strong-motion accelerograms recorded by an experimental array in Tangshan, China  

Microsoft Academic Search

A joint research project on strong-motion earthquake studies between the People's Republic of China and the United States is in progress. As a part of this project, an experimental strong-motion array, consisting of twelve Kinemetrics PDR-1 Digital Event Recorders, was deployed in the meizoseismal area of the Ms = 7.8 Tangshan earthquake of July 28, 1976. These instruments have automatic

Kezhong Peng; Lili Xie; Shabai Li; D. M. Boore; W. D. Iwan; T. L. Teng

1985-01-01

69

Strong ground-motion prediction and uncertainties estimation for Delhi, India  

Microsoft Academic Search

An endeavour has been made in the present study to estimate the uncertainties in strong ground-motion estimation for Delhi\\u000a region. The strong ground motion (SGM) has been estimated using the logic-tree approach with equal weights chosen for the\\u000a branches of the logic tree because a scientific preference has not yet been developed for the area. Coefficient of variation\\u000a (COV) maps

G. C. Joshi; M. L. Sharma

70

Rupture history of the 2000 Tottori earthquake from inversion of strong motion and geodetic coseismic data  

Microsoft Academic Search

Strong motion and geodetic coseismic data (23 strong motion and 14 GPS stations) are used to constrain the evolution of the slip on the fault plane in time and space during the 2000 Tottori (Japan) earthquake (Mw=6.6~6.8). This strike-slip earthquake is comparable in size to the 1995 Kobe, Japan event. In spite of this large magnitude, no clear surface rupture

F. Semmane; F. Cotton; M. Campillo

2003-01-01

71

The U.S. Army Corps of Engineers Seismic Strong-Motion Instrumentation Program  

Microsoft Academic Search

\\u000a The U.S. Army Corps of Engineers (USACE) currently operates a seismic Strong-Motion Instrumentation Program (SMIP) throughout\\u000a the United States to provide a measure of project performance, provide insight into the safety of USACE projects, and establish\\u000a a data base for earthquake research. Strong-motion instruments used for SMIP consist of digital and analog accelerographs,\\u000a peak acceleration recorders, and seismic alarm devices.

72

Estimation of strong ground motions from hypothetical earthquakes on the Cascadia subduction zone, Pacific Northwest  

USGS Publications Warehouse

Strong ground motions are estimated for the Pacific Northwest assuming that large shallow earthquakes, similar to those experienced in southern Chile, southwestern Japan, and Colombia, may also occur on the Cascadia subduction zone. Fifty-six strong motion recordings for twenty-five subduction earthquakes of Ms???7.0 are used to estimate the response spectra that may result from earthquakes Mw<81/4. Large variations in observed ground motion levels are noted for a given site distance and earthquake magnitude. When compared with motions that have been observed in the western United States, large subduction zone earthquakes produce relatively large ground motions at surprisingly large distances. An earthquake similar to the 22 May 1960 Chilean earthquake (Mw 9.5) is the largest event that is considered to be plausible for the Cascadia subduction zone. This event has a moment which is two orders of magnitude larger than the largest earthquake for which we have strong motion records. The empirical Green's function technique is used to synthesize strong ground motions for such giant earthquakes. Observed teleseismic P-waveforms from giant earthquakes are also modeled using the empirical Green's function technique in order to constrain model parameters. The teleseismic modeling in the period range of 1.0 to 50 sec strongly suggests that fewer Green's functions should be randomly summed than is required to match the long-period moments of giant earthquakes. It appears that a large portion of the moment associated with giant earthquakes occurs at very long periods that are outside the frequency band of interest for strong ground motions. Nevertheless, the occurrence of a giant earthquake in the Pacific Northwest may produce quite strong shaking over a very large region. ?? 1989 Birkha??user Verlag.

Heaton, T. H.; Hartzell, S. H.

1989-01-01

73

Comparisons of Ground Motions from Five Aftershocks of the 1999 Chi-Chi, Taiwan, Earthquake with Empirical Predictions Largely Based on Data from California  

Microsoft Academic Search

The observed ground motions from five large aftershocks of the 1999 Chi-Chi, Taiwan, earthquake are compared with predictions from four equations based primarily on data from California. The four equations for active tectonic re- gions are those developed by Abrahamson and Silva (1997), Boore et al. (1997), Campbell (1997, 2001), and Sadigh et al. (1997). Comparisons are made for horizontal-component

Guo-Quan Wang; David M. Boore; Heiner Igel; Xi-Yuan Zhou

2004-01-01

74

Earthquake Strong Ground Motion Scenario at the 2008 Olympic Games Sites, Beijing, China  

Microsoft Academic Search

Historic earthquake record indicates mediate to strong earthquakes have been frequently hit greater Beijing metropolitan area where is going to host the 2008 summer Olympic Games. For the readiness preparation of emergency response to the earthquake shaking for a mega event in a mega city like Beijing in summer 2008, this paper tries to construct the strong ground motion scenario

L. Liu; E. A. Rohrbach; Q. Chen; Y. Chen

2006-01-01

75

Current Status of Strong-Motion Monitoring and Notification at the United States Bureau of Reclamation  

Microsoft Academic Search

\\u000a Acquisition of strong motion data at the Bureau of Reclamation provides near real time notification of strong shaking at our\\u000a structures as well as recordings of earthquakes for use in the dynamic analyses of large, engineered structures. To facilitate\\u000a rapid notification following strong ground shaking, we have developed a low-cost, automated system to retrieve event-triggered\\u000a seismic waveform data from digital

Chris Wood; Andy Viksne; Jon Ake; David Copeland

76

Final report on repair procedure of strong ground motion data from underground nuclear tests  

Microsoft Academic Search

Certain difficulties arise when recording close-in around motion from underground nuclear explosions. Data quality can be compromised by a variety of factors, including electromagnetic pulse, noise spikes, direct current effect, and gauge clipping and gauge tilt. From March 1988 through September 1994, EG&G Energy Measurements repaired strong round-motion data (acceleration data) from underground nuclear tests for the Los Alamos National

Tunnell

1995-01-01

77

ANALYSIS OF STRONG-MOTION EARTHQUAKE RECORDS FROM A WELL-INSTRUMENTED EARTH DAM.  

USGS Publications Warehouse

Strong-motion records from Long Valley Dam during the Mammoth Lakes earthquake sequence of May 1980 are analyzed to determine the main features of the dam's motions. The dam was instrumented with 22 accelerometers on its embankment and in the immediate vicinity, and more than 60 high-quality, long-duration accelerograms were recorded for the three largest earthquakes of the sequence. Free-field responses are compared with embankment responses to help establish the amplification of the structural motions and to identify modes of vibration of the structure.

Fedock, Joseph, J.

1986-01-01

78

Shear-wave velocity compilation for Northridge strong-motion recording sites  

USGS Publications Warehouse

Borehole and other geotechnical information collected at the strong-motion recording sites of the Northridge earthquake of January 17,1994 provide an important new basis for the characterization of local site conditions. These geotechnical data, when combined with analysis of strong-motion recordings, provide an empirical basis to evaluate site coefficients used in current versions of US building codes. Shear-wave-velocity estimates to a depth of 30 meters are derived for 176 strong-motion recording sites. The estimates are based on borehole shear-velocity logs, physical property logs, correlations with physical properties and digital geologic maps. Surface-wave velocity measurements and standard penetration data are compiled as additional constraints. These data as compiled from a variety of databases are presented via GIS maps and corresponding tables to facilitate use by other investigators.

Borcherdt, Roger D.; Fumal, Thomas E.

2002-01-01

79

Strong Motion Instrumentation of Seismically-Strengthened Port Structures in California by CSMIP  

USGS Publications Warehouse

The California Strong Motion Instrumentation Program (CSMIP) has instrumented five port structures. Instrumentation of two more port structures is underway and another one is in planning. Two of the port structures have been seismically strengthened. The primary goals of the strong motion instrumentation are to obtain strong earthquake shaking data for verifying seismic analysis procedures and strengthening schemes, and for post-earthquake evaluations of port structures. The wharves instrumented by CSMIP were recommended by the Strong Motion Instrumentation Advisory Committee, a committee of the California Seismic Safety Commission. Extensive instrumentation of a wharf is difficult and would be impossible without the cooperation of the owners and the involvement of the design engineers. The instrumentation plan for a wharf is developed through study of the retrofit plans of the wharf, and the strong-motion sensors are installed at locations where specific instrumentation objectives can be achieved and access is possible. Some sensor locations have to be planned during design; otherwise they are not possible to install after construction. This paper summarizes the two seismically-strengthened wharves and discusses the instrumentation schemes and objectives. ?? 2009 ASCE.

Huang, M. J.; Shakal, A. F.

2009-01-01

80

Strong motion recordings of the 2008/12/23 earthquake in Northern Italy: another case of very weak motion?  

NASA Astrophysics Data System (ADS)

On December 23 2008 an earthquake of magnitude ML=5.1 (INGV) Mw=5.4 (INGV-Harvard Global CMT) occurred in northern Italy close to the cities of Parma and Reggio Emilia. The earthquake, with a macroseismic intensity of VI MCS, caused a very slight damage (some tens of unusable buildings and some hundreds of damaged buildings), substantially lower than the damage estimated by the loss simulation scenario currently used by the Italian Civil Protection. Due to the recent upgrading of the Italian strong motion network (RAN), the event has been recorded by a great number of accelerometers (the largest ever obtained in Italy for a single shock): 21 digital and 8 analog instruments with epicentral distances ranging from 16 to 140 km. The comparison of recorded PGA, PGV, Arias intensity, and spectral values with several widely used Ground Motion Prediction Equations (GMPEs) showed much lower ground motion values respect to the empirical predictions (a factor ranging from 4 to 2). A first explanation of the strong differences, in damage and ground motion, between actual data and predictions could be, at a first sight, attributed to the rather high focal depth of 27 km. However, even the adoption of GMPEs accounting for depth of the source and using hypocentral distance (Berge et al 2003, Pousse et al 2005), does not predict large differences in motions, especially at distances larger than 30 km where most of the data are concentrated and where the effect of depth on source-to-site distance is small. At the same time the adoption of the most recent GMPEs (Ambraseys et al 2005, Akkar & bommer 2007) taking into account the different magnitude scaling and the faster attenuation of small magnitudes through magnitude-dependent attenuation, does not show a better agreement with the recorded data. The real reasons of the above mentioned discrepancies need to be further investigated, however a possible explanation could be a low source rupture velocity, likewise the 2002 Molise earthquake that also generated very weak motions. Another explanation comes from the fact that the moment magnitude estimated by the INGV network on the basis of body-waves instead of surface-waves used by Harvard CMT, is 4.9 and not 5.4, providing a much better fit of recorded ground motions with GMPEs.

Sabetta, F.; Zambonelli, E.

2009-04-01

81

A note on filtering strong- motion accelerograms to produce response spectra of specified shape and amplitude  

Microsoft Academic Search

SUMMARY - For a recorded strong motion accelerogram, it is often convenient for some engineering applications to modify it so that the resulting response spectra will have predetermined shape and amplitudes. This requirements often arises in those analyses where design spectra of given shape and amplitude are given by some code requirement. Rather than to create artificial acceleration data, compatible

V. W. Lee; M. D. Trifunac

1989-01-01

82

Strong motion waves estimation for seismic control of nuclear power plant  

Microsoft Academic Search

The problem of forecasting in general and in real-time of the behavior of seismic wave is discussed. Seismic waves classification on the base of principle axis transformation and evolutionary power spectrum estimation is provided for it implementation in an intelligent hybrid model. A hybrid model for real-time forecasting of strong motion acceleration on the bases of general, tectonic, seismic and

Svetla Tsoneva Radeva; Raimar Josef Scherer; Dimitar Radev

2005-01-01

83

Real-Time Forecasting of Strong Motion Acceleration for Seismic Control of Nuclear Power Plant  

Microsoft Academic Search

The problem of forecasting in general and in real-time of the behaviour of seismic wave is discussed. A hybrid model for real-time forecasting of strong motion acceleration on the bases of general, tectonic, seismic and site parameters is developed. On the base of this forecasting can be made right decision for activating different devices and systems for passive, active or

Svetla Tsoneva Radeva; Raimar Josef Scherer; Dimitar Radev

84

Stochastic Strong Ground Motion Simulation of the 7 September 1999 Athens (Greece) Earthquake  

Microsoft Academic Search

The stochastic method for finite faults is applied to simulate the strong ground motion from the 7 September 1999, M 5.9 Athens earthquake. The method includes descritization of the fault plane into certain number of subfaults, each of which is assigned an omega 2 spectrum. A slip distribution model, derived from previous studies of this earthquake, is used to specifically

Z. Roumelioti; A. Kiratzi; N. Theodoulidis

2003-01-01

85

Hybrid Slip Model for Predicting Near-field Strong Ground Motion  

Microsoft Academic Search

A hybrid slip model combined an Asperity model and k-2 model for predicting near-field strong ground motion is proposed in this paper. Firstly, the asperity model charactering lower wave number of slip distribution is estimated based on works of Wang (2004), Wang and Tao (2004a, b). Secondly, k square slip model charactering higher wave number of slip distribution was determined

Haiyun Wang; Xiaxin Tao

86

Strong ground-motion prediction from Stochastic-dynamic source models  

USGS Publications Warehouse

In the absence of sufficient data in the very near source, predictions of the intensity and variability of ground motions from future large earthquakes depend strongly on our ability to develop realistic models of the earthquake source. In this article we simulate near-fault strong ground motion using dynamic source models. We use a boundary integral method to simulate dynamic rupture of earthquakes by specifying dynamic source parameters (fracture energy and stress drop) as spatial random fields. We choose these quantities such that they are consistent with the statistical properties of slip heterogeneity found in finite-source models of past earthquakes. From these rupture models we compute theoretical strong-motion seismograms up to a frequency of 2 Hz for several realizations of a scenario strike-slip Mw 7.0 earthquake and compare empirical response spectra, spectra obtained from our dynamic models, and spectra determined from corresponding kinematic simulations. We find that spatial and temporal variations in slip, slip rise time, and rupture propagation consistent with dynamic rupture models exert a strong influence on near-source ground motion. Our results lead to a feasible approach to specify the variability in the rupture time distribution in kinematic models through a generalization of Andrews' (1976) result relating rupture speed to apparent fracture energy, stress drop, and crack length to 3D dynamic models. This suggests that a simplified representation of dynamic rupture may be obtained to approximate the effects of dynamic rupture without having to do full dynamic simulations.

Guatteri, M.; Mai, P. M.; Beroza, G. C.; Boatwright, J.

2003-01-01

87

Simulation of strong earthquake motion by explosions — experiments at the Lyaur testing range in Tajikistan  

Microsoft Academic Search

Strong motion data of 10 controlled explosion experiments conducted in 1977 at the Lyaur testing range in the Republic of Tajikistan are revisited. The explosions were detonated in arrays, with time delay between detonation of array lines. Ground accelerations, as large as ?1.6g, were recorded at 4 sites by SMA-1 accelerographs. The records were recently digitized and processed with modern

S. Kh. Negmatullaev; M. I. Todorovska; M. D. Trifunac

1999-01-01

88

Simulation of strong earthquake motion by explosions — experiments at the Lyaur testing range in Tajikistan  

Microsoft Academic Search

Strong motion data of 10 controlled explosion experiments conducted in 1977 at the Lyaur testing range in the Republic of Tajikistan are revisited. The explosions were detonated in arrays, with time delay between detonation of array lines. Ground accelerations, as large as , 1.6g, were recorded at 4 sites by SMA-1 accelerographs. The records were recently digitized and processed with

S. Kh; M. D. Trifunac

89

STRONG MOTION DATA PROCESSING AND RECORDING AT UNIVERSITY OF SOUTHERN CALIFORNIA  

Microsoft Academic Search

A brief review is presented of the Los Angeles and Vicinity Strong Motion Network operated by the University of Southern California (USC), consisting of 80 stations deployed in 1978-1980, and of software developed and used at USC for digitization of accelerograms recorded on film, and for routine and specialized data processing of digitized or digitally recorded accelerograms. The currently used

MARIA I. TODOROVSKA; VINCENT W. LEE

90

Moment Tensor Inversions of 20 October 1999 Taiwan earthquake sequence  

Microsoft Academic Search

We study the accelerograms recorded by the Taiwan Strong-motion Instrumentation Program (TSMIP) stations during the 20 October 1999 earthquake sequence (0218:56.930 UT; located at 23.53±0.04N, 120.45±0.03E, and depth of 16 km), which occurred a month after the 1999 Chi-Chi, Taiwan, earthquake. These events are too small to be studied teleseismically, yet they are important for better understanding the tectonics and

K. Chang; W. Chi; Y. Gung; H. Chiu

2009-01-01

91

Strong Earthquake Motion Estimates for Three Sites on the U.C. Riverside Campus  

SciTech Connect

The approach of the Campus Earthquake Program (CEP) is to combine the substantial expertise that exists within the UC system in geology, seismology, and geotechnical engineering, to estimate the earthquake strong motion exposure of UC facilities. These estimates draw upon recent advances in hazard assessment, seismic wave propagation modeling in rocks and soils, and dynamic soil testing. The UC campuses currently chosen for application of our integrated methodology are Riverside, San Diego, and Santa Barbara. The procedure starts with the identification of possible earthquake sources in the region and the determination of the most critical fault(s) related to earthquake exposure of the campus. Combined geological, geophysical, and geotechnical studies are then conducted to characterize each campus with specific focus on the location of particular target buildings of special interest to the campus administrators. We drill and geophysically log deep boreholes next to the target structure, to provide direct in-situ measurements of subsurface material properties, and to install uphole and downhole 3-component seismic sensors capable of recording both weak and strong motions. The boreholes provide access below the soil layers, to deeper materials that have relatively high seismic shear-wave velocities. Analyses of conjugate downhole and uphole records provide a basis for optimizing the representation of the low-strain response of the sites. Earthquake rupture scenarios of identified causative faults are combined with the earthquake records and with nonlinear soil models to provide site-specific estimates of strong motions at the selected target locations. The predicted ground motions are shared with the UC consultants, so that they can be used as input to the dynamic analysis of the buildings. Thus, for each campus targeted by the CEP project, the strong motion studies consist of two phases, Phase 1--initial source and site characterization, drilling, geophysical logging, installation of the seismic station, and initial seismic monitoring, and Phase 2--extended seismic monitoring, dynamic soil testing, calculation of estimated site-specific earthquake strong motions at depth and at the surface, and, where applicable, estimation of the response of selected buildings to the CEP-estimated strong motions.

Archuleta, R.; Elgamal, A.; Heuze, F.; Lai, T.; Lavalle, D.; Lawrence, B.; Liu, P.C.; Matesic, L.; Park, S.; Riemar, M.; Steidl, J.; Vucetic, M.; Wagoner, J.; Yang, Z.

2000-11-01

92

Strong earthquake motion estimates for three sites on the U.C. San Diego campus  

SciTech Connect

The approach of the Campus Earthquake Program (CEP) is to combine the substantial expertise that exists within the UC system in geology, seismology, and geotechnical engineering, to estimate the earthquake strong motion exposure of UC facilities. These estimates draw upon recent advances in hazard assessment, seismic wave propagation modeling in rocks and soils, and dynamic soil testing. The UC campuses currently chosen for application of our integrated methodology are Riverside, San Diego, and Santa Barbara. The procedure starts with the identification of possible earthquake sources in the region and the determination of the most critical fault(s) related to earthquake exposure of the campus. Combined geological, geophysical, and geotechnical studies are then conducted to characterize each campus with specific focus on the location of particular target buildings of special interest to the campus administrators. We drill, sample, and geophysically log deep boreholes next to the target structure, to provide direct in-situ measurements of subsurface material properties, and to install uphole and downhole 3-component seismic sensors capable of recording both weak and strong motions. The boreholes provide access below the soil layers, to deeper materials that have relatively high seismic shear-wave velocities. Analyses of conjugate downhole and uphole records provide a basis for optimizing the representation of the low-strain response of the sites. Earthquake rupture scenarios of identified causative faults are combined with the earthquake records and with nonlinear soil models to provide site-specific estimates of strong motions at the selected target locations. The predicted ground motions are shared with the UC consultants, so that they can be used as input to the dynamic analysis of the buildings. Thus, for each campus targeted by the CEP project, the strong motion studies consist of two phases, Phase 1--initial source and site characterization, drilling, geophysical logging, installation of the seismic station, and initial seismic monitoring, and Phase 2--extended seismic monitoring, dynamic soil testing, calculation of estimated site-specific earthquake strong motions at depth and at the surface, and , where applicable, estimation of the response of selected buildings to the CEP-estimated strong motions.

Day, S; Doroudian, M; Elgamal, A; Gonzales, S; Heuze, F; Lai, T; Minster, B; Oglesby, D; Riemer, M; Vernon, F; Vucetic, M; Wagoner, J; Yang, Z

2002-05-07

93

the correlation of landslide and strong ground motion in Ms8.0 Wenchuan earthquake  

NASA Astrophysics Data System (ADS)

slope failure trigged by strong earthuqake is main factor to bring great losses in Ms. 8.0 Wenchuan earthquake occurred on May 12, 2008, in Sichuan province, south-western China. According to the site investigation, about twenty shousands of slopes were found to lose their stabilities, main including landslides, collapsed rock, debris and ground crack, etc. The paper presents a statistic model discribing the correlation between landslide and strong ground motion.In this model, slope stability index (SSI) is defined based on the spatial distribution characteristics of peak ground acceleration (PGA), peak ground velocity (PGV), peak ground displacement (PGD) and earthuqake intensity(EI). SSI is related to not only slope parameters such as height, slope natural angle, rock hardness and attitude of stratum, but also PGA or PGV or PGD. This index had successfully been used to quickly assess the slope failure under strong ground motion in this Wenchuan earthquake.

Tang, Aping

2010-05-01

94

Strong Motion Amplitudes in Himalayas and Deterministic Approach towards First Order Microzonation Studies in a Part of Delhi City  

Microsoft Academic Search

The interdependence among the strong-motion amplitude, earthquake magnitude and hypocentral distance was established 1 for the Himalayan region using the dataset of six earthquakes, two from western and four from Eastern Himalayas (Mw = 5.2-7.2) recorded by strong-motion networks in the Himalayas. The significant result of this study was that the level of peak strong motion amplitudes in the Eastern

Imtiyaz A. Parvez; G. F. Panza; A. A. Gusev; F. Vaccari

95

Hanford strong motion accelerometer network: A summary of the first year of operation  

SciTech Connect

The Hanford Seismic Monitoring Network consists of two designs of equipment and sites: seismometer sites and strong motion accelerometer (SMA) sites. Seismometer sites are designed to locate earthquakes on and near the Hanford Site and determine their magnitude and hypocenter location. The US Department of Energy (DOE) Order 5480.28, Natural Phenomena Hazards (DOE 1993) requires that facilities or sites that have structures or components in Performance Category 2 with hazardous material, and all Performance Category 3 and 4 facilities shall have instrumentation or other means to detect and record the occurrence and severity of seismic events. In order to comply with DOE Order 5480.28, the Hanford Seismic Monitoring Network seismometer sites needed to be complemented with strong motion accelerometers to record the ground motion at specific sites. The combined seismometer sites and strong motion accelerometer sites provide the Hanford Site with earthquake information to comply with DOE Order 5480.28. The data from these instruments will be used by the PHMC staff to assess the damage to facilities following a significant earthquake.

Conrads, T.J.

1997-09-22

96

Strong Ground Motion Generation during the 2011 Tohoku-Oki Earthquake  

NASA Astrophysics Data System (ADS)

Strong ground motions during the 2011 Tohoku-Oki earthquake (Mw9.0) were densely observed by the strong motion observation networks all over Japan. Seeing the acceleration and velocity waveforms observed at strong stations in northeast Japan along the source region, those ground motions are characterized by plural wave packets with duration of about twenty seconds. Particularly, two wave packets separated by about fifty seconds could be found on the records in the northern part of the damaged area, whereas only one significant wave packets could be recognized on the records in the southern part of the damaged area. The record section shows four isolated wave packets propagating from different locations to north and south, and it gives us a hint of the strong motion generation process on the source fault which is related to the heterogeneous rupture process in the scale of tens of kilometers. In order to solve it, we assume that each isolated wave packet is contributed by the corresponding strong motion generation area (SMGA). It is a source patch whose slip velocity is larger than off the area (Miyake et al., 2003). That is, the source model of the 2011 Tohoku-Oki earthquake consists of four SMGAs. The SMGA source model has succeeded in reproducing broadband strong ground motions for past subduction-zone events (e.g., Suzuki and Iwata, 2007). The target frequency range is set to be 0.1-10 Hz in this study as this range is significantly related to seismic damage generation to general man-made structures. First, we identified the rupture starting points of each SMGA by picking up the onset of individual packets. The source fault plane is set following the GCMT solution. The first two SMGAs were located approximately 70 km and 30 km west of the hypocenter. The third and forth SMGAs were located approximately 160 km and 230 km southwest of the hypocenter. Then, the model parameters (size, rise time, stress drop, rupture velocity, rupture propagation pattern) of these four SMGAs were determined by waveform modeling using the empirical Green's function method (Irikura, 1986). The first and second SMGAs are located close to each other, and they are partially overlapped though the difference in the rupture time between them is more than 40 s. Those two SMGA appear to be included in the source region of the past repeating Miyagi-Oki subduction-zone event in 1936. The third and fourth SMGAs appear to be located in the source region of the past Fukushima-Oki events in 1938. Each of Those regions has been expected to cause next major earthquakes in the long-term evaluation. The obtained source model explains the acceleration, velocity, and displacement time histories in the target frequency range at most stations well. All of four SMGAs exist apparently outside of the large slip area along the trench east of the hypocenter, which was estimated by the seismic, geodetic, and tsunami inversion analyses, and this large slip zone near the trench does not contribute to strong motion much. At this point, we can conclude that the 2011 Tohoku-Oki earthquake has a possibility to be a complex event rupturing multiple preexisting asperities in terms of strong ground motion generation. It should be helpful to validate and improve the applicability of the strong motion prediction recipe for great subduction-zone earthquakes.

Asano, K.; Iwata, T.

2011-12-01

97

Comparisons of ground motions from five aftershocks of the 1999 Chi-Chi, Taiwan, earthquake with empirical predictions largely based on data from California  

USGS Publications Warehouse

The observed ground motions from five large aftershocks of the 1999 Chi-Chi, Taiwan, earthquake are compared with predictions from four equations based primarily on data from California. The four equations for active tectonic regions are those developed by Abrahamson and Silva (1997), Boore et al. (1997), Campbell (1997, 2001), and Sadigh et al. (1997). Comparisons are made for horizontal-component peak ground accelerations and 5%-damped pseudoacceleration response spectra at periods between 0.02 sec and 5 sec. The observed motions are in reasonable agreement with the predictions, particularly for distances from 10 to 30 km. This is in marked contrast to the motions from the Chi-Chi mainshock, which are much lower than the predicted motions for periods less than about 1 sec. The results indicate that the low motions in the mainshock are not due to unusual, localized absorption of seismic energy, because waves from the mainshock and the aftershocks generally traverse the same section of the crust and are recorded at the same stations. The aftershock motions at distances of 30-60 km are somewhat lower than the predictions (but not nearly by as small a factor as those for the mainshock), suggesting that the ground motion attenuates more rapidly in this region of Taiwan than it does in the areas we compare with it. We provide equations for the regional attenuation of response spectra, which show increasing decay of motion with distance for decreasing oscillator periods. This observational study also demonstrates that ground motions have large earthquake-location-dependent variability for a specific site. This variability reduces the accuracy with which an earthquake-specific prediction of site response can be predicted. Online Material: PGAs and PSAs from the 1999 Chi-Chi earthquake and five aftershocks.

Wang, G. -Q.; Boore, D. M.; Igel, H.; Zhou, X. -Y.

2004-01-01

98

Chapter A. The Loma Prieta, California, Earthquake of October 17, 1989 - Strong Ground Motion  

USGS Publications Warehouse

Strong ground motion generated by the Loma Prieta, Calif., earthquake (MS~7.1) of October 17, 1989, resulted in at least 63 deaths, more than 3,757 injuries, and damage estimated to exceed $5.9 billion. Strong ground motion severely damaged critical lifelines (freeway overpasses, bridges, and pipelines), caused severe damage to poorly constructed buildings, and induced a significant number of ground failures associated with liquefaction and landsliding. It also caused a significant proportion of the damage and loss of life at distances as far as 100 km from the epicenter. Consequently, understanding the characteristics of the strong ground motion associated with the earthquake is fundamental to understanding the earthquake's devastating impact on society. The papers assembled in this chapter address this problem. Damage to vulnerable structures from the earthquake varied substantially with the distance from the causative fault and the type of underlying geologic deposits. Most of the damage and loss of life occurred in areas underlain by 'soft soil'. Quantifying these effects is important for understanding the tragic concentrations of damage in such areas as Santa Cruz and the Marina and Embarcadero Districts of San Francisco, and the failures of the San Francisco-Oakland Bay Bridge and the Interstate Highway 880 overpass. Most importantly, understanding these effects is a necessary prerequisite for improving mitigation measures for larger earthquakes likely to occur much closer to densely urbanized areas in the San Francisco Bay region. The earthquake generated an especially important data set for understanding variations in the severity of strong ground motion. Instrumental strong-motion recordings were obtained at 131 sites located from about 6 to 175 km from the rupture zone. This set of recordings, the largest yet collected for an event of this size, was obtained from sites on various geologic deposits, including a unique set on 'soft soil' deposits (artificial fill and bay mud). These exceptional ground-motion data are used by the authors of the papers in this chapter to infer radiation characteristics of the earthquake source, identify dominant propagation characteristics of the Earth?s crust, quantify amplification characteristics of near-surface geologic deposits, develop general amplification factors for site-dependent building-code provisions, and revise earthquake-hazard assessments for the San Francisco Bay region. Interpretations of additional data recorded in well-instrumented buildings, dams, and freeway overpasses are provided in other chapters of this report.

Edited by Borcherdt, Roger D.

1994-01-01

99

Dense Strong Motion Seismograph Networks in Canada: Opportunities and Applications. (Invited)  

NASA Astrophysics Data System (ADS)

Strong motion monitoring has undergone a revolution in Canada in recent years. Most analogue, non-communicating instruments have been replaced with modern, smart digital instruments that provide information in real-time. These new instruments have on-board computing capabilities and can serve multiple purposes when connected in networks with fast Internet based telemetry. As of 2010, the Geological Survey of Canada operates 110 strong motion instruments (Internet Acclerometers or IA=s) across Canada, most of which are deployed in or near the urban centres of high seismic hazard in southwest British Columbia. Partner organisations operate an additional 70 strong motion instruments monitoring critical infrastructure in western Canada. These instruments and data serve multiple purposes: 1. They help to fill the still sparse data-base of strong ground motions required for seismic engineering and hazard and risk assessment in general. 2. Recordings of small, moderate (and large) earthquakes can be utilised for earthquake site response studies - mapping the variation in shaking across urban areas and the effects of surface geology, sedimentary basins, and topography. 3. They contribute to the development of real-time warning systems. 4. They contribute to situational awareness after a major earthquake (e.g., shaking maps). 5. Their data can be integrated with structural monitoring systems to aide in the rapid assessment of critical infrastructure and life lines in the aftermath of a large earthquake. These applications require a sufficiently high density of stations in a high earthquake risk area and as well a new type of smart instrument which can provide a tailored parameter set describing the nature and severity of earthquake ground motion in real time and in a form suitable as input for engineering models. The real time transmittal of data into easily accessible displays can facilitate post earthquake response and inspection, and can enable emergency funding agencies to focus recovery efforts. Here, we provide an overview of how the strong motion network in the high-risk region of southwest British Columbia operates and present some examples of new opportunities and applications.

Cassidy, J. F.; Rosenberger, A.; Rogers, G. C.; Huffman, S.

2010-12-01

100

A Simplified Technique for Simulating Wide-band Strong Ground Motion for Two Recent Himalayan Earthquakes  

NASA Astrophysics Data System (ADS)

A simplified technique for simulation of wide-band strong motion based on simple regression relations and Empirical Green's Function (EGF) technique by Irikura (1986) is presented in this paper. The method uses the acceleration envelope as a shaping window for a filtered white Gaussian noise, to get the synthetic accelerogram from each subfault. Correction factors for slip of large and small events and transmission factors at each boundary of different layers are included in this synthetic accelerogram. The synthetic accelerogram obtained from each subfault is used as the Green's function to get resultant records. Simulations are made for the confirmed models of the Uttarkashi and the Chamoli earthquakes at a number of stations to get wide-band strong ground motion. The comparison of synthetic with the observed records over a wide range of frequencies for two different Himalayan earthquakes establishes the efficacy of the present technique.

Joshi, A.

101

A Note of the Accuracy of Computed Ground Displacements from Strong-Motion Accelerogram  

Microsoft Academic Search

ABSTRACT In this paper the accuracy of routine methods for processing strong-motion earthquake accelerograms (Trifunac, 1971, 1972; Hudson et aL, 1971) has been tested by comparing displacement curves computed from the twice-integrated accelerograph recordings with displacement curves computed from displacement- meter measurements. The displacement meters have transducers with natural periods typically several seconds long. Agreement is found to be very

M. D. Trifunac; V. W. Lee

1974-01-01

102

Estimates of Stress Drop and High Frequency Diminution Parameter from Strong Motion Data Recorded in Albania  

Microsoft Academic Search

We analyze ten recent records of the Albanian strong motion network with the aim to estimate the stress drop and high-frequency\\u000a diminution parameters. Except for the earthquake record of 23\\/11\\/2004 in Leskoviku, near the border with Greece (Mw = 5.4),\\u000a all the others are small intensity records with the value of Mw around Mw = 3.9–4.9. From seven accelerograms we

L. Lambro Duni; Neki Kuka

103

Estimation of strong seismic ground motion for engineering use in Perth Western Australia  

Microsoft Academic Search

Probabilistic seismic hazard analysis (PSHA) was performed to determine two alternate magnitude-distance combinations for the 475yr event, and the worst-case scenario event in Perth, Western Australia. Regional strong ground motion (SGM) time histories on rock sites are used to modify an eastern North America (ENA) seismic model to suit southwest Western Australian (SWWA) conditions. This model is then used to

Hong Hao; Brian A. Gaull

2009-01-01

104

Integrated Surface and Borehole Strong-Motion, Soil-Response Arrays in San Francisco, California  

Microsoft Academic Search

\\u000a An integrated set of four borehole arraysand ten surface installations is installed in the city of San Francisco, California\\u000a to measure the response of soft-soil deposits to strong earthquake ground motions. The borehole arrays extend through thick\\u000a layers of softwater-saturated soils of Holocene age and older more consolidated soils of Pleistocene age into bedrock at depths\\u000a up to 100 m.

R. D. Borcherdt; H. P. Lid; R. E. Westerlund; C. Dietel; J. F. Gibbs; R. E. Warrick

105

On robust and reliable automated baseline corrections for strong motion seismology  

NASA Astrophysics Data System (ADS)

Computation of displacements from strong motion inertial sensors is to date an open problem. Two distinct methodologies have been proposed to solve it. One involves baseline corrections determined from the inertial data themselves and the other a combination with other geophysical sensors such as GPS. Here we analyze a proposed automated baseline correction algorithm using only accelerometer data and compare it to the results from the real-time combination of strong motion and GPS data. The analysis is performed on 48 collocated GPS and accelerometers in Japan that recorded the 2011 Mw 9.0 Tohoku-oki earthquake. We study the time and frequency domain behavior of both methodologies. We find that the error incurred from automated baseline corrections that rely on seismic data alone is complex and can be large in both the time and frequency domains of interest in seismological and engineering applications. The GPS/accelerometer combination has no such problems and can adequately recover broadband strong motion displacements for this event. The problems and ambiguities with baseline corrections and the success of the GPS/accelerometer combination lead us to advocate for instrument collocations as opposed to automated baseline correction algorithms for accelerometers.

Melgar, Diego; Bock, Yehuda; Sanchez, Dominga; Crowell, Brendan W.

2013-03-01

106

Prediction of broad-band strong ground motions from large subduction earthquakes using a characterized source model  

Microsoft Academic Search

In Japan, long-term probabilities of several large subduction earthquakes have been evaluated by the Headquaters for Earthquake Research Promotion. In order to mitigate the disaster caused by such earthquakes, it is very important to predict broad-band strong ground motions of engineering interest before events. A methodology has been proposed for estimating strong ground motions from scenario earthquakes caused by active

K. Kamae; H. Kawabe; K. Irikura

2002-01-01

107

Slip history of the 2003 San Simeon earthquake constrained by combining 1Hz GPS, strong motion, and teleseismic data  

Microsoft Academic Search

The slip history of the 2003 San Simeon earthquake is constrained by combining strong motion and teleseismic data, along with GPS static offsets and 1-Hz GPS observations. Comparisons of a 1-Hz GPS time series and a co-located strong motion data are in very good agreement, demonstrating a new application of GPS. The inversion results for this event indicate that the

Chen Ji; Kristine M. Larson; Ying Tan; Kyuhong Choi

2004-01-01

108

Near-fault strong motion complexity of the 2000 Tottori earthquake (Japan) from a broadband source asperity model  

Microsoft Academic Search

The October 6\\/2000 Tottori earthquake that occurred in central Japan was an intermediate size strike-slip event that produced a very large number of near field strong motion recordings. The large amount of recorded data provides a unique opportunity for investigating a source asperity model of the Tottori earthquake that, combined with a hybrid strong motion simulation technique, is able to

N. Pulido; T. Kubo

2004-01-01

109

Addressing earthquake strong ground motion issues at the Idaho National Engineering Laboratory  

SciTech Connect

In the course of reassessing seismic hazards at the Idaho National Engineering Laboratory (INEL), several key issues have been raised concerning the effects of the earthquake source and site geology on potential strong ground motions that might be generated by a large earthquake. The design earthquake for the INEL is an approximate moment magnitude (M{sub w}) 7 event that may occur on the southern portion of the Lemhi fault, a Basin and Range normal fault that is located on the northwestern boundary of the eastern Snake River Plain and the INEL, within 10 to 27km of several major facilities. Because the locations of these facilities place them at close distances to a large earthquake and generally along strike of the causative fault, the effects of source rupture dynamics (e.g., directivity) could be critical in enhancing potential ground shaking at the INEL. An additional source issue that has been addressed is the value of stress drop to use in ground motions predictions. In terms of site geology, it has been questioned whether the interbedded volcanic stratigraphy beneath the ESRP and the INEL attenuates ground motions to a greater degree than a typical rock site in the western US. These three issues have been investigated employing a stochastic ground motion methodology which incorporates the Band-Limited-White-Noise source model for both a point source and finite fault, random vibration theory and an equivalent linear approach to model soil response.

Wong, I.G. [Woodward-Clyde Consultants, Oakland, CA (United States); Silva, W.J.; Stark, C.L. [Pacific Engineering & Analysis, El Cerrito, CA (United States); Jackson, S.; Smith, R.P. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

1991-12-31

110

Addressing earthquake strong ground motion issues at the Idaho National Engineering Laboratory  

SciTech Connect

In the course of reassessing seismic hazards at the Idaho National Engineering Laboratory (INEL), several key issues have been raised concerning the effects of the earthquake source and site geology on potential strong ground motions that might be generated by a large earthquake. The design earthquake for the INEL is an approximate moment magnitude (M{sub w}) 7 event that may occur on the southern portion of the Lemhi fault, a Basin and Range normal fault that is located on the northwestern boundary of the eastern Snake River Plain and the INEL, within 10 to 27km of several major facilities. Because the locations of these facilities place them at close distances to a large earthquake and generally along strike of the causative fault, the effects of source rupture dynamics (e.g., directivity) could be critical in enhancing potential ground shaking at the INEL. An additional source issue that has been addressed is the value of stress drop to use in ground motions predictions. In terms of site geology, it has been questioned whether the interbedded volcanic stratigraphy beneath the ESRP and the INEL attenuates ground motions to a greater degree than a typical rock site in the western US. These three issues have been investigated employing a stochastic ground motion methodology which incorporates the Band-Limited-White-Noise source model for both a point source and finite fault, random vibration theory and an equivalent linear approach to model soil response.

Wong, I.G. (Woodward-Clyde Consultants, Oakland, CA (United States)); Silva, W.J.; Stark, C.L. (Pacific Engineering Analysis, El Cerrito, CA (United States)); Jackson, S.; Smith, R.P. (EG and G Idaho, Inc., Idaho Falls, ID (United States))

1991-01-01

111

Geodetic, teleseismic, and strong motion constraints on slip from recent southern Peru subduction zone earthquakes  

NASA Astrophysics Data System (ADS)

We use seismic and geodetic data both jointly and separately to constrain coseismic slip from the 12 November 1996 Mw 7.7 and 23 June 2001 Mw 8.5 southern Peru subduction zone earthquakes, as well as two large aftershocks following the 2001 earthquake on 26 June and 7 July 2001. We use all available data in our inversions: GPS, interferometric synthetic aperture radar (InSAR) from the ERS-1, ERS-2, JERS, and RADARSAT-1 satellites, and seismic data from teleseismic and strong motion stations. Our two-dimensional slip models derived from only teleseismic body waves from South American subduction zone earthquakes with Mw > 7.5 do not reliably predict available geodetic data. In particular, we find significant differences in the distribution of slip for the 2001 earthquake from models that use only seismic (teleseismic and two strong motion stations) or geodetic (InSAR and GPS) data. The differences might be related to postseismic deformation or, more likely, the different sensitivities of the teleseismic and geodetic data to coseismic rupture properties. The earthquakes studied here follow the pattern of earthquake directivity along the coast of western South America, north of 5°S, earthquakes rupture to the north; south of about 12°S, directivity is southerly; and in between, earthquakes are bilateral. The predicted deformation at the Arequipa GPS station from the seismic-only slip model for the 7 July 2001 aftershock is not consistent with significant preseismic motion.

Pritchard, M. E.; Norabuena, E. O.; Ji, C.; Boroschek, R.; Comte, D.; Simons, M.; Dixon, T. H.; Rosen, P. A.

2007-03-01

112

Dynamic geometrical effects on strong ground motion in a normal fault model  

SciTech Connect

We report results of measurement of particle motion in a foam-rubber model of normal faulting and compare the results with similar results for a strike-slip geometry. Standard computer modeling of strong ground motion from normal fault earthquakes has used dislocation theory, in which slip along the shallow part of the fault is prescribed by assuming particular time functions for fault slip. Unfortunately, in the case of normal faults, there are essentially no near-fault data from large earthquakes to constrain the modeling. In an extensional faulting regime the static normal and shear stresses along the fault must approach zero at the surface, and thus the upper few kilometers of the fault have inherently less stored strain energy than the maximum possible for strike-slip faults. In addition there are dynamic effects from geometry and drop in fault-normal stress which affect the fault motion. Physical models of faulting, such as foam-rubber modeling, are guaranteed to obey static and dynamic mechanical laws and thus can be used to gain insight into the physical processes involved. In this study we compare surface accelerations from normal fault and strike-slip geometries. The data show surface accelerations near the normal fault trace that are systematically lower, by an average factor of about 0.1, compared to the accelerations at the side sensors, which represent strike-slip motion. These results suggest that kinematic modeling of ground motion using classical dislocation techniques is inappropriate on the shallow part of the fault. The results of this study are qualitatively similar to those obtained for numerical models, such as a dynamic lattice model [{ital Shi} {ital et al.}, 1997] and a finite element model [{ital Oglesby} {ital et al.}, 1998], lending support to the probability that similar effects take place in the real Earth. {copyright} 1999 American Geophysical Union

Brune, J.N.; Anooshehpoor, A. [Seismological Laboratory, University of Nevada, Reno (United States)

1999-01-01

113

Translational motion of two interacting bubbles in a strong acoustic field.  

PubMed

Using the Lagrangian formalism, equations of radial and translational motions of two coupled spherical gas bubbles have been derived up to terms of third order in the inverse distance between the bubbles. The equations of radial pulsations were then modified, for the purpose of allowing for effects of liquid compressibility, using Keller-Miksis' approach, and the equations of translation were added by viscous forces in the form of the Levich drag. This model was then used in a numerical investigation of the translational motion of two small, driven well below resonance, bubbles in strong acoustic fields with pressure amplitudes exceeding 1 bar. It has been found that, if the forcing is strong enough, the bubbles form a bound pair with a steady spacing rather than collide and coalesce, as classical Bjerknes theory predicts. Moreover, the viscous forces cause skewness in the system, which results in self-propulsion of the bubble pair. The latter travels as a unit along the center line in a direction that is determined by the ratio of the initial bubble radii. The results obtained are of immediate interest for understanding and modeling collective bubble phenomena in strong fields, such as acoustic cavitation streamers. PMID:11497693

Doinikov, A A

2001-07-16

114

Strong ground motions of the 2009 L'Aquila earthquake: modeling and scenario simulations  

NASA Astrophysics Data System (ADS)

On April 6, 2009 a Mw 6.3 earthquake struck the L'Aquila city, one of the largest urban centers in the Abruzzo region (Central Italy), causing a large number of casualties and damage in the town and surrounding villages. The earthquake has been recorded by several digital stations of the Italian Strong-Motion Network. The collected records represent a unique dataset in Italy in terms of number and quality of records, azimuthal coverage and presence of near-fault recordings. Soon after the earthquake the damage in the epicentral area was also assessed providing macroseismic intensity estimates, in MCS scale, for 314 localities (I ?5). Despite the moderate magnitude of the L'Aquila earthquake, the strong-motion and macroseismic data in the vicinity of the fault depict a large variability of the observed shaking and damage. In this study we present broadband (0.1 - 10 Hz) ground motion simulations of the 2009 L'Aquila earthquake to be used for engineering purposes in the region. We utilize Hybrid Integral-Composite (HIC, Gallovi? and Brokešová, 2007) approach based on a k-square kinematic rupture model, combining low-frequency coherent and high-frequency incoherent source radiation and providing omega-squared source spectral decay. We first model the recorded seismograms in order to calibrate source parameters and to assess the capabilities of the broadband simulation model. To this end, position and slip amount of the two main asperities, the largest asperity time delay and the rupture velocity distribution on the fault is constrained, based on the low-frequency slip inversion result. Synthetic Green's functions are calculated in a 1D-layered crustal model including 1D soil profiles to account for site-specific response (where available). The goodness-of-fit is evaluated in time (peak values and duration) and frequency domains (elastic and inelastic response spectra) and shows a remarkable agreement between observed and simulated data at most of the stations. The results show that not only the local site effects improve the modeling results, but also that the spatial broadband ground-motion variability is to large extent controlled by the rupture kinematics revealed by the low-frequency inversion. We simulate the ground motion at a grid of sites and compared the observed macroseismic intensity distribution with that obtained applying ground-motion to intensity conversion equations to the synthetic data. We find that the spectral ordinates at periods larger than 2s are well correlated with the macroseismic intensity pattern observed in the epicentral area. Finally, we compare the synthetic ground-motion parameters with estimates from several empirical ground motion prediction equations (GMPEs). The comparison highlights potential drawbacks in using GMPEs to validate simulated motions and/or when used for engineering purposes.

Gallovi?, F.; Ameri, G.; Pacor, F.

2012-04-01

115

Earthquake Strong Ground Motion Scenario at the 2008 Olympic Games Sites, Beijing, China  

NASA Astrophysics Data System (ADS)

Historic earthquake record indicates mediate to strong earthquakes have been frequently hit greater Beijing metropolitan area where is going to host the 2008 summer Olympic Games. For the readiness preparation of emergency response to the earthquake shaking for a mega event in a mega city like Beijing in summer 2008, this paper tries to construct the strong ground motion scenario at a number of gymnasium sites for the 2008 Olympic Games. During the last 500 years (the Ming and Qing Dynasties) in which the historic earthquake record are thorough and complete, there are at least 12 earthquake events with the maximum intensity of VI or greater occurred within 100 km radius centered at the Tiananmen Square, the center of Beijing City. Numerical simulation of the seismic wave propagation and surface strong ground motion is carried out by the pseudospectral time domain methods with viscoelastic material properties. To improve the modeling efficiency and accuracy, a multi-scale approach is adapted: the seismic wave propagation originated from an earthquake rupture source is first simulated by a model with larger physical domain with coarser grids. Then the wavefield at a given plane is taken as the source input for the small-scale, fine grid model for the strong ground motion study at the sites. The earthquake source rupture scenario is based on two particular historic earthquake events: One is the Great 1679 Sanhe-Pinggu Earthquake (M~8, Maximum Intensity XI at the epicenter and Intensity VIII in city center)) whose epicenter is about 60 km ENE of the city center. The other one is the 1730 Haidian Earthquake (M~6, Maximum Intensity IX at the epicenter and Intensity VIII in city center) with the epicentral distance less than 20 km away from the city center in the NW Haidian District. The exist of the thick Tertiary-Quaternary sediments (maximum thickness ~ 2 km) in Beijing area plays a critical role on estimating the surface ground motion at the Olympic Games sites, which are most located north of the city center.

Liu, L.; Rohrbach, E. A.; Chen, Q.; Chen, Y.

2006-12-01

116

Preliminary analysis of strong-motion recordings from the 28 September 2004 Parkfield, California earthquake  

USGS Publications Warehouse

The Parkfield 2004 earthquake yielded the most extensive set of strong-motion data in the near-source region of a magnitude 6 earthquake yet obtained. The recordings of acceleration and volumetric strain provide an unprecedented document of the near-source seismic radiation for a moderate earthquake. The spatial density of the measurements alon g the fault zone and in the linear arrays perpendicular to the fault is expected to provide an exceptional opportunity to develop improved models of the rupture process. The closely spaced measurements should help infer the temporal and spatial distribution of the rupture process at much higher resolution than previously possible. Preliminary analyses of the peak a cceleration data presented herein shows that the motions vary significantly along the rupture zone, from 0.13 g to more than 2.5 g, with a map of the values showing that the larger values are concentrated in three areas. Particle motions at the near-fault stations are consistent with bilateral rupture. Fault-normal pulses similar to those observed in recent strike-slip earthquakes are apparent at several of the stations. The attenuation of peak ground acceleration with distance is more rapid than that indicated by some standard relationships but adequately fits others. Evidence for directivity in the peak acceleration data is not strong. Several stations very near, or over, the rupturing fault recorded relatively low accelerations. These recordings may provide a quantitative basis to understand observations of low near-fault shaking damage that has been reported in other large strike-slip earthquak.

Shakal, A.; Graizer, V.; Huang, M.; Borcherdt, R.; Haddadi, H.; Lin, K. -W.; Stephens, C.; Roffers, P.

2005-01-01

117

3D Modeling of Strong Ground Motion in the Pacific Northwest From Large Earthquakes in the Cascadia Subduction Zone  

Microsoft Academic Search

The Cascadia subduction zone in the Pacific Northwest, USA, generates Great (megathrust) earthquakes with a recurrence period of about 500 years, most recently the M~9 event on January 26, 1700. Since no earthquake of such magnitude has occurred in the Pacific Northwest since the deployment of strong ground motion instruments, a large uncertainty is associated with the ground motions expected

K. B. Olsen; A. Geisselmeyer; W. J. Stephenson; P. M. Mai

2007-01-01

118

A method of prediction of strong ground motion by stochastic green function considering 3-D attenuation structure  

Microsoft Academic Search

The 3-D attenuation structure is a big problem to evaluate seismic ground motion when the seismic motion that uses a statistical Green function in the great earthquake such as Tonankai earthquake generated along subduction zone. On the other hand, Q structure analysis results (ex, Nakamura and Uetake,2004) of the short period beneath the Japanese Islands show strong inhomogeneity. Therefore, We

R. Nakamura

2004-01-01

119

Detecting Motion Regions in the Presence of a Strong Parallax from a Moving Camera by Multiview Geometric Constraints  

Microsoft Academic Search

We present a method for detecting motion regions in video sequences observed by a moving camera in the presence of a strong parallax due to static 3D structures. The proposed method classifies each image pixel into planar background, parallax, or motion regions by sequentially applying 2D planar homographies, the epipolar constraint, and a novel geometric constraint called the \\

Chang Yuan; Gérard G. Medioni; Jinman Kang; Isaac Cohen

2007-01-01

120

Regional Characterization of the Crust in Metropolitan Areas for Prediction of Strong Ground Motion  

NASA Astrophysics Data System (ADS)

Introduction: After the 1995 Kobe earthquake, the Japanese government increased its focus and funding of earthquake hazards evaluation, studies of man-made structures integrity, and emergency response planning in the major urban centers. A new agency, the Ministry of Education, Science, Sports and Culture (MEXT) has started a five-year program titled as Special Project for Earthquake Disaster Mitigation in Urban Areas (abbreviated to Dai-dai-toku in Japanese) since 2002. The project includes four programs: I. Regional characterization of the crust in metropolitan areas for prediction of strong ground motion. II. Significant improvement of seismic performance of structure. III. Advanced disaster management system. IV. Investigation of earthquake disaster mitigation research results. We will present the results from the first program conducted in 2002 and 2003. Regional Characterization of the Crust in Metropolitan Areas for Prediction of Strong Ground Motion: A long-term goal is to produce map of reliable estimations of strong ground motion. This requires accurate determination of ground motion response, which includes a source process, an effect of propagation path, and near surface response. The new five-year project was aimed to characterize the "source" and "propagation path" in the Kanto (Tokyo) region and Kinki (Osaka) region. The 1923 Kanto Earthquake is one of the important targets to be addressed in the project. The proximity of the Pacific and Philippine Sea subducting plates requires study of the relationship between earthquakes and regional tectonics. This project focuses on identification and geometry of: 1) Source faults, 2) Subducting plates and mega-thrust faults, 3) Crustal structure, 4) Seismogenic zone, 5) Sedimentary basins, 6) 3D velocity properties We have conducted a series of seismic reflection and refraction experiment in the Kanto region. In 2002 we have completed to deploy seismic profiling lines in the Boso peninsula (112 km) and the Sagami bay area (75 km) to image the subducting Philippine Sea plate. On the Boso line we drilled a hole at a depth of 2000 m with core sampling and logging including VSP. A high sensitivity down hole seismometer will bee installed at the hole. In 2003, a 71-km-long reflection/refraction line covered the Tokyo bay area to characterize the source area of the 1923 Kanto quake. The southern part of the line ran through the Miura peninsula, which was covered by a 20 x 15 km array consisting of 51 3-component continuously recording seismographs to identify the asperities suggested by strong motion studies. We also cover the eastern boundary of the Kanto Mountains in this fall. Reconstruction of source fault and velocity models allow for more realistic 3D seimic wave simulations. All of this information will be synthesized and provided to communities involved in probabilistic hazards analysis, risk assessment and societal response.

Hirata, N.; Sato, H.; Koketsu, K.; Umeda, Y.; Iwata, T.; Kasahara, K.

2003-12-01

121

Broadband strong motion simulation in layered half-space using stochastic Green's function technique  

NASA Astrophysics Data System (ADS)

The stochastic Green’s function method, which simulates one component of the far-field S-waves from an extended fault plane at high frequencies (Kamae et al., J Struct Constr Eng Trans AIJ, 430:1 9, 1991), is extended to simulate the three components of the full waveform in layered half-spaces for broadband frequency range. The method firstly computes ground motions from small earthquakes, which correspond to the ruptures of sub-faults on a fault plane of a large earthquake, and secondly constructs the strong motions of the large earthquake by superposing the small ground motions using the empirical Green’s function technique (e.g., Irikura, Proc 7th Japan Earthq Eng Symp, 151 156, 1986). The broadband stochastic omega-square model is proposed as the moment rate functions of the small earthquakes, in which random and zero phases are used at higher and lower frequencies, respectively. The zero phases are introduced to simulate a smooth ramp function of the moment function with the duration of 1/fc s (fc: the corner frequency) and to reproduce coherent strong motions at low frequencies (i.e., the directivity pulse). As for the radiation coefficients, the theoretical values of double couple sources for lower frequencies and the theoretical isotropic values for the P-, SV-, and SH-waves (Onishi and Horike, J Struct Constr Eng Trans AIJ, 586:37 44, 2004) for high frequencies are used. The proposed method uses the theoretical Green’s functions of layered half-spaces instead of the far-field S-waves, which reproduce the complete waves including the direct and reflected P- and S-waves and surface waves at broadband frequencies. Finally, the proposed method is applied to the 1994 Northridge earthquake, and results show excellent agreement with the observation records at broadband frequencies. At the same time, the method still needs improvements especially because it underestimates the high-frequency vertical components in the near fault range. Nonetheless, the method will be useful for modeling high frequency contributions in the hybrid methods, which use stochastic and deterministic methods for high and low frequencies, respectively (e.g., the stochastic Green’s function method + finite difference methods; Kamae et al., Bull Seism Soc Am, 88:357 367, 1998; Pitarka et al., Bull Seism Soc Am 90:566 586, 2000), because it reproduces the full waveforms in layered media including not only random characteristics at higher frequencies but also theoretical and deterministic coherencies at lower frequencies.

Hisada, Y.

2008-04-01

122

Site effects in Avcilar, West of Istanbul, Turkey, from strong- and weak-motion data  

USGS Publications Warehouse

Approximately 1000 people were killed in the collapse of buildings in Istanbul, Turkey, during the 17 August 1999 I??zmit earthquake, whose epicenter was roughly 90 km east of the city. Most of the fatalities and damage occurred in the suburb of Avcilar that is 20 km further west of the epicenter than the city proper. To investigate this pattern of damage, the U.S. Geological Survey, in cooperation with the Kandilli Observatory and Earthquake Research Institute (KOERI), deployed portable digital seismographs at seven free-field sites in western Istanbul, to record aftershocks during the period from 24 August to 2 September. The primary objective of this deployment was to study the site effects by comparing the aftershock ground motions recorded at sites inside and outside the damaged area, and to correlate site effects with the distribution of the damaged buildings. In addition to using weak-motion data, mainshock and aftershock acceleration records from the KOERI permanent strong-motion array were also used in estimating the site effects. Site effects were estimated using S waves from both types of records. For the weak-motion data set, 22 events were selected according to the criteria of signal-to-noise ratio (S/N ratio) and the number of stations recording the same event. The magnitudes of these events ranged from 3.0 to 5.2. The acceleration data set consisted of 12 events with magnitudes ranging from 4.3 to 5.8 and included two mainshock events. Results show that the amplifying frequency band is, in general, less than 4 Hz, and the physical properties of the geologic materials are capable of amplifying the motions by a factor of 5-10. In this frequency band, there is a good agreement among the spectral ratios obtained from the two mainshocks and their aftershocks. The damage pattern for the 17 August I??zmit earthquake is determined by several factors. However, our study suggests that the site effects in Avcilar played an important role in contributing to the damage.

Ozel, O.; Cranswick, E.; Meremonte, M.; Erdik, M.; Safak, E.

2002-01-01

123

NetQuakes - A new approach to urban strong-motion seismology  

NASA Astrophysics Data System (ADS)

There is a recognized need for more densely sampled strong ground motion recordings in urban areas to provide more accurate ShakeMaps for post-earthquake disaster assessment and to provide data for structural engineers to improve design standards. Ideally, the San Francisco Bay area would have a strong ground motion recorder every 1-2 km to adequately sample the region’s varied geology and built environment. This would require the addition of thousands of instruments to the existing network. There are several fiscal and logistical constraints that prevent us from doing this with traditional strong motion instrumentation and telemetry. In addition to the initial expense of instruments and their installation, there are the continuing costs of telemetry and maintenance. To address these issues, the USGS implemented the NetQuakes project to deploy small, relatively inexpensive seismographs for installation in 1-2 story homes and businesses that utilize the host’s existing Internet connection. The recorder has 18 bit resolution with ±3g internal tri-axial MEMS accelerometers. Data is continuously recorded at 200 sps into a 1-2 week ringbuffer. When triggered, a miniSEED file is sent to USGS servers via the Internet. Data can also be recovered from the ringbuffer by a remote request through the servers. Following a power failure, the instrument can run for 36 hours using its internal battery. All client-server interactions are initiated by the instrument, so it safely resides behind a host’s firewall. Instrument and battery replacement can be performed by hosts to reduce maintenance costs. A connection to the host’s LAN, and thence to the public Internet, can be made using WiFi to minimize cabling. Although timing via a cable to an external GPS antenna is possible, it is simpler to use the Network Time Protocol (NTP) to synchronize the internal clock. NTP achieves timing accuracy generally better than a sample interval. Since February, 2009, we have installed more than 60 NetQuakes instruments in the San Francisco Bay Area and have successfully integrated their data into the near real time data stream of the Northern California Seismic System.

Luetgert, J. H.; Evans, J. R.; Hamilton, J.; Hutt, C. R.; Jensen, E. G.; Oppenheimer, D. H.

2009-12-01

124

Unusual Strong Ground Motion Amplification at the Coyote Lake Dam, California  

NASA Astrophysics Data System (ADS)

Comparison is made of strong ground motions recorded at the Coyote Lake at the two stations: Coyote Lake Dam - Southwest Abutment and Coyote Lake Dam - Downstream. An unexpectedly high peak acceleration of 1.2 g was recorded on the 285-degree component at the abutment site during the 1984 Morgan Hill earthquake. After this earthquake the California Strong Motion Instrumentation Program installed the downstream site about 700 m from the abutment site. The records of the four earthquakes (the M5.8 Coyote Lake of 8/6/79, the M6.2 Morgan Hill of 4/24/84, the M7.0 Loma Prieta of 10/18/89 and the M4.8 Gilroy of 1/16/93) were digitized and processed. Of the four events recorded at Coyote Lake Dam the last two (Loma Prieta, and Gilroy) were recorded simultaneously at the abutment and downstream sites. Site geology for the abutment station is described as "fill (about 1.5 m) over carbonate rock", and for the downstream station as "alluvium". The abutment station lies within the Calaveras fault zone, and the downstream station is located less than 250 m from the fault zone. The ground motion recorded during the M7.0 Loma Prieta earthquake of 10/18/89 demonstrates relatively high amplitudes on the 285-degree component at the abutment site. Amplitude of this component is more than 3 times higher than that of the 195-degree component. This component is also more than 2 times higher than the motion on the corresponding component at the downstream site in the period range between 0.3-0.8 seconds. This difference can not result from source directivity, because the two horizontal components at the nearby downstream station have almost the same amplitude. It is also unlikely that fault-zone trapped waves are important, because the source is well outside of the fault zone, and the azimuth to the site is almost perpendicular to the fault zone. Note that the 285-degree component is almost perpendicular to the orientation of the dam. The relationship of the abutment/downstream recordings of the M4.8 Gilroy earthquake of 1/16/1993 is almost completely different from that of the Loma Prieta earthquake. The amplitudes of motion are more than 20% higher at the downstream site than at the abutment site. The abutment-to-downstream spectral ratios are less than unity in the period range from 0.3 to 0.6 sec. The epicenter to station azimuth for the Loma Prieta earthquake is 73 degrees, and it is 325 degrees for the Gilroy event. These two earthquakes are located on different sides of the Calaveras fault zone, suggesting significantly different geology for the wave propagation paths to the stations. Combination of differences in source-station orientation, and complex 3-D structure around the fault zone and stations may be responsible for such large differences in the ratios of ground motions at the two nearby Coyote Lake stations.

Graizer, V.; Boore, D.; Shakal, A.; Tinsley, J.

2002-12-01

125

Final report on repair procedure of strong ground motion data from underground nuclear tests  

SciTech Connect

Certain difficulties arise when recording close-in around motion from underground nuclear explosions. Data quality can be compromised by a variety of factors, including electromagnetic pulse, noise spikes, direct current effect, and gauge clipping and gauge tilt. From March 1988 through September 1994, EG&G Energy Measurements repaired strong round-motion data (acceleration data) from underground nuclear tests for the Los Alamos National Laboratory using, an automated repair procedure. The automated repair determined and implemented the required repairs based on user input and a consistent set of criteria. A log was kept of each repair so that the repair procedure could be duplicated. This relaxed the requirement to save the repaired data. Developed for the VAX system, the procedure allowed the user to stack up a large number of repairs, plot the repaired data, and obtain hard copies. The plotted data could then be reviewed for a given test to determine the consistency of repair for a given underground test. This feature released the user to perform other tasks while the data were being repaired.

Tunnell, T.W.

1995-04-01

126

Strong Motion Networks - Rapid Response and Early Warning Applications in Istanbul  

NASA Astrophysics Data System (ADS)

In recent years several strong motion networks have been established in Istanbul with a preparation purpose for future probable earthquake. This study addresses the introduction of current seismic networks and presentation of some recent results recorded in these networks. Istanbul Earthquake Early Warning System Istanbul Earthquake Early Warning System has ten strong motion stations which were installed as close as possible to Marmara Sea main fault zone. Continuous on-line data from these stations via digital radio modem provide early warning for potentially disastrous earthquakes. Considering the complexity of fault rupture and the short fault distances involved, a simple and robust Early Warning algorithm, based on the exceedance of specified threshold time domain amplitude levels is implemented. The current algorithm compares the band-pass filtered accelerations and the cumulative absolute velocity (CAV) with specified threshold levels. Istanbul Earthquake Rapid Response System Istanbul Earthquake Rapid Response System has one hundred 18 bit-resolution strong motion accelerometers which were placed in quasi-free field locations (basement of small buildings) in the populated areas of the city, within an area of approximately 50x30km, to constitute a network that will enable early damage assessment and rapid response information after a damaging earthquake. Early response information is achieved through fast acquisition and analysis of processed data obtained from the network. The stations are routinely interrogated on regular basis by the main data center. After triggered by an earthquake, each station processes the streaming strong motion data to yield the spectral accelerations at specific periods and sends these parameters in the form of SMS messages at every 20s directly to the main data center through a designated GSM network and through a microwave system. A shake map and damage distribution map (using aggregate building inventories and fragility curves) will then be automatically generated using the algorithm developed for this purpose. Loss assessment studies are complemented by a large citywide digital database on the topography, geology, soil conditions, building, infrastructure and lifeline inventory. The shake and damage maps will be conveyed to the governor's and mayor's offices, fire, police and army headquarters within 3 minutes using radio modem and GPRS communication. Self Organizing Seismic Early Warning Information Network (SOSEWIN) in Atakoy District SOSEWIN sensors were developed by GFZ and Humbold University as part of SAFER project and EDIM project, and with cooperation of KOERI, the sensors were installed in Atakoy district of Istanbul city with Early Warning purpose. The main features of the SOSEWIN system are each sensing unit is comprised of low-cost components, undertakes its own seismological data processing, analysis and archiving, and its self-organizing capability with wireless mesh network communication. Seismic Network in Important Structures Some of the critical structures located in Istanbul city such as Fatih Sultan Mehmet Suspension Bridge which is connecting Asian and European sides of the city, Hagia Sophia Museum and Suleymaniye Mosque which are historical structures with an age of over 1000 years and 450 years respectively, and Isbank Tower which is one of the tallest structures in the city with a height of 181.2m are monitorized to observe their seismic behavior.

Zulfikar, C.; Alcik, H.; Ozel, O.; Erdik, M.

2009-04-01

127

Statistical Analysis of Ground Motions Estimated on the Basis of a Recipe for Strong-motion Prediction: Approach to Quantitative Evaluation of Average and Standard Deviation of Ground Motion Distribution  

Microsoft Academic Search

For seismic hazard assessment, we study the variabilities of predicted ground motion on the basis of a “recipe for predicting\\u000a strong ground motion” and propose approximations to evaluate spatial distributions of the standard deviation for PGV, R1.0,\\u000a R2.0, and R5.0 in the estimated ground motions. For strong-motion prediction, we use a finite difference method for a long\\u000a period range (>1.0 s).

Masayuki Yamada; Shigeki Senna; Hiroyuki Fujiwara

2011-01-01

128

Simulation of strong ground motion for moderate earthquakes: comparison between two high frequency approaches  

NASA Astrophysics Data System (ADS)

We used two different strong ground motion simulation techniques to generate shaking scenarios for the 1997 Colfiorito earthquake (Mw=6.0). This earthquake has been studied in the framework of a Italian research project (supported by Gruppo Nazionale per la Difesa dai Terremoti - INGV, 2002-2003). The project concerns the design of ground shaking scenarios based on the identification of the position, geometry and rupture mechanism of seismogenetic faults and on the characterization of the crustal structure. Both techniques use the high frequency solution (ray theory) to compute the Green functions in a flat-layered velocity model. While one method (ASymptotic Method, ASM) solves numerically the representation integral, the other one (Deterministic-Stochastic Method, DSM) generalizes the point-source stochastic method using a deterministic acceleration envelope for an extended fault. Only the direct S wave field is computed because, in the near source range, it can be considered dominant in amplitude with respect to the P wave field and secondary phases. We computed synthetic time histories at 64 nodes of a grid area (60km x 60km) up to fmax=5 Hz. First of all, we compared the methods for two source models obtained, for the Colfioririto earthquake, by the inversion of geodetic and accelerometric data. Both techniques give similar distribution of PGA and integral ground motion parameters. In particular, peak values are not symmetrically distributed around the fault, but show the largest amplitude values north to the Colfiorito fault, in the directive direction. The reliability of the proposed rupture scenario has been checked for 6 accelerometric stations located at epicentral distances ranging from 5 to 30 Km that recorded the mainshock. We then generated shaking scenarios varying several parameters, such as the nucleation position, the slip distribution and the rupture velocity. Fault geometry, source mechanism and propagation medium are fixed. The results of the simulations have been grouped in three families, on the base of the position of the nucleation point (on the left side, in the middle and on the right side of the fault) to emphasise directivity effects associated to the rupture propagation along an extended fault. For each family of rupture scenarios, a statistical analysis was performed to evaluate the variability of strong ground motion parameters.

Emolo, A.; Pacor, F.; Cultrera, G.; Franceschina, G.; Zollo, A.; Cocco, M.

2003-04-01

129

Influence of strong monsoon winds on the water quality around a marine cage-culture zone in a shallow and semi-enclosed bay in Taiwan.  

PubMed

Influences of marine cage culture and monsoonal disturbances, northeasterly (NE) and southwesterly (SW) monsoons on the proximal marine environment were investigated across a gradient of sites in a semi-enclosed bay, Magong Bay (Penghu Islands, Taiwan). Elevated levels of ammonia produced by the cages were the main pollutant and distinguished the cage-culture and intermediary zones (1000 m away from the cages) from the reference zone in the NE monsoon, indicating currents produced by the strong monsoon may have extended the spread of nutrient-enriched waters without necessarily flushing such effluents outside Magong Bay. Moreover, the levels of chlorophyll-a, dissolved oxygen, and turbidity were distinguishable between two seasons, suggesting that resuspension caused by the NE monsoon winds may also influence the water quality across this bay. It indicated that the impacts of marine cage culture vary as a function of distance, and also in response to seasonal movements of water driven by local climatic occurrences. PMID:22306313

Huang, Yuan-Chao Angelo; Huang, Shou-Chung; Meng, Pei-Jie; Hsieh, Hernyi Justin; Chen, Chaolun Allen

2012-02-04

130

Analysis of Iranian strong-motion data using the specific barrier model  

NASA Astrophysics Data System (ADS)

Two decades after the development of the specific barrier model (SBM) by Papageorgiou and Aki (1983a Bull. Seism. Soc. Am. 73 693-722, 1983b Bull. Seism. Soc. Am. 73 953-78), it remains to be the most sophisticated, yet simple, theoretical description of the earthquake faulting process. In this study, strong-motion accelerograms recorded in Iran are used in the context of 'random vibration theory' to calibrate the SBM. The database consists of 136 three-component records from 19 earthquakes of magnitude ranging from Mw 5.2 to Mw 7.4, recorded at hypocentral distances up to 200 km. Regression analysis has been conducted for pseudospectral velocity (PSV) using the 'random-effects' model that accounts for correlations in the data recorded by a single earthquake. A rough estimation of site amplification functions, is first obtained by the incorporation of mean frequency-dependent site-amplification factors, based on a gross characterization of the site class. However, a repetition of regression analysis with the use of a site-specific amplification function estimated by the horizontal-to-vertical ratio technique improved the fit to the observed amplitudes over the lower frequencies. The average values of the local and global stress drops, which are the two key parameters of the SBM, are determined to be 90 and 44 bars, respectively. The predicted PSV values agree well with available Iranian strong-motion data, as evidenced by the near-zero average of differences between the logarithms of the observed and predicted values (residuals) for all frequencies and the lack of any significant residual trends with distance and magnitude. A comparison of the SBM source spectra of this study with those of California and eastern North America (ENA) reveals that the spectral amplitudes are more like typical Californian source models than ENA in the frequency range studied here, from 1 to 10 Hz. Moreover, the calibrated model of this study which provides an efficient and physical representation of Iranian plateau source characteristics is found to be in reasonably good agreement with other local and regional attenuation relationships. Investigation of the residuals showed only a weak influence of soil nonlinearity; however, because of the relatively weak levels of acceleration in our database, it is not yet adequate to clearly distinguish this effect.

Mousavi, M.; Zafarani, H.; Noorzad, A.; Ansari, A.; Bargi, K.

2007-12-01

131

An evaluation of the strong ground motion recorded during the May 1, 2003 Bingo??l Turkey, earthquake  

USGS Publications Warehouse

An important record of ground motion from a M6.4 earthquake occurring on May 1, 2003, at epicentral and fault distances of about 12 and 9km, respectively, was obtained at a station near the city of Bingo??l, Turkey. The maximum peak ground values of 0.55 g and 36 cm/s are among the largest ground-motion amplitudes recorded in Turkey. From simulations and comparisons with ground motions from other earthquakes of comparable magnitude, we conclude that the ground motion over a range of frequencies is unusually high. Site response may be responsible for the elevated ground motion, as suggested from analysis of numerous aftershock recordings from the same station. The mainshock motions have some interesting seismological features, including ramps between the P-and S-wave that are probably due to near- and intermediate-field elastic motions and strong polarisation oriented at about 39 degrees to the fault (and therefore not in the fault-normal direction). Simulations of motions from an extended rupture explain these features. The N10E component shows a high-amplitude spectral acceleration at a period of 0.15 seconds resulting in a site specific design spectrum that significantly overestimates the actual strength and displacement demands of the record. The pulse signal in the N10E component affects the inelastic spectral displacement and increases the inelastic displacement demand with respect to elastic demand for very long periods. ?? Imperial College Press.

Akkar, S.; Boore, D. M.; Gulkan, P.

2005-01-01

132

Preliminary site classification of free-field strong motion stations based on Wenchuan earthquake records  

NASA Astrophysics Data System (ADS)

During the great Wenchuan earthquake, about 460 permanent free-field stations in National Strong Motion Observation Network System (NSMONS) of China captured the main shock acceleration records. These records can be applied to site effect analyses, and then the site classification of those permanent stations can be carried out firstly, which will served as the fundamental information for further research. In this paper, the site of near-fault stations is classified by horizontal-to-vertical spectral ratio (HVSR) method according to the site class description of Japan earthquake resistant design code and response spectral shapes (RSS) method following the site class description of the 1997 Uniform Building Code (UBC) provisions. Then based on the detailed borehole data of those free-field stations, the equivalent shear wave velocity and overburden thickness are calculated and the site classifications are given by Chinese code for seismic design of buildings. Furthermore, for the stations having successful microtremor test data, the site dominant periods are computed to verify the results of site classification. Finally, combined with all the above results, the recommended site classes of near-fault permanent free-field stations are given.

Wen, Ruizhi; Ren, Yefei; Zhou, Zhenghua; Shi, Dacheng

2010-02-01

133

Survey of strong motion earthquake effects on thermal power plants in California with emphasis on piping systems. Volume 2, Appendices  

SciTech Connect

Volume 2 of the ``Survey of Strong Motion Earthquake Effects on Thermal Power Plants in California with Emphasis on Piping Systems`` contains Appendices which detail the detail design and seismic response of several power plants subjected to strong motion earthquakes. The particular plants considered include the Ormond Beach, Long Beach and Seal Beach, Burbank, El Centro, Glendale, Humboldt Bay, Kem Valley, Pasadena and Valley power plants. Included is a typical power plant piping specification and photographs of typical power plant piping specification and photographs of typical piping and support installations for the plants surveyed. Detailed piping support spacing data are also included.

Stevenson, J.D. [Stevenson and Associates, Cleveland, OH (United States)

1995-11-01

134

Strong ground motion synthesis along the Sanyi-Tungshih-Puli seismic zone using empirical Green`s functions  

SciTech Connect

We synthesize strong ground motion from a M=7.25 earthquake along the NW-trending Sanyi-Tungshih-Puli seismic zone. This trend extends from Houlong to Taichung and forms a nearly continuous 78 km long seismic zone identified by the occurrence of M<5 events. It extends from a shallow depth all the way down to about 40 km. The entire length of the fault, if activated at one time, can lead to an event comparable to that the 1995 Kobe earthquake. With the improved digital CWBSN data now provided routinely by CWBSN, it becomes possible to use these data as empirical Green`s functions to synthesize potential ground motion for future large earthquakes. We developed a suite of 100 rupture scenarios for the earthquake and computed the commensurate strong ground motion time histories. We synthesized strong ground motion with physics-based solutions of earthquake rupture and applied physical bounds on rupture parameters. the synthesized ground motions obtained for a fixed magnitude and identifying the hazard to a site from the statistical distribution of engineering parameters, we have introduced a probabilistic component to the deterministic hazard calculation, The time histories suggested for engineering design are the ones that most closely match either the average or one standard deviation absolute acceleration response values.

Hutchings, L.; Foxall, W.; Kasameyer, P. [Lawrence Livermore National Lab., CA (United States); Wu, F.T. [State Univ. of New York, Buffalo, NY (United States). Dept. of Geological Sciences; Rau, R.-J. [Academia Sinica, Taipei (Taiwan, Province of China). Inst. of Earth Sciences; Jarpe, S. [California Univ., Santa Barbara, CA (United States). Inst. for Crustal Studies

1997-01-01

135

Strong-Field Modulated Diffraction Effects in the Correlated Electron-Nuclear Motion in Dissociating H{sup +}  

Microsoft Academic Search

We show that the electronic dynamics in a molecule driven by a strong field is complex and potentially even counterintuitive. As a prototype example, we simulate the interaction of a dissociating H{sup +} molecule with an intense infrared laser pulse. Depending on the laser intensity, the direction of the electron's motion between the two nuclei is found to follow or

He Feng; Andreas Becker; Uwe Thumm

2008-01-01

136

Strong-Field Modulated Diffraction Effects in the Correlated Electron-Nuclear Motion in Dissociating H2+  

Microsoft Academic Search

We show that the electronic dynamics in a molecule driven by a strong field is complex and potentially even counterintuitive. As a prototype example, we simulate the interaction of a dissociating H2+ molecule with an intense infrared laser pulse. Depending on the laser intensity, the direction of the electron's motion between the two nuclei is found to follow or oppose

Feng He; Andreas Becker; Uwe Thumm

2008-01-01

137

An estimate of the attenuation relationship for strong ground motion in the Kivu Province, Western Rift Valley of Africa  

Microsoft Academic Search

On the basis of the assumption of identical seismic response at three sites (Lwiro, Katale and Kunene) located within the Western Rift Valley of Africa, attenuation relationship based on simulating strong motions of large earthquakes using recordings of small earthquakes has been calculated. Results show that the attenuation of average peak ground acceleration Y is related to the magnitude M

Mavonga Tuluka

2007-01-01

138

Simulations of the strong ground motion for the Mw6.9 Yushu earthquake of 14 April 2010  

Microsoft Academic Search

The Mw6.9 Yushu earthquake of 14 April, 2010, which occurred at the western province of China, Qinghai, caused more than 2000 people died and serious damage to the Yushu city. The earthquake had duration of about 16s and ruptured nearly 80 km. In order to investigate the strong motion caused by this earthquake, we simulate the Yushu earthquake, based on

Z. Zhang; X. Chen

2010-01-01

139

Relationship Between the JMA and MM Instrumental Intensities as Determined With K-NET Strong Motion Data  

Microsoft Academic Search

We obtained a relationship between the JMA (Japan Meteorological Agency) instrumental intensity (IJMA) and the instrumentalized Modified Mercalli intensity (IMM) on the basis on strong motion records. These intensity scales are of high importance as they are in use in Japan and California where the seismic hazard is high. We used 3,197 K-NET (NIED, Japan) accelerograms (flat response from DC

T. Kunugi; H. Fujiwara

2001-01-01

140

Observing Structure and Motion in Molecules with Ultrafast Strong Field and Short Wavelength Laser Radiation  

SciTech Connect

The term "molecular movie" has come to describe efforts to track and record Angstrom-scale coherent atomic and electronic motion in a molecule. The relevant time scales for this range cover several orders of magnitude, from sub-femtosecond motion associated with electron-electron correlations, to 100-fs internal vibrations, to multi-picosecond motion associated with the dispersion and quantum revivals of molecular reorientation. Conventional methods of cinematography do not work well in this ultrafast and ultrasmall regime, but stroboscopic "pump and probe" techniques can reveal this motion with high fidelity. This talk will describe some of the methods and recent progress in exciting and controlling this motion, using both laboratory lasers and the SLAC Linac Coherent Light Source x-ray free electron laser, and will further try to relate the date to the goal of molecular movies.

Bucksbaum, Philip H

2011-04-13

141

Strong Ground-Motion Prediction in Seismic Hazard Analysis: PEGASOS and Beyond  

NASA Astrophysics Data System (ADS)

The SSHAC Level 4 approach to probabilistic seismic hazard analysis (PSHA), which could be considered to define the state-of-the-art in PSHA using multiple expert opinions, has been fully applied only twice, firstly in the multi-year Yucca Mountain study and subsequently (2002-2004) in the PEGASOS project. The authors of this paper participated as ground-motion experts in this latter project, the objective of which was comprehensive seismic hazard analysis for four nuclear power plant sites in Switzerland, considering annual exceedance frequencies down to 1/10000000. Following SSHAC procedure, particular emphasis was put on capturing both the aleatory and epistemic uncertainties. As a consequence, ground motion prediction was performed by combining several empirical ground motion models within a logic tree framework with the weights on each logic tree branch expressing the personal degree-of-belief of each ground-motion expert. In the present paper, we critically review the current state of ground motion prediction methodology in PSHA in particular for regions of low seismicity. One of the toughest lessons from PEGASOS was that in systematically and rigorously applying the laws of uncertainty propagation to all of the required conversions and adjustments of ground motion models, a huge price has to be paid in an ever-growing aleatory variability. Once this path has been followed, these large sigma values will drive the hazard, particularly for low annual frequencies of exceedance. Therefore, from a post-PEGASOS perspective, the key issues in the context of ground-motion prediction for PSHA for the near future are to better understand the aleatory variability of ground motion and to develop suites of ground-motion prediction equations that employ the same parameter definitions. The latter is a global rather than a regional challenge which might be a desirable long-term goal for projects similar to the PEER NGA (Pacific Earthquake Engineering Research Center, Next Generation of Attenuation of Ground Motions) project.

Scherbaum, F.; Bommer, J. J.; Cotton, F.; Bungum, H.; Sabetta, F.

2005-12-01

142

Rupture process of the 2009 L'Aquila, Italy, earthquake inferred from inversions of teleseismic and strong motion datasets  

NASA Astrophysics Data System (ADS)

The L'Aquila, Central Italy earthquake, occurred on April 6, 2009 at 01:32:40 UTC time. This Mw 6.3 (Global CMT) event caused large damages to the city of L'Aquila and surrounding villages of the Abruzzi region. A detailed study of the source process of this event is essential in understanding the observed macrosesmic effects and the relation between the causative fault and the aftershock activity. The use of the seismological datasets recorded at different distance range is expected to give supplementary information on the rupture process offering a more stable and detailed image of the source area, while each of the teleseismic and strong motion data carries information on different period ranges of the process at the source. In this study we developed a rupture model for the L'Aquila event by analyzing the teleseismic waveform data of IRIS-DMC and near-field strong motion records from the Italian Strong Motion Network (RAN). We also examined what details of the rupture history can be deduced from the teleseismic data alone, the strong motion data alone, and the combined teleseismic and strong motion data sets. At first, we estimated the general pattern of the source rupture area and determined the hypocentral depth, by performing the moment tensor analysis as well as the source inversion of broadband teleseismic records using the methods developed by Kikuchi and Kanamori (1982, 1991), Kikuchi et al. (2003) and Yoshida et al. (1996). Based on the aftershock study (Chiarabba et al., 2009) we assumed that the rupture occurred on the SW dipping fault plane with the dimensions of 25 km in length by 15 km in width. We also assumed strike = 148 deg. and dip = 44 deg., based on the residuals of the point source analysis and the aftershock distribution. The optimal depth that maximizes the waveform fit was found to be 6 km. The total seismic moment corresponds to Mo = 3.10 x 10**18 Nm. The inverted slip model shows one main asperity located in the upper shallow part of the fault close to the hypocenter, and a rupture extension towards the southeast. We further performed a waveform inversion of near-field strong motion data from ITACA database using the method of Yoshida et al. (1996) and fault parameters from the teleseismic waveform inversion. We used three component velocity records from the stations located within the distance of 55 km from the epicenter. The velocity structure for each of the stations is approximated by a 1D model adjusted by the forward modeling of the aftershocks records available from the ITACA database. The slip distribution of our best model shows a major asperity located about 18 km SE from the hypocenter. The total seismic moment corresponds to Mo = 3.5610 x 10**18 Nm and the optimal depth is found to be 8 km. We also determined the average rupture velocity that minimizes the residuals between observed and synthetic waveforms to be 1.9 km/s. The resulted source model, location of the main asperity, in generally agrees well with the studies by other authors (Cirella et al., 2009, Atzori et al., 2009). However, the slip distributions obtained from the inversion of the teleseismic and the strong motion datasets are largely different. We further investigated the possible explanation of this difference by performing the forward modeling of the teleseismic data using the source model from the strong motion inversion and the joint inversion of the teleseismic and the strong motion datasets. The results of these analysis as well as the details on the origin of the differences in the teleseismic and strong motion models will be presented in the meeting.

Poiata, Natalia; Koketsu, Kazuki; Vuan, Alessandro; Miyake, Hiroe

2010-05-01

143

Earthquake ground motion estimation using strong-motion records: a review of equations for the estimation of peak ground acceleration and response spectral ordinates  

NASA Astrophysics Data System (ADS)

Engineering seismology is the link between earth sciences and engineering. The main input of engineering seismology in engineering design are loading conditions which must satisfy certain conditions regarding their level and frequency of occurrence during the lifetime of a structure. One method for estimating these loading conditions is through equations based on strong ground motion recorded during previous earthquakes. These equations have a handful of independent parameters, such as magnitude and source-to-site distance, and a dependent parameter, such as peak ground acceleration (PGA) or spectral acceleration, and the coefficients in the equation are usually found by regression analysis. This review examines such equations in terms of data selection, accelerogram processing techniques of the strong-motion records used to construct the equations, the characterisation of earthquake source, travel path and local site used and regression techniques employed to find the final equations. It is found that little agreement has been reached in the past 30 years of ground motion estimation relation studies. Workers have chosen their techniques based on the available data, which varies greatly with geographical region. Also it is noted that there is a need to include more independent parameters into ground motion estimation equations if the large uncertainties associated with such equations are to be significantly reduced. The data required to do this is, unfortunately, scarce.

Douglas, J.

2003-04-01

144

Simulation of Ground Motion from Strong Earthquakes of Kamchatka Region (1992-1993) at Rock and Soil Sites  

NASA Astrophysics Data System (ADS)

To estimate the parameters of ground motion in future strong earthquakes, characteristics of radiation and propagation of seismic waves in the Kamchatka region were studied. Regional parameters of radiation and propagation of seismic waves were estimated by comparing simulations of earthquake records with data recorded by stations of the Kamchatka Strong Motion Network. Acceleration time histories of strong earthquakes ( M w = 6.8-7.5, depths 45-55 km) that occurred near the eastern coast of Kamchatka in 1992-1993 were simulated at rock and soil stations located at epicentral distances of 67-195 km. In these calculations, the source spectra and the estimates of frequency-dependent attenuation and geometrical spreading obtained earlier for Kamchatka were used. The local seismic-wave amplification was estimated based on shallow geophysical site investigations and deep crustal seismic explorations, and parameters defining the shapes of the waveforms, the duration, etc. were selected, showing the best-fit to the observations. The estimated parameters of radiation and propagation of seismic waves describe all the studied earthquakes well. Based on the waveforms of the acceleration time histories, models of slip distribution over the fault planes were constructed for the studied earthquakes. Station PET can be considered as a reference rock station having the minimum site effects. The intensity of ground motion at the other studied stations was higher than at PET due to the soil response or other effects, primarily topographic ones. At soil stations INS, AER, and DCH the parameters of soil profiles (homogeneous pyroclastic deposits) were estimated, and nonlinear models of their behavior in the strong motion were constructed. The obtained parameters of radiation and propagation of seismic waves and models of soil behavior can be used for forecasting ground motion in future strong earthquakes in Kamchatka.

Pavlenko, O. V.

2013-04-01

145

Strong Motion Simulation of the Niigata-ken Chuetsu-oki Earthquake (2007), Japan  

NASA Astrophysics Data System (ADS)

On July 16th, 2007, the Niigata-ken Chuetsu-oki Earthquake (M6.8) occurred off Niigata Prefecture in Japan, claiming 68 casualties and more than 4,000 injured. The heavily damaged areas were Kariwa Village and Kashiwazaki City of Niigata Prefecture, and a fire broke out in an electrical transformer at the Kashiwazaki-Kariwa Nuclear Power Plant (KKNPP). Regarding this earthquake, the several source models have been proposed. Based on the dimensions of the proposed source models, we simulate strong motion in the epicentral area including the KKNPP site by using the fourth order 3-D finite-difference method with staggered-discontinuous-grids, that is, GMS code (Aoi.S and H. Fujiwara, 1999). First, we try to modify the 3-D subsurface structure model of Niigata Prefecture, developed and provided by JNES (Japan Nuclear Energy Safety Organization). To calibrate this model, we simulate three aftershocks recordings at KKNPP, assuming point sources with the source mechanisms provided by F-net. The shapes of the main portion of the velocity waveform are well reproduced in general. However, regarding the time differences between P-wave and S-wave (i.e., S-P time), the results do not show good match between observed data and calculations. In order to correct the difference in S-P time, we set a horizontal boundary at the depth of 12.5km in the bedrock and assigned different velocity structures for the shallow and deep part of the bedrock. As a result, we can match S-P time of the shallow aftershock. Next, we simulate the main shock recordings using the modified subsurface structure described above. Since the observed data of the main shock shows three distinctive velocity pulses, the initial model that we adopt consists of a three asperities source model from the previous study of Kawabe and Kamae (2008). The following is our calculation procedure. First, the shapes of slip velocity time functions are assumed to be a simple triangle. Then, simulated time histories are convolved with the shapes of the assumed slip velocity time function for each asperity. Finally, time histories of each asperity are overlapped considering the time delay between ruptures. As a result, by multiplying the seismic moment of two asperities (Asperity 1 and 3) by 1.5 and searching appropriate shapes of the slip velocity functions for three asperities, we can reproduce the observation recordings at KKNPP. However, large amplitude of the third velocity pulse in EW component cannot be reproduced. By plotting the particle motions of velocity time histories, we confirm that the third pulse with large amplitude at station KK1 appears in a different direction from the predominant direction seen in the calculated velocities. We will include the other observed sites to our targets and modify the shape of slip velocity time functions. We will also investigate the cause of conspicuous velocity pulse dominantly in the EW component, scrutinizing either from the local subsurface structure or the source process complexity.

Nitta, Y.; Matsushima, S.; Kawase, H.

2010-12-01

146

Estimation of Strong Ground Motions for 2001 Bhuj ( M w 7.6), India Earthquake  

NASA Astrophysics Data System (ADS)

The strong ground motions for the 2001 Bhuj ( M w 7.6) India earthquake have been estimated on hard rock and B/C boundary (NEHRP) levels using a recently modified version of stochastic finite fault modeling based on dynamic corner frequency (M otazedian and A tkinson in Bull Seismol Soc Am 95, 995-1010 2005). Incorporation of dynamic corner frequency removes the limitations of earlier stochastic methods. Simulations were carried out at 13 sites in Gujarat where structural response recorder (SRR) recordings are available. In addition, accelerograms were simulated at the B/C boundary at a large number of points distributed on a grid. The corresponding response spectra have also been estimated. The values of peak ground accelerations and spectral accelerations at three periods (0.4, 0.75 and 1.25 s) are presented in the form of contour maps. The maximum value of peak ground acceleration (PGA) in the center of meizoseismal zone is 550 cm/s2. The response spectral acceleration in same zone is 900 cm/s2 ( T = 0.4 s), 600 cm/s2 ( T = 0.75 s) and 300 cm/s2 ( T = 1.25 s). The innermost PGA contour is on the fault plane. A comparison of the PGA values obtained at 13 sites in this study with those obtained in earlier studies on the same sites, but employing different methods, show that the present PGA values are comparable at most of the sites. The rate of decay of PGA values is fast at short distances as compared to that at longer distances. The PGA values obtained here put some constraints on the expected values from a similar earthquake in the region. A synthetic intensity map has been prepared from the estimated values of PGA using an empirical relation. A comparison with the reported intensity map of the earthquake shows the synthetic MMI values, as expected, are lower by 1 unit compared to reported intensity map. The contour map of PGA along with the contour maps of spectral acceleration at various periods permit the assessment of damage potential to various categories of houses and other structures. Such information will be quite important in planning of mitigation and disaster management programs in the region.

Chopra, Sumer; Kumar, Dinesh; Rastogi, Bal Krishna

2010-11-01

147

Bayesian inference of kinematic earthquake rupture parameters through fitting of strong motion data  

NASA Astrophysics Data System (ADS)

Due to uncertainties in data and in forward modelling, the inherent limitations in data coverage and the non-linearity of the governing equation, earthquake source imaging is a problem with multiple solutions. The multiplicity of solutions can be conveniently expressed using a Bayesian approach, which allow to state inferences on model parameters in terms of probability density functions. The estimation of the posterior state of information, expressing the combination of the a priori knowledge on model parameters with the information contained in the data, is achieved in two steps. First, we explore the model space using an evolutionary algorithm to identify good data fitting regions. Secondly, using a neighbourhood algorithm and considering the entire ensemble of models found during the search stage, we compute a geometric approximation of the true posterior that is used to generate a second ensemble of models from which Bayesian inference can be performed. We apply this methodology to infer kinematic parameters of a synthetic fault rupture through fitting of strong motion data. We show how multiple rupture models are able to reproduce the observed waveforms within the same level of fit, suggesting therefore that the solution of the inversion cannot be expressed in terms of a single model but rather as a set of models which show certain statistical properties. For all model parameters we compute the posterior marginal distribution. We show how for some parameters the posterior do not follow a Gaussian distribution rendering the usual characterization in terms of mean value and standard deviation not correct. We compare the posterior marginal distributions with the `raw' marginal distributions computed from the ensemble of models generated by the evolutionary algorithm. We show how they are systematically different proving therefore that the search algorithm we adopt cannot be directly used to estimate uncertainties. We also analyse the stability of our inferences comparing the posterior marginals computed by different independent ensembles. The solutions provided by independent explorations are similar but not identical because each ensemble searches the model space differently resulting in different reconstructed posteriors. Our study illustrates how uncertainty estimates derive from the topology of the objective function, and how accurate and reliable resolution analysis is limited by the intrinsic difficulty of mapping the `true' structure of the objective function.

Monelli, D.; Mai, P. M.

2008-04-01

148

Comparison of strong-motion spectra with teleseismic spectra for three magnitude 8 subduction-zone earthquakes  

NASA Astrophysics Data System (ADS)

A comparison of strong-motion spectra and teleseismic spectra was made for three Mw 7.8 to 8.0 earthquakes: the 1985 Michoacan (Mexico) earthquake, the 1985 Valparaiso (Chile) earthquake, and the 1983 Akita-Oki (Japan) earthquake. The decay of spectral amplitude with the distance from the station was determined, considering different measures of distance from a finite fault, and it was found to be different for these three events. The results can be used to establish empirical relations between the observed spectra and the half-space responses depending on the distance and the site condition, making it possible to estimate strong motions from source spectra determined from teleseismic records.

Houston, Heidi; Kanamori, Hiroo

1990-08-01

149

Estimation of local magnitude of rockbursts using strong motion accelerograms in the mines of Kolar Gold Fields  

NASA Astrophysics Data System (ADS)

Rockbursts are minor earthquakes induced due to mining operations. The seismic signals recorded using geophones in the near field are generally saturated and are not suitable for estimating the true magnitudes. The strong-motion accelerograms recorded due to rockbursts are therefore used to obtain the Wood-Anderson synthetic seismograms for getting accurate and reliable values of the local magnitudes. Using several typical strong-motion accelerograms of rockbursts in the mines of Kolar Gold Fields, the magnitudes have been computed in the present study. Correlations of peak ground acceleration and peak ground velocity with the magnitude, studied for the rockbursts vis-à-vis the natural earthquakes in the Koyna dam area, suggest the mechanical similarity between the two different types of events. The results and findings are described in this paper.

Srinivasan, Chinnappa; Willy, Yesurathenam Ahnoch; Gupta, Iswar D.

2010-04-01

150

Ground-motion Attenuation Relation from Strong-motion Records of the 2001 Mw 7.7 Bhuj Earthquake Sequence (2001-2006), Gujarat, India  

NASA Astrophysics Data System (ADS)

Predictive relations are developed for peak ground acceleration (PGA) from the engineering seismoscope (SRR) records of the 2001 Mw 7.7 Bhuj earthquake and 239 strong-motion records of 32 significant aftershocks of 3.1 ? Mw ? 5.6 at epicentral distances of 1 ? R ? 288 km. We have taken advantage of the recent increase in strong-motion data at close distances to derive new attenuation relation for peak horizontal acceleration in the Kachchh seismic zone, Gujarat. This new analysis uses the Joyner-Boore’s method for a magnitude-independent shape, based on geometrical spreading and anelastic attenuation, for the attenuation curve. The resulting attenuation equation is, eqalign{ ln ({Y}) = -7.9527 + 1.4043 {M}_{{W}} - ln left( {{r}_{{jb}}2 + 19.822} right)^{1/2} - 0.0682 {S} ?{for} 3.1 { < M}_{{W}} le 7.7quad quad {std}. {dev}. left(? right): ± 0.8243, ?} where, Y is peak horizontal acceleration in g, Mw is moment magnitude, rjb is the closest distance to the surface projection of the fault rupture in kilometers, and S is a variable taking the values of 0 and 1 according to the local site geology. S is 0 for a rock site, and, S is 1 for a soil site. The relation differs from previous work in the improved reliability of input parameters and large numbers of strong-motion PGA data recorded at short distances (0-50 km) from the source. The relation is in demonstrable agreement with the recorded strong-ground motion data from earthquakes of Mw 3.5, 4.1, 4.5, 5.6, and 7.7. There are insufficient data from the Kachchh region to adequately judge the relation for the magnitude range 5.7 ? Mw ? 7.7. But, our ground-motion prediction model shows a reasonable correlation with the PGA data of the 29 March, 1999 Chamoli main shock (Mw 6.5), validating our ground-motion attenuation model for an Mw6.5 event. However, our ground-motion prediction shows no correlation with the PGA data of the 10 December, 1967 Koyna main shock (Mw 6.3). Our ground-motion predictions show more scatter in estimated residual for the distance range (0-30 km), which could be due to the amplification/noise at near stations situated in the Kachchh sedimentary basin. We also noticed smaller residuals for the distance range (30-300 km), which could be due to less amplification/noise at sites distant from the Kachchh basin. However, the observed less residuals for the longer distance range (100-300 km) are less reliable due to the lack of available PGA values in the same distance range.

Mandal, Prantik; Kumar, N.; Satyamurthy, C.; Raju, I. P.

2009-03-01

151

Structural health monitoring of an existing 8-story building using strong motion observation data and structural design data  

Microsoft Academic Search

Target building is an 8-story steel encased reinforced concrete building which was constructed in 1998. In this structural health monitoring system, strong motion observation data is used and accelerometers were installed just after the completion of construction at 1st story, 2nd story, 5th story and 8th story. By use of system identification using ARX model, natural frequency, damping ratio and

Koichi Morita; Masaomi Teshigawara

2006-01-01

152

Peak horizontal acceleration and velocity from strong-motion records including records from the 1979 imperial valley, California, earthquake  

USGS Publications Warehouse

We have taken advantage of the recent increase in strong-motion data at close distances to derive new attenuation relations for peak horizontal acceleration and velocity. This new analysis uses a magnitude-independent shape, based on geometrical spreading and anelastic attenuation, for the attenuation curve. An innovation in technique is introduced that decouples the determination of the distance dependence of the data from the magnitude dependence.

Joyner, William B.; Boore, David M.

1981-01-01

153

Source Modeling of the Kozani and Arnea 1995 Events with Strong Motion Estimates for the City of Thessaloniki  

Microsoft Academic Search

We first estimate the source parameters related to the two 1995 events near Thessaloniki (Greece): the Kozani (Ms = 6.6) and the Arnea (Ms = 5.8) earthquakes. We use the strong motion waveforms recorded in Northern Greece to retrieve by forward modeling the source characteristics of the two events. Both point-source and finite-source models are used and different 1-D velocity

P. Suhadolc; L. Moratto; G. Costa; P. Triantafyllidis

2007-01-01

154

Source Process of the 2007 Niigata-ken Chuetsu-oki Earthquake Derived from Near-fault Strong Motion Data  

Microsoft Academic Search

The 2007 Niigata-ken Chuetsu-oki earthquake occurred on July 16th, 2007, 10:13 JST. We performed a multi- time window linear waveform inversion analysis (Hartzell and Heaton, 1983) to estimate the rupture process from the near fault strong motion data of 14 stations from K-NET, KiK-net, F-net, JMA, and Niigata prefecture. The fault plane for the mainshock has not been clearly determined

S. Aoi; H. Sekiguchi; N. Morikawa; T. Ozawa; T. Kunugi; M. Shirasaka

2007-01-01

155

Distributed system for strong motion data retrieval and archiving : metadata, databases and data exchange within the NA5 framework  

Microsoft Academic Search

The goal of the NERIES NA5 activity (http:\\/\\/www.neries-eu.org, Improving Accelerometric Data Access) is the development of common access to equally formatted event based accelerometric data and to the corresponding sheet of strong motion parameters. The core of the NA5 is made of 5 European institutes and the final protocol should permit other European institutes to integrate the NA5 portal. More

C. Pequegnat; P. Gueguen; R. Jacquot

2009-01-01

156

Revelations from a single strong-motion record retreived during the 27 June 1998 Adana (Turkey) earthquake  

USGS Publications Warehouse

During the 27 June 1998 Adana (Turkey) earthquake, only one strong-motion record was retrieved in the region where the most damage occurred. This single record from the station in Ceyhan, approximately 15 km from the epicenter of that earthquake, exhibits characteristics that are related to the dominant frequencies of the ground and structures. The purpose of this paper is to explain the causes of the damage as inferred from both field observations and the characteristics of a single strong-motion record retrieved from the immediate epicentral area. In the town of Ceyhan there was considerable but selective damage to a significant number of mid-rise (7-12 stories high) buildings. The strong-motion record exhibits dominant frequencies that are typically similar for the mid-rise building structures. This is further supported by spectral ratios derived using Nakamura's method [QR of RTRI, 30 (1989) 25] that facilitates computation of a spectral ratio from a single tri-axial record as the ratio of amplitude spectrum of horizontal component to that of the vertical component [R = H(f)/V(f)]. The correlation between the damage and the characteristics exhibited from the single strong-motion record is remarkable. Although deficient construction practices played a significant role in the extent of damage to the mid-rise buildings, it is clear that site resonance also contributed to the detrimental fate of most of the mid-rise buildings. Therefore, even a single record can be useful to explain the effect of site resonance on building response and performance. Such information can be very useful for developing zonation criteria in similar alluvial valleys. Published by Elsevier Science Ltd.

Celebi, M.

2000-01-01

157

An Approximate Expression of Slip Velocity Time Function for Simulation of Near-field Strong Ground Motion  

Microsoft Academic Search

Nakamura and Miyatake (2000) proposed an approximate expression of slip velocity time function for simulation of near-field strong ground motion on the basis of the numerical solution of 2D and 3D crack simulations including a slip-weakening friction law. The approximate slip rate time functions are applied to near-source seismic waves from various fault models, (a) rectangular crack in which rupture

T. Miyatake

2002-01-01

158

Source process of the 2007 Niigata-ken Chuetsu-oki earthquake derived from near-fault strong motion data  

Microsoft Academic Search

The 2007 Niigata-ken Chuetsu-oki earthquake generated strong ground motions in Kashiwazaki and Kariwa, where the world largest nuclear power plant was in operation. Due to the complexity of the aftershock distribution, activation of the northwest-dipping fault and\\/or the southeast-dipping fault is proposed. To explore the fault geometry and source process of the earthquake, we performed multi-time window linear waveform inversions

S. Aoi; H. Sekiguchi; N. Morikawa; T. Kunugi

2008-01-01

159

Source Process and Near-source Strong Ground Motion Generation of the 2004 Mid Niigata Prefecture (Chuetsu), Japan, Earthquake  

NASA Astrophysics Data System (ADS)

The 2004 Mid Niigata Prefecture Earthquake occurred on October 23, 2004 in the central Japan with large strong ground motions in the near source region. We estimate a source rupture process of this event using strong motion records. Then we simulate strong ground motions in the source area using the obtained source model together with the three-dimensional underground structure model derived by Yamanaka et al. (2005). To obtain a source model we performed the kinematic linear waveform inversion using multiple time-windows by Sekiguchi et al. (2000). We assumed the hypocenter and the fault plane by event relocation research studies (Kato et al., 2005; Okada et al., 2005; Shibutani et al., 2005). We used the S-wave portion of velocity waveforms that were bandpass-filterd between 0.05 1 Hz, and we used 16 strong motion stations of K-NET, KiK-net, JMA and Niigata Prefecture Government near source area. We constructed a one-dimensional underground structure model for GreenOs function calculation at each site by forward waveform modeling of aftershock records. We used the S-wave velocity structure model proposed by Yamanaka et al. (2005a) as a reference model, and modified the thickness of the layer using GA approach. Green's functions were calculated by the discrete wavenumber method (Bouchon, 1981) with the reflection and transmission matrix (Kennett and Kerry, 1979). The final slip distribution obtained by the inversion shows that the rupture propagated to shallower part from the rupture starting point. The large slip occurred shallower part of the assumed fault plane. Slip distribution is more or less complex. Total seismic moment is 1.06_~10**19Nm (Mw6.6), with maximum slip is 1.4m. The synthetic waveforms fit the observed ones fairly well. The first time-window front propagates at a velocity of 2.4km/s, which is a little bit smaller value among ordinary crustal earthquakes. Yamanaka et al. (2005a) conducted microtremor array observation to estimate S-wave velocity structure in the source area. Yamanaka et al.(2005b) constructed a three-dimensional underground structure model (from engineering bedrock to seismic bedrock) in this area using their microtremor observation result, gravity anomaly information, and boring information. The underground structure is very complex, e.g. the seismic bedrock depth is changing from approximately 6km to 0km (outcrop rock area) in this source region. We conduct ground motion simulation using the obtained source model and this three-dimensional underground structure model. We obtained strong ground motions in the hanging wall area with deep basin, that corresponds to severely damaged area. Because of the limitation of the underground structure model, it is hard to discuss the validity of the ground motion distribution quantitatively. However, characteristics of the simulated ground motions at several stations in the strong motion area match more or less those of the observed records.

Iwata, T.; Asano, K.; Yamanaka, H.; Yamada, N.; Fukumoto, S.

2005-12-01

160

GA-BASED SELECTION AND SCALING OF STRONG GROUND MOTION RECORDS FOR STRUCTURAL DESIGN  

Microsoft Academic Search

SUMMARY A new approach in selection, scaling and classification of sets of recorded earthquake ground motions using soft computing methods is presented. First, the optimization basis of search and scaling procedure for site-specific design spectrum matching with minimum alteration of phase and shape of spectra is explained. Contrary to the prevailing scaling methods where a preset number of earthquake records

Arzhang ALIMORADI; Farzad NAEIM; Shahram PEZESHK

161

Relationship between geomorphological land classification and site amplification ratio based on JMA strong motion records  

Microsoft Academic Search

The relationship between the amplification ratio of earthquake ground motion and geologic conditions at Japan Meteorological Agency (JMA) stations nationwide was examined to propose an estimation method of the amplification ratio that is applicable to entire Japan. The amplification ratios for the instrumental JMA intensity, as well as for the peak ground acceleration and velocity, were obtained from the station

F Yamazaki; K Wakamatsu; J Onishi; K. T Shabestari

2000-01-01

162

Relationship between geomorphological land classification and site amplification ratio based on JMA strong motion records  

Microsoft Academic Search

The relationship between the amplification ratio of earthquake ground motion and geologic conditions at Japan Meteorological Agency (JMA) stations nationwide was examined to propose an estimation method of the amplification ratio that is applicable to entire Japan. The amplification ratios for the instrumental JMA intensity, as well as for the peak ground acceleration and velocity, were obtained from the station

F. Yamazakia; K. Wakamatsua; J. Onishi; K. T. Shabestari

163

Attenuation and Directivity of Peak Ground Acceleration (PGA) in Near Fault Strong Motion from M6.0 Parkfield, California Earthquake  

Microsoft Academic Search

The Parkfield earthquake strong motion data set presents a rare opportunity to study a relatively large number of data recordings at stations near a fault. The earthquake was recorded by 46 strong motion stations located within 10 km from the fault with most of the data recorded by the film SMA-1 instruments. A comparison of the peak acceleration data for

V. Graizer; A. Shakal

2004-01-01

164

Strong ground motion simulation during the November 1759 Earthquake along Serghaya Fault in the metropolitan of Damascus, Syria  

NASA Astrophysics Data System (ADS)

The seismic hazard potential for metropolitan of Damascus, Syria is mainly controlled by earthquakes along Serghaya Fault which is a branch of Dead Sea Fault System. In this study, strong ground motion due to the November 1759 Earthquake along the fault of Serghaya was estimated with a numerical simulation technique. In the simulation, the Kostrov-like slip-velocity function was used as an input to the discrete wave number method to simulate the strong ground motions in a broadband frequency range. In order to model the incoherent rupture propagation which can excite large high-frequency waves, random numbers are added to arrival time of circular rupture front. MMI intensities calculated from the synthetic ground motions are compared with the observed values by Ambraseys and Barazangi (J Geophys Res 94:4007-4013, 1989). The calculated intensities are in good agreement with the observed ones at the most sites that validate appropriateness of the proposed source model. The PGA and PGV in the eastern region of Damascus city are higher than those in the western region due to the effects of local site amplification. The simulated high-frequency (1.0-6.0 Hz) ground motions for the sites in the Damascus city are higher than the design requirements defined by the Syrian building code. Furthermore, the simulated high-frequency ground motions for sites in the focal region are bigger than the design requirements in the case of the near-fault factors and are not considered. That demonstrates the appropriateness of considering the near-fault factors for a site near the focal region as introduced by the new building code.

Zaineh, Hussam Eldein; Yamanaka, Hiroaki; Dhakal, Yadab Prasad; Dakkak, Rawaa; Daoud, Mohamad

2013-10-01

165

Taiwan’s industrial robots  

Microsoft Academic Search

Examines the growth in the use of, and versatility of industrial robots worldwide and looks at the current situation in Taiwan, which is reported to have the highest annual growth rate of robots. With a shortage of manpower, Taiwan sees automation as its best alternative, particularly in the automotive industry. Discusses robot research and development in Taiwan and compares it

Chiu-Chi Wei

1995-01-01

166

Modeling Strong Ground Motion in the Wellington Metropolitan Area, New Zealand  

Microsoft Academic Search

The Wellington Metropolitan Area, New Zealand, about 35 km by 10 km, is crossed by the southernmost segment of the Wellington fault, striking roughly in the northeast-southwest direction. Numerical modeling of M 6.7 earth- quakes due to ruptures on this fault, intended to characterize the 3D effects of the region's main geological features on the ground motion, are performed by

Rafael Benites; Kim B. Olsen

2005-01-01

167

Illusory movement of stationary stimuli in the visual periphery: evidence for a strong centrifugal prior in motion processing  

PubMed Central

Visual input is remarkably diverse. Certain sensory inputs are more probable than others, mirroring statistical regularities of the visual environment. The visual system exploits many of these regularities, resulting, on average, in better inferences about visual stimuli. However, by incorporating prior knowledge into perceptual decisions, visual processing can also result in perceptions that do not match sensory inputs. Such perceptual biases can often reveal unique insights into underlying mechanisms and computations. For example, a prior assumption that objects move slowly can explain a wide range of motion phenomena. The prior on slow speed is usually rationalized by its match with visual input, which typically includes stationary or slow moving objects. However, this only holds for foveal and parafoveal stimulation. The visual periphery tends to be exposed to faster motions, which are biased toward centrifugal directions. Thus, if prior assumptions derive from experience, peripheral motion processing should be biased toward centrifugal speeds. Here, in experiments with human participants, we support this hypothesis and report a novel visual illusion where stationary objects in the visual periphery are perceived as moving centrifugally, while objects moving as fast as 7°/s toward fovea are perceived as stationary. These behavioral results were quantitatively explained by a Bayesian observer that has a strong centrifugal prior. This prior is consistent with both the prevalence of centrifugal motions in the visual periphery and a centrifugal bias of direction tuning in cortical area MT, supporting the notion that visual processing mirrors its input statistics.

Zhang, Ruyuan; Kwon, Oh-Sang; Tadin, Duje

2013-01-01

168

Simulations of the strong ground motion for the Mw6.9 Yushu earthquake of 14 April 2010  

NASA Astrophysics Data System (ADS)

The Mw6.9 Yushu earthquake of 14 April, 2010, which occurred at the western province of China, Qinghai, caused more than 2000 people died and serious damage to the Yushu city. The earthquake had duration of about 16s and ruptured nearly 80 km. In order to investigate the strong motion caused by this earthquake, we simulate the Yushu earthquake, based on the spectral-element method (SEM). The finite-fault rupture, real topography variations and modified crustal model are considered. To incorporate the topography model SRTM-500, whose resolution is approximately 500 m in horizontal dimension, a buffer layer is applied to prevent from extremely distortion of mapping from the real physical region to the compute region. Our simulation shows a good agreement between observed and simulated results. According to the earthquake damage survey by China Earthquake Administration (CEA), the intensity of four observed points had reached scale IX,; whereas our simulated results show those points are located in the regions with our predicted intensity scale IX or VIII. Our predicted intensity map is inferred from the simulated strong motion and empirical regression relation of Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV) and Intensity. Besides the simulation, we discuss the effects of topography on ground motions.

Zhang, Z.; Chen, X.

2010-12-01

169

Real-time coseismic displacements from tightly-integrated processing of high-rate GNSS and strong motion data  

NASA Astrophysics Data System (ADS)

Precise point positioning (PPP), which can provide "absolute" coseismic displacements with respect to a global reference frame (defined by the satellite orbits and clocks) with a stand-alone GNSS receiver, is advantageous and being used more and more widely for high-rate GNSS seismology. Following the availability of real-time high-rate GNSS observations and precise satellite orbit and clock products, the interest in the real-time PPP technique has greatly increased to construct displacement waveforms and to invert for source parameters of earthquakes in real time. Furthermore, PPP ambiguity fixing approaches developed in recent years provide an important promise to overcome the accuracy limitation of the traditional PPP float solution and to achieve comparable accuracy with relative/network positioning. The main weaknesses of current GNSS measurements are the lower sampling rates (1~50Hz) and the larger high-frequency noise contribution compared to the seismic sensors. Strong motion sensors are able to sample at very high rates (e.g. 200Hz) and perform very well in the high-frequency range as it is much more sensitive to ground motions than GNSS receiver, especially in the vertical direction. However, the double integration is accompanied by unphysical drifts due to sensor rotation and tilt, hysteresis, and imprecision in the numerical integration process. GNSS and seismic instruments are mutually beneficial for geophysical applications because weaknesses of one observation technique are offset by strengths in the other. In order to take full use of the complementary of GNSS and strong motion sensors, we propose an approach of integrating the strong motion data into the real-time ambiguity-fixed PPP processing. A tightly-integrated filter is developed to estimate coseismic displacements from raw GNSS phase and pseudorange observations and raw strong motion data. The performance of the proposed tightly-integrated approach was demonstrated using the collocated high-rate GNSS and strong motion data collected during the 2010, Mw 7.2 El Mayor-Cucapah earthquake(Mw 7.2, 4 April, 2010) in Baja California, Mexico. Taking advantage of the greater precision of the accelerometer observations, small-amplitude P-wave arrivals can be detected in the integrated solution. That is not detectable in the GNSS-only approach because of the reduced sensitivity of GNSS especially in vertical component. On the other hand, the seismic-only solution does not show the permanent co-seismic offset correctly, but it can be obtained from the integrated solution exactly. Furthermore, the proposed tightly-integrated algorithm can significantly improve the ability of resolving integer-cycle phase ambiguities in real-time scenarios, which is required to derive displacements with highest accuracy. Based on the integrated results, we detected the P-wave arrival, located the epicenter and estimated the magnitude. The P-wave-based earthquake parameters such as epicenter and origin time can be issued before the arrival of the destructive S-wave. The reliable estimation of the earthquake magnitude is an important contribution for earthquake early warning especially in case of large magnitude earthquakes. Keywords: Real-time high-rate GNSS; strong motion sensor; tight integration; precise point positioning; PPP ambiguity fixing;

Li, Xingxing; Ge, Maorong; Zhang, Yong; Wang, Rongjiang; Klotz, Jürgen; Wickert, Jens; Schuh, Harald

2013-04-01

170

Contributions to the European Workshop on Investigation of Strong Motion Processing Procedures.  

National Technical Information Service (NTIS)

The first paper is one contribution to a joint study program in the numerical processing of accelerograms from strong earthquakes. A method is proposed for generating an analytic signal having characteristics similar to those of an actual ground displacem...

B. Mohammadioun X. Goula D. Hamaide

1985-01-01

171

An Effective and Fairly Simple Expression for Predicting the Polarization of Strong Ground Motions  

NASA Astrophysics Data System (ADS)

Fault-normal ground motions often exceed fault-parallel motions within a few km of the surface trace of faults that rupture in large (M>6.0) earthquakes (Somerville et al., Seismol. Res. Let., 1997). We seek a very simple method for predicting the S-wave polarization of a hypothetical earthquake. Our method uses the S-wave radiation pattern of two point double-couples to predict the ratio of fault-normal to fault-parallel motion in the region around a finite fault having a uniform slip distribution and known rake. One point source is located at the hypocenter, and the other is located at a theoretically optimal intermediate point lying on the line between the hypocenter and the point on the fault closest to the observation location. For both radiation patterns we assume that the S wave travels a straight line from its point source to the observation location, and that the S wave is vertically incident at the Earth's surface, to account for ray bending from low velocity near-surface materials. We also assume that nodes in the radiation patterns are filled with an empirically determined water- level that depends on frequency and distance to the observation point. We have determined the empirical water-level by comparison of our predictions with observed fault-normal and fault-parallel response spectral accelerations in the 0.5 - 6.0 s band from 39 earthquake having M = 6.0 or greater, taken from the data set of the Next Generation Attenuation Project of the PEER Lifelines Project. At 0.4 s almost no evidence of systematic polarization can be seen in the data. However, as period increases stronger polarization can be seen in the data at progressively larger distances from the source, extending as far as 200 km. Our predictions of fault-normal / fault-parallel motion fit the data better than those of Somerville et al. (1997) for all distances greater than 5 km, but our predictions are worse than Somerville's for sites within 2 km of a rupturing fault.

Spudich, P.; Chiou, B.

2006-12-01

172

Evaluation model of landslide hazards induced by the 2008 Wenchuan earthquake using strong motion data  

NASA Astrophysics Data System (ADS)

Landslides induced by the 2008 Wenchuan earthquake in the Longmenshan area were relatively well instrumented, which makes it possible to investigate the landslides using ground motion records. Firstly, this paper analyzes the data from Wenchuan earthquake on both regional and local site scale. The analyses show that the Newmark accumulative displacement calculated from the ground motion recorded in a particular geological hazard zone corresponds to the hazard intensity in that zone; the larger the displacement, the more serious the geologic hazard. The calculated result also shows that the displacement is related to the Arias intensity, which represents the total energy released during the earthquake at the observation site. Secondly, this paper constructs an evaluation model of Newmark displacement calculated with Arias intensities to estimate the subsequent slope failure resulting from the earthquake. The calculated results based on the model fit well with the distribution of actual landslides, suggesting that this method is useful for hazard evaluation. Therefore, this type of model can be used for estimating regional-scale distribution of earthquake-induced landslides and their associated hazards immediately after an earthquake.

Wang, Xiuying; Nie, Gaozhong; Ma, Mujun

2011-06-01

173

Structure and dynamics of an imidazoline nitroxide side chain with strongly hindered internal motion in proteins.  

PubMed

A disulfide-linked imidazoline nitroxide side chain (V1) has a similar and highly constrained internal motion at diverse topological sites in a protein, unlike that for the disulfide-linked pyrroline nitroxide side chain (R1) widely used in site directed spin labeling EPR. Crystal structures of V1 at two positions in a helix of T4 Lysozyme and quantum mechanical calculations suggest the source of the constraints as intra-side chain interactions of the disulfide sulfur atoms with both the protein backbone and the 3-nitrogen in the imidazoline ring. These interactions apparently limit the conformation of the side chain to one of only three possible rotamers, two of which are observed in the crystal structure. An inter-spin distance measurement in frozen solution using double electron-electron resonance (DEER) gives a value essentially identical to that determined from the crystal structure of the protein containing two copies of V1, indicating that lattice forces do not dictate the rotamers observed. Collectively, the results suggest the possibility of predetermining a unique rotamer of V1 in helical structures. In general, the reduced rotameric space of V1 compared to R1 should simplify interpretation of inter-spin distance information in terms of protein structure, while the highly constrained internal motion is expected to extend the dynamic range for characterizing large amplitude nanosecond backbone fluctuations. PMID:23694751

Toledo Warshaviak, Dora; Khramtsov, Valery V; Cascio, Duilio; Altenbach, Christian; Hubbell, Wayne L

2013-04-30

174

Displaced rocks, strong motion, and the mechanics of shallow faulting associated with the 1999 Hector Mine, California, earthquake  

USGS Publications Warehouse

The paucity of strong-motion stations near the 1999 Hector Mine earthquake makes it impossible to make instrumental studies of key questions about near-fault strong-motion patterns associated with this event. However, observations of displaced rocks allow a qualitative investigation of these problems. By observing the slope of the desert surface and the frictional coefficient between these rocks and the desert surface, we estimate the minimum horizontal acceleration needed to displace the rocks. Combining this information with observations of how many rocks were displaced in different areas near the fault, we infer the level of shaking. Given current empirical shaking attenuation relationships, the number of rocks that moved is slightly lower than expected; this implies that slightly lower than expected shaking occurred during the Hector Mine earthquake. Perhaps more importantly, stretches of the fault with 4 m of total displacement at the surface displaced few nearby rocks on 15?? slopes, suggesting that the horizontal accelerations were below 0.2g within meters of the fault scarp. This low level of shaking suggests that the shallow parts of this rupture did not produce strong accelerations. Finally, we did not observe an increased incidence of displaced rocks along the fault zone itself. This suggests that, despite observations of fault-zone-trapped waves generated by aftershocks of the Hector Mine earthquake, such waves were not an important factor in controlling peak ground acceleration during the mainshock.

Michael, A. J.; Ross, S. L.; Stenner, H. D.

2002-01-01

175

Simulation of Earthquake Strong Ground Motion Using the Specific Barrier Model  

NASA Astrophysics Data System (ADS)

There are two key fault parameters that represent length scales and control the intermediate and high frequency content of near-fault ground motion: (1) the barrier interval; and, (2) the length of the cohesive end-zone at the crack tip. The barrier interval controls the rise time and therefore is related to the pulse duration of the near-fault pulses that carry considerable destructive potential for man-made structures. On the other hand, the length of the cohesive end-zone at the crack tip, which is a measure of the effective thickness of the fault gauge, is expected to control the intensity of the radiated near-fault pulses. In the present work we focus on the barrier interval, which is equal to the size of the representative sub-event of a main event. The barrier interval is equal to the diameter of the circular cracks of the equal-size sub-events that compose the main event in the Specific Barrier Model (SBM) proposed by Papageorgiou and Aki (1983). We have recently calibrated the model using the most up-to-date databases of earthquake events representing three tectonic regimes (Halldorsson and Papageorgiou, 2004). Using the parameters of the SBM that were obtained from the above calibration, we proceed to simulate time histories for a number of earthquake events that were well recorded, cover a wide magnitude range (Mw 5.9 - 7.9), and are representative samples of different source mechanisms. Objective measures are used to assess the quality of fit of the simulated time histories to the recorded motions. A key assumption of the SBM is the uniform distribution of the seismic moment released over the fault plane (i.e., all sub-events are of equal size). We assess the bias (if any) introduced to the overall simulation by the above assumption. The overall goal of the exercise is to assess the effectiveness of the SBM to provide time histories of earthquake ground motion that can be used with confidence by earthquake engineers in aseismic design.

Halldorsson, B.; Dong, G.; Mavroeidis, G.; Zhang, F.; Papageorgiou, A.

2004-12-01

176

Source model for strong ground motion generation in the frequency range 0.1-10 Hz during the 2011 Tohoku earthquake  

NASA Astrophysics Data System (ADS)

The source model of the 2011 Tohoku earthquake, which is composed of four strong motion generation areas (SMGAs), is estimated based on the broadband strong ground motion simulations in the frequency range 0.1-10 Hz using the empirical Green's function method. Two strong motion generation areas are identified in the Miyagi-oki region west of the hypocenter. Another two strong motion generation areas are located in the Fukushima-oki region southwest of the hypocenter. The strong ground motions in the frequency range 0.1-10 Hz along the Pacific coast are mainly controlled by these SMGAs. All the strong motion generation areas exist in the deeper portion of the source fault plane. The stress drops of the four SMGAs range from 6.6 to 27.8 MPa, which are similar to estimations for past M 7-class events occurring in this region. Compared with the slip models and aftershock distributions of past interplate earthquakes in the Miyagi-oki and Fukushima-oki regions since the 1930s, the SMGAs of the 2011 Tohoku earthquake spatially correspond to the asperities of M 7-class events in 1930s. In terms of broadband strong ground motions, the 2011 Tohoku earthquake is not only a tsunamigenic event with a huge coseismic slip near the trench but is also a complex event simultaneously rupturing pre-existing asperities.

Asano, K.; Iwata, T.

2012-12-01

177

Re-digitization of Strong Motion Accelerogram at Hachinohe Harbor during the 1968 Tokachi-oki, Japan Earthquake  

NASA Astrophysics Data System (ADS)

The strong motion accelerogram observed at Hachinohe harbor during the 1968 Tokachi-oki earthquake is re-digitized and examined because of frequent use of the record in seismic design of high-rise buildings. After the data processing, the digitized data are obtained for 234 seconds. The data indicate that 1) the spectra are almost same as those of the previous digital data, but not at periods longer than 5 seconds, 2) the duration of acceleration is about 70 seconds, but longer for velocity and displacement, and 3) the combination of the S-waves and basin-induced surface waves may produce the larger amplitudes at longer periods.

Midorikawa, Saburoh; Miura, Hiroyuki

178

Combining High Rate GPS and Strong Motion Data: A Kalman Filter Formulation for Real-Time Displacement Waveforms  

NASA Astrophysics Data System (ADS)

Displacement waveforms in seismology are traditionally obtained by integration, polynomial fitting and filtering of strong motion records. The displacements so obtained are band-limited since the low frequency components (including the static deformation) are not accurately determined. Additionally there is no objective way of determining the proper parameters for this numerical process (filter corner frequency, polynomial order, etc.) and they have to be tailored by each researcher to what “works best” for every station-event pair. This hinders the automatization of the process, the application to large networks, and real-time processing. We demonstrate a new technique that utilizes elements from the theory of stochastic estimation and control to derive a multi-rate Kalman filter that fuses data from strong motion and GPS instruments in order to obtain real-time total (dynamic and static) displacement waveforms. The filter allows one to combine data streams with different sampling rates. Our formulation assumes Gaussian white noise in both accelerometer and GPS observations, whose variances are determined objectively from pre-event windows for each data type. We demonstrate the multi-rate Kalman filter with two examples: (1) Outdoor experiments at the NEES Large High-Performance Outdoor Shake Table at UCSD in which real recorded seismograms from the 1971 San Fernando and 1994 Northridge earthquakes were utilized as input, with observations taken by 250 Hz accelerometers and 50 Hz GPS receivers; (2) Data from the April 4, 2010 El Mayor-Cucapah earthquake (Mw 7.2) collected by 100 Hz strong motion recordings from stations of the California Integrated Seismic Network (CISN) and 1 Hz GPS data from the California Real Time Network (CRTN), at co-located stations as far as 300 km from the epicenter. Spectral analysis of the resulting displacement waveforms shows some limitations in the Kalman filter’s real-time epoch-by-epoch formulation that depend on the slower sampling rate of the GPS receivers. However, as we show these limitations have little practical consequence, and near-real-time Kalman filter smoothing can recover the full spectral content. We conclude that this formulation is superior to traditional methodologies by providing total displacement waveforms at the sampling rate of the higher-rate accelerometers. As such, we propose that the future of strong motion sensing should include a co-location of accelerometers and high rate GPS and the corresponding integrated processing of both data streams. This configuration is ideal as part of earthquake early warning systems.

Melgar Moctezuma, D.; Bock, Y.; Crowell, B. W.

2010-12-01

179

Motion of particles of magnetically hard powder in a constant magnetic and strongly nonuniform electromagnetic fields  

Microsoft Academic Search

The breakup process of floccules in the fluid state under the action of a constant magnetic and of strongly nonuniform electromagnetic fields was described and recorded by comparing the magnetic properties of samples pressed from powders, texturized, and prefluidized. Commercial barium ferrite powder was fluidized in a dielectric mold. A vibration magnetometer measured the magnetic properties. To evaluate the role

N. S. Bitkina; Yu. M. Vernigorov; B. P. Ignatov; G. F. Lemeshko

1988-01-01

180

Dynamic triggering of high-frequency bursts by strong motions during the 2004 Parkfield earthquake sequence  

Microsoft Academic Search

High-pass filtering (>20 Hz) of acceleration records from the USGS Parkfield Dense Seismograph Array (UPSAR) reveals a series of bursts that occur only during strong shaking from the 2004 Mw6 Parkfield, California, earthquake and its immediate aftershocks. Because there is no correlation between these high frequency bursts observed at closely spaced stations, we hypothesize that they are associated with dynamically

Adam D. Fischer; Zhigang Peng; Charles G. Sammis

2008-01-01

181

Frequency-Dependent Site Amplifications with f >= 0.01 Hz Evaluated from Velocity and Density Models in Central Taiwan  

Microsoft Academic Search

The frequency-dependent site amplifications at 87 free-field strong- motion station sites in central Taiwan are evaluated from the velocity and density structures constructed from borehole data measured at shallow depths and the veloc- ity models inferred from earthquake data at great depths. Results based on the quarter- wavelength approximation method proposed by Boore and Joyner (1997) show that the site

Ming-Wey Huang; Jeen-Hwa Wang; Kuo-Fong Ma; Chien-Ying Wang; Jih-Hao Hung; Kuo-Liang Wen

2007-01-01

182

Strong motion characteristics of the 2011 Tohoku-Oki earthquake observed by K-NET and KiK-net  

NASA Astrophysics Data System (ADS)

The Tohoku-Oki earthquake was the largest earthquake occurred in and around Japan since the recorded history. This magnitude 9.0 megathrust earthquake initiated approximately 100 km off-shore Miyagi prefecture and the rupture extended 400 - 500 km along the subducting Pacific plate. Due to the large ground motions and tsunami associated by this event, more than twenty thousands people were killed or missing and more than 220 thousands houses and buildings were totally or partially destroyed. The Tohoku-Oki earthquake was the first M9-class earthquake that is closely recorded by a dense seismograph network. In this paper, we summarize the characteristics of the strong motions and the source process revealed by those data. The ground motions were recorded at more than 1200 K-NET and KiK-net stations. The peak ground accelerations (PGA) exceeded 1g at 20 sites and the largest PGA, 2933 gals, was observed at the K-NET Tsukidate station (MYG004). We estimated the precise spatial distribution of seismic intensity from the observed data considering the near-surface amplification, and found that roughly twenty million people were exposed to a shaking larger than JMA seismic intensity 5+ (>MMI 7). Huge numbers of large aftershocks and triggered earthquakes including M7-class crustal and intraslab earthquakes have been recorded. Those earthquakes occurred not only in the source area but also several hundreds kilometers away. Some of them were located much nearer to the populated urban areas than the main shock and human fatalities as well as severe building damages were caused by large ground shakings. The observed waveforms from the main shock are very complex; depending on the region, accelerograms show one to three conspicuous and long-duration phases as well as several phases with smaller amplitudes and shorter durations. A paste-up of accelerograms in Iwate, Miyagi and Fukushima prefectures ordered by latitude from north displays an initial strong seismic phase first observed at Miyagi stations and then propagating towards the north and south. A subsequent phase uniformly delayed by approximately 40 s is also clearly observed in the paste-up. In the southern region, Ibaraki and Chiba prefectures, only one distinct phase is observed. Fault rupture process inverted by a multi-time window analysis using the strong-motion waveforms is characterized by one large slip area with maximum slip of 48 m which extends from the area near the hypocenter toward the shallow part of the fault plane, far off the coast of Iwate, Miyagi and Fukushima prefectures (Suzuki et al., 2011, AGU fall meeting). Though the distribution of the total slip is simple, the feature of the rupture progression is very complicated. The duration and the timing of the slip have a large spatial variety within the fault. The fault slip near the coast off Miyagi prefecture, which is small compared to the peak fault slip, had a large contribution to the observed strong motions in Miyagi and Iwate prefectures. The complicated relationship between the rupture model derived using long period strong motions and the features of the observed acceleration waveforms suggests a frequency dependency of the seismic wave radiation and source process.

Aoi, S.; Kunugi, T.; Suzuki, W.; Morikawa, N.; Nakamura, H.; Pulido Hernandez, N. E.; Fujiwara, H.

2011-12-01

183

3D simulation of near-fault strong ground motion: comparison between surface rupture fault and buried fault  

NASA Astrophysics Data System (ADS)

In this paper, near-fault strong ground motions caused by a surface rupture fault (SRF) and a buried fault (BF) are numerically simulated and compared by using a time-space-decoupled, explicit finite element method combined with a multi-transmitting formula (MTF) of an artificial boundary. Prior to the comparison, verification of the explicit element method and the MTF is conducted. The comparison results show that the final dislocation of the SRF is larger than the BF for the same stress drop on the fault plane. The maximum final dislocation occurs on the fault upper line for the SRF; however, for the BF, the maximum final dislocation is located on the fault central part. Meanwhile, the PGA, PGV and PGD of long period ground motions (?1 Hz) generated by the SRF are much higher than those of the BF in the near-fault region. The peak value of the velocity pulse generated by the SRF is also higher than the BF. Furthermore, it is found that in a very narrow region along the fault trace, ground motions caused by the SRF are much higher than by the BF. These results may explain why SRFs almost always cause heavy damage in near-fault regions compared to buried faults.

Liu, Qifang; Yuan, Yifan; Jin, Xing

2007-12-01

184

Strong ground motion and source mechanism studies for earthquakes in the northern Baja California/southern California region  

SciTech Connect

Earthquake data sets collected from arrays of digital seismic event recorders and strong motion instruments operated in the northern Baja California/southern California region are analyzed. Complementing these near-source data sets with data from more distant seismic stations it was possible to begin to separate and understand the effects of stress drop, source size, sediment amplification, and physical attenuation on the variation of ground motion with distance. Surprisingly large ground accelerations, over 0.5g, were recorded for some relatively small (M/sub L/ < 5) earthquakes in the Victoria, Baja California earthquake swarm of March 1978. It was concluded that this is a result of relatively high stress drops (approx. 1 kilobar) and a relatively high sediment amplification factor of about 3.4. The ground motion from these earthquakes was relatively high frequency, which was somewhat surprising since the well-established depth of the events is about 10-12 km and the energy thus passed through the 5 km thick column of sediments of the Imperial and Mexicali Valleys, which might have been expected to produce severe attenuation. The primary factors which influence the results of studies with distant station data are geologic complexities, especially the boundary region between the Imperial Valley and the granitic batholith of the Peninsular Ranges.

Munguia-Orozco, L.

1983-01-01

185

Quick Finite-Fault Inversion and Strong Motion Prediction: Feasibility, Process, and Developments  

NASA Astrophysics Data System (ADS)

As part of a larger, concerted effort to rapidly assess the impact of major earthquakes globally and to provide input into other post-earthquake analyses (e.g., ground motions, stress changes, tectonic implications, etc.), we are developing and testing a new system to automatically determine finite-fault characteristics by inversion of teleseismic body waveforms. Although initially constrained from teleseismic data alone, which currently are the only rapid and reliable available data after major events worldwide, additional data will be used (either directly or as constraints) as they become available, including aftershock locations, geodetic displacements, and regional waveforms. Our ultimate goal is to provide well-constrained, estimated peak ground motions for input into a global ShakeMap, which in turn will allow automatic, reliable estimates of losses and overall impact. To evaluate the feasibility of such a system, we inverted for slip variations on a single plane for the 1999 ChiChi (M7.6) earthquake using only teleseismic data and then compared the 2-sec peak ground velocity map predicted by this model with the observations (constrained by over 400 stations). Even though the fault geometry of this earthquake was more complex than our simple approximation, as would be the case for our initial, automated solution, the predicted map matches the overall observed amplitude variations. While successful in that case, a fully automated system requires overcoming additional, significant hurdles, many of which we are discovering and addressing as we develop the processing system. One such hurdle addressed was the choice of the causative rupture plane from the two nodal planes of a moment tensor solution. We simply conduct finite fault inversions on the two planes simultaneously, and select the solution with a smaller error function. This approach worked well for recent the 2003 Carlsberg Ridge earthquake (M7.6), for which the inverted result matches the trend and extent of its aftershock sequence. Among the more challenging hurdles is compensating for travel time anomalies within an automated system. Using the 2002 Denali earthquake as an example, we show the importance of this correction and how we calibrated the teleseismic path effects with proximal fore- or aftershocks. We also show how an improved fault geometry based on a high-resolution DEM map enhanced the solution. Finally, we discuss ongoing developments, further results, and plans for this system.

Wald, D. J.; Ji, C.; Helmberger, D. V.

2003-12-01

186

Running On-Demand Strong Ground Motion Simulations with the Second-Generation Broadband Platform  

NASA Astrophysics Data System (ADS)

We have developed the second-generation Southern California Earthquake Center (SCEC) Broadband Platform by integrating scientific modeling codes into a system capable of computing broadband seismograms (0-10 Hz) for historical and scenario earthquakes in California. The SCEC Broadband Platform is a collaborative software development project involving SCEC researchers, graduate students, and the SCEC Community Modeling Environment (SCEC/CME) software development group. SCEC scientific groups have contributed software modules to the Broadband Platform including rupture generation, low-frequency deterministic seismogram synthesis, high-frequency stochastic seismogram synthesis, and non-linear site effects. These complex scientific codes have been integrated into a system that supports easy on-demand computation of broadband seismograms. The SCEC Broadband Platform is designed to be used by both scientific and engineering researchers familiar with ground motion simulations. Users may calculate broadband seismograms for both historical earthquakes (validation events including Northridge, Loma Prieta, and Landers) and user-defined earthquakes. Users may select among various codebases for rupture generation, low-frequency synthesis, high-frequency synthesis, and incorporation of site effects, with the option of running a goodness-of-fit comparison against observed or simulated seismograms. The platform produces a variety of data products, including broadband seismograms, rupture visualizations, and goodness-of-fit plots. The Broadband Platform was implemented using software development best practices that support software accuracy, reliability, and ease of use, including version control, user documentation, acceptance tests, and formal software releases. Users can install the platform on their own machine, verify that it is installed correctly, and run their own simulations on demand. The Broadband Platform enables users to run complex ground motion modeling codes without detailed knowledge about how the codes are implemented. Users may run a validation event, supply their own simple source description, or provide a rupture description in Standard Rupture Format (SRF). Users may specify their own list of stations or use a provided list. Currently the platform supports stations and events in Southern California, the Bay Area, and the Mojave. In our poster, we will discuss the scientific capabilities of the Broadband Platform. We will describe the software engineering behind the platform development and the rigorous release procedure involved. Additionally, we will present simulations performed using the platform, including goodness-of-fit results, and discuss potential applications of on-demand broadband seismogram computation.

Callaghan, S.; Maechling, P. J.; Graves, R. W.; Somerville, P. G.; Collins, N.; Olsen, K. B.; Imperatori, W.; Jones, M.; Archuleta, R. J.; Schmedes, J.; Jordan, T. H.; Broadband Platform Working Group

2010-12-01

187

Seismic Strong Motion Array Project (SSMAP) to Record Future Large Earthquakes in the Nicoya Peninsula area, Costa Rica  

NASA Astrophysics Data System (ADS)

The seismic strong motion array project (SSMAP) for the Nicoya Peninsula in northwestern Costa Rica is composed of 10 13 sites including Geotech A900/A800 accelerographs (three-component), Ref-Teks (three- component velocity), and Kinemetric Episensors. The main objectives of the array are to: 1) record and locate strong subduction zone mainshocks [and foreshocks, "early aftershocks", and preshocks] in Nicoya Peninsula, at the entrance of the Nicoya Gulf, and in the Papagayo Gulf regions of Costa Rica, and 2) record and locate any moderate to strong upper plate earthquakes triggered by a large subduction zone earthquake in the above regions. Our digital accelerograph array has been deployed as part of our ongoing research on large earthquakes in conjunction with the Earthquake and Volcano Observatory (OVSICORI) at the Universidad Nacional in Costa Rica. The country wide seismographic network has been operating continuously since the 1980's, with the first earthquake bulletin published more than 20 years ago, in 1984. The recording of seismicity and strong motion data for large earthquakes along the Middle America Trench (MAT) has been a major research project priority over these years, and this network spans nearly half the time of a "repeat cycle" (50 years) for large (Ms 7.5- 7.7) earthquakes beneath the Nicoya Peninsula, with the last event in 1950. Our long time co-collaborators include the seismology group OVSICORI, with coordination for this project by Dr. Ronnie Quintero and Mr. Juan Segura. Numerous international investigators are also studying this region with GPS and seismic stations (US, Japan, Germany, Switzerland, etc.). Also, there are various strong motion instruments operated by local engineers, for building purposes and mainly concentrated in the population centers of the Central Valley. The major goal of our project is to contribute unique scientific information pertaining to a large subduction zone earthquake and its related seismic activity when the next large earthquake occurs in Nicoya. A centralized data base will be created within the main seismic network files at OVSICORI, with various local personnel working in teams that will be responsible to collect data within 3 days following a large mainshock.

Simila, G.; McNally, K.; Quintero, R.; Segura, J.

2006-12-01

188

Probing strong-field gravity at the galactic center using stellar motions  

NASA Astrophysics Data System (ADS)

The center of our galaxy contains the nearest supermassive black hole, with a mass four million times that of the Sun. The black hole's location and mass have been accurately determined by tracing the motions of a handful of bright young stars that move in tight orbits about the Galactic center, some with periods as short as 15 years. Until now, the measured orbits have been found to be consistent with Keplerian ellipses about a Newtonian point mass. But the stellar orbits potentially contain much more information: about the distributed mass in the inner parsec (consisting of faint stars, dark stellar remnants, and possibly particle dark matter); and also about the non-Newtonian contributions to the gravitational potential from the supermassive black hole. For stars nearer than about one milli-parsec from the singularity, frame-dragging torques should induce precession of orbital planes at a rate that is potentially observable after a few years' monitoring using the next generation of optical astrometric instruments, allowing a direct determination of the black hole's spin. Even more challenging would be a test of 'no hair' theorems by comparing the frame-dragging precession with that induced by the black hole's quadrupole moment. Results of detailed numerical simulations of the nuclear star cluster that include relativistic terms will be presented, which demonstrate the feasibility of testing theories of gravity using stellar orbits, given the inevitable noise from star-star perturbations and perturbations due to the unseen stellar remnants. )

Merritt, David

2010-02-01

189

Stochastic Strong Ground Motion Simulations on Eastern North Anatolian Fault Zone: A Sensitivity Study  

NASA Astrophysics Data System (ADS)

The Eastern segments of the North Anatolian Fault Zone of Turkey are less investigated and have less dense seismic networks than the Western ones. Thus, regional seismic parameters related to source, path and site effects are not well-established. In this study, we aim to study the ability of stochastic finite-fault simulations in verifying the regional seismic parameters of an area with a sparse seismic network. For this purpose, initially the ground motions of 13 March 1992 Erzincan (Turkey) earthquake are simulated using the few available seismic model parameters from previous studies. To quantify the error, misfit functions in terms of observed and synthetic Fourier Amplitude Spectra (FAS), PGA and PGV values are defined. The misfits are computed for a large set of simulations generated with all possible combinations of input parameters. The parameters that minimize the error in the frequency domain are validated to be the optimum model parameters of Erzincan region. Next, we investigate how sensitive the simulations are with respect to the input models. With the objective of observing the variation of the simulated waveforms regarding small perturbations in the input parameters, a local sensitivity study is conducted around the optimum parameters.

Ugurhan, B.; Askan, A.

2010-12-01

190

Should We Consider Sea in Simulating Strong Ground Motion? - Numerical Examination of Effects of Sea in the 2-D P-SV Wave Field -  

Microsoft Academic Search

I investigated the effects of the sea on seismic ground motion through some numerical experiments and examined the necessity of considering the sea in simulating strong ground motion. To specify the effects of the sea, I compared the waveforms calculated for the models with and without the sea. The depth of the sea examined here ranges from several ten to

K. Hatayama

2003-01-01

191

The Loma Prieta, California, Earthquake of October 17, 1989: Strong Ground Motion and Ground Failure  

USGS Publications Warehouse

Professional Paper 1551 describes the effects at the land surface caused by the Loma Prieta earthquake. These effects: include the pattern and characteristics of strong ground shaking, liquefaction of both floodplain deposits along the Pajaro and Salinas Rivers in the Monterey Bay region and sandy artificial fills along the margins of San Francisco Bay, landslides in the epicentral region, and increased stream flow. Some significant findings and their impacts were: * Strong shaking that was amplified by a factor of about two by soft soils caused damage at up to 100 kilometers (60 miles) from the epicenter. * Instrumental recordings of the ground shaking have been used to improve how building codes consider site amplification effects from soft soils. * Liquefaction at 134 locations caused $99.2 million of the total earthquake loss of $5.9 billion. Liquefaction of floodplain deposits and sandy artificial fills was similar in nature to that which occurred in the 1906 San Francisco earthquake and indicated that many areas remain susceptible to liquefaction damage in the San Francisco and Monterey Bay regions. * Landslides caused $30 million in earthquake losses, damaging at least 200 residences. Many landslides showed evidence of movement in previous earthquakes. * Recognition of the similarities between liquefaction and landslides in 1906 and 1989 and research in intervening years that established methodologies to map liquefaction and landslide hazards prompted the California legislature to pass in 1990 the Seismic Hazards Mapping Act that required the California Geological Survey to delineate regulatory zones of areas potentially susceptible to these hazards. * The earthquake caused the flow of many streams in the epicentral region to increase. Effects were noted up to 88 km from the epicenter. * Post-earthquake studies of the Marina District of San Francisco provide perhaps the most comprehensive case history of earthquake effects at a specific site developed for any earthquake. Soft soils beneath the Marina amplified ground shaking to damaging levels and caused liquefaction of sandy artificial fills. Liquefaction required 123 repairs of pipelines in the Municipal Water Supply System, more than three times the number of repairs elsewhere in the system. Approximately 13.6 km of gas-distribution lines were replaced, and more than 20% of the wastewater collection lines were repaired or replaced.

Coordinated by Holzer, Thomas L.

1992-01-01

192

A PHYSICAL MODEL OF THE EFFECT OF A SHALLOW WEAK LAYER ON STRONG GROUND MOTION FOR STRIKE-SLIP RUPTURES  

SciTech Connect

We report results of foam-rubber modeling of the effect of a shallow weak layer on ground motion from strike-slip ruptures. Computer modeling of strong ground motion from strike-slip earthquakes has involved somewhat arbitrary assumptions about the nature of slip along the shallow part of the fault (e.g., fixing the slip to be zero along the upper 2 kilometers of the fault plane) in order to match certain strong motion accelerograms. Most modeling studies of earthquake strong ground motion have used what is termed kinematic dislocation modeling. In kinematic modeling the time function for slip on the fault is prescribed, and the response of the layered medium is calculated. Unfortunately, there is no guarantee that the model and the prescribed slip are physically reasonable unless the true nature of the medium and its motions are known ahead of time. There is good reason to believe that in many cases faults are weak along the upper few kilometers of the fault zone and may not be able to maintain high levels of shear strain required for high dynamic energy release during earthquakes. Physical models of faulting, as distinct from numerical or mathematical models, are guaranteed to obey static and dynamic mechanical laws. Foam-rubber modeling studies have been reported in a number of publications. The object of this paper is to present results of physical modeling using a shallow weak layer, in order to verify the physical basis for assuming a long rise time and a reduced high frequency pulse for the slip on the shallow part of faults. It appears a 2-kilometer deep, weak zone along strike-slip faults could indeed reduce the high frequency energy radiated from shallow slip, and that this effect can best be represented by superimposing a small amplitude, short rise-time pulse at the onset of a much longer rise-time slip. A weak zone was modeled by inserting weak plastic layers of a few inches in thickness into the foam rubber model. For the 15 cm weak zone the average pulse is reduced by a factor of 0.46. The factor for the 20 cm case reduction is 0.11. For the 30 cm case it is 0.045. From these results we can see that, the thicker the weak layer, the more difficult it is for a short rise-time acceleration pulse to push its way through the weak layer to the surface. This is thus an approximate justification for reducing the high frequency radiation from shallower parts of strike-slip faults if it is known that the shallow part of the fault is weak or has not stored up shear stress.

JAMES N. BRUNE AND ABDOLRASOOL ANOOSHEHPOOR

1998-02-23

193

Comments on baseline correction of digital strong-motion data: Examples from the 1999 Hector Mine, California, earthquake  

USGS Publications Warehouse

Residual displacements for large earthquakes can sometimes be determined from recordings on modern digital instruments, but baseline offsets of unknown origin make it difficult in many cases to do so. To recover the residual displacement, we suggest tailoring a correction scheme by studying the character of the velocity obtained by integration of zeroth-order-corrected acceleration and then seeing if the residual displacements are stable when the various parameters in the particular correction scheme are varied. For many seismological and engineering purposes, however, the residual displacement are of lesser importance than ground motions at periods less than about 20 sec. These ground motions are often recoverable with simple baseline correction and low-cut filtering. In this largely empirical study, we illustrate the consequences of various correction schemes, drawing primarily from digital recordings of the 1999 Hector Mine, California, earthquake. We show that with simple processing the displacement waveforms for this event are very similar for stations separated by as much as 20 km. We also show that a strong pulse on the transverse component was radiated from the Hector Mine earthquake and propagated with little distortion to distances exceeding 170 km; this pulse leads to large response spectral amplitudes around 10 sec.

Boore, D. M.; Stephens, C. D.; Joyner, W. B.

2002-01-01

194

Source Rupture Process of the 2008 Iwate-Miyagi Nairiku, Japan, Earthquake Revealed from Near Fault Strong Motion Records  

NASA Astrophysics Data System (ADS)

We reveal the source rupture process of the 2008 Iwate-Miyagi Nairiku earthquake through the waveform inversion of the near fault strong motion records. At 8:43, June 14, 2008 (JST), a M7.2 shallow inland crustal earthquake struck Iwate and Miyagi Prefectures, northeast Japan. This earthquake, the 2008 Iwate-Miyagi Nairiku earthquake, is a reverse fault event, whose fault plane strikes to the southwest and dips to the northwest according to moment tensor solutions, aftershock distribution, and surface fault break. Strong motion networks, K-NET and KiK-net, operated by the National Research Institute for Earth Science and Disaster Prevention (NIED) obtained lots of the strong motion records at the near source region, which provide the information of the detailed source rupture process. We employ the multi-time-window linear waveform inversion method (Hartzell and Heaton, 1983). S-wave portion of the velocity waveforms (0.1-1 Hz) are used for the inversion. We use mainly borehole data at KiK- net stations. Green's functions are calculated using the discrete wavenumber method (Bouchon, 1981) and reflection/transmission coefficient matrix method (Kennett and Kerry, 1979) on the assumption of 1-D layered velocity structure. The rupture propagation effect within the subfault is included in the Green's function following Sekiguchi et al. (2002). Some stations are located on thick sediment. In order to take into account their effect on the observed waveforms, we construct the velocity structure model for each station referring to a 3-D subsurface structure model compiled for strong motion evaluation of whole Japan (Fujiwara et al., 2006). Validity of the assumed velocity structure is confirmed by simulating the aftershock records. The rupture starting point is set on the hypocenter relocated by Sekine et al. (2008) using double-difference method (Waldhauser and Ellsworth, 2000). Assumed fault plane covers a space of 40 km × 18 km. Its strike angle is 209° referring to F-net moment tensor (NIED) and dip angle is 40° considering the location of the observed surface fault trace. The fault plane is divided into 2 km × 2 km subfaults. The slip history on each subfault is represented by 7 smoothed ramp functions whose duration is 0.8 s at 0.4 s interval. The weight of each function, model parameter in the inversion, is obtained by minimizing the L-2 norm between the observed and synthetic waveforms using the least square method. Restriction of the variation in the rake angle and the spatio-temporal smoothing of the model parameter are applied as constraint conditions to stabilize the inversion. The obtained rupture model shows that the rupture propagated mainly southward. There are two large slip areas. One is located at the hypocenter and the other lies at the shallow part of the fault, which is to the south of the hypocenter. The extent of the large slip area at the hypocenter is rather small. The southern large slip area occupies larger area, from which the seismic moment is largely released between 4 s and 7 s after rupture started. The fitting between the observed and synthetic waveforms is favorable except for IWTH25, which is closest to the epicenter (epicentral distance is 3 km). For further study, we will improve the waveform fitting of IWTH25 since the data of this very near source station constrain the source rupture model better.

Suzuki, W.; Aoi, S.; Sekiguchi, H.

2008-12-01

195

Motion.  

ERIC Educational Resources Information Center

This monograph was written for the Conference on the New Instructional Materials in Physics held at the University of Washington in summer, 1965. It is intended for use in an introductory course in college physics. It consists of an extensive qualitative discussion of motion followed by a detailed development of the quantitative methods needed to…

Gerhart, James B.; Nussbaum, Rudi H.

196

Motion.  

ERIC Educational Resources Information Center

|This issue of Exploratorium Magazine focuses on the topic of motion. Contents include: (1) "First Word" (Zach Tobias); (2) "Cosmic Collisions" (Robert Irion); (3) "The Mobile Cell" (Karen E. Kalumuck); (4) "The Paths of Paths" (Steven Vogel); (5) "Fragments" (Pearl Tesler); (6) "Moving Pictures" (Amy Snyder); (7) "Plants on the Go" (Katharine…

Brand, Judith, Ed.

2002-01-01

197

Modeling Strong Ground Motions of the 2004 Mw 6.3 Les Saintes Earthquake Using Hybrid Green's Functions  

NASA Astrophysics Data System (ADS)

A semi-empirical approach is presented to simulate the strong ground motion recordings of the Mw 6.3 Les Saintes earthquake that occurred on November 21th, 2004, near the Guadeloupe Island. This study is based on a kinematic fractal k-2 composite source model where subevents are generated using a fractal distribution of sizes. Assuming a constant rupture velocity, each elementary source is described as a crack-type slip model that starts radiating when the rupture front reaches a nucleation point located inside the crack. Each subevent is set up with a scale-dependent rise-time. In order to better control the rupture directivity effect, a size-dependent nucleation region is defined inside the crack surface in which the nucleation point is randomly located. The synthetics follow a ?2 acceleration spectrum shape. Taking advantage of records available for several small earthquakes, the kinematic rupture model is combined with these recordings, which are used as empirical Green's function (EGF). The procedure consists to model a hybrid Green's function (HGF) combining the synthetic low-frequency and the empirical high-frequency Green's functions with appropriate delay times due to the S-wave travel time propagation. A discrete version of seismic source representation theorem is used, and synthetic seismograms are then computed convolving each slip-velocity function with the corresponding HGF. A new hybrid Green's function computation is proposed to use at each station several EGFs coming from various sources near the assumed fault plane. This allows to better sample the high-frequency content radiated from the fault to the receiver. Synthetic strong ground motions reproduce quite well the observed main shock waveforms.

Ruiz-Paredes, J. A.; Bengoubou-Valérius, M.; Bouin, M.; Bernard, P.

2011-12-01

198

The design and performance of a low-cost strong-motion sensor using the ICS-3028 micromachined accelerometer  

USGS Publications Warehouse

The severity of earthquake ground shaking varies tremendously over very short distances (Figures 1a-c). Within a distance of as little as 1 km from the nearest station, one knows little more than what can be obtained from an attenuation relation, given only distance from the fault rupture and the geology of the site. For example, if some station measures 0.5 g peak ground acceleration (PGA), then at a distance of 1 km from that site, under otherwise identical conditions, the shaking has one chance in three of being under 0.36 g or over 0.70 g, based on the curve shown in Figures la, c. Similarly, pseudovelocity (PSV) response spectra have a 5% chance of differing by 2? at 1 km distance (Figure 1 b). This variance can be the difference between moderate and severe damage. Hence, there are critical needs, both in emergency response and in mitigation (prediction of shaking strength, building codes, structural engineering), to sample ground shaking densely enough to identify individual neighborhoods suffering localized, strong shaking. These needs imply a spatially dense network of strong-motion seismographs, probably numbering thousands of sites in an urban region the size of the San Francisco Bay Area, California (Figure 1 c). It has not been economically feasible to field that many instruments, since existing ones cost many thousands of dollars apiece. For example, there are currently just a few dozen digital free-field instruments in the Bay Area. This paper is one step toward a solution to this conundrum. I demonstrate that a recently developed class of accelerometers, those constructed from silicon by 'micromachining' (a process similar to integrated circuit fabrication), is now capable of resolving ground motion with the necessary accuracy while greatly lowering both acquisition and maintenance costs.

Evans, J. R.

1998-01-01

199

Joint inversion of teleseismic and strong motion data for the rupture process of the 2008 Wenchuan, China, earthquake  

NASA Astrophysics Data System (ADS)

The 2008 Wenchuan, China, earthquake, that is the largest and deadliest earthquake of the world for 2008, occurred on May 12, 2008 (local time). We first obtained teleseismic data observed at stations of FDSN from IRIS DMC, and carried out preliminary point sources analyses of them using the algorithm of Kikuchi and Kanamori (1991). The results of these analyses and aftershock distribution by USGS indicate low-angle dip slips in the southern half and high-angle strike slips in the northern half. Some surface fault investigations (e.g., Hao et al., 2009) suggest two parallel fault traces in the southern half, but only the one closer to the Sichuan basin should be related to the source fault of the earthquake, because the other cannot be of low angle. Accordingly, we defined a fault system consisting of two single-trace segments. The strike and dip angles for the southern and northern segments are respectively given to be (228, 35) and (232, 65) based on the results of the point source analyses. We next used strong motion data observed by the Institute of Engineering Mechanics of the China Earthquake Administration, and then carried out a joint finite source inversion of them and the teleseismic data mentioned above. We adopted the Green's functions of Kohketsu (1985) and Kikuchi and Kanamori (1991). We also used the inverse algorithm of Yoshida et al. (1996) with the revisions of Hikima and Koketsu (2005), and the location of the hypocenter determined by USGS (103.33E, 30.99N, depth 12 km) as a rupture initiation point. The resultant slip distribution indicates the first asperity with the largest reverse-faulting slip of about 7 m and the second asperity with a strike slip of about 3 m to be located in the southern and northern segments, respectively. The total seismic moment is 1.0 x 10**21 Nm, which corresponds to a moment magnitude (Mw) of 7.9. Significant slips appear in a 250 km long region (10,000 km**2) of the source fault, and these length and area are close to averages for an Mw 7.9 low-angle reverse-faulting earthquake. The strong motion records closest to the source fault mainly consist of the ground motions from the southern asperity and the slips around the hypocenter. They overlap each other because of the rupture velocity (Vr) nearly equal to the S-wave velocity (Vs). Heavily damaged towns such as Yingxiu and Beichuan and the zones of seismic intensity XI determined by IEM were located just above the southern asperity or at the end of the southern segment. The Vr nearly equal to Vs resulted in strong directivity effects and these caused the damaging ground motion at the end of the southern segment.

Koketsu, Kazuki; Hikima, Kazuhito; Yokota, Yusuke; Wang, Zifa

2010-05-01

200

The influence of critical Moho reflections on strong ground motions recorded in San Francisco and Oakland during the 1989 Loma Prieta earthquake  

SciTech Connect

The amplitudes of strong ground motions from the Loma Prieta earthquake recorded in the San Francisco and Oakland areas exceeded the levels predicted by standard empirical attenuation relations. Preliminary analysis of accelerograms having known trigger times strongly suggests that the elevation of ground motion amplitudes in the distance range of approximately 40 to 100 km was due to critical reflections from the base of the crust. These reflections, which are identified on the basis of their arrival times and phase velocity, and by comparison with simulated accelerograms, were large and occurred at relatively close range because of the deep focal depth of the earthquake and the strong velocity gradient at the base of the crust. These motions were further amplified, presumably by impedance contrast effects, at soft soil sites in San Francisco and Oakland. The effect of the critical reflections in amplifying peak accelerations of the Loma Prieta earthquake in the San Francisco and Oakland regions was as large as the effect of soft soil site conditions. Focal depth has an important influence on strong motion attenuation at distances beyond about 40 km, and empirical attenuation relations derived from shallow crustal earthquakes may underpredict the ground motions of deeper crustal events in this distance range. Further analyses using an expanded data base that includes recordings of aftershocks are required to rigorously test the proposed explanation of the ground motions recorded in San Francisco and Oakland, and the conclusions drawn from that explanation.

Somerville, P.; Yoshimura, J. (Woodward-Clyde Consultants, Pasadena, CA (USA))

1990-07-01

201

Linear Amplification of Horizontal Strong Ground Motion in Zagreb (Croatia) for a Realistic Range of Scaled Point Sources  

NASA Astrophysics Data System (ADS)

The linear amplification of the larger horizontal component of strong ground motion along a selected profile in the city of Zagreb is estimated by examining the synthetic waveforms corresponding to a suite of 16 realistically chosen scaled point sources. The accelerograms, computed for the average bedrock model by modal summation, are propagated through local laterally heterogeneous anelastic models by the finite-difference algorithm. The ratio of peak ground acceleration (PGA) and of the response spectra (RS), obtained by using local and bedrock models, define the PGA and RS amplification AMP(PGA) and AMP(RS), respectively. Even variations of the order of commonly observed uncertainties of only dip and rake angles of the causative fault show that both AMP(PGA) and AMP(RS) vary at some sites by more than a factor of two. It follows that, especially for strongly laterally heterogeneous structures, local effects must be determined for each of the relevant sources considering all associated uncertainties as completely as possible. Such a conclusion certainly holds for the case of the microzonation of Zagreb, where the local geology is quite complex, and the seismicity is not confined to a single seismic source zone.

Herak, Marijan; Lokmer, Ivan; Vaccari, Franco; Panza, Giuliano F.

202

H/V ratio in Athens and the strong motion at the Ano Liosia site during the 1999 Athens earthquake  

NASA Astrophysics Data System (ADS)

The damaging 1999 Athens earthquake of Mw=5.9 occurred at about 20km from the city center. The intensity distribution in the capital, ranging from V to IX, was quite irregular due to combination of the source, path and site effects. The 30-stations temporary network of the University of Patras, installed in the area of Attica for 50 days, recorded a significant part of the aftershock sequence. The aftershocks not only delineated the mainshock fault plane, but they also provided important site classification. The Horizontal-to-Vertical spectral ratio method was applied, and the most significant amplification (H/V exceeding 4 in the frequency range 1-4Hz) was found at the Ano Liosia site, belonging to the most heavily damaged zones with intensity IX. The site is situated in a shallow basin, whose surface extent is about 4x4 km, and the maximum depth is of about 150 m. Based on geological and geophysical data (Vp, Vs, Q) measured at the site, the numerical modeling of the seismic site response was carried out. The finite-differences technique was used for a 2D modeling, and significant edge effects were revealed, e.g. the amplification by a factor of 3, with respect to the outcropping bedrock. The 1D effects of the sediment layering, modeled by the matrix technique, would produce much weaker amplification, and simpler time history of the response. No recording of the mainshock is available from Ano Liosia. Nevertheless, based on the finite-extent source model validated by the existing strong motion records in Athens, we assume that the bedrock motion in Ano Liosia had its PGA ranging from 0.2 to 0.3 g, resulting from the relatively small epicentral distance (~ 10 km) and the forward source directivity (Serpetsidaki et al., session SM10). When combined with the above discussed site effect, the PGA values in Ano Liosia might locally exceed 0.6g.

Serpetsidaki, A.; Tselentis, G.-A.; Zahradnik, J.

2003-04-01

203

Third-and-a-half order post-Newtonian equations of motion for relativistic compact binaries using the strong field point particle limit  

SciTech Connect

We report our rederivation of the equations of motion for relativistic compact binaries through the third-and-a-half post-Newtonian (3.5 PN) order approximation to general relativity using the strong field point particle limit to describe self-gravitating stars instead of the Dirac delta functional. The computation is done in harmonic coordinates. Our equations of motion describe the orbital motion of the binary consisting of spherically symmetric nonrotating stars. The resulting equations of motion fully agree with the 3.5 PN equations of motion derived in the previous works. We also show that the locally defined energy of the star has a simple relation with its mass up to the 3.5 PN order.

Itoh, Yousuke [Astronomical Institute, Graduate School of Science, Tohoku University, 6-3 Aoba Aramaki Aoba Sendai 980-8578 (Japan)

2009-12-15

204

Reconciling strong slab pull and weak plate bending: The plate motion constraint on the strength of mantle slabs  

Microsoft Academic Search

Although subducting slabs undergo a bending deformation that resists tectonic plate motions, the magnitude of this resistance is not known because of poor constraints on slab strength. However, because slab bending slows the relatively rapid motions of oceanic plates, observed plate motions constrain the importance of bending. We estimated the slab pull force and the bending resistance globally for 207

Benjun Wu; Clinton P. Conrad; Arnauld Heuret; Carolina Lithgow-Bertelloni; Serge Lallemand

2008-01-01

205

Determination of site amplification in the Los Angeles urban area from inversion of strong-motion records  

USGS Publications Warehouse

The amplification of strong ground motion at sites in the greater Los Angeles, California, region is determined using the generalized-inverse method of Andrews (1986). Site-amplification estimates are determined at 281 strong-motion sites that provided horizontal-component accelerograms from the 1971 San Fernando, 1987 Whittier Narrows, 1991 Sierra Madre, or 1994 Northridge mainshocks. The estimates are determined relative to the spectral level recorded at a single reference site. In a second inversion, a source-site interaction term is added to Andrews's (1986) model to quantify the effect selected mainshock records have on site-amplification estimates. The source-site interaction term is applied to the San Fernando Valley sites' records of the Northridge earthquake and to three Los Angeles basin sites' records of the Whittier Narrows mainshock. Site-amplification spectra are averaged within two frequency bands: the intermediate-frequency band (IFB) from 0.5 to 1.5 Hz and the high-frequency band (HFB) from 2 to 6 Hz. Results are displayed on maps of surficial geology. Average spectral levels are correlated with average shear-wave velocity in the uppermost 30 m, a geotechnical parameter used by the National Earthquake Hazards Reduction Program (NEHRP) to characterize site amplification. Statistically significant correlation is found in both frequency bands. Average spectral amplification levels for NEHRP class B, C, and D sites in the LA urban area are determined. These averages display an expected increase in spectral amplification with category, with a more pronounced variation in the IFB than in the HFB. Considerable overlap in the one-standard-deviation range of the C and D site levels is found in both IFB and HFB, suggesting that site-specific spectral amplification is influenced by more than just near-surface shear-wave velocity. Average site-amplification levels are compared with those obtained from Northridge aftershock records at 28 collocated sites and are found to be in reasonably good agreement in both frequency bands. Some interesting outliers, that is, sites for which the mainshock- and aftershock-determined amplifications differ significantly, are identified as sites that experienced ground failure during the Northridge mainshock.

Harmsen, S. C.

1997-01-01

206

Spectra and times series of selected processed SMIP (Strong Motion Instrumentation Program) records from the Loma Prieta earthquake of 17 October 1989  

SciTech Connect

An extensive strong-motion data set from a magnitude 7 earthquake is unprecedented, worldwide. Early analysis of the spectra and the velocity and displacement time series is important to begin to understand the impact of these new data existing assumptions for earthquakes of this size. SMIP, the Strong Motion Instrumentation Program of the Division of Mines and Geology, has processed the records from a subset of the 93 strong-motion stations that recorded the 17 October 1989 Loma Prieta earthquake. The spectra and time series to be presented include those from a station directly over the aftershock zone near the San Andreas fault, and other stations in the near-field, within 10 km (6 miles) of the surface trace of the San Andreas. In addition, spectra and time series are presented for Oakland and San Francisco stations located both on rock and near areas of intensive damage during the earthquake.

Shakal, A.; Cao, T.; Darragh, R.; Reichle, M.

1990-01-01

207

Rupture Process of the March 2011 Tohoku-Oki Earthquake from Back-Projection of Local Strong-Motion Records  

NASA Astrophysics Data System (ADS)

The Mw 9.0 megathrust earthquake off northeastern Honshu, Japan, in March 2011 had an unexpected size for a region which experienced only few events with magnitude larger than 8.0 in the past millennium. The event originated at crustal depths along a segment of the Pacific slab of the Japanese subduction zone. Large slip deficit and strong interplate coupling have been previously detected there by inland deformation measurements. The pattern of seismicity occurrence and the mechanical coupling between the different sectors of the Japan slab suggest that its morphology and segmentation may be strongly influenced by the presence of landward oceanic fracture zones. The aim of this study is to image the locations of strongly radiating sources and the rupture development during the faulting process. We used strong-motion records from the dense Japanese accelerometer arrays, integrated twice to obtain ground displacement, and filtered in different frequency bands between 0.04 Hz and 2.0 Hz. We applied a move-out and stacking technique to back-project the S-wave displacement amplitudes onto the subducting plate boundary, including the proper correction for geometrical spreading and source radiation pattern. Thus, the resulting images are consistently mapped into the slip distribution during the rupture development. Image resolution and sensitivity to processing parameters is assessed by synthetic tests. Our results show that the great Tohoku earthquake started as a smaller size rupture, slowly propagating upward along the slab segment and triggering the break of a larger size asperity at shallower depths near the trench. In that region also the largest slip has been observed in various studies. For a large amount of its duration, the rupture remained confined in a 100-150 km wide slab stripe, delimited by two Northwest-Southeast trending oceanic fractures. After about a minute, the rupture propagated at relatively high speed toward Southwest, parallel to the trench. The occurrence of large slip amplitudes at shallow depths likely favored the rupture to propagate across contiguous slab segments and contributed to build up a giant size earthquake. The lateral variations in the slab surface geometry may act as geometrical and/or mechanical barriers finally controlling the earthquake rupture nucleation, evolution and arrest.

Maercklin, N.; Festa, G.; Colombelli, S.; Zollo, A.

2011-12-01

208

Combining Broadband, Strong Motion, and other geophysical data in real time data acquisition and processing at the Swiss Seismological Service SED  

NASA Astrophysics Data System (ADS)

The Swiss Seismological Service (SED) operates one of the densest seismic broadband networks in Europe with 27 STS2 stations transmitting 24 bit 120sps data in real time. In addition the SED operates a network of 77 strong-motion recorders (65 free-field, 12 on hard rock co-located with broadband sensors). At 16 of the free-field sites and the 12 hard-rock sites Episensor accelerometers and 24 bit digitizers are installed and data is also transmitted in real time, while the other stations are equipped with 1990-era Geosig strong motion sensors, 16 bit A/D converters, and dial-up telephone links. Over the next 10years it is planned to replace those older strong motion stations with Episensors, 24 bit digitizers, and real-time data links, and to install an additional 51 free-field stations of that type. Past experience has shown that the strong motion data is very useful for refining the hypocentral parameters especially for smaller earthquakes, so in future all new strong motion channels will be integrated into the real-time processing.According to the SED open data policy all this data will be freely available e.g. through ORFEUS. Furthermore, new regional experiments in Switzerland (in particular COGEAR, "Coupled seismogenic Geohazards in Alpine Regions") will provide additional data from dense temporary deployments of strong motion stations and real-time GPS, but also from other geophysical methods like geochemical and magnetotelluric measurements with significantly different data types and sampling rates. Apart from the challenges of integrated acquisition and quasi-real-time processing of all that data the provision of efficient access to data streams and station metadata requires new concepts of web-based data visualisation and retrieval implementations (e.g. webmap services).

Clinton, J.; Haslinger, F.; Fäh, D.; Zweifel, P.; Schnabel, O.; Giardini, D.

2009-04-01

209

A teleseismic study of the 2002 Denali fault, Alaska, earthquake and implications for rapid strong-motion estimation  

USGS Publications Warehouse

Slip histories for the 2002 M7.9 Denali fault, Alaska, earthquake are derived rapidly from global teleseismic waveform data. In phases, three models improve matching waveform data and recovery of rupture details. In the first model (Phase I), analogous to an automated solution, a simple fault plane is fixed based on the preliminary Harvard Centroid Moment Tensor mechanism and the epicenter provided by the Preliminary Determination of Epicenters. This model is then updated (Phase II) by implementing a more realistic fault geometry inferred from Digital Elevation Model topography and further (Phase III) by using the calibrated P-wave and SH-wave arrival times derived from modeling of the nearby 2002 M6.7 Nenana Mountain earthquake. These models are used to predict the peak ground velocity and the shaking intensity field in the fault vicinity. The procedure to estimate local strong motion could be automated and used for global real-time earthquake shaking and damage assessment. ?? 2004, Earthquake Engineering Research Institute.

Ji, C.; Helmberger, D. V.; Wald, D. J.

2004-01-01

210

Taiwan's Identity Challenge  

Microsoft Academic Search

Taiwan’s geo-strategic position and its domestic political development have been in conflict throughout its modern, post-Chinese civil war history. Taiwan’s geo-strategic position, defined by its oppositional relationship to China, has ensured that Taiwan and the cross-strait relations have remained a global flash point for close to 60 years. For the first 40 years, Taiwan’s goal to reclaim China has underpinned

Malcolm Cook

2005-01-01

211

Strong ground motion synthesis for a M=7.2 earthquake in the Gulf of Corinth, Greece using Empirical Green`s functions  

SciTech Connect

We synthesize strong ground motion at three sites from a M=7.2 earthquake along the MW-trending Gulf of Cornith seismic zone. We model rupture along an 80 segment of the zone. The entire length of the fault, if activated at one time, can lead to an event comparable to that of the 1995 Kobe earthquake. With the improved digital data now routinely available, it becomes possible to use recordings of small earthquakes as empirical Green`s functions to synthesize potential ground motion for future large earthquakes. We developed a suite of 100 rupture scenarios for the earthquake and computed the commensurate strong ground motion time histories. We synthesized strong ground motion with physics-based solutions of earthquake rupture and applied physical bounds on rupture parameters. The synthesized ground motions obtained are source and site specific. By having a suite of rupture scenarios of hazardous earthquakes for a fixed magnitude and identifying the hazard to a site from the statistical distribution of engineering parameters, we have introduced a probabilistic component to the deterministic hazard calculation. The time histories suggested for engineering design are the ones that most closely match either the average or one standard deviation absolute accelerations response values.

Hutchings, L.; Stavrakakis, G.N.; Ioannidou, E.; Wu, F.T.; Jarpe, S.; Kasameyer, P.

1998-01-01

212

3D Modeling of Strong Ground Motion in the Pacific Northwest From Large Earthquakes in the Cascadia Subduction Zone  

NASA Astrophysics Data System (ADS)

The Cascadia subduction zone in the Pacific Northwest, USA, generates Great (megathrust) earthquakes with a recurrence period of about 500 years, most recently the M~9 event on January 26, 1700. Since no earthquake of such magnitude has occurred in the Pacific Northwest since the deployment of strong ground motion instruments, a large uncertainty is associated with the ground motions expected from such event. To decrease this uncertainty, we have carried out the first 3D simulations of megathrust earthquakes (Mw8.5 and Mw9.0) rupturing along the Cascadia subduction zone. The simulations were carried out in a recently developed 3D velocity model of the region of dimensions 1050 km by 550 km, discretized into 2 billion 250 m3 cubes with a minimum S-wave velocity of 625 m/s. The model includes the subduction slab, accretionary sediments, local sedimentary basins, and the ocean layer. About 6 minutes of wave propagation for each scenario consumed about 24 Wall-clock hours using a parallel fourth-order finite-difference method with 1600 processors on the San Diego Supercomputer Center Datastar supercomputer. The source descriptions for the Mw9.0 scenarios were designed by mapping the inversion results for the December 26, 2004 M9+ Sumatra-Andaman Islands earthquake (Ji, 2006) onto a 950 km by 150 km large rupture for the Pacific Northwest model. Simulations were carried out for hypocenters located toward the northern and southern ends of the subduction zone. In addition, we simulated two M8.5 events with a source area of 275 km by 150 km located in the northern and central parts of the model area. The sources for the M8.5 events were generated using the pseudo-dynamic model by Guatteri et al. (2004). All sources used spatially-variable slip, rise time and rupture velocity. Three major metropolitan areas are located in the model region, namely Seattle (3 million+ people), Vancouver (2 million+ people), and Portland (2 million+ people), all located above sedimentary basins amplifying the waves incident from the subduction zone. The estimated peak ground velocities (PGVs) for frequencies less than 0.5 Hz vary significantly with the assumed rise time. Using a mean rise of 32 s, as estimated from source inversion of the 2004 M9+ Sumatra-Andeman event (Ji, 2006), PGVs reached 40 cm/s in Seattle and 10 cm/s in Vancouver and Portland. However, if the mean rise time is decreased to about 14 s, as suggested by the empirical regression by Somerville et al. (1999), PGVs are increased by 2-3 times at these locations. For the Mw8.5 events, PGVs would reach about 10 cm/s in Seattle, and about 5 cm/s in Vancouver and Portland. Combined with extended duration of the shaking exceeding 1 minute for the Mw8.5 events and 2 minutes for the Mw9 events, these long-period ground motions may inflict significant damage on the built environment, in particular on the highrises in downtown Seattle. However, the strongest shaking arrives 1-2 minutes after the earthquake nucleates, indicating that an early warning system in place may help mitigate loss of life in case of a megathrust earthquake in the Pacific Northwest. Additional efforts should analyse the simulated displacements on the ocean bottom for tsunami generation potential.

Olsen, K. B.; Geisselmeyer, A.; Stephenson, W. J.; Mai, P. M.

2007-12-01

213

Characterized Source Model and Strong Ground Motion Simulation for the 2004 Mid Niigata Prefecture (Niigata-ken Chuetsu) Earthquake Based on Empirical Site Amplification and Phase Effects  

NASA Astrophysics Data System (ADS)

In this article, a characterized source model is proposed for the 2004 Mid Niigata Prefecture, Japan, earthquake (MJ=6.8) by using the stochastic Green's function method, taking into account the site specific amplification and phase characteristics. The strong motions are simulated based on the source model with four asperities, referring to the result of waveform inversion. The simulated ground motions are well consistent with the observed records. It is found from the simulation that the large-amplitude velocity-pulses observed at K-NET NIG019 are generated by small asperities nearby the hypocenter. Furthermore, validity of the strong motion simulation technique using site specific phase characteristics is studied. The result indicates the importance of using the site-specific phase characteristics for reliable response analyses of structures.

Sakai, Kimitoshi; Nozu, Atsushi

214

Source Process of the 2007 Niigata-ken Chuetsu-oki Earthquake Derived from Near-fault Strong Motion Data  

NASA Astrophysics Data System (ADS)

The 2007 Niigata-ken Chuetsu-oki earthquake occurred on July 16th, 2007, 10:13 JST. We performed a multi- time window linear waveform inversion analysis (Hartzell and Heaton, 1983) to estimate the rupture process from the near fault strong motion data of 14 stations from K-NET, KiK-net, F-net, JMA, and Niigata prefecture. The fault plane for the mainshock has not been clearly determined yet from the aftershock distribution, so that we performed two waveform inversions for north-west dipping fault (Model A) and south-east dipping fault (Model B). Their strike, dip, and rake are set to those of the moment tensor solutions by F-net. Fault plane model of 30 km length by 24 km width is set to cover aftershock distribution within 24 hours after the mainshock. Theoretical Green's functions were calculated by the discrete wavenumber method (Bouchon, 1981) and the R/T matrix method (Kennett, 1983) with the different stratified medium for each station based on the velocity structure including the information form the reflection survey and borehole logging data. Convolution of moving dislocation was introduced to represent the rupture propagation in an each subfault (Sekiguchi et al., 2002). The observed acceleration records were integrated into velocity except of F-net velocity data, and bandpass filtered between 0.1 and 1.0 Hz. We solved least-squared equation to obtain slip amount of each time window on each subfault to minimize squared residual of the waveform fitting between observed and synthetic waveforms. Both models provide moment magnitudes of 6.7. Regarding Model A, we obtained large slip in the south-west deeper part of the rupture starting point, which is close to Kashiwazaki-city. The second or third velocity pulses of observed velocity waveforms seem to be composed of slip from the asperity. Regarding Model B, we obtained large slip in the southwest shallower part of the rupture starting point, which is also close to Kashiwazaki-city. In both models, we found small slip near the rupture starting point, and largest slip at about ten kilometer in the south-west of the rupture starting point with the maximum slip of 2.3 and 2.5 m for Models A and B, respectively. The difference of the residual between observed and synthetic waveforms for both models is not significant, therefore it is difficult to conclude which fault plane is appropriate to explain. The estimated large-slip regions in the inverted source models with the Models A and B are located near the cross point of the two fault plane models, which should have similar radiation pattern. This situation may be one of the reasons why judgment of the fault plane orientation is such difficult. We need careful examinations not only strong motion data but also geodetic data to further explore the fault orientation and the source process of this earthquake.

Aoi, S.; Sekiguchi, H.; Morikawa, N.; Ozawa, T.; Kunugi, T.; Shirasaka, M.

2007-12-01

215

Joint inversion of strong motion, teleseismic, geodetic, and tsunami datasets for the rupture process of the 2011 Tohoku earthquake  

NASA Astrophysics Data System (ADS)

The 2011 Tohoku earthquake of magnitude 9.0 occurred at 5:46 a.m. on March 11, 2011 (UTC), on the megathrust where the Pacific Plate is subducting below Japan. This earthquake was observed by dense networks of strong motion, teleseismic, geodetic, and tsunami sensors; hence, four types of abundant datasets were produced. Various source models were inferred using one of these datasets [e.g., Ide et al., 2011; Simons et al., 2011; Yoshida et al., 2011; Ozawa et al., 2011; Fujii et al., 2011]. However, these models have somewhat different features from each other because of the limitations peculiar to each dataset. In this study, in order to overcome the differences in each case, a quadruple joint inversion of these datasets was carried out to obtain a final solution. The fault model with a strike of 200° having dimensions of 480 × 180 km2 was used. This model was divided into 96 subfaults of 30 × 30 km2. The dips of these subfaults were set to 20°, 12°, and 5° in every two rows from the relatively deep part. Firstly, we performed a separate inversion of each single dataset using the method of Yoshida et al. [1996] with the revisions of Hikima and Koketsu [2005], and examined the resolution of each single dataset by means of a checkerboard test. For the inversion of the strong motion dataset, Green's functions were calculated using the method of Kohketsu [1985]. We selected 20 K-NET and KiK-net stations. For the inversion of the teleseismic dataset, Green's functions were calculated using the method of Kikuchi and Kanamori [1991]. We selected 45 GSN stations. For the inversion of the geodetic dataset, Green's functions were calculated using the method of Zhu and Rivera [2002]. We used 343 GEONET stations and the seafloor data observed by Sato et al. [2011]. For the inversion of the tsunami dataset, Green's functions were calculated using the method of Fujii and Satake [2007]. We selected the 33 stations. These separate inversion results revealed different source models owing to the limited resolution of each single dataset. In order to overcome differences in these results, we performed a quadruple joint inversion of all datasets. In the obtained source model, the maximum coseismic slip is about 35 m and the total seismic moment was calculated to be 4.2 × 1022 Nm, which yields Mw = 9.0. This result revealed that the main rupture was located around the hypocenter. This rupture propagated not only in the strike direction but also in the dip direction and included both the deep area called the Miyagi-oki region and the compact shallow area near the Japan Trench. This compact shallow area is located within the tsunamigenic slip zone of Koketsu et al. [2011], but our result indicates the rupture there to be a usual fault slip.

Yokota, Y.; Koketsu, K.; Fujii, Y.; Satake, K.; Sakai, S.; Shinohara, M.; Kanazawa, T.

2011-12-01

216

Characterized Fault Model of Scenario Earthquake Caused by the Itoigawa-Shizuoka Tectonic Line Fault Zone in Central Japan and Strong Ground Motion Prediction  

Microsoft Academic Search

Based on the existing ideas on characterizing complex fault rupture process, we constructed four different characterized fault models for predicting strong motions from the most likely scenario earthquake along the active fault zone of the Itoigawa-Shizuoka Tectonic Line in central Japan. The Headquarters for Earthquake Research Promotion in Japanese government (2001) estimated that the earthquake (8 +\\/- 0.5) has the

T. Sato; K. Dan; K. Irikura; M. Furumura

2001-01-01

217

D R A F T Is the strong motion response of a shallow alluvium site in a plain easily foreseeable using standard techniques?  

Microsoft Academic Search

In this applicative work, we try to answer the titl e-question for a typical site (Tomba di Buia) of th e alluvial Friuli Plain (NE Italy) with known stratig raphy and geophysical properties. The strong motion analog recordings taken at the study site in Septem ber 1976 with SMA-1 accelerometers were used for this showing interesting amplifications and deampli fications.

F. Pettenati

218

SEISMIC VULNERABILITY EVALUATION OF URBAN STRUCTURES IN METRO MANILA PART 1: GENERATION OF STRONG GROUND MOTION FROM A SCENARIO EARTHQUAKE OF THE WEST VALLEY FAULT  

Microsoft Academic Search

The West Valley Fault System, which crosses Metro Manila from the south to the north, poses a very important seismic hazard to the city. We performed a broadband frequency strong ground motion simulation in the Metro Manila region, for an outcropping engineering bedrock site condition, based on several fault rupture scenarios and a multi- asperity model. We considered two possible

Nelson Pulido; Bartolome Bautista; Leonila Bautista; Hisakazu Sakai; Hiroshi Arai; Tetsuo Kubo

219

Survey of strong motion earthquake effects on thermal power plants in California with emphasis on piping systems. Volume 1, Main report  

SciTech Connect

Since 1982, there has been a major effort expended to evaluate the susceptibility of nuclear Power plant equipment to failure and significant damage during seismic events. This was done by making use of data on the performance of electrical and mechanical equipment in conventional power plants and other similar industrial facilities during strong motion earthquakes. This report is intended as an extension of the seismic experience data collection effort and a compilation of experience data specific to power plant piping and supports designed and constructed US power piping code requirements which have experienced strong motion earthquakes. Eight damaging (Richter Magnitude 7.7 to 5.5) California earthquakes and their effects on 8 power generating facilities in use natural gas and California were reviewed. All of these facilities were visited and evaluated. Seven fossel-fueled (dual use natural gas and oil) and one nuclear fueled plants consisting of a total of 36 individual boiler or reactor units were investigated. Peak horizontal ground accelerations that either had been recorded on site at these facilities or were considered applicable to these power plants on the basis of nearby recordings ranged between 0.20g and 0.5lg with strong motion durations which varied from 3.5 to 15 seconds. Most US nuclear power plants are designed for a safe shutdown earthquake peak ground acceleration equal to 0.20g or less with strong motion durations which vary from 10 to 15 seconds.

Stevenson, J.D. [Stevenson and Associates, Cleveland, OH (United States)

1995-11-01

220

Inertial effects in the rotationally driven melt motion during the Czochralski growth of silicon crystals with a strong axial magnetic field  

Microsoft Academic Search

This article treats the melt motion driven by the rotations of the crystal and crucible about their common vertical axis during the Czochralski growth of silicon crystals with a strong, uniform, vertical magnetic field produced by a solenoid around the crystal growth furnace. Since molten silicon is an excellent electrical conductor, the interaction parameter N and the Hartmann number Ha

G. Talmage; S.-H. Shyu; J. S. Walker; J. M. Lopez

2000-01-01

221

Inertial effects in the rotationally driven melt motion during the Czochralski growth of silicon crystals with a strong axial magnetic field  

Microsoft Academic Search

This article treats the melt motion driven by the rotations of the crystal and crucible about their common vertical axis during the Czochralski growth of silicon crystals with a strong, uniform, vertical magnetic eld produced by a solenoid around the crystal growth furnace. Since molten silicon is an excellent electrical conductor, the interaction parameter N and the Hart- mann number

G. Talmage; S.-H. Shyu; J. S. Walker; J. M. Lopez

2000-01-01

222

Inertial eects in the rotationally driven melt motion during the Czochralski growth of silicon crystals with a strong axial magnetic eld  

Microsoft Academic Search

This article treats the melt motion driven by the rotations of the crystal and crucible about their common vertical axis during the Czochralski growth of silicon crystals with a strong, uniform, vertical magnetic eld produced by a solenoid around the crystal growth furnace. Since molten silicon is an excellent electrical conductor, the interaction parameter N and the Hart- mann number

G. Talmage; S.-H. Shyu; J. M. Lopez; J. S. Walker

2000-01-01

223

Strong motion envelope modelling of the source of the Chamoli earthquake of March 28, 1999 in the Garhwal Himalaya, India  

NASA Astrophysics Data System (ADS)

Garhwal Himalaya has been rocked by two major earthquakes in the span of just eight years, viz. Uttarkashi earthquake of 20th Oct, 1991 and Chamoli earthquake of 28th March, 1999. Chamoli earthquake of March 28, 1999 was recorded at 11 different stations of a strong motion array installed in the epicentral region. The maximum peak ground acceleration (353 cm/s2) was recorded at an accelerograph located at Gopeshwar. The data from eleven stations has been used for comparison with the simulated acceleration envelopes due to a model of the rupture responsible for this earthquake. For simulation of acceleration envelope the method of Midorikawa (1993) has been modified for its applicability to Himalayan region. This method has earlier been used by Joshi and Patel (1997) and Joshi (1999) for the studyof Uttarkashi earthquake of 20th Oct, 1991. The same method has been used for study of Chamoli earthquake. Layered earth crust has been introduced in place of homogeneous one in this method. The model of rupture is placed at a depth of 12 km below the Munsiari thrust for modelling Chamoli earthquake. Peak ground acceleration was calculated from simulated acceleration envelope using layered as well as homogeneous earth crust. For the rupture placed in a layered crust model peak ground acceleration of order 312 cm/s2 was simulated at Gopeshwar which is quite close to actually recorded value. The comparison of peak ground acceleration values in terms of root mean square error at eleven stations suggests that the root mean square error is reduced by inclusion of a layered earth crust in place of homogeneous earth crust.

Joshi, A.

224

Country Analysis Briefs: Taiwan.  

National Technical Information Service (NTIS)

Located across the Taiwan Strait from mainland China, Taiwan is an important economic and trading center, with one of the busiest ports in the world (Kaohsiung). As Taiwan lacks sufficient domestic energy sources, it is almost totally dependent on energy ...

2008-01-01

225

Comparison of the Inelastic Response of Steel Building Frames to Strong Earthquake and Underground Nuclear Explosion Ground Motion.  

National Technical Information Service (NTIS)

Analytic studies were made of the adequacy of simulating earthquake effects at the Nevada Test Site for structural testing purposes. It is concluded that underground nuclear explosion ground motion will produce inelastic behavior and damage comparable to ...

R. C. Murray F. J. Tokarz

1976-01-01

226

Strong-Motion Earthquake Accelerograms. Digitized and Plotted Data. Volume I. Uncorrected Accelerograms. Part C. Accelerograms IC041 through IC055. Accelerograms from the San Fernando, California, Earthquake of Feb ruary 9, 1971.  

National Technical Information Service (NTIS)

Contents: Instrument characteristics for the San Fernando Earthquake; Earthquake data and references; Reproduction of the Pacoima Dam strong motion accelerogram; Print-out of accelerograms; Plots of accelerograms.

1971-01-01

227

Some Key Features of the Strong-Motion Data from the M 6.0 Parkfield, California, Earthquake of 28 September 2004  

USGS Publications Warehouse

The 2004 Parkfield, California, earthquake was recorded by an extensive set of strong-motion instruments well positioned to record details of the motion in the near-fault region, where there has previously been very little recorded data. The strong-motion measurements obtained are highly varied, with significant variations occurring over only a few kilometers. The peak accelerations in the near fault region range from 0.13g to over 1.8g (one of the highest acceleration recorded to date, exceeding the capacity of the recording instrument The largest accelerations occurred near the northwest end of the inferred rupture zone. These motions are consistent with directivity for a fault rupturing from the hypocenter near Gold Hill toward the northwest. However, accelerations up to 0.8g were also observed in the opposite direction, at the south end of the Cholame Valley near Highway 41, consistent with bilateral rupture, with rupture southeast of the hypocenter. Several stations near and over the rupturing fault recorded relatively weak motions, consistent with seemingly paradoxical observations of low shaking damage near strike-slip faults. This event had more ground-motion observations within 10 km of the fault than many other earthquakes combined. At moderate distances peak horizontal ground acceleration (PGA) values dropped off more rapidly with distance than standard relationships. At close-in distance the wide variation of PGA suggests a distance-dependent sigma may be important to consider. The near-fault ground-motion variation is greater than that assumed in ShakeMap interpolations, based on the existing set of observed data. Higher density of stations near faults may be the only means in the near future to reduce uncertainty in the interpolations. Outside of the near-fault zone the variance is closer to that assumed. This set of data provides the first case where near-fault radiation has been observed at an adequate number of stations around the fault to allow detailed study of the fault-normal and fault-parallel motion and the near-field S-wave radiation. The fault-normal motions are significant, but they are not large at the central part of the fault, away from the ends. The fault-normal and fault-parallel motions drop off quite rapidly with distance from the fault. Analysis of directivity indicates increased values of peak velocity in the rupture direction. No such dependence is observed in the peak acceleration, except for stations close to the strike of the fault near and beyond the ends of the faulting.

Shakal, A.; Haddadi, H.; Graizer, V.; Lin, K.; Huang, M.

2006-01-01

228

Rupture process and strong ground motions of the 2007 Niigataken Chuetsu-Oki earthquake -Directivity pulses striking the Kashiwazaki-Kariwa Nuclear Power Plant-  

NASA Astrophysics Data System (ADS)

The Niigataken Chuetsu-Oki earthquake occurred on July 16, 2007, northwest-off Kashiwazaki in Niigata Prefecture, Japan, causing severe damages of ten people dead, about 1300 injured, about 1000 collapsed houses and major lifelines suspended. In particular, strong ground motions from the earthquake struck the Kashiwazaki-Kariwa nuclear power plant (hereafter KKNPP), triggering a fire at an electric transformer and other problems such as leakage of water containing radioactive materials into air and the sea, although the radioactivity levels of the releases are as low as those of the radiation which normal citizens would receive from the natural environment in a year. The source mechanism of this earthquake is a reverse fault, but whether it is the NE-SW strike and NW dip or the SW-NE strike and SE dip are still controversial from the aftershock distribution and geological surveys near the source. Results of the rupture processes inverted by using the GPS and SAR data, tsunami data and teleseismic data so far did not succeed in determining which fault planes moved. Strong ground motions were recorded at about 390 stations by the K-NET of NIED including the stations very close to the source area. There was the KKNPP which is probably one of buildings and facilities closest to the source area. They have their own strong motion network with 22 three-components' accelerographs locating at ground-surface, underground, buildings and basements of reactors. The PGA attenuation-distance relationships made setting the fault plane estimated from the GPS data generally follow the empirical relations in Japan, for example, Fukushima and Tanaka (1990) and Si and Midorikawa (1999), even if either fault plane, SE dip or NW dip, is assumed. However, the strong ground motions in the site of the KKNPP had very large accelerations and velocities more than those expected from the empirical relations. The surface motions there had the PGA of more than 1200 gals and even underground motions at the basements of the reactors locating five stories below the ground had the PGA of 680 gals. We simulated ground motions using the characterized source model (Kamae and Irikura, 1998) with three asperities and the empirical Green's function method (Irikura, 1986). Then, we found that the source model should be a reverse fault with the NE-SW strike and NW dip to explain the strong motion records obtained near the source area. In particular, strong ground motions in the site of the KKNPP had three significant pulses which are generated as directivity pulses in forward direction of rupture propagation. This is the reason why the strong ground motions in the site of the KKNPP had very large accelerations and velocities. The source model is also verified comparing the observed records at the KKNPP with the numerical simulations by the discrete wavenumber method (Bouchon, 1981).

Irikura, K.; Kagawa, T.; Miyakoshi, K.; Kurahashi, S.

2007-12-01

229

Evaluation of Relative Site Amplification Factors by Combining Average Spectral Ratios of Strong Ground Motions Simultaneously Observed at Adjacent Two Sites  

NASA Astrophysics Data System (ADS)

A new method to evaluate relative site amplification factors (RSF) of strong motion sites scattered in a wide area without assumption of attenuation functions is proposed. In this method RSF between adjacent two sites is evaluated by average spectral ratio of strong ground motions simultaneously observed at those two sites. RSF of distant sites are estimated by least squares method, combining RSF of adjacent sites in the network consists of adjacent site pairs in the area. This method is applied to K-NET and KiK-net sites in the Pacific coast side of Tohoku district. Evaluated RSF between adjacent sites are interpreted by theoretical amplification factors based on one dimensional wave theory. Relations of the evaluated RSF with geological condition, and with those estimated by spectral inversion analysis are discussed.

Ikeura, Tomonori; Kato, Kenichi

230

Application of bounding spectra to seismic design of piping based on the performance of above ground piping in power plants subjected to strong motion earthquakes  

SciTech Connect

This report extends the potential application of Bounding Spectra evaluation procedures, developed as part of the A-46 Unresolved Safety Issue applicable to seismic verification of in-situ electrical and mechanical equipment, to in-situ safety related piping in nuclear power plants. The report presents a summary of earthquake experience data which define the behavior of typical U.S. power plant piping subject to strong motion earthquakes. The report defines those piping system caveats which would assure the seismic adequacy of the piping systems which meet those caveats and whose seismic demand are within the bounding spectra input. Based on the observed behavior of piping in strong motion earthquakes, the report describes the capabilities of the piping system to carry seismic loads as a function of the type of connection (i.e. threaded versus welded). This report also discusses in some detail the basic causes and mechanisms for earthquake damages and failures to power plant piping systems.

Stevenson, J.D. [Stevenson and Associates, Cleveland, OH (United States)

1995-02-01

231

A note on the L’Aquila earthquake of 6 April 2009: Permanent ground displacements obtained from strong-motion accelerograms  

Microsoft Academic Search

On 6 April 2009, 01:32 GMT, an Mw 6.3 earthquake hit the Abruzzi region of central Italy causing widespread damage in the City of L’Aquila and its nearby villages. The mainshock of this earthquake was recorded by 57 digital strong-motion instruments, four of which are located on the hanging wall of the Paganica Fault near L’Aquila. These stations are no

R. Rupakhety; R. Sigbjörnsson

2010-01-01

232

Strong motion simulation by the composite source modeling: A case study of 1679 M 8.0 Sanhe-Pinggu earthquake  

Microsoft Academic Search

In this study, a composite source model has been used to calculate the realistic strong ground motions in Beijing area, caused\\u000a by 1679 M\\u000a S8.0 earthquake in Sanhe-Pinggu. The results could provide us the useful physical parameters for the future seismic hazard\\u000a analysis in this area. Considering the regional geological\\/geophysical background, we simulated the scenario earthquake with\\u000a an associated ground

Bo-Yan Liu; Bao-Ping Shi; Jian Zhang

2007-01-01

233

Rupture process and strong ground motions of the 2007 Niigataken Chuetsu-Oki earthquake Directivity pulses striking the Kashiwazaki-Kariwa Nuclear Power Plant  

Microsoft Academic Search

The Niigataken Chuetsu-Oki earthquake occurred on July 16, 2007, northwest-off Kashiwazaki in Niigata Prefecture, Japan, causing severe damages of ten people dead, about 1300 injured, about 1000 collapsed houses and major lifelines suspended. In particular, strong ground motions from the earthquake struck the Kashiwazaki-Kariwa nuclear power plant (hereafter KKNPP), triggering a fire at an electric transformer and other problems such

K. Irikura; T. Kagawa; K. Miyakoshi; S. Kurahashi

2007-01-01

234

Rupture history of September 30, 1999 intraplate earthquake of Oaxaca, Mexico (MW=7.5) from inversion of strong-motion data  

Microsoft Academic Search

Near-source strong motions are inverted to estimate the rupture history of intraslab, normal-faulting September 30, 1999, Oaxaca, Mexico earthquake. Two focal mechanisms (Harvard and NEIC CMT solutions) are tested for the source geometry. The inversion with the NE dipping fault plane of the Harvard solution best matches the data (strike=295°, dip=50°, rake=-82°). We estimated the slip distribution on the fault

B. Hernandez; N. M. Shapiro; S. K. Singh; J. F. Pacheco; F. Cotton; M. Campillo; A. Iglesias; V. Cruz; J. M. Gómez; L. Alcántara

2001-01-01

235

ESTIMATION OF STRONG GROUND MOTIONS IN MEXICO CITY EXPECTED FOR LARGE EARTHQUAKES IN THE GUERRERO SEISMIC GAP  

Microsoft Academic Search

We performed simulations of ground motions in Mexico City expected for large earthquakes in the Guerrero seismic gap in Mexico. The simulation method uses as empirical Green's functions the accelerograms recorded in Mexico City during four small to moderate earthquakes (8 Feb. 1988, M s = 5.8; 25 April 1989, M w = 6.9; 11 May 1990, M w =

HIROO KANAMORI; PAUL C. JENNINGS; SHRI KRISHNA SINGH; LUCIANA ASTIZ

1993-01-01

236

Predicting strong motion parameters for the Chamoli earthquake of 28th March, 1999, Garhwal Himalaya, India, from simplified finite fault model  

NASA Astrophysics Data System (ADS)

State of Uttaranchal in the northern part of India in the Garhwal Himalaya was hit by the Chamoli earthquake on 28th March, 1999 (GMT). This earthquake was recorded on a strong motion array installed in this region. The maximum peak ground acceleration of 353 cm/sec2 was recorded at an accelerograph located at the Gopeshwar station at an approximate epicentral distance of 14 km. The simplified method of Midorikawa (1993) has been used to model finite fault responsible for causing the Chamoli earthquake. This method is based on the Empirical Green's Function (EGF) technique of Irikura (1986).Modifications in this method have been made to include layered earth model and transmission effects at each boundary by Joshi (2001). Rupture causing the Chamoli earthquake is placed in two structural models of the earth in this work: one is a homogeneous half space and other is the multi layered earth model. Comparison in terms of root mean square error (RMSE) is made between the simulated and actual strong motion parameters like peak acceleration and duration. It is seen that the introduction of multi layered earth system in this simplified technique is capable of significantly reducing the RMSE in observed and predicted strong motion parameters and defining the attenuation rate for peak ground acceleration of this earthquake.

Joshi, A.

237

EARTHQUAKE RESPONSE ANALYSES OF A LEVEE USING STRONG MOTION RECORD DURING THE 2011 OFF THE PACIFIC COAST OF TOHOKU EARTHQUAKE  

NASA Astrophysics Data System (ADS)

Time history records of ground acceleration and pore water pressure were obtained at a levee during the 2011 off the Pacific coast of Tohoku earthquake. The earthquake response of the levee is simulated by 1-D equivalent linear analysis and 1-D effective stress analysis using the ground motion recorded in the base layer as input motion. Frequency dependence of effective shear strain is taken into account to reproduce short period component of the response by the 1-D equivalent linear analysis. Hydrodynamic pressure and dissipation of pore water pressure are not reproduced by the 1-D effective stress analysis; freezing soil sampling and 2-D simulation may be required for improving the analytical results.

Matsuoka, Kazunari; Kataoka, Shojiro; Nagaya, Kazuhiro; Kaneko, Masahiro

238

Distributed system for strong motion data retrieval and archiving : metadata, databases and data exchange within the NA5 framework  

NASA Astrophysics Data System (ADS)

The goal of the NERIES NA5 activity (http://www.neries-eu.org, Improving Accelerometric Data Access) is the development of common access to equally formatted event based accelerometric data and to the corresponding sheet of strong motion parameters. The core of the NA5 is made of 5 European institutes and the final protocol should permit other European institutes to integrate the NA5 portal. More precisely, the aim of the NA5 distributed data system is (1) to make available the data in a in specific format for the engineering community (i.e., ASCII) and in standard format for the seismological community (i.e. full SEED, SAC) and (2) to retrieve data at an unique portal on seismological and - accelerometric criteria, using relations between seismic sources and recordings and using specific parameters for the engineering community, i.e. site conditions and parameter thresholds (e.g., PGA, Ia, Duration, Sa(T), Sv(T)…). Parametric data as well as the procedures to compute them have been defined, implemented and make avalaible for all the NA5 partners. The final product will be a system based on a distributed '3 tiers' architecture, the three main nodes of which are : (1) the primary data servers of NA5 data providers, who make available waveforms (in ascii format) and the associated parameters and events-records tables, via ftp or http protocols (2) the NA5 portal, which supports metadata databases (events and stations metadata) and the associated user interfaces and webservices (3) the NA5 dataserver, the main function of which is the evaluation of the end-users requests, involving data retrieval, data conversion (sac, ascii and miniseed) and metadata formatting (sac, ascii and seed headers). Both NA5 portal and NA5 dataserver are presently under development, the former at EMSC, the latter at LGIT. Our presentation will point out the main features and resources of the NA5 dataserver : - a database of the instrument response files for the accelerometric channels (coefficient, poles and zeros) called PZ database has been set up, as well as some database maintenance tools. The PZ database is hierarchically structured into three directories : sensor, ana_filter and digitizer. - user requests are materialized by a specific xml structure generated at the portal and pushed to the dataserver via QWID/EIDS (Earthquake Information Distribution System). A NA5 xml request contains all the information (metadata) needed for its evaluation : requested data files matching the user search criteria are described by their URL, their network, site of installation and acquisition channel, the events and hypocentral informations they are linked to, as well as values of the parametric data. - the NA5 server notifies a xml parser, which checks and compiles the structure and store the information into an internal permanent relational metadata database. This database and the PZ directory are linked together by the way of a dedicated table, which contains directories and files names. Thus, the NA5 dataserver database will progressively be filled up by values carried on by NA5 requests. - once a request has been loaded into the database, the NA5 archiver process will then fork into four different sub-processes, each of them calling the internal database to get value(s) for its parameters : (a) get the ascii native waveforms files by downloading their URL if needed, i-e if the data are not already stored in the local cache, convert them into sac binary and miniseed (if needed, ie if miniseed files have not already been generated for this native waveforms files). (b) build the linked seed dataless, if the PZ files for these channels are available. (c) build the headers files (such headers will contain some more specific information about event, site condition and soil classification, max accelaration, aso. ) (d) pack the parametric data before archiving and compressing the result. The archiver process will end by filling up and re-writing the xml request file with updated information (archive URL for download, waveforms found and packed, size, etc.),

Pequegnat, C.; Gueguen, P.; Jacquot, R.

2009-04-01

239

Strong motion simulation by the composite source modeling: A case study of 1679 M8.0 Sanhe-Pinggu earthquake  

NASA Astrophysics Data System (ADS)

In this study, a composite source model has been used to calculate the realistic strong ground motions in Beijing area, caused by 1679 M S8.0 earthquake in Sanhe-Pinggu. The results could provide us the useful physical parameters for the future seismic hazard analysis in this area. Considering the regional geological/geophysical background, we simulated the scenario earthquake with an associated ground motions in the area ranging from 39.3°N to 41.1°N in latitude and from 115.35°E to 117.55°E in longitude. Some of the key factors which could influence the characteristics of strong ground motion have been discussed, and the resultant peak ground acceleration (PGA) distribution and the peak ground velocity (PGV) distribution around Beijing area also have been made as well. A comparison of the simulated result with the results derived from the attenuation relation has been made, and a sufficient discussion about the advantages and disadvantages of composite source model also has been given in this study. The numerical results, such as the PGA, PGV, peak ground displacement (PGD), and the three-component time-histories developed for Beijing area, have a potential application in earthquake engineering field and building code design, especially for the evaluation of critical constructions, government decision making and the seismic hazard assessment by financial/insurance companies.

Liu, Bo-Yan; Shi, Bao-Ping; Zhang, Jian

2007-05-01

240

Excitation of Radial Ion Motion in an rf-Only Multipole Ion Guide Immersed in a Strong Magnetic Field Gradient  

Microsoft Academic Search

Radiofrequency (rf) multipole ion guides are widely used to transfer ions through the strong magnetic field gradient between\\u000a source and analyzer regions of external source Fourier transform ion cyclotron resonance mass spectrometers. Although ion\\u000a transfer as determined solely by the electric field in a multipole ion guide has been thoroughly studied, transfer influenced\\u000a by immersion in a strong magnetic field

Steven C. Beu; Christopher L. Hendrickson; Alan G. Marshall

2011-01-01

241

Deep Borehole Instrumentation Along San Francisco Bay Bridges: 1996 - 2003 and Strong Ground Motion Systhesis Along the San Francisco/Oakland Bay Bridge  

SciTech Connect

As a result of collaboration between the Berkeley Seismographic Station, Lawrence Livermore National Laboratory, and Caltrans, instrument packages have been placed in bedrock in six boreholes and two surface sites along the San Francisco/Oakland Bay Bridge. Since 1996 over 200 local earthquakes have been recorded. Prior to this study few seismic recording instruments existed in bed-rock in San Francisco Bay. We utilized the data to perform analysis of ground motion variability, wave passage, site response, and up-and down-hole wave propagation along the Bay Bridge. We also synthesized strong ground motion at nine locations along the Bay Bridge. Key to these studies is LLNL's effort to exploit the information available in weak ground motions (generally from earthquakes < M=4.0) to enhance predictions of seismic hazards. We found that Yerba Island has no apparent site response at the surface relative to a borehole site. The horizontal to vertical spectral ratio method best revealed no site response, while the complex signal spectral ratio method had the lowest variance for spectral ratios and best predicted surface recordings when the borehole recording was used as input. Both methods identified resonances at about the same frequencies. Regional attenuation results in a significant loss of high frequencies in both surface and borehole recordings. Records are band limited at near 3 Hz. Therefore a traditional rock outcrop site response, flat to high frequency in displacement, is not available. We applied a methodology to predict and synthesize strong ground motion along the San Francisco/Oakland Bay Bridge from a M=7.25 earthquake along the Hayward fault, about12 km distant. We synthesized for three-components and broad-band (0.0-25.0 Hz) ground motion accelerations, velocities, and displacements. We examined two different possible rupture scenarios, a ''mean'' and ''one standard deviation'' model. We combined the high frequency calculations (Hz > 0.7) based on empirical Green's functions with finite difference calculations for frequencies less than 0.7 Hz. We found that in the near-source region, far-field shear-wave generation and near-field tectonic ground displacements can result in very large long period ground displacements and velocity pulses. Far-field arrivals have the strongest energy in periods of about 2 to 5 s, and near-field arrivals have the strongest energy in periods of about 5 to 10 s. Much of these near-source ground motions would not be observed by conventional strong motion recording systems, which typically are high-pass band limited at 2-5 s periods, and therefore have not been included as standard practice structural input ground motions. For some fault rupture scenarios, the large tectonic displacement pulse would initially drive the bridge with motions parallel to tectonic fault displacement, and before the bridge would start to rebound, the far-field S-wave would arrive and drive the bridge in the opposite direction. This type of multiple long-period modal response can occur in other long period structures such as base-isolated systems and tall buildings.

Hutchings, L; Foxall, W; Kasameyer, P; larsen, S; Hayek, C; Tyler-Turpin, C; Aquilino, J; Long, L

2005-04-22

242

Strong-motion, site-effects and hazard issues in rebuilding Turkey: In light of the 17 August, 1999 earthquake and its aftershocks  

USGS Publications Warehouse

The August 17, 1999 Izmit (Turkey) earthquake (Mw=7.4) will be remembered as one of the largest earthquakes of recent times that affected a large urban environment (U.S. Geological Survey, 1999). The shaking that caused the widespread damage and destruction was recorded only by a handful of accelerographs in the earthquake area operated by different networks. The characteristics of these records show that the recorded peak accelerations, even those from near field stations, are smaller than expected. On the other hand, smaller magnitude aftershocks yielded larger peak accelerations. This is attributed to the sparse networks, which possibly missed recording of larger motions during the main shock. As rebuilding of Turkey starts, strong-motion networks that yield essential data must be enlarged. In addition, attention must be paid to new developments elsewhere, such as earthquake zoning maps, earthquake hazard maps, liquefaction potentials and susceptibility. This paper aims to discuss these issues. Copyright??2000 IAHS.

Celebi, M.; Toprak, S.; Holzer, T.

2000-01-01

243

English speakers attend more strongly than Spanish speakers to manner of motion when classifying novel objects and events.  

PubMed

Three experiments provide evidence that the conceptualization of moving objects and events is influenced by one's native language, consistent with linguistic relativity theory. Monolingual English speakers and bilingual Spanish/English speakers tested in an English-speaking context performed better than monolingual Spanish speakers and bilingual Spanish/English speakers tested in a Spanish-speaking context at sorting novel, animated objects and events into categories on the basis of manner of motion, an attribute that is prominently marked in English but not in Spanish. In contrast, English and Spanish speakers performed similarly at classifying on the basis of path, an attribute that is prominently marked in both languages. Similar results were obtained regardless of whether categories were labeled by novel words or numbered, suggesting that an English-speaking tendency to focus on manner of motion is a general phenomenon and not limited to word learning. Effects of age of acquisition of English were also observed on the performance of bilinguals, with early bilinguals performing similarly in the 2 language contexts and later bilinguals showing greater contextual variation. PMID:20853990

Kersten, Alan W; Meissner, Christian A; Lechuga, Julia; Schwartz, Bennett L; Albrechtsen, Justin S; Iglesias, Adam

2010-11-01

244

Source Rupture Process for the February 21, 2011, Mw6.1, New Zealand Earthquake and the Characteristics of Near-field Strong Ground Motion  

NASA Astrophysics Data System (ADS)

The New Zealand Earthquake of February 21, 2011, Mw 6.1 occurred in the South Island, New Zealand with the epicenter at longitude 172.70°E and latitude 43.58°S, and with depth of 5 km. The Mw 6.1 earthquake occurred on an unknown blind fault involving oblique-thrust faulting, which is 9 km away from southern of the Christchurch, the third largest city of New Zealand, with a striking direction from east toward west (United State Geology Survey, USGS, 2011). The earthquake killed at least 163 people and caused a lot of construction damages in Christchurch city. The Peak Ground Acceleration (PGA) observed at station Heathcote Valley Primary School (HVSC), which is 1 km away from the epicenter, is up to almost 2.0g. The ground-motion observation suggests that the buried earthquake source generates much higher near-fault ground motion. In this study, we have analyzed the earthquake source spectral parameters based on the strong motion observations, and estimated the near-fault ground motion based on the Brune's circular fault model. The results indicate that the larger ground motion may be caused by a higher dynamic stress drop,??d , or effect stress drop named by Brune, in the major source rupture region. In addition, a dynamical composite source model (DCSM) has been developed to simulate the near-fault strong ground motion with associated fault rupture properties from the kinematic point of view. For comparison purpose, we also conducted the broadband ground motion predictions for the station of HVSC; the synthetic seismogram of time histories produced for this station has good agreement with the observations in the waveforms, peak values and frequency contents, which clearly indicate that the higher dynamic stress drop during the fault rupture may play an important role to the anomalous ground-motion amplification. The preliminary simulated result illustrated in at Station HVSC is that the synthetics seismograms have a realistic appearance in the waveform and time duration to the observations, especially for the vertical component. Synthetics Fourier spectra are reasonably similar to the recordings. The simulated PGA values of vertical and S26W components are consistent with the recorded, and for the S64E component, the PGA derived from our simulation is smaller than that from observation. The resultant Fourier spectra both for the synthetic and observation is much similar with each other for three components of acceleration time histories, except for the vertical component, where the derived spectra from synthetic data is smaller than that resultant from observation when the frequency is above 10 Hz. Both theoretical study and numerical simulation indicate that, for the 2011 Mw 6.1, New Zealand Earthquake, the higher dynamic stress drop during the source rupture process could play an important role to the anomalous ground-motion amplification beside to the other site-related seismic effects. The composite source modeling based on the simple Brune's pulse model could approximately provide us a good insight into earthquake source related rupture processes for a moderate-sized earthquake.

Meng, L.; Shi, B.

2011-12-01

245

Application of an iterative least-squares waveform inversion of strong-motion and teleseismic records to the 1978 Tabas, Iran, earthquake  

USGS Publications Warehouse

An iterative least-squares technique is used to simultaneously invert the strong-motion records and teleseismic P waveforms for the 1978 Tabas, Iran, earthquake to deduce the rupture history. The effects of using different data sets and different parametrizations of the problem (linear versus nonlinear) are considered. A consensus of all the inversion runs indicates a complex, multiple source for the Tabas earthquake, with four main source regions over a fault length of 90 km and an average rupture velocity of 2.5 km/sec. -from Authors

Hartzell, S.; Mendoza, C.

1991-01-01

246

Estimation of Strong Ground Motion from a Great Earthquake Mw 8.5 in Central Seismic Gap Region, Himalaya (India) Using Empirical Green's Function Technique  

NASA Astrophysics Data System (ADS)

In the present study ground motions for a Mw 8.5 scenario earthquake are estimated at 13 sites in Kumaun-Garhwal region using the empirical Green's function technique. The recordings of 1991 Uttarkashi earthquake of Mw 6.8 at these sites are used as an element earthquake. A heterogeneous source model consisting of two asperities is considered for simulating the ground motions. The entire central seismic gap (CSG) can expect acceleration in excess of 100 cm/s2 with NW portion in excess of 400 cm/s2 and SE between 100 and 200 cm/s2. The central portion can expect peak ground acceleration (PGA) between 200 and 400 cm/s2. It has been observed from simulation of strong ground motion that sites located near the rupture initiation point can expect accelerations in excess of 1g. In the present analysis, Bhatwari and Uttarkashi can expect ground accelerations in excess of 1g. The estimates of the PGA are compared with earlier studies in the same region using different methodologies and it was found that the results are comparable. This has put constrains on the expected PGAs in this region. The obtained PGA values can be used in identifying the vulnerable areas in the central Himalaya, thereby facilitating the planning, design and construction of new structures and strengthening of the existing structures in the region.

Sharma, Babita; Chopra, Sumer; Sutar, Anup Kumar; Bansal, B. K.

2013-02-01

247

Integrated System for Earthquake Early Warning and Quick Response Against Strong Motion - In Case of the Tokyo Metro Company  

NASA Astrophysics Data System (ADS)

In July 2005, an earthquake of M6.0 attacked the Tokyo metropolitan area. This earthquake occurred at 35.5N and 140.2E with about 73km in depth, and the maximum JMA intensity was 5+ corresponding to MMI VIII approximately. This earthquake occurred at north-west of Chiba prefecture and caused a traffic disturbance widely in Tokyo metropolitan area. All the train operation had been stopped for a long time after the earthquake, although a severe damage was not caused even in the area of high intensity. The longest down time for the train operation was more than seven hours. After the earthquake, we proposed a new system for early warning and quick response. Tokyo Metro Company accepted our proposal, and we replaced and built the new early warning/quick response system as followed. The system consists of two seismometer networks. One is the early warning system FREQL network with six seismometers to control or stop the train operation immediately after the earthquake occurrence. And the other is the portable digital seismometer AcCo network distributing 33 seismometers in every about three kilometers mesh to grasp more detailed seismic motion on their service area. The information from both FREQL network and AcCo network are gathered to the operation center and displayed on the individual monitoring system. The monitoring system for AcCo can indicate the integrated information from AcCo and FREQL on the subway network image. The AcCo monitoring system is also installed on the control table for each subway line. At the time of the earthquake, the early warning system detects at first the earthquake immediately and then the 33 local seismometers inform the actual earthquake motion of each site independently and rapidly. This system realized quick response and restart of the train operation because the early warning became faster and checking zone after earthquake was optimized. This updated system is expected to realize quicker response during and after. For the large system as the train operation, it is necessary for the control against the earthquake to equip the system not only to issue the early warning but also to support the quick and rational recovery work after the earthquake.

Sato, T.; Saita, J.; Nakamura, Y.

2007-12-01

248

Nanotechnologies in Taiwan.  

National Technical Information Service (NTIS)

The purpose of our visit was to promote the Taiwan AFOSR Nanoscience Initiative and encourage white papers for review and consideration of rfp (request for proposal) from the institutions visited. The goal of the Taiwan AFOSR Nanoscience Initiative is to ...

F. L. Madarasz

2002-01-01

249

Rupture process of 2009 Mw 8.1 Samoa earthquake constrained by joint inverting teleseismic body, surface waves and local strong motion  

NASA Astrophysics Data System (ADS)

The 2009 Mw 8.1 Samoa earthquake occurred in the outer rise region of the Tonga subduction zone where the pacific plane subducts down the Australia plane in a speed of 9 cm/s to the west. This event is the largest earthquake in year 2009 and also the largest normal fault earthquake since the 2007 Mw 8.1 Kuril island earthquake. The Tsunami excited by this event killed nearly 200 people. Unlike other magnitude 8 earthquakes, there were big controversies among the preliminary seismological solutions in terms of the size of non-double couple component and the causative fault plane. Here, we intend to better constrain the rupture process of this earthquake with the additional strong motion record at GSN station AFI, 178 km away from the hypocenter. Our preliminary result shows that combined dataset including teleseismic P, SH, surface waves and AFI strong motion records favors a causative fault plane striking 345° and dipping 54° northeast, consistent with the preliminary USGS finite fault solution; but if we only use the teleseismic P waves, the conjugate fault plane striking 124 degrees and dipping southwest is the optimal, agreeing with Dr. Yagi's solution. The major slip located in the northwest of hypocenter, regardless of the choice of the preferred nodal plane

Li, X.; Shao, G.; Ji, C.

2009-12-01

250

Taiwan: Background Notes Series.  

ERIC Educational Resources Information Center

|Concise background information on Taiwan is provided. The publication begins with a profile of Taiwan, discussing the people, geography, political establishment, and economy. A map of the country is provided. The bulk of the publication then provides more detailed information on Taiwan's people, geography, history, administration, political…

Reams, Joanne Reppert

251

Taiwan, Rose or Thorn.  

National Technical Information Service (NTIS)

The ramifications of the present status quo and the future of Taiwan as it affects the major powers of the Western Pacific is examined. A free Taiwan versus a Chinese Taiwan is examined in relation to Japanese, Russian, Chinese, and US national interests ...

C. Q. Shelton

1974-01-01

252

Rupture-process images deduced from array back-projection analysis using data of a dense strong ground-motion seismograph network  

NASA Astrophysics Data System (ADS)

An M6.5 earthquake occurred beneath Suruga Bay on 11 August 2009. Japanese seismic intensity scale 6- was recorded near the source region. The earthquake on 11 August occurred in the Philippine Sea plate which subducts beneath the Tokai region on the Suruga Trough and the mechanism was estimated as a thrust-type with strike-slip components. The rupture area is within the expected source region of the so-called M8 Tokai earthquake. Although strong ground motions were observed widely around the source area, it is difficult to recover the rupture process by the waveform inversions in detail, because magnitude of the earthquake is not so large and the dominant frequency is outside of suitable range for the waveform inversions. In this study, we estimated the rupture process by performing an array back-projection analysis (e.g., Honda and Aoi, 2009). A strong ground motion seismograph network has been deployed in Hakone caldera about 40 km to the northeast from the source region. The seismograph network was regarded as a dense array. Hereafter, we call the array as HK-net. Resolution of the analysis is affected by the array size. Seismographs of HK-net are distributed extensively in Hakone caldera whose diameter is about 10 km and the site separations in HK-net are less than 1 km. We expected that this array configuration is appropriate for the analysis using the waveforms whose frequency range is higher than 1 Hz. The waveforms are band-pass filtered in the frequency range of 0.5-5Hz and integrated into velocity. We adopted the hypocenter determined by NIED (138.502, 34.805, 21.6km) and took the nodal plane dipping south-eastward as the fault plane on which the hypocenter was located, although aftershocks were also seen to have been distributed on another plane dipping northeastward. Two peaks appeared in strong ground motion records observed in HK-net and this means there are two sources (asperities) on the fault. In order to determine the sources of the pulses, semblance-enhanced waveform stacking was performed. By projecting the power of the stacked waveforms on to the fault plane, two asperities that generated significant pulses were successfully imaged at the hypocenter and the northwestern edge of the fault, respectively. The rupture seems to have started at the hypocenter and propagated unilaterally toward the northwestern edge of the fault. These results agree with the fact that two pulses were observed only at the eastern side of the source region but not observed at the western side, which is reasonable if the directivity effect is taken into account.

Honda, R.; Yukutake, Y.; Tanada, T.; Yoshida, A.

2009-12-01

253

Rupture process and wave radiation characteristics of the 2011 Tohoku-Oki mega-thrust earthquake examined using the strong-motion data  

NASA Astrophysics Data System (ADS)

The 2011 Tohoku-Oki earthquake is the first M9 earthquake that has been recorded by the dense strong-motion networks in the near-fault region. The strong-motion waveforms obtained by the two nation-wide networks, K-NET and KiK-net operated by the National Research Institute for Earth Science and Disaster Prevention (Aoi et al., 2011, Kunugi et al., 2011, this meeting), can provide the detailed information about the source of the mega-thrust earthquake. As a first step to elucidating the generation mechanism of this devastating earthquake that caused the severe ground shaking and catastrophic tsunami, we derive the rupture process using the relatively low-frequency (0.01-0.125 Hz) strong-motion data. We performed the multi-time-window linear waveform inversion analysis. The derived slip model has one prominent large slip area extending from the area around the hypocenter to the shallow part of the fault plane along the trench axis. This shallow large slip area is located far off southern Iwate, Miyagi, and northern Fukushima prefectures, where the tsunami damage was huge. The rupture of this area started 60 s after the initial break with a long duration of 40 s. This rupture event radiated the seismic waves rich in very low-frequency content. The deep portion of the fault between the hypocenter and the coast of Miyagi prefecture experienced the two down-dip rupture events in 20-50 s and 60-100 s, which largely contributed to the waveform synthesis at the stations to the west of the central part of the fault plane although the slip there is relatively small compared to the shallow slip area along the trench axis. Particularly, the second rupture event makes a significant contribution to the phase with largest amplitude. The shallow large slip also contributes to this largest amplitude phase. The former and latter make contribution in relatively high and low frequency ranges, respectively. Rupture after 100 s propagated in the southern part of the fault and generated the distinct phase observed in the southern stations. We also examine the frequency dependency of the wave radiation process considering the features of the observed acceleration waveforms.

Suzuki, W.; Aoi, S.; Sekiguchi, H.; Kunugi, T.

2011-12-01

254

Numerical Simulation of Strong Ground Motion for the Ms 8.0 Wenchuan Earthquake of 12 May 2008 With Realistic Surface Topography  

NASA Astrophysics Data System (ADS)

The Wenchuan earthquake of 12 May 2008 is the most destructive earthquake in China in the past 30 years in terms of property damage and human losses. In order to understand the earthquake process and the geo- morphological factors affecting the seismic hazard, we simulated the strong ground motion caused by the earthquake, incorporating three-dimensional earth structure, finite-fault rupture, and realistic surface topography. The simulated ground motions reveal that the fault rupture and basin structure control the overall pattern of the peak ground shaking. Large peak ground velocity (PGV) is distributed in two narrow areas: The one with the largest PGV values is above the hanging wall of the fault and attributed to the locations of fault asperities and rupture directivity, the other is along the northwestern margin of the Sichuan Basin and caused by both the directivity of fault rupture and the amplification in the thick sediment basin. Rough topography above the rupture fault causes wave scattering, resulting in significantly larger peak ground motion on the apex of topographic relief than in the valley. Topography and scattering also reduce the wave energy in the forward direction of fault rupture but increase the PGV in other parts of the basin. These results suggest the need for a localized hazard assessment in places of rough topography that takes into account of the topographic effects. Finally, had the earthquake started at the northeast end of the fault zone and ruptured to the southwest, Chengdu would have suffered a much stronger shaking than it experienced on 12 May, 2008.

Zhang, W.; Shen, Y.; Chen, X.

2008-12-01

255

Buddhism, Taoism, Folk Religions, and Rebellions: Empirical Evidence from Taiwan  

Microsoft Academic Search

This study investigates the influences of religion in determining whether to support what might be perceived to be rebellious actions in Taiwan where most people are adherents of Buddhism, Taoism, and folk religions. Using data from the Taiwan Social Change Survey 2004, the estimations of the probit model suggest that there are some strong links between religion and the attitudes

Wen-Chun Chang

2010-01-01

256

A multiple time window rupture model for the 1999 Chi-Chi earthquake from a combined inversion of teleseismic, surface wave, strong motion, and GPS data  

Microsoft Academic Search

We present the results of a comprehensive analysis of the rupture process of the 1999 Chi-Chi, Taiwan, earthquake using a broad array of seismic as well as geodetic data, spanning a very wide frequency band. Our results indicate that the rupture was quite smooth, with the slip concentrated in a wide arcuate region north of the epicenter with very little

H. K. Thio; R. W. Graves; P. G. Somerville; T. Sato; T. Ishii

2004-01-01

257

Site Amplification Characteristics and Their Relationship with Averaged S-wave Velocities Derived From K-NET and KiK-Net Strong Motion Records in Japan  

NASA Astrophysics Data System (ADS)

To predict strong ground motions for future scenario earthquake in a broad-band frequency, we need to characterize both source spectra and site amplification. For high frequency we can use statistical method based on the observed records and the summation technique. Thanks to the advent of the K-Net and KiK-net (by NIED) in Japan, we have now plenty of weak motion data, enough to construct statistical Green_fs functions. In order to represent long- and intermediate period nature of the strong ground motion in the near field region, we want to use theoretical technique such as three-dimensional finite difference method. Any theoretical methods need S-wave velocity structures that should reproduce the observed site amplification quantitatively. In this study we perform first the analysis to separate the so-called source spectra, attenuation coefficient, and the site amplification factors from about 15,000 K-NET, KiK-Net, and JMA records observed at 1,700 stations in Japan. The separation method is the well-established one of Andrews (1980) and the resultant source spectra are modeled as omega-square spectra. As a reference site we use one rock station of KiK-Net in Yamaguchi Prefecture, from which we remove amplification of shallow surface deposits. Once we obtain site amplification factors, we try to reproduce them by using one-dimensional S-wave velocity structures below each site of K-NET and KiK-Net (in total, 1,300). We use Genetic Algorithm to invert the S-wave structures with fixed S-wave velocities in the shallow part. We succeed to reproduce site amplification factors at about one thirds of the sites very well. The majority of not-so-good sites need modification of S-wave velocities in the shallow part based on logging data. We also perform the same kind of separation analysis for PGA, PGV, and JMA Seismic Intensity. We found that PGA site factors correlate best with 5.0 Hz spectral amplification and PGV 2.5 Hz spectral amplification. We also found that the best correlation of site factors can be obtained with the average S wave velocity only for top 5 m for PGA and 10 m to 20 m for PGV. Since we have a space for better representation of velocity structures, the results reported here are not conclusive. Once we get better S-wave velocity structures at as many sites as possible, we expect to extrapolate them and construct an initial model of the three-dimensional basin structure of the whole Japanese islands.

Kawase, H.; Matsuo, H.

2003-12-01

258

Evidence of sudden rupture of a large asperity during the 2008 Mw7.9 Wenchuan earthquake based on strong motion analysis  

NASA Astrophysics Data System (ADS)

We investigate the rupture process of the 12 May 2008 Wenchuan earthquake using the records of 26 strong-motion stations, located 20-120 km from the seismic fault and with a good azimuthal coverage. The wave velocity model required to conduct this analysis has been validated against aftershocks, for which the point source hypothesis is a very good approximation. The inversion of the main shock rupture process confirms the slip distribution and the average rupture velocity (˜3 km/s) previously determined. However, a very peculiar behavior is clearly resolved by the extensive data set used in this study: the major slip area of the Wenchuan earthquake, located at 20-50 km North-East of the epicenter, is shown to break almost simultaneously, 25 s after earthquake initiation. This implies that slip in this part of the fault cannot be understood by simple stress release at the rupture front. A more likely interpretation is the presence of a strong asperity, which could break only when it was completely surrounded by stress increase, resulting in a delayed but brutal rupture.

Zhang, Guohong; Vallée, Martin; Shan, Xinjian; Delouis, Bertrand

2012-09-01

259

Strong ground motion recorded by high-rate sampling GPS at the closest site to the 2003 Tokachi-oki earthquake  

NASA Astrophysics Data System (ADS)

The Mw 8.1 earthquake occurred on September 25, 2003, off the southeast coast of Hokkaido, Japan. Since 2000 we have conducted high-rate sampling GPS measurements and precise gravity surveys in Erimo Peninsula, the closest site to the source region of the 2003 event. Strong ground motion recorded by GPS at the point of Erimo Peninsula, located just above the second asperity of the earthquake, shows two major pulses as large as about 56 cm on the EW component. Displacements obtained from the integration of accelerograms very close to our GPS site are consistent with each other, showing the absolute displacement field generated by the magnitude 8-class earthquake. Synthetic seismogram from a similar fault model by Yamanaka and Kikuchi (2003) would predict the amplitude of the second pulse to be about one half of that observed. Synthetic NS component from the GSI fault model (2003) is not consistent with our observations both on amplitude and polarity. The amplitude of ground motions detected by our GPS observation is more than one order larger than the noise level of the GPS survey, so this discrepancy is not due to insufficient GPS observation. We rather think that this suggests that our observations closest to the earthquake would give an insight into the detail of the source processes of the earthquake, which cannot be resolved from observations away from the source region. Static deformation at the point of Erimo Peninsula is consistent with the GSI fault model but not with the Yamanaka and Kikuchi model. The static analysis of our GPS measurement evidently describes the continuous post-seismic deformation as well as the co-seismic displacement in the source region until November.

Koyama, J.; Shestakov, N. V.; Honda, R.

2004-03-01

260

Comparison of shear-wave slowness profiles at 10 strong-motion sites from noninvasive SASW measurements and measurements made in boreholes  

USGS Publications Warehouse

The spectral-analysis-of-surface-waves (SASW) method is a relatively new in situ method for determining shear-wave slownesses. All measurements are made on the ground surface, making it much less costly than methods that require boreholes. The SASW method uses a number of active sources (ranging from a commercial Vibroseis truck to a small handheld hammer for the study conducted here) and different receiver spacings to map a curve of apparent phase velocity versus frequency. With the simplifying assumption that the phase velocities correspond to fundamental mode surface waves, forward modeling yields an estimate of the sub-surface shear-wave slownesses. To establish the reliability of this indirect technique, we conducted a blind evaluation of the SASW method. SASW testing was performed at 10 strong-motion stations at which borehole seismic measurements were previously or subsequently made; if previously made, the borehole results were not used for the interpretation of the SASW data, and vice-versa. Comparisons of the shear-wave slownesses from the SASW and borehole measurements are generally very good. The differences in predicted ground-motion amplifications are less than about 15% for most frequencies. In addition, both methods gave the same NEHRP site classification for seven of the sites. For the other three sites the average velocities from the downhole measurements were only 5-13 m/sec larger than the velocity defining the class C/D boundary. This study demonstrates that in many situations the SASW method can provide subsurface information suitable for site response predictions.

Brown, L. T.; Boore, D. M.; Stokoe, II, K. H.

2002-01-01

261

Inertial effects in the rotationally driven melt motion during the Czochralski growth of silicon crystals with a strong axial magnetic field  

NASA Astrophysics Data System (ADS)

This article treats the melt motion driven by the rotations of the crystal and crucible about their common vertical axis during the Czochralski growth of silicon crystals with a strong, uniform, vertical magnetic field produced by a solenoid around the crystal growth furnace. Since molten silicon is an excellent electrical conductor, the interaction parameter N and the Hartmann number Ha are both large for typical magnetic field strengths, so that composite singular perturbation techniques for N>>1 and Ha>>1 are appropriate. An inertialess solution, which also assumed that N>> Ha3/2, was presented in a previous paper. In the inertialess solution, the largest gradient of the azimuthal velocity v? and the largest secondary flow with radial and axial velocities vr and vz both occur inside an interior layer with an O(Ha-1/2) radial thickness at the vertical cylinder directly beneath the periphery of the crystal, where the growth interface meets the free surface. For all current experimental studies, the assumption that N>> Ha3/2 is not satisfied. The appropriate assumption is that N=O(Ha3/2), and inertial effects are not negligible inside the interior layer. An intersection region, which is formed by the intersection of the interior layer and a Hartmann layer with an O(Ha-1) axial thickness adjacent to the crystal-melt interface and free surface, is intrinsically coupled to the interior layer. This article treats inertial effects in the interior layer and intersection region for N=O(Ha3/2) and Ha>>1. Non-linear governing equations were derived and solved numerically. A fourth-order Adams-Bashforth-Moulton predictor-corrector method was used to solve the transport equations for the primary azimuthal velocity and for the secondary-flow vorticity. Poisson equations, which govern the stream functions for both the secondary flow and the electric current density, were solved using a matrix diagonalization technique. The effects of inertia on the melt motion are discussed. This type of study provides for a fuller understanding of the melt motion, without which defect-free crystals will be difficult to grow on a consistent basis.

Talmage, G.; Shyu, S.-H.; Walker, J. S.; Lopez, J. M.

262

S-wave velocity structures of sediments estimated from array microtremor records and site responses in the near-fault region of the 1999 Chi-Chi, Taiwan earthquake  

Microsoft Academic Search

The 1999 Chi-Chi, Taiwan earthquake, MW = 7.6, caused severe damage in the near-fault region of the earthquake. In order to evaluate site effects in the near-field strong motions we estimate S-wave velocity structures of sediments at four sites using array records of microtremors. We also recalculated S-wave velocity structures at other four sites previously reported. To show the validity

Satoh Toshimi; Hiroshi Kawase; Tomotaka Iwata; Sadanori Higashi; Sato Toshiaki; Huey-Chu Huang

2004-01-01

263

The Dam1 ring binds microtubules strongly enough to be a processive as well as energy-efficient coupler for chromosome motion  

PubMed Central

Accurate chromosome segregation during mitotic division of budding yeast depends on the multiprotein kinetochore complex, Dam1 (also known as DASH). Purified Dam1 heterodecamers encircle microtubules (MTs) to form rings that can function as “couplers,” molecular devices that transduce energy from MT disassembly into the motion of a cargo. Here we show that MT depolymerization develops a force against a Dam1 ring that is sixfold larger than the force exerted on a coupler that binds only one side of an MT. Wild-type rings slow depolymerization fourfold, but rings that include a mutant Dam1p with truncated C terminus slow depolymerization less, consistent with the idea that this tail is part of a strong bond between rings and MTs. A molecular-mechanical model for Dam1-MT interaction predicts that binding between this flexible tail and the MT wall should cause a Dam1 ring to wobble, and Fourier analysis of moving, ring-attached beads corroborates this prediction. Comparison of the forces generated against wild-type and mutant complexes confirms the importance of tight Dam1-MT association for processive cargo movement under load.

Grishchuk, Ekaterina L.; Efremov, Artem K.; Volkov, Vladimir A.; Spiridonov, Ilia S.; Gudimchuk, Nikita; Westermann, Stefan; Drubin, David; Barnes, Georjana; McIntosh, J. Richard; Ataullakhanov, Fazly I.

2008-01-01

264

Renewable energy in Taiwan  

Microsoft Academic Search

With limited indigenous conventional energy resources, Taiwan imports over 99% of its energy supply from foreign countries, mostly from the Middle East. Developing independent renewable energy resources is thus of priority concern for the Taiwanese government. A medium subtropical island surrounded by the Pacific Ocean, Taiwan has enormous potential to develop various renewable energies, such as solar energy, biomass energy,

Falin Chen; Shyi-Min Lu; Eric Wang; Kuo-Tung Tseng

2010-01-01

265

Maternity Leave in Taiwan  

ERIC Educational Resources Information Center

|Using the first nationally representative birth cohort study in Taiwan, this paper examines the role that maternity leave policy in Taiwan plays in the timing of mothers returning to work after giving birth, as well as the extent to which this timing is linked to the amount of time mothers spend with their children and their use of breast milk…

Feng, Joyce Yen; Han, Wen-Jui

2010-01-01

266

Modeling lunar calendar effects in Taiwan  

Microsoft Academic Search

The three most important Chinese holidays, Chinese New Year, the Dragon- boat Festival, and Mid-Autumn Holiday have dates determined by a lunar calendar and move between two solar months. Consumption, production, and other economic behavior in countries with large Chinese population including Taiwan are strongly affected by these holidays. For example, production accelerates before lunar new year, almost completely stops

Jin-Lung Lin; Tian-Syh Liu

2002-01-01

267

Modeling lunar calendar effects in taiwan  

Microsoft Academic Search

The three most important Chinese holidays, Chinese New Year, the Dragon- boat Festival, and Mid-Autumn Holiday have dates determined by a lunar calendar and move between two solar months. Consumption, production, and other economic behavior in countries with large Chinese population including Taiwan are strongly affected by these holidays. For example, production accelerates before lunar new year, almost completely stops

Jin-Lung Lin; Tian-Syh Liu

2003-01-01

268

Modeling Lunar Calendar Holiday Effects in Taiwan  

Microsoft Academic Search

Abstract The three most important Chinese holidays, Chinese New Year, the Dragon-boat Festival, and Mid- Autumn Holiday have dates determined by a lunar calendar and move between two solar months. Consumption, production, and other economic behavior in countries with large Chinese population including Taiwan are strongly affected by these holidays. For example, production accelerates be- fore lunar new year, almost

Jin-Lung Lin; Tian-Syh Liu

269

Regime transition and the media in Taiwan  

Microsoft Academic Search

Taiwan's recent experience of political regime transition suggests the existence of a strong correlation between the promotion of free and diverse media and the level of political change. The government's efforts to create a more liberal media environment are commendable, but, owing to the structure of the market and ownership patterns, the party of government (the Kuomintang) maintains a powerful

Gary D. Rawnsley

1998-01-01

270

Rupture process of the 2009 L'Aquila, central Italy, earthquake, from the separate and joint inversion of Strong Motion, GPS and DInSAR data.  

NASA Astrophysics Data System (ADS)

In this study, we investigate the rupture history of the April 6th 2009 (Mw 6.1) L'Aquila normal faulting earthquake by using a nonlinear inversion of strong motion, GPS and DInSAR data. We use a two-stage non-linear inversion technique. During the first stage, an algorithm based on the heat-bath simulated annealing generates an ensemble of models that efficiently sample the good data-fitting regions of parameter space. In the second stage the algorithm performs a statistical analysis of the ensemble providing us the best-fitting model, the average model, the associated standard deviation and coefficient of variation. This technique, rather than simply looking at the best model, extracts the most stable features of the earthquake rupture that are consistent with the data and gives an estimate of the variability of each model parameter. The application to the 2009 L'Aquila main-shock shows that both the separate and joint inversion solutions reveal a complex rupture process and a heterogeneous slip distribution. Slip is concentrated in two main asperities: a smaller shallow patch of slip located up-dip from the hypocenter and a second deeper and larger asperity located southeastward along strike direction. The key feature of the source process emerging from our inverted models concerns the rupture history, which is characterized by two distinct stages. The first stage begins with rupture initiation and with a modest moment release lasting nearly 0.9 seconds, which is followed by a sharp increase in slip velocity and rupture speed located 2 km up-dip from the nucleation. During this first stage the rupture front propagated up-dip from the hypocenter at relatively high (˜ 4.0 km/s), but still sub-shear, rupture velocity. The second stage starts nearly 2 seconds after nucleation and it is characterized by the along strike rupture propagation. The largest and deeper asperity fails during this stage of the rupture process. The rupture velocity is larger in the up-dip than in the along-strike direction. The up-dip and along-strike rupture propagation are separated in time and associated with a Mode II and a Mode III crack, respectively. Our results show that the 2009 L'Aquila earthquake featured a very complex rupture, with strong spatial and temporal heterogeneities suggesting a strong frictional and/or structural control of the rupture process.

Cirella, A.; Piatanesi, A.; Tinti, E.; Chini, M.; Cocco, M.

2012-04-01

271

Taper Angle Evolution in Taiwan Accretionary Wedge  

NASA Astrophysics Data System (ADS)

Liwen Chena,b, Wu-Cheng Chia, Char-Shine Liuc aInstitute of Earth Sciences, Academia Sinica, Taipei, Taiwan bInstitute of Geosciences, National Taiwan University, Taipei, Taiwan cInstitute of Oceanography, National Taiwan University, Taipei, Taiwan The critical taper model, originally developed using onland Taiwan as an example, is governed by force balance of a horizontal compressional wedge. This model has been successfully applied to many mountainous regions around the world. Among them, Taiwan is located in an oblique collision between the Luzon Arc and the Chinese Passive margin. Previous critical taper angle studies of Taiwan are mainly focusing on utilizing land data. In this study we want to extend these studies to offshore region from the subduction zone to collision zone. Here we study the varying taper angles of the double-vergent wedge derived from 1,000 km of reflection seismic profiles in both the pro-wedge and retro-wedge locations. These profiles were collected in the last two decades. For the retro-wedge, the topography slope angle changes from 2 to 8.8 degrees; some of the steep slope suggests that some part of the retrowedge is currently in a super-critical angle state. Such dramatic changes in taper angle probably strongly affect regional sedimentary processes, including slumping, in addition to structural deformation. These complex processes might even help develop a mélange or re-open a closed basin. We are currently working on studying the taper angle evolution of the pro-wedge from subduction to arc-continent collision zone in the offshore region. Though further works are needed, our preliminary results show that the evolution of wedge angles and the geometry of the wedge are closely linked and inseparable. The structures of the subducting plate might have strong influence on the deformation style of the over-riding plate. It would be interesting to combine the angle variation with the structure interpretation of the accretionary wedge, both in the pro- and retro-wedge regions. And the results might help us to better understand the evolution of Taiwan Accretionary Prism.

Chen, L.; Chi, W.; Liu, C.

2011-12-01

272

High remanence intensity of breccia samples: Taiwan Chelungpu-fault Drilling Project (TCDP)  

NASA Astrophysics Data System (ADS)

A negative pulse-like geomagnetic fluctuation had been detected for more than a month prior to the Taiwan Chi-Chi earthquake (M7.6) in 1999 (Yen et al., 2004). Freund (2003) interpreted from his laboratory experiments that a nearly 106 ampere electric current along the fault zones caused the geomagnetic fluctuations. If such electric currents discharged, we can hypothesize that the fault zone rocks might have recorded the strong current-induced magnetic field. Here, we present paleomagnetic evidence for the hypothesis from thousand-meter deep drilled fault breccia samples of Taiwan Chelungpu-fault Drilling Project (TCDP). Three major fault zones at 1136m, 1194m and 1243m in depth showed anomalously strong natural remanent magnetizations (NRM) which were 10~100 times larger than those of host rocks, and the ratio (REM) of NRM over saturation isothermal remanences of breccia samples shows a one-order-of-magnitude higher value of 0.12 than that of normal volcanic lavas in thermal origin. To evaluate if these samples acquired the thermal remanent magnetization (TRM) accompanying the fault motions, we carried out simple heating experiments of host rock samples to acquire a TRM. In the result, the REM ratio of a sample heated to 600°C and cooled in 100µT (twice as strong as Earth’s field) is 0.03, suggesting that 0.12 cannot be explained by TRM in Earth’s field. Additionally, the bedding-corrected paleomagnetic directions for these samples showed a much shallower or deeper paleomagnetic inclination data, which are no correspondence to the geomagnetic inclination at Taiwan. These suggest the presence of strong ambient fields, if the magnetic carrier is magnetite. We are carrying out X-ray diffraction experiments (heavy liquid differentiation) to make solid identifications of magnetic minerals about the other samples now.

Tachibana, S.; Nakamura, N.; Mishima, T.; Hirono, T.; Soh, W.; Song, S.

2009-12-01

273

Simultaneous Estimation of Earthquake Source Parameters and Site Response from Inversion of Strong Motion Network Data in Kachchh Seismic Zone, Gujarat, India  

NASA Astrophysics Data System (ADS)

Inversion of horizontal components of S-wave spectral data in the frequency range 0.1-10.0 Hz has been carried out to estimate simultaneously the source spectra of 38 aftershocks (Mw 2.93-5.32) of the 2001 Bhuj earthquake (Mw 7.7) and site response at 18 strong motion sites in the Kachchh Seismic Zone, Gujarat, India. The spatial variation of site response (SR) in the region has been studied by averaging the SR values obtained from the inversion in two frequency bands; 0.2-1.8 Hz and 3.0-7.0 Hz, respectively. In 0.2-1.8 Hz frequency band, the high SR values are observed in the southern part of the Kachchh Mainland Fault that had suffered extensively during the 2001 Bhuj Earthquake. However, for 3.0-7.0 Hz band, the area of Jurassic and Quaternary Formations show predominantly high SR. The source spectral data obtained from the inversion were used to estimate various source parameters namely, the seismic moment, stress drop, corner frequency and radius of source rupture by using an iterative least squares inversion approach based on the Marquardt-Levenberg algorithm. It has been observed that the seismic moment and radius of rupture from 38 aftershocks vary between 3.1x10^{13} to 2.0x10^{17} Nm and 226 to 889 m, respectively. The stress drop values from these aftershocks are found to vary from 0.11 to 7.44 MPa. A significant scatter of stress drop values has been noticed in case of larger aftershocks while for smaller magnitude events, it varies proportionally with the seismic moment. The regression analysis between seismic moment and radius of rupture indicates a break in linear scaling around 10^{15.3} Nm. The seismic moment of these aftershocks found to be proportional to the corner frequency, which is consistent for earthquakes with such short rupture length.

Dutta, U.; Mandal, P.

2010-12-01

274

Source process and slip model of 2005 Dahuiyeh-Zarand earthquake (Iran) using inversion of near-field strong motion data  

NASA Astrophysics Data System (ADS)

On 2005 February 22, the Dahuiyeh-Zarand earthquake, Mw 6.5, struck one of the most seismically active regions in south-central Iran, east of Zarand City in Kerman province, causing more than 500 fatalities. The causative fault of the 2005 Dahuiyeh-Zarand earthquake, a reverse fault, striking nearly EW and dipping to the north, was located within a mountainous region and therefore more difficult to identify compared to the range-bounded faults. Its identification, after the 2005 event, is very important for both the estimation of seismic hazard as well as for the damage and fatality functions. We have inverted six three-component near-field strong motion waveforms to obtain the complete earthquake rupture history and slip distribution. Accelerograms are bandpass filtered with 0.2-1.0 Hz, and a length of 15-17 s of the waveforms is inverted. The lack of absolute timing has been successfully overcome by estimating, from the velocity model of the region, the propagation of P and S waves from the epicentre to the stations. The final fault slip model and the estimated source parameters are able to explain the observed waveforms. The rupture is found to be bilateral with a maximum slip of 2.4 m concentrated on two asperities in the west and east sides of the nucleation point at depths of 6-12 km. The western asperity is located to the east of Zarand City and beneath the Dahuiyeh village, which might explain why the Dahuiyeh village was totally destroyed by this earthquake.

Rouhollahi, R.; Ghayamghamian, M. R.; Yaminifard, F.; Suhadolc, P.; Tatar, M.

2012-04-01

275

Rupture process of the 2011 Tohoku-Oki mega-thrust earthquake (M9.0) inverted from strong-motion data  

NASA Astrophysics Data System (ADS)

We investigate the rupture process of the M9.0 Tohoku-Oki mega-thrust earthquake using the relatively low-frequency strong-motion records (0.01-0.125 Hz) observed at 36 K-NET and KiK-net stations, the epicentral distances of which range from 120 km to 400 km. The fault model is a rectangular plane, the length and width of which are 510 km along the Japan Trench and 210 km along subducting direction of the Pacific Plate, respectively. We perform the multi-time-window inversion analysis with a 30 × 30 km2 subfault. The derived slip model has one large slip area. This area extends from the region around the hypocenter to the shallow part of the fault plane and further to the north and south along the trench axis, located far off southern Iwate, Miyagi, and northern Fukushima prefectures. The seismic moment is 4.42 × 1022 Nm (Mw 9.0) and the maximum slip is 48 m. The slips near the coast are relatively small, except off Miyagi prefecture, which experienced a slip greater than 5 m. The shallow large slip area, which continuously ruptured from 60 s to 100 s after the initial break, radiated seismic waves rich in very-low-frequency content (<0.02 Hz). The rupture after 100 s propagating to the southern fault area, contributes to the distinct phases observed for Fukushima and Ibaraki prefectures. The relationship between the proposed rupture model and the feature of the acceleration waveforms is not straightforward and suggests the frequency dependency of the seismic wave radiation.

Suzuki, Wataru; Aoi, Shin; Sekiguchi, Haruko; Kunugi, Takashi

2011-10-01

276

The Rupture History of the 2009 L’Aquila earthquake by non-linear joint inversion of strong motion and GPS data  

NASA Astrophysics Data System (ADS)

The 2009 L’Aquila earthquake (Mw 6.3) occurred in the Central Apennines (Italy) on April 6th at the 01:32 UTC and caused nearly 300 fatalities and heavy damages in the L’Aquila town and in several villages nearby. The main shock ruptured a normal fault striking along the Apennine axis and dipping at nearly 50° to the SW. Most of the aftershocks are also associated with normal faulting, which is consistent with the present-day tectonic setting of this sector of the Apennines. The identification of the fault geometry of the L’Aquila main shock relies on the aftershock pattern, the SAR interferometric data, the GPS displacements as well as the induced surface breakages. The earthquake allowed for the collection of an excellent data set for normal faulting events. In this study, we have imaged the rupture history of the L’Aquila earthquake using a nonlinear joint inversion of strong motion and GPS data. Our results show that slip distribution on the fault is quite heterogeneous and characterized by a small shallow slip patch located up-dip the hypocenter and a large and deeper patch located southeastward. The rupture velocity is larger in the up-dip than in the along-strike direction. This difference can be partially accounted by the local crustal structure, which is characterized by a high velocity layer above the hypocenter (9.46 km) and a lower velocity below. The latter velocity seems to have affected the along strike propagation since the largest slip patch is located at depths between 9 and 14 km. The imaged slip distribution correlates well with the on-fault aftershock pattern as well as with mapped surface breakages. The rupture history is also consistent with the large PGA values recorded at L’Aquila that is located right above the hypocenter.

Piatanesi, A.; Cirella, A.; Cocco, M.; Tinti, E.; Scognamiglio, L.; Michelini, A.; Lomax, A.

2009-12-01

277

Image-based motion blur for stop motion animation  

Microsoft Academic Search

Stop motion animation is a well-established technique where still pictures of static scenes are taken and then played at film speeds to show motion. A major limitation of this method appears when fast motions are desired; most motion appears to have sharp edges and there is no visible motion blur. Appearance of motion blur is a strong perceptual cue, which

Gabriel J. Brostow; Irfan A. Essa

2001-01-01

278

B values and ??-?? seismic source models: Implications for tectonic stress variations along active crustal fault zones and the estimation of high-frequency strong ground motion  

USGS Publications Warehouse

In this study the tectonic stress along active crustal fault zones is taken to be of the form ??(y) + ????p(x, y), where ??(y) is the average tectonic stress at depth y and ???? p(x, y) is a seismologically observable, essentially random function of both fault plane coordinates; the stress differences arising in the course of crustal faulting are derived from ????p(x, y). Empirically known frequency of occurrence statistics, moment-magnitude relationships, and the constancy of earthquake stress drops may be used to infer that the number of earthquakes N of dimension ???r is of the form N ?? 1/r2 and that the spectral composition of ????p(x, y) is of the form |????p(k)| ?? l/k2, where ????p(k) is the two-dimensional Fourier transform of ????p(x, y) expressed in radial wave number k. The y = 2 model of the far-field shear wave displacement spectrum is consistent with the spectral composition |????p(K)| ?? l/k2, provided that the number of contributions to the spectral representation of the radiated field at frequency f goes as (k/ko), consistent with the quasi-static frequency of occurrence relation N ?? 1/r2; K o is a reference wave number associated with the reciprocal source dimension. Separately, a variety of seismologic observations suggests that the ?? = 2 model is the one generally, although certainly not always, applicable to the high-frequency spectral decay of the far-field radiation of earthquakes. In this framework, then, b values near 1, the general validity of the y = 2 model, and the constancy of earthquake stress drops independent of size are all related to the average spectral composition of ???? p(x, y), |????p(k)| ?? l/k2. Should one of these change as a result of premonitory effects leading to failure, as has been specifically proposed for b values, it seems likely that one or all of the other characteristics will change as well from their normative values. Irrespective of these associations, the far-field, high-frequency shear radiation for the y = 2 model in the presence of anelastic attenuation may be interpreted as band-limited, finite duration white noise in acceleration. Its rms value, arms, is given by the expression arme = 0.85[21/2(2??)2/106] (????/pR)(f max/f0)1/2, where ???? is the earthquake stress drop, p is density, R is hypocentral distance, fo is the spectral corner frequency, and fmax is determined by R and specific attenuation 1/Q. For several reasons, one of which is that it may be estimated in the absence of empirically defined ground motion correlations, a rms holds considerable promise as a measure of high-frequency strong ground motion for engineering purposes. Copyright ?? 1979 by the American Geophysical Union.

Hanks, T. C.

1979-01-01

279

Liver Disease on Taiwan.  

National Technical Information Service (NTIS)

Review of 762 liver biopsies from 2 Chinese military hospitals on Taiwan over a 5 year period revealed the major distribution of clinically manifested liver diseases to be as follows: hepatitis (presumable viral) 42%; cirrhosis 19%; and primary carcinoma ...

P. C. Chu S. C. Sun W. H. Liang J. W. Fresh

1965-01-01

280

Taiwan Space Programs  

Microsoft Academic Search

Taiwan space programs consist of FORMOSAT-1, -2, and -3, sounding rockets, and international cooperation. FORMOSAT-1, a low-earth-orbit (LEO) scientific experimental satellite, was launched on January 26, 1999. It circulates with an altitude of 600 km and 35 degree inclination around the Earth every 97 minutes, transmitting collected data to Taiwan's receiving stations approximately six times a day. The major mission

Jann-Yenq Liu

2008-01-01

281

Time Dependent Fluid Occurrence Offshore Taiwan  

NASA Astrophysics Data System (ADS)

Time Dependent Fluid Occurrence Offshore Taiwan Liwen Chenab, Wu-Cheng Chia, Char-Shine Liuc (mma@earth.sinica.edu.tw)(wchi@gate.sinica.edu.tw) ; aInstitute of Earth Sciences, Academia Sinica, Taipei, Taiwan bInstitute of Geosciences, National Taiwan University, Taipei, Taiwan ; cInstitute of Oceanography, National Taiwan University, Taipei, Taiwan Earthquake-induced groundwater flows have been observed recently. Such fluid flow might temporarily change the temperature field in the crust. Here we used seismically detected gas hydrate under seafloor to study the temperature fields at a few hundred meters subbottom depth before, and after the 2006 Henchuan earthquake (Mw7.0). We used the hydrate-related bottom-simulating-reflector (BSR) in seismic profiles to study the effects of gas/fluid migration on the BSR attributes. We have conducted two seismic experiments before and after the earthquake across the same transects near the hypocenter of the earthquake using similar air gun arrays and streamers. By analyzing this unique dataset, we found enhanced BSR reflectivity in average after the earthquake (~0.03), but the Sea-floor reflectivity is very similar (~0.5). We also found changed amplitudes versus offset (AVO) in the dataset (the gradient of reflection coefficient versus the angles was ~-0.34). We interpret these results as a consequence of earthquake-induced gas and fluid migration, bringing the gases underneath the BSR, thus the enhanced reflection coefficients. Next we will explore new methods to use the BSR as a flow meter. Using time-dependent seismic attribute analyses across transects before and after a large earthquake, we found strong evidences of earthquake-related fluid migrations and possibly associated temperature perturbations. This is among the first studies to document such feature in the offshore region.

Chen, L.

2010-12-01

282

High-Resolution Source Imaging of the 2007 Niigataken Chuetsu-oki Earthquake From Dense Strong-Motion Networks: Focus on the First 5 Seconds of the Rupture Process  

NASA Astrophysics Data System (ADS)

The 2007 Niigataken Chuetsu-oki earthquake (Mw6.6) occurred on 16 July 2007 (JST) in the western offshore of Niigata Prefecture, Japan, which strongly shook the near-source area and was recorded with dense strong- motion observation networks. Although no station was in the source region because this earthquake occurred in offshore, many strong-motion stations recorded the seismic motion near the source region. The local strong- motion records of this earthquake have a remarkable feature: the records show several seconds of small but increasing amplitude arrival ("initial rupture phase") followed by the onset of the main energy release ("main rupture phase"). In this study we get from these records the high resolution image of the source process during the five seconds after the rupture initiation of this earthquake. To investigate source rupture process, waveform inversions are now popular, but these source inversion methods do not have so high resolution. Recently another approach with high resolution, the back-projection method (e.g., Ishii et al., 2005; Yamamoto and Takenaka, 2006) was exploited, which images earthquake rupture directly from dense network data. The back- projection method is useful to teleseismic array data of an earthquake with very large dimension such as the 2004 Sumatra-Andaman earthquake (Mw9.3), as mentioned by Ishii et al. (2005, Nature). The back-projection method was also adapted for analyzing local strong-motion records of a middle earthquake, the 2005 Fukuoka earthquake (Mw 6.6), by Yamamoto and Takenaka (2006, AGU Fall Meeting). Their imaging technique is useful to middle to large earthquakes. Here we applied their technique to near-source strong-motion records of the 2007 Chuetsu-oki earthquake. We used P-wave portion of UD motion records and derived the following detailed process during the five seconds after the rupture initiation: The rupture plane is a NW-dipping one which is one of the P-nodal planes in the focal mechanism solution. The rupture mainly propagated toward the direction of Kashiwazaki City (around N200E). The main rupture (breaking of the asperity) began at a position of 4 km apart and southwest above the original hypocenter at 2.1 seconds after the origin time. The asperity distributed toward the direction of Kashiwazaki City on the fault plane. This spatial configuration suggests that the rupture front then swept the asperity upward and to the southwest, so that Kashiwazaki City directly suffered the strong effects of the forward rupture directivity ("killer pulse"). (Acknowledgements) We used the strong-motion records supplied by the National Institute for Earth Science and Disaster Prevention (NIED; K-NET, KiK-net, F-net), and the Japan Meteorological Agency (JMA). This study are patially supported by "Special Project for Earthquake Disaster Mitigation in Metropolitan Tokyo Area".

Takenaka, H.; Yamamoto, Y.; Yamasaki, H.

2007-12-01

283

Crustal deformation in Taiwan: Results from finite source inversions of six Mw > 5.8 Chi-Chi aftershocks  

NASA Astrophysics Data System (ADS)

We inverted strong motion data for the finite source parameters of six large aftershocks of the 1999 Chi-Chi, Taiwan, earthquake to investigate seismogenic structure in Taiwan. For each event we derived a preferred model by testing different focal mechanisms, hypocenters, rupture velocities, and dislocation risetimes, as well as different combinations of stations in more than 1000 inversions. We documented how the fits between the waveforms and the corresponding synthetics deteriorated as the hypocenter and focal mechanism deviate from those of the preferred model. If the deviation in focal mechanisms and hypocenters is less than 20° and 5 km, respectively, we generally recovered 80% of the preferred model's synthetic waveform fit. Unlike the dislocation risetime, the rupture velocity used in the inversion had a strong influence on the waveform fits in this study. We also used the slip models to study fault geometry. Two of the aftershocks ruptured on the southern extension of the main shock slip area. One strike-slip aftershock nucleated within the basement but ruptured mainly within the overlying sedimentary strata, suggesting that seismogenic deformation in the basement can influence shallow structures. P axes of the derived models have azimuths consistent with current plate motion. Finally, GPS displacement derived from the six slip models can explain 80% of the postseismic deformation observed in the aftershock regions, indicating that studies of postseismic deformation must take into account the cumulative effects of large, shallow aftershocks.

Chi, Wu-Cheng; Dreger, Doug

2004-07-01

284

STRONG MOTION ESTIMATION AT THE EMBANKMENT OF THE JOBAN EXPRESSWAY DAMAGED BY THE 2011 OFF THE PACIFIC COAST OF TOHOKU EARTHQUAKE AND ITS LARGEST AFTERSHOCK BASED ON SITE EFFECT SUBSTITUTION METHOD  

NASA Astrophysics Data System (ADS)

Slope failure occurred in an embankment of the Joban expressway during the 2011 off the Pacific coast of Tohoku Earthquake and its largest aftershock. Therefore, the evaluation of strong seismic motion at this site with high accuracy is very important to clarify the failure mechanism. In this study, the seismic waveform at this site was estimated based on empirical site amplification and phase effects. The estimated seismic waveform will be useful for rational safety assessment of road embankments.

Hata, Yoshiya; Ichii, Koji; Tokida, Ken-Ichi; Nozu, Atsushi; Yokota, Seiya; Kaneta, Kazuo

285

Strong ground motion data recorded at the Idaho National Laboratory during the 1983 Borah Peak, Idaho earthquake. [Appendix contains plot generated by accelerogram showing peak valves amplitude, response spectra, displacement, veolocity and acceleration  

SciTech Connect

The Idaho National Engineering Laboratory (INEL) is located approximately 80 km southeast of the epicenter for the 1983 M{sub S} 7.3 Borah Peak Idaho earthquake. Thirteen strong-motion accelerographs located at various facilities around the INEL Site recorded strong-ground motions from the Borah Peak earthquake. The strong-motion records were digitized and processed resulting in corrected acceleration, velocity, and displacement time-histories and response and Fourier spectra. Peak horizontal accelerations had a range of 0.022 to 0.078 g for accelerographs located at free-field and basement sites. Values of 0.037 {minus} 0.817 g were recorded at accelerographs located within structures above basement level. Peak vertical accelerations ranged from 0.16 (basement level) to 0.059 g (top of structures). The peak amplitudes of the response and Fourier Spectra occur in the 2 -- 10 hz frequency range. Appendices include Borah Peak earthquake accelerograph data printouts. 8 refs., 4 figs., 7 tabs.

Jackson, S.M.; King, J.J.; Anderson, D.M.; Carpenter, G.S.; Adams, H.A.

1991-06-01

286

Off-equatorial orbits in strong gravitational fields near compact objects—II: halo motion around magnetic compact stars and magnetized black holes  

NASA Astrophysics Data System (ADS)

Off-equatorial circular orbits with constant latitudes (halo orbits) of electrically charged particles exist near compact objects. In the previous paper, we discussed this kind of motion and demonstrated the existence of minima of the two-dimensional effective potential which correspond to the stable halo orbits. Here, we relax previous assumptions of the pseudo-Newtonian approach for the gravitational field of the central body and study properties of the halo orbits in detail. Within the general relativistic approach, we carry out our calculations in two cases. Firstly, we examine the case of a rotating magnetic compact star. Assuming that the magnetic field axis and the rotation axis are aligned with each other, we study the orientation of motion along the stable halo orbits. In the poloidal plane, we also discuss shapes of the related effective potential halo lobes where the general off-equatorial motion can be bound. Then we focus on the halo orbits near a Kerr black hole immersed in an asymptotically uniform magnetic field of external origin. We demonstrate that, in both the cases considered, the lobes exhibit two different regimes, namely one where completely disjoint lobes occur symmetrically above and below the equatorial plane, and another where the lobes are joined across the plane. A possible application of the model concerns the structure of putative circumpulsar discs consisting of dust particles. We suggest that the particles can acquire a small (but non-zero) net electric charge, and this drives them to form the halo lobes.

Ková?, J.; Kopá?ek, O.; Karas, V.; Stuchlík, Z.

2010-07-01

287

The Impact of an Antiamphetamine Law on Juvenile Delinquency in Taiwan  

Microsoft Academic Search

In October 1990, Taiwan changed its criminal code on amphetamines, making possession and use of such substances a punishable act. Strong government intervention against amphetamines-related offenses supported by an uncritical general public has created an increasing criminal population. This article focuses on how the newly enacted antiamphetamines law affects the extent and nature ofjuvenile delinquency in Taiwan. Data arefrom the

Bohsiu Wu

1996-01-01

288

Strong Libraries, Strong Scores  

ERIC Educational Resources Information Center

|This article talks about the first-ever Texas Conference on School Libraries on April 6, 2005 that was attended by one hundred thirty-five school administrators and trustees. The miniconference, entitled Strong Libraries, Strong Scores, was held at the Austin Hilton, Austin, Texas during the Texas Library Association's Annual Conference and was…

Gray, Carlyn

2006-01-01

289

Analysis of Active Crustal Deformation in Chiayi Area, Southwestern Taiwan by Continues GPS network and numerical modeling  

NASA Astrophysics Data System (ADS)

Locating in the boundary between the Eurasia Plate and the Philippine Sea Plate, the island of Taiwan lies in a complex tectonic area. The fold-and-thrust belt in the southwestern Taiwan provides distinctive morphotectonic features reflecting the initial mountain building stage in Taiwan orogeny. Several devastating earthquakes have occurred in this region since 1900, the famous one is M7.1 Meishan earthquake in 1906. In addition, a seismic concentration zone is observed in Coastal plain in Chiayi counties, which no active faults have been reported in this region. The active deformation in SW Taiwan has been suggested to be related to active growing folding initiated by the blind thrust fault system. How surface deformation related to the subsurface active structures is a crucial topic for seismic hazard assessment in study area. The newly initiated blind fault system increases potential earthquake hazard in the southwestern alluvial plain where is densely populated. Thus we try to characterize the existence of blind fault-folding system beneath the coastal plain area by geodetic method. We derive a velocity field based on data at 55 continuous GPS (CGPS) stations from 2006 to 2010, and data at 97 campaign mode GPS over a time period between 2002 to 2010. The CGPS data used in this study were processed with the GAMIT/GLOBK software version 10.4. The crustal motion in this area shows the horizontal displacement about 30 mm/yr with the directions of 297° in the easternmost part of the Western Foothills, and crossing the main active structures, Chiushiunkeng-Chukou Fault and blind fault systems, the velocities significantly decrease to 3 mm/yr with the directions of 288° in the westernmost part in the coastal plan, with respect to Paisha station, S01R. The compressional strain rate dominates and the larger compressional strain rate is observed at the Foothill region, the east side of Chiushiunkeng- Chukou Fault. In some coordinate time-series of our CGPS sites, the strong periodic signals whether in horizontal component or vertical component is observed. These signals might include the effect of variation of ground water level or tectonic motion. In this study, we try to use the available geological structural profiles from CPC to characterize complex motions in Chiayi region and to assess the fault activity based on 2-D dislocation model. Further, we try to use Poly3D to inverse the fault motion during interseismic period.

Chung, W. C.; Hu, J. C.

2012-04-01

290

Measurement of Structural Response Characteristics of Full-Scale Buildings: Comparison of Results from Strong-Motion and Ambient Vibration Records.  

National Technical Information Service (NTIS)

The report describes the collection and analysis of ambient vibration data from five buildings in the San Francisco Bay area that experienced strong shaking during the Loma Prieta earthquake of October 17, 1989. The buildings represent a range of construc...

R. D. Marshall L. T. Phan M. Celebi

1992-01-01

291

Introduced Leishmaniasis on Taiwan.  

National Technical Information Service (NTIS)

Leishmaniasis is not known to be indigenous to Taiwan but a number of imported cases of visceral as well as post-kala-azar dermal leishmaniasis have been seen. Only two autochthonous cases of cutaneous-subcutaneous diseases have been documented in aborigi...

J. H. Cross J. J. Gunning D. J. Drutz J. C. Lien

1985-01-01

292

Technology Education in Taiwan.  

ERIC Educational Resources Information Center

Technology education focusing on technological literacy is provided to Taiwanese students in grades 1-11, primarily through the secondary school subject Living Technology (LT). Taiwan's newly promulgated national curriculum for grades 1-9 has integrated LT with natural science for the key learning area (KLA) Natural Science and Living Technology.…

Lee, Lung-Sheng Steven

293

Medical education in Taiwan.  

PubMed

Taiwan's medical education system bears a close relationship with its colonial and post-colonial history. Since the late nineteenth century, Western medicine, Chinese medicine, and the practice of the other forms of traditional healing have encountered complex transactions with the state and one another, eventually evolving into the present medical system. Nowadays, the mainstream form of medical education in Taiwan is a 7-year Western program; other forms of medical education include a 5-year graduate program and traditional medicine programs. Challenged by the National Health Insurance that emphasizes cost management since 1995 and criticized by the US National Committee on Foreign Medical Education and Accreditation in 1998, medical education reform was implemented by the Taiwan Medical Accreditation Council established in 2000. The reform tries to bring humanities into various aspects of medical education, including student recruitment, curriculum, licensing, and continuing education. Similar to other modernization projects, the reform transplants the American and British standards to Taiwan. These changes hope to insure the reflective capabilities in physicians on the welfare of patients. However, frustration of current and future physicians may be deepened if the reform is insensitive to local issues or incapable of addressing new global tendencies. PMID:22364449

Chou, Jen-Yu; Chiu, Chiung-Hsuan; Lai, Enoch; Tsai, Duujian; Tzeng, Chii-Ruey

2012-01-01

294

75 FR 61175 - Polyvinyl Alcohol From Taiwan  

Federal Register 2010, 2011, 2012, 2013

...731-TA-1088 (Final)] Polyvinyl Alcohol From Taiwan AGENCY: United...less-than-fair-value imports from Taiwan of polyvinyl alcohol, provided for in subheading...of Commerce that imports of polyvinyl alcohol from Taiwan are being sold...

2010-10-04

295

76 FR 13660 - Polyvinyl Alcohol From Taiwan  

Federal Register 2010, 2011, 2012, 2013

...731-TA-1088 (Final)] Polyvinyl Alcohol From Taiwan Determination On...reason of imports from Taiwan of polyvinyl alcohol, provided for under subheading...by Commerce that imports of polyvinyl alcohol from Taiwan were being...

2011-03-14

296

Country Marketing Plan for Taiwan, FY 1993.  

National Technical Information Service (NTIS)

The report is a comprehensive marketing plan aimed at firms currently exporting to Taiwan, considering exporting to Taiwan, or considering establishing operations in Taiwan. It analyzes the country's business and economic climate, giving emphasis to marke...

1992-01-01

297

Anomalous Magnetization of Brecciated Samples from the Taiwan Chelungpu-fault Drilling Project (TCDP)  

NASA Astrophysics Data System (ADS)

A negative pulse-like geomagnetic fluctuations had been detected for more than a month prior to the Taiwan Chi-Chi earthquake (M7.6) in 1999 (Yen et al., 2004). Freund (2003) proposed the hypothesis from his experimental results that earthquake-related electric currents along the fault zones caused the geomagnetic fluctuations. If such electric currents discharged, the fault zone rocks might have recorded the strong current- induced magnetic field. Here, we present paleomagnetic evidence for the hypothesis from a thousand-meter deep drilled fault brecciated samples of Taiwan Chelungpu-fault Drilling Project (TCDP). Three major fault zone around 1136m, 1194m, 1243m showed anomalously strong natural remanent magnetizations (NRM) which were 10~100 times larger than those of host rocks, and the ratio (REM) of NRM and saturation isothermal remanences of brecciated rocks show a one-order-of-magnitude higher value of 0.12 than that of normal volcanic lavas in thermal origin. To estimate the REM value if such lithofacies samples acquired the thermal remanent magnetization (TRM) accompanying the fault motions, we carried out an examination to make host rock samples acquire TRM. In the result, the REM value of a sample heated to 600Ž and cooled in 100/muT (twice as strong as earth field) is 0.03, so that 0.12 cannot be considered TRM acquired in earth field. Additionally, the paleomagnetic directions for these samples showed a much shallower or deeper paleomagnetic inclination data which didn't correspond to the geomagnetic inclination at Taiwan. These suggest the presence of strong ambient fields induced from lightning-like currents despite beneath a deep crust if the magnetic carrier is magnetite. To confirm the magnetic mineral carries the remanent magnetization, we examined the magnetic mineralogy by Electron Backscatter Diffraction (EBSD) and scanning magneto-impedance (MI) microscopy. As a result, we identified magnetite as the magnetic carrier. Because such strong magnetic field cannot be produced by geomagnetic dynamo, these data may provide a natural example of earthquake-associated underground strong currents.

Tachibana, S.; Nakamura, N.; Mishima, T.; Hirono, T.; Soh, W.; Song, S.

2009-05-01

298

Further considerations of evaluation competencies in Taiwan.  

PubMed

A list of evaluator competencies (Stevahn, King, Ghere, & Minnema, 2005) was adapted to fit the Taiwanese context by Lee, Altschuld, & Lee (2012). It was studied as to how it generalized to a large sample in Taiwan. Likert and Fuzzy surveys with needs assessment formats (importance and competence) were mailed via random assignment to two groups of participants. The questions for the study were: do the modified competencies relate country-wide to Taiwan, did the investigation uncover training needs for evaluators, and were there convergent rating patterns across the two forms of the instrument? The results supported a fit of the modified competencies to the context and convergent validity was observed but strong competency needs were not apparent. Reasons for the findings and implications for future research are discussed. PMID:23856505

Lee, Yi-Fang; Altschuld, James W; Lee, Lung-Sheng Steven

2013-06-20

299

Deformation and seismicity of Taiwan.  

PubMed

14C-dated Holocene coastal uplift, conventional and satellite geodetic measurements, and coseismic and aseismic fault slip reveal the pattern of distributed deformation at Taiwan resulting from convergence between the Philippine Sea plate and Eurasia; as in other subduction orogenic settings, the locus of strain release and accumulation is strongly influenced by changes in fault geometry across strike. Uplift evidence from the islands of Lutao and Lanhsu is consistent with progressive oblique collision between the Luzon arc and the Chinese continental margin. In the Coastal Range, geodetic and seismic records show that shortening is taken up serially by discontinuous slip on imbricate faults. The geodetic data point to net extension across the Central Range, but deformed Holocene shorelines in the Hengchun Peninsula at its southern extremity suggest that the extension is a superficial effect partly caused by blind reverse faulting. The fastest shortening rates indicated by geodesy are recorded on the Longitudinal Valley fault and across the Chukou fault within the fold-and-thrust belt. In the former, the strain is dissipated mainly as aseismic reverse and strike-slip displacement. In contrast, the fold-and-thrust belt has witnessed five earthquakes with magnitudes of 6.5 or above in the 20th century, including the 1999.9.21 Chi-Chi earthquake (magnitude approximately 7.6) on a branch of the Chukou fault. The neotectonic and geodetic data for Taiwan as a whole suggest that the fold-and-thrust belt will continue to host the majority of great earthquakes on the island. PMID:11016964

Vita-Finzi, C

2000-10-10

300

Observation of 2009 Typhoon Morakot induced excess freshwater pulse in Taiwan surrounding seas  

NASA Astrophysics Data System (ADS)

Typhoon Morakot was a category 2 typhoon hit southern Taiwan and brought record-breaking rainfall, ~4 m at some spots, during 8-10 August 2009. The estimate volume of freshwater discharged into Taiwan Strait amounts up to 32 cubic km from the major rivers in Taiwan’s west coast. The excess freshwater pulse mixed with ambient seawater and was transported by Taiwan Strait current. Two joint hydrographic surveys using two research vessels each were conducted in the Taiwan Strait and the sea northeast of Taiwan roughly 5 days and 2.5 weeks after Morakot, which captured the unusual mixed water. During the first survey, a ?-shaped diluted water plume with salinity ~1 psu less than climatology, 33-33.5, was found off northern tip of Taiwan. The diluted plume met the Kuroshio in the sea northeast of Taiwan forming strong salinity front and thus strong velocity vertical shear which may drag the Kuroshio landward onto the East China Sea shelf. The hydrography obtained in the second survey suggests that the diluted plume merged to and was carried by the Kuroshio towards northeast. The Kuroshio presented a meander like path northeast of Taiwan. A cold anomaly which is frequently called cold-dome appeared in the upper layer off northeastern Taiwan. The typhoon-caused excess freshwater pulse must induce considerable baroclinic effect along the coast and may affect current structure in coastal region. It may cause biological blooms in the upper layer due to its nutrient richness and the physical processes in the vertical. Although the record-breaking rainfall-caused freshwater pulse was a once every 50 years event, it may become more frequent hereafter due to global climate change.

Jan, S.; Yang, Y.; Wang, J.; Gawarkiewicz, G.; Kuo, J.

2010-12-01

301

Onychomycosis in Taiwan.  

PubMed

The pathogens of onychomycosis have implications in choosing therapy. We aimed to survey the pathogens of onychomycosis in Taiwan and further analyse the distribution of pathogens in various conditions. We also compared the distribution of pathogens in Taiwan with those in various countries. This study included 182 cases of onychomycosis who attended our clinic between January and December 2001. Histopathologic examination and fungus culture of the nail specimens were performed to confirm the diagnosis and identify the pathogens. The pathogens were dermatophytes in 101 patients (55.5%), Candida in 66 (36.3%), and non-dermatophyte moulds in 16 (8.2%). Candida was more frequently seen in patients older than 60 years (40.9%), females with fingernail onychomycosis (66.7%) or combined fingernail and toenail onychomycosis (58.3%), and presence of paronychia (57.9%). Dermatophytes are the predominant pathogens in temperate Western countries; meanwhile, Candida and non-dermatophyte moulds are prevailing in Mediterranean and tropical countries including Taiwan. Clinicians should appreciate that the pathogens of onychomycosis may vary in different patient groups and geographical locations, and choose optimal antifungal agents accordingly. PMID:16033611

Wang, S H; Chi, C C

2005-08-01

302

Management and Performance of Taiwan’s Waste Recycling Fund  

Microsoft Academic Search

Taiwan’s resource recycling program was formally established in 1989, starting with the mandatory recycling of polyethylene terephthalate bottles. The number of mandatory regulated materials was extended to 8 categories with 27 items by 2002. Because of false data reporting, financial scandal, lack of transparency of the system, and the demand from parliament, the recycling policy has gradually changed from entirely

Kuo-Shuh Fan; Chun-Hsu Lin; Tien-Chin Chang

2005-01-01

303

Erosion effects assessed by repeated gravity measurements in southern Taiwan  

NASA Astrophysics Data System (ADS)

We analyse temporal variations of gravity measured in southern Taiwan since November 2006 at 10 sites using absolute gravimeters and, since November 2008, at 70 sites using a relative gravimeter. We describe and apply methods to interpret the gravity changes in terms of local hydrological processes and vertical ground motions. The effect of land water is computed from local rainfall data and a model of rain accumulation and discharge in the ground. The effect of the vertical motions of the ground is estimated using time-series of permanent Global Positioning System (GPS) stations and the theoretical gravity to height ratio of -2 ?Gal cm-1. Unexpectedly, Morakot typhoon (2009 August), the strongest typhoon in Taiwan in 50 yr, was responsible for the highest gravity changes. Morakot triggered numerous large landslides and debris flow deposits. Their thicknesses are estimated from the gravity changes (up to ˜280 ?Gal) along with field observations and satellite images.

Mouyen, M.; Masson, F.; Hwang, C.; Cheng, C.-C.; Le Moigne, N.; Lee, C. W.-.; Kao, R.; Hsieh, W.-C.

2013-01-01

304

Efficient tracking of cyclic human motion by component motion  

Microsoft Academic Search

A set of techniques are presented for Bayesian tracking of cyclic human motion based on decomposing a complex cyclic motion into component motions. Phases of the component motions are defined and two different mechanisms for coupling the phases are described: importance sampling and an observation model. The intensity of coupling is adaptively adjusted during tracking such that strong coupling is

Cheng Chang; Rashid Ansari; Ashfaq Khokhar

2004-01-01

305

Shear Wave Structure of Umbria and Marche, Italy, Strong Motion Seismometer Sites Affected by the 1997-98 Umbria-Marche, Italy, Earthquake Sequence  

USGS Publications Warehouse

A long sequence of earthquakes, eight with magnitudes between 5 and 6, struck the Umbria and Marche regions of central Italy between September 26, 1997 and July 1998. The earthquake swarm caused severe structural damage, particularly to masonry buildings, and resulted in the loss of twelve lives and about 150 injuries. The source of the events was a single seismogenic structure that consists of several faults with a prevailing northwest-southeast strike and crosses the Umbria-Marche border. The focal mechanism of the largest shocks indicates that the events were the product of shallow extensional normal faulting along a NE-SW extension perpendicular to the trend of the Apennines. The network of analog seismometer stations in the Umbria and Marche regions recorded motions of the main September and October 1997 events and a dense array of mobile digital stations, installed since September 29, recorded most of the swarm. The permanent national network Rete Accelerometrica Nazionale (RAN) is administered and maintained by Dipartimento delle Protezione Civile (DPC: Civil Protection Department); the temporary array was managed by Servizio Sismico Nazionale (SSN) in cooperation with small agencies and Universities. ENEA, the operator of many seismometer stations in Umbria, is the public Italian National Agency for New Technologies, Energy and the Environment. Many of the temporary and permanent stations in the Italian seismic network have little or no characterization of seismic velocities. In this study, we investigated 17 Italian sites using an active-source approach that employs low frequency harmonic waves to measure the dispersive nature of surface waves in the ground. We used the Spectral Analysis of Surface Wave (SASW) approach, coupled with an array of harmonic-wave electro-mechanical sources that are driven in-phase to excite the ground. An inversion algorithm using a non-linear least-squares best-fit method is used to compute shear wave velocities for up to 100 meters of the soil column. A draft report was published in the summer of 2008, followed by a comment period, lengthy discussions with Italian colleagues, and improved knowledge of the subsurface at the sites from soil logs. Four of the sites were reprocessed in order to correct issues with phase unwrapping of the field dispersion curves that complicated the velocity profile calculations at the lowest velocity sites. This report presents the final results from the reprocessing effort.

Kayen, Robert; Scasserra, Giuseppe; Stewart, Jonathan P.; Lanzo, Giuseppe

2008-01-01

306

Car-Parrinello simulation of the vibrational spectrum of a medium strong hydrogen bond by two-dimensional quantization of the nuclear motion: application to 2-hydroxy-5-nitrobenzamide.  

PubMed

The nature of medium strong intra- and intermolecular hydrogen bonding in 2-hydroxy-5-nitrobenzamide in the crystal phase was examined by infrared spectroscopy and Car-Parrinello molecular dynamics simulation. The focal point of our study was the part of the infrared spectra associated with the O-H and N-H stretching modes that are very sensitive to the strength of hydrogen bonding. For spectra calculations we used an isolated dimer and the fully periodic crystal environment. We calculated the spectra by using harmonic approximation, the time course of the dipole moment function as obtained from the Car-Parrinello simulation, and the quantization of the nuclear motion of the proton for an instantaneous snapshot of the structures in one and two dimensions. Although quantitative assessment of the agreement between the computed and experimental band contour is difficult due to the fact that the experimental band is very broad, we feel that the most reasonable qualitative agreement with the experiment is obtained from snapshot structures and two-dimensional quantization of the proton motion. We have also critically examined the methods of constructing the one-dimensional proton potential. Perspectives are given for the treatment of nuclear quantum effects in biocatalysis. PMID:22429110

Brela, Mateusz; Stare, Jernej; Pirc, Gordana; Sollner-Dolenc, Marija; Boczar, Marek; Wójcik, Marek J; Mavri, Janez

2012-04-06

307

Deterministic seismic hazard map for Taiwan developed using an in-house Excel-based program  

NASA Astrophysics Data System (ADS)

Seismic hazard analyses, either in a deterministic (DSHA) or probabilistic (PSHA) framework, are both commonly adopted for evaluating earthquake risk. Although different in methodology, both approaches involving tedious calculation are certainly a computer-aided analysis. For Taiwan, a few PSHA studies have been conducted, but not a single comprehensive DSHA study is yet available for this region. As a result, this study aims to develop a DSHA seismic hazard map for Taiwan through an Excel-based program. In use of the in-house program, the result shows that the deterministic seismic hazards for Taiwan are comparable to those estimated by the recent PSHA; in particular the 50th PGA (mean motion) in this DSHA was found in a good agreement with the PSHA at 10% exceedance probability in 50 years. In addition to developing the DSHA map for Taiwan, this paper provides the details of the in-house, Excel-based tool for Excel applications in geosciences studies.

Wang, Jui-Pin; Huang, Duruo; Yang, Zijiang

2012-11-01

308

Combining strong-motion, InSAR and GPS data to refine the fault geometry and source kinematics of the 2011, Mw 6.2, Christchurch earthquake (New Zealand)  

NASA Astrophysics Data System (ADS)

The space-time distribution of coseismic slip of the 2011 February 21, Mw 6.2, Christchurch earthquake, New Zealand, is explored, differently from all previous studies, through a joint inversion of geodetic and strong-motion data. The geodetic data consist of both global position system (GPS), from campaign and continuous stations, and synthetic aperture radar (SAR) interferograms from two ascending satellite tracks. The strong motion data consist of 10 stations located in the Canterbury plains, these stations offering a good azimuthal coverage of the event. The kinematic rupture model for the analysed event was obtained using the parametrization and non-linear inversion scheme proposed by Delouis et al. In particular, for any subfault we explore for the local source time function (local slip history), slip direction and rupture onset time. The geometry of the fault plane used for the kinematic inversion is inferred from the analysis of the geodetic data. To validate our results we perform a resolution study for both the single and complete data sets, and an errors analysis of our final kinematic rupture model. Considering the complexity highlighted by superficial deformation data, we adopted a fault model consisting of two partially overlapping segments, with dimensions 15 × 11 and 7 × 7 km2, corresponding to different faulting types. This two-fault model, instead of single-fault model, is needed to reconstruct the complex shape of the superficial deformation data. The total seismic moment resulting from the joint inversion is 3.0 × 1025 dyne · cm (Mw = 6.2) with an average rupture velocity of 2.0 km s-1.

Toraldo Serra, Eugenio Maria; Delouis, Bertrand; Emolo, Antonio; Zollo, Aldo

2013-09-01

309

76 FR 13982 - Antidumping Duty Order: Polyvinyl Alcohol From Taiwan  

Federal Register 2010, 2011, 2012, 2013

...A-583-841] Antidumping Duty Order: Polyvinyl Alcohol From Taiwan AGENCY: Import...an antidumping duty order on polyvinyl alcohol (PVA) from Taiwan. DATES...investigation of PVA from Taiwan. See Polyvinyl Alcohol From Taiwan: Final...

2011-03-15

310

Motion graphs  

Microsoft Academic Search

In this paper we present a novel method for creating realistic, controllable motion. Given a corpus of motion capture data, we automatically construct a directed graph called a motion graph that encapsulates connections among the database. The motion graph consists both of pieces of original motion and automatically generated transitions. Motion can be generated simply by building walks on the

Lucas Kovar; Michael Gleicher; Frederic H. Pighin

2002-01-01

311

Taiwan’s 1991 second national assembly election  

Microsoft Academic Search

The author assesses Taiwan’s fifth competitive national election and its first ever nonsupplementary election. The electorate\\u000a picked a “new” National Assembly, absent those elected on the mainland before 1949 or later appointed to fill vacancies. The\\u000a election was a major victory for the ruling Nationalist Party or Kuomintang (KMT) affording it perhaps its first real mandate\\u000a — a product of

John F. Copper

1992-01-01

312

Industry Sector Analysis, Taiwan: Cosmetics.  

National Technical Information Service (NTIS)

The market survey covers the cosmetics market in Taiwan. The analysis contains statistical and narrative information on projected market demand, end-users; receptivity of Taiwanese consumers to U.S. products; the competitive situation, and market access (...

1993-01-01

313

The Political Environment on Taiwan.  

National Technical Information Service (NTIS)

This paper examines the political framework within which foreign businessmen operate on Taiwan. In brief, the government supervises the economy and the foreign businessman more closely than has been the case in, for example, Singapore and Hong Kong. On th...

M. Pillsbury

1975-01-01

314

Liver Disease Survey on Taiwan.  

National Technical Information Service (NTIS)

The results of a review of liver biopsy tissue from 220 Chinese jaundiced individuals on Taiwan showed that the three most common diseases were viral hepatitis, postnecrotic cirrhosis, and hepatocarcinoma. The results of transaminase tests are given for 4...

S. C. Sun W. C. Cooper R. K. Gershon J. W. Fresh

1965-01-01

315

Progress and Prospect of Physics Research and Education in Taiwan  

NASA Astrophysics Data System (ADS)

Started about two decades ago, the global trend of shifting industrial manufacture power from western developed countries toward developing countries in Asia has in turn become the impetus in building up physical science and research in these areas. A very good example is the remarkable progress of physical research and education in Taiwan, in terms of quantity and quality. The continuous elevation of Taiwan's high education into graduate level plus the government's strong commitment to research and development on a level of 2.62 % GDP have led to an impressive physics program with an annual budget ˜32 million USD from National Science Council in supporting 568 PIs. The investigation scope encompasses high energy and astrophysics, nano and condensed matter, and semiconductor, optoelectronic physics, etc. The former is vigorously conducted via international collaborative efforts of LHC, KEK, ALMA, Pan-STARRS, etc. The latter is driven by vital Taiwan high tech industry mostly semiconductor IC and optoelectronics flourished during this period. The early trend of outflows of BS physics majors to western world for advanced studies has reversed dramatically. Nearly 80% of the BS students continue their MS and PhD degrees in Taiwan, attracted by lucrative job markets of high tech industry. In addition, healthy inflow of high-quality science manpower of well trained PhDs and senior scholars returning to homeland has strengthened the competitiveness. Overall, the physics community in Taiwan is thriving. The annual Physical Society meeting is expanding at a rate of 6%, reaching ˜1800 attendants and 1200 papers, and dedicated to promotions of female physicists and students. The publication quantity of Taiwan in top journals of PRs and PRL is ranked among top 20^th for all fields of physics, and ranked the 6^th in APL. Clearly Taiwan has now emerged as a strong power in applied science, not limited by its population size. Concerted efforts on scientific exchanges are being taken to connect to international societies. The bright outlook of physical science and its vital power in Taiwan is anticipated to provide a stimulus to benefit South East Asia, and have far-reaching impacts on China and worldwide.

Raynien Kwo, J.

2010-03-01

316

Tide-surge Interaction Intensified by the Taiwan Strait  

NASA Astrophysics Data System (ADS)

The Taiwan Strait is a long and wide shelf-channel where the hydrodynamics is extremely complex, being characterized by strong tides, and where storm surges frequently occur during the typhoon season. Obvious oscillations due to tide-surge interaction were observed by tide gauges along the northern Fujian coast, the west bank of the Taiwan Strait, during Typhoon Dan (1999). Numerical experiments indicate that nonlinear bottom friction (described by the quadratic formula) is a major factor to predict these oscillations while the nonlinear advective terms and the shallow water effect have little contribution. It is found that the tide-surge interaction in the northern portion of the Taiwan Strait is intensified by the strait. Simulations based on simplified topographies with and without the island of Taiwan show that, in the presence of the island, the channel effect strengthens tidal currents and tends to align the major axes of tidal ellipses along the channel direction. Storm-induced currents are also strengthened by the channel. The pattern of strong tidal currents and storm-induced currents along the channel direction enhances tide-surge interaction via the nonlinear bottom friction, resulting in the obvious oscillations along the northern Fujian coast.

Zhang, Wen-Zhou; Shi, Fengyan; Hong, Hua-Sheng; Shang, Shao-Ping; Kirby, James T.

2010-06-01

317

Taiwan and ROC: A critical analysis of President Chen Shui-bien's construction of Taiwan identity in national speeches  

Microsoft Academic Search

Names used to address Taiwan – such as taiwan and zhonghuamingguo (Republic of China [ROC]) – are symbols defining Taiwan's political realities, each with their own unique historical significance. Since his election in 2000, Taiwan's president Chen Shui-bien has had to alternate between taiwan and ROC to strike a balance among conflicting ideas about Taiwan's national identity. The act is

Hui-Ching Chang; Rich Holt

2009-01-01

318

Why do companies choose to go ipos? New results using data from Taiwan  

Microsoft Academic Search

We examine the determinants of IPOs in Taiwan for the period 1989 to 2000. The regulations in Taiwan permit us to identify\\u000a firms that met IPO requirements but chose not to go public, allowing for comparisons of firms that choose IPOs and those do\\u000a not. We find strong evidence that IPOs are not motivated by financing need, that larger and

Yang-Pin Shen; Peihwang Wei

2007-01-01

319

Characters of Vertical Variability with Geodetic Satellites and Ground-based Continuous GPS in Taiwan  

Microsoft Academic Search

Present-day GPS network have been extensively used to monitor crustal deformation due to various geodynamic mechanisms. Situated among the Pacific Ring of Fire on the suture zone of Eurasian and Philippine Sea Plates, the island of Taiwan with a dense continuous GPS network since ~1996 and now over 300 stations sees plenty of geophysical phenomena including particularly prominent crustal motions.

C.-C. Yang; Y.-H. Wu; B. F. Chao; S.-B. Yu

2009-01-01

320

Joint Inversion of Seismic and Geodetic Data for the Source of the 4th March 2010 MW 6.3 Jia-Shian, SW Taiwan, Earthquake  

NASA Astrophysics Data System (ADS)

The 4th March 2010 Jia-Shian (MW 6.3) earthquake occurred in SW Taiwan and caused moderate damage. According to the Central Weather Bureau (CWB) report, this event is located at a depth of ~23 km under the Central Range. No fault related surface rupture was observed, reflecting an unusually deep source that is relatively rare in west Taiwan. The coseismic GPS measurements show a fan shape pattern with azimuths from SW to NW. The highest observed horizontal displacement is 3.67 cm in the direction of N80°W and is about 20 km far away from the epicenter. We develop finite-source models using a combination of Global Positioning System (GPS), synthetic aperture radar interferometry (InSAR), and seismic strong motion waveform data to understand the rupture process of this event. The preferred model shows a primary slip patch that is about 20 km in diameter with a peak slip of 25.1 cm and total scalar seismic moment of 1.96 × 1018 N m (MW 6.13). This fault geometry is N38°W in strike and 27° dipping to NE. The majority of slip is between 8 and 14 cm located to the NW of the hypocenter, which is very close to the northern end of the active Chi-Shan Fault (CSF) and the high angle reverse Chao-Chou Fault (CCF). Our moment tensor solution using data from the Broadband Array in Taiwan for Seismology (BATS) shows a NW-striking and east dipping thrust with a left-lateral strike-slip component to the focal mechanism, which is close to the current direction of plate motion in Taiwan. The main shock mechanism and the aftershock distribution have different orientations, neither of which is similar to NS or NE-SW trending Chi-Shan and Chao-Chou surface faults. The aftershock sequence extends nearly 25 km into western Foothills striking EW when close to the epicenter but in a NW direction farther west from the epicenter. The different directions from the main shock to the aftershock distribution may imply different fault planes being ruptured during coseismic and postseismic periods. In addition, the focal mechanisms of aftershocks show two strikes and two senses of motions: one is close to the main shock and another is in a more E-W direction with a larger left-lateral strike-slip component. Both agree well with the orientations of the aftershock sequence. The primary east-dipping detachment of Taiwan is generally at the depths of 10-15 km in the north-central Taiwan but becomes deeper in the south, which is very close to the Jia-Shian earthquake hypocenter. As the result, the main shock might locate right above the detachment and then transferred the stress westward. This stress change might induce a series of aftershocks, and then illuminated a pre-existing fault. Hence, the stress changes from this event could enhance or decrease the regional Coulomb stress level to the nearby faults, which could be an important indicator of potential earthquake hazards in SW Taiwan.

Huang, M.; Dreger, D. S.; Burgmann, R.; Suppe, J.; Hashimoto, M.

2010-12-01

321

The regulation of new media in Taiwan  

Microsoft Academic Search

This paper discusses the development of the new media in Taiwan, and the related regulatory issues debated by government officials, academicians, and the telecommunications industry. The cable laws, satellite policy, and telecommunications law emerging in Taiwan are looked at.

Bonnie Peng

1994-01-01

322

Investigation of Flood Inundation Probability in Taiwan  

Microsoft Academic Search

Taiwan is located at a special point, which is in the path of typhoons from northeast Pacific Ocean. Taiwan is also situated in a tropical-subtropical transition zone. As a result, rainfall is abundant all the year round, especially in summer and autumn. For flood inundation analysis in Taiwan, there exist a lot of uncertainties in hydrological, hydraulic and land-surface topography

Chia-Ho Wang; Yen-Wei Lai; Tsang-Jung Chang

2010-01-01

323

Fluctuations of the thermal fronts off northeastern Taiwan  

NASA Astrophysics Data System (ADS)

A high-resolution sea surface temperature (SST) data derived from several satellites is used to investigate the variability of the thermal front off northeastern Taiwan. Hidden by a dominant annual cycle, the SST data cannot reveal the thermal front fluctuation in the form of Hovmöller diagram. An innovative methodology has been applied to the SST satellite imagery to derive the SST Standardized Index (SSTSI), capable of revealing the frontal variability with multiple time scales. Principal component analysis shows that the SSTSI variation consists mainly of two modes. Mode 1 represents a strong annual cycle related to the seasonal reversal of the monsoonal winds. The temperature gradient is enhanced in winter and a cold dome is observed off northern Taiwan in summer. Mode 2 is highly correlated with the upstream Kuroshio variability. The shoreward (seaward) migration of the thermal front takes place when the Kuroshio transport weakens (strengthens). The results are consistent with transports estimated by tidal gauge measurements, satellite altimeter-based sea level anomaly, and surface flow patterns derived from high-frequency radars. Mode 2 is coherent with the Kuroshio transport through the East Taiwan Channel at periods of 120 and 45 d with a time lag of 40 and 11 d, respectively. This 120 d fluctuation is due to the interaction between westward-propagating eddies and the Kuroshio east of Taiwan, while the 45 d signal arises from the Kuroshio's self-instability. The interannual variations of the SST pattern in winter and summer are also discussed.

Hsin, Yi-Chia; Chiang, Tzu-Ling; Wu, Chau-Ron

2011-10-01

324

Water mass and throughflow transport variability in the Taiwan Strait  

Microsoft Academic Search

Variability of water mass and throughflow transport in the Taiwan Strait are analyzed using strait-wide conductivity-temperature-depth (1985–2003) and sectional acoustic Doppler current profiler (1999–2001) data. Results from a cluster analysis, temperature-salinity diagrams, and direct transport calculations indicate that the strong northeast monsoon drives the brackish Mixed China Coastal Water into the northern strait and hinders the northward intruded saline Kuroshio

Sen Jan; David D. Sheu; Huei-Ming Kuo

2006-01-01

325

Largest Taiwan SPM terminal installed  

SciTech Connect

This paper reports on the largest Taiwan single-point mooring (SPM) terminal. Chinese Petroleum Corp. (CPC) last year installed and commissioned Taiwan's SPM terminal. This, the third of four planned SPM terminals, is unloading 100,000-300,000 dwt crude-oil tankers 5 miles offshore Kaohsiung, Taiwan, on the southwest coast of the Republic of China. Construction on the fourth SPM terminal, for unloading naphtha and diesel gas oil from 20,000 -100,000 dwt tankers, began late last year. The third terminal consists of a catenary anchor leg mooring (CALM) system, a 56-in, (1,422 mm) OD crude-oil pipeline and a 16-in. (406 mm) OD fuel-oil pipeline. The subsea pipelines extend from the CALM installed in a water depth of 118 ft to an existing shore tank farm tie-in valve station.

Schultz, A.R. (Intec Engineering Inc., Houston, TX (US))

1992-02-17

326

Motion Commotion  

NSDL National Science Digital Library

Students learn why and how motion occurs and what governs changes in motion, as described by Newton's three laws of motion. They gain hands-on experience with the concepts of forces, changes in motion, and action and reaction. In an associated literacy activity, students design a behavioral survey and learn basic protocol for primary research, survey design and report writing.

Integrated Teaching And Learning Program

327

Seeing Motion  

NSDL National Science Digital Library

Explore your own straight-line motion using a motion sensor to generate distance versus time graphs of your own motion. Learn how changes in speed and direction affect the graph, and gain an understanding of how motion can be represented on a graph.

Consortium, The C.

2011-12-11

328

International Benchmarking with the Best Universities: Policy and Practice in Mainland China and Taiwan  

ERIC Educational Resources Information Center

|With a strong conviction to enhance their global competitiveness, governments across different parts of the world have tried various means to promote the ranking of their universities in the global university leagues. With a strong determination to do better in such global ranking exercises, universities in mainland China and Taiwan have…

Mok, Ka Ho; Chan, Ying

2008-01-01

329

Shear wave anisotropy beneath the Taiwan orogen  

NASA Astrophysics Data System (ADS)

Shear wave splitting in regional and teleseismic shear waves (ScS and S) has been analyzed for fast polarization directions and delay times at 33 short-period and 17 broad-band permanent and temporary seismic stations in the Taiwan region. The orientations of anisotropy for the Taiwan stations are generally parallel to the strike of the mountain belt, with a clockwise rotation following the trend of regional geologic fabric in north Taiwan. The delay times, on the other hand, vary greatly from 0.5 to 2.1 s; the largest values are from the southwestern Taiwan foothills, and an abrupt change in delay times is found in south Taiwan. The main source of shear wave splitting in Taiwan is compatible with an anisotropic region between 25 and 230 km depths. The observed splitting parameters are consistent with upper mantle anisotropy resulting from the collisional tectonics that built the Taiwan orogen.

Rau, R.-J.; Liang, W.-T.; Kao, H.; Huang, B.-S.

2000-04-01

330

Strong Interaction  

SciTech Connect

We will give here an overview of our theory of the strong interactions, Quantum Chromo Dynamics (QCD) and its properties. We will also briefly review the history of the study of the strong interactions, and the discoveries that ultimately led to the formulation of QCD. The strong force is one of the four known fundamental forces in nature, the others being the electromagnetic, the weak and the gravitational force. The strong force, usually referred to by scientists as the 'strong interaction', is relevant at the subatomic level, where it is responsible for the binding of protons and neutrons to atomic nuclei. To do this, it must overcome the electric repulsion between the protons in an atomic nucleus and be the most powerful force over distances of a few fm (1fm=1 femtometer=1 fermi=10{sup -15}m), the typical size of a nucleus. This property gave the strong force its name.

Karsch, F.; Vogelsang, V.

2009-09-29

331

The 2005 Ilan earthquake doublet and seismic crisis in northeastern Taiwan: evidence for dyke intrusion associated with on-land propagation of the Okinawa Trough  

NASA Astrophysics Data System (ADS)

Northern Taiwan underwent mountain building in the early stage of the Taiwan orogeny but is currently subjected to post-collisional crustal extension. It may be related to gravitational collapse or to the rifting of the Okinawa Trough, which lies offshore northeastern Taiwan. The Ilan Plain, northeastern Taiwan, which is bounded by the normal fault systems and filled up with thick Pliocene-Pleistocene sedimentary sequences, formed under such an extension environment. Over there on 2005 March 5 two earthquakes with about the same magnitude (ML = 5.9) occurred within 68 s and produced intense aftershocks activity according to the records of Central Weather Bureau Seismic Network of Taiwan. We relocated the earthquake sequence by the three-dimension earthquake location algorithm with the newly published 3-D Vp and Vp/Vs velocity model, and determined the first-polarity focal mechanisms of the earthquake doublet. One major cluster of aftershocks which trends E-W and dips steeply to the south can be identified and picked up as a potential fault plane. The focal mechanisms of the two main shocks are both classified as normal type by first-polarity but strike-slip by centroid moment tensor inversion; however two methods both yield consistent E-W strike. Static coseismic deformation was additionally determined from Global Positioning System (GPS) daily solutions at a set of continuous GPS stations and from strong-motion seismographs. These data show NW-SE extension at high angle to the fault plane, which cannot be explained from a simple strike-slip double-couple mechanism. On the other hand, the small vertical displacements and steep fault plane cannot be explained from a simple normal event as well. We present from elastic dislocation modelling that the geodetic data are best explained by significant component of tensile source with centimetre-scale of opening on a 15-km-long fault extending from 1 to 13 km depth. We therefore interpret the crisis as the result of dyke intrusion at the very tip of the Okinawa Trough, which is reasonably driven by backarc spreading.

Lai, Kuang-Yin; Chen, Yue-Gau; Wu, Yih-Min; Avouac, Jean-Philippe; Kuo, Yu-Ting; Wang, Yu; Chang, Chien-Hsin; Lin, Kuan-Chuan

2009-11-01

332

Herbal Medicine Research in Taiwan*  

PubMed Central

Of all the countries in the world, why did you choose Taiwan to pursue your study? It is a question that I (comments of the first author) have answered a thousand times. My first visit to a laboratory at National Taiwan University opened my eyes to the possibilities of herbal medicine research, especially in the area of veterinary medicine. It became my ambition to link the knowledge of Traditional Chinese Medicine (TCM) and Ayurveda from the Indian subcontinent and their integration with other systems of medicine, including Western medicine (WM), to achieve the concept of Sustainable Medicine, firstly for animals and then for humans. The Ministry of Economic Affairs (MOEA) has implemented a technology development program to quickly establish the key technologies, and this is a moment of opportunity for Taiwan's traditional herbal medicine industry to upgrade and transform itself. This paper, initially intended to be a student's narration, has evolved into a multi-author treatise on the present state and likely future scenario of herbal medicine research in Taiwan.

Kaphle, Krishna; Wu, Leang-Shin; Yang, Nai-Yen Jack; Lin, Jen-Hsou

2006-01-01

333

Orientation and Mobility in Taiwan.  

ERIC Educational Resources Information Center

|This article describes a three-month orientation and mobility (O&M) program conducted for four potential teachers of individuals with blindness in Taipei (Taiwan). Challenges in residential areas, business areas, buildings, and use of mass transit are illustrated. Although the travel environments were more complex than those in the United States,…

Leja, James A.

1993-01-01

334

Kindergartener's Technology Education in Taiwan.  

ERIC Educational Resources Information Center

|According to the American Association for Advancement of Sciences, the National Academy of Engineering, and the International Technology Education Association (ITEA) and its Technology for All Americans Project (TfAAP), technology education should begin in kindergarten. Educators in Taiwan have also advocated beginning technology education in…

Lai, Chun-Chin

335

Sinonasal Metastatic Tumors in Taiwan  

Microsoft Academic Search

Background: To analyze the incidence of the metastatic tumors within sinonasal tract in Taiwan and review the data in the English literature. Methods: Retrospective reviewed of patients from 1990 to 2005 with a histologically proven diagnosis of metastatic malignancies in the sinonasal tract. Results: Among seventeen enrolled patients, 9 were men and 8 were women, with ages ranging from 24

Hsueh-Hsin Huang; Tuan-Jen Fang; Po-Hung Chang; Ta-Jen Lee

336

Orientation-Independent Measures of Ground Motion  

Microsoft Academic Search

The geometric mean of the response spectra for two orthogonal hori- zontal components of motion, commonly used as the response variable in predictions of strong ground motion, depends on the orientation of the sensors as installed in the field. This means that the measure of ground-motion intensity could differ for the same actual ground motion. This dependence on sensor orientation

David M. Boore; Jennie Watson-Lamprey; Norman A. Abrahamson

2006-01-01

337

Motion Sickness  

MedlinePLUS

... alone. Motion sickness, whether on boats or in planes, cars or amusement rides, can strike anyone. 290229 ... alone. Motion sickness, whether on boats or in planes, cars or amusement rides, can strike anyone. Take ...

338

The network structure of big business in Taiwan  

Microsoft Academic Search

This paper takes a network approach to understanding ownership patterns and director interlocks in Taiwan. In particular,\\u000a this paper analyzes ties among Taiwan’s top 200 publicly listed companies in 1990 and 2000. The speed of change in Taiwan’s\\u000a economic organization during the period has been striking. Not only have the identities of many of Taiwan’s largest firms\\u000a changed, there seems

Jonathan Brookfield

2010-01-01

339

Arsenic and Humic Substances in Alluvial Aquifers of Bangladesh and Taiwan: A Comparative Study  

NASA Astrophysics Data System (ADS)

Humic substances in groundwater samples from the arsenicosis area in Bangladesh, northern Taiwan and the Blackfoot disease (BFD) area in southwestern Taiwan were characterized by Fluorescence Spectroscopy (FS), and Fourier Transform Infrared Spectroscopy (FTIR) analyses. As, Mn, Fe, Sr, Se levels in these groundwaters were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Major ions and selected water parameters including pH, electrical conductivity (EC), oxidation reduction potential (ORP), and dissolved oxygen (DO) were also determined. Groundwater As concentration ranges from 1.4 to 140 ?g/L in the alluvial aquifers located in the Chapai-Nawabganj district of Bangladesh. As levels in groundwater ranges from 0.5 to 560 ?g/L in the Ilan Plain of northern Taiwan. Geothermal waters in the Beitou hot springs contain high concentrations of inorganic As (up to 3,975 ?g/L); geothermal activity is likely responsible for the significant discharge of arsenic to the downstream Kwandu Plain. As levels in the BFD area of southwestern Taiwan ranges from 25 ?g/L to 967 ?g/L. Interestingly, groundwater arsenic in the BFD area of southwestern Taiwan correlates positively with strong fluorescence (maximum relative fluorescence intensity upto 495) and the content of humic substances. In contrast, As-rich groundwaters from Chapai-Nawabganj district of Bangladesh and northern part of Taiwan generally have relatively low content of humic substances with weak fluorescence (maximum relative fluorescence intensity upto 65 and 121, respectively). Moreover, results of FTIR analysis show that humic substances extracted from water samples of the Taiwan BFD area contain phenolic and amines groups of humic substances, which tend to form organo-metal complexes with As and other trace elements. High levels of As and humic substances probably play a critical role in causing the Black foot disease in Chia-Nan plain of southwestern Taiwan.

Reza, A.; Jean, J.; Lee, M.

2007-12-01

340

Motion warping  

Microsoft Academic Search

We describe a simple technique for editing captured or keyframed animation based on warping of the motion parameter curves. The animator interactively defines a set of keyframe-like constraints which are used to derive a smooth deformation that preserves the fine structure of the original motion. Motion clips are combined by overlapping and blending of the parameter curves. We show that

Andrew P. Witkin; Zoran Popovic

1995-01-01

341

Motion Constants  

Microsoft Academic Search

A Bose condensate of electrons may exist in nickel hydrogen and palladium hydrogen systems. The motion constants associated with the gravitational and nuclear forces motion tend toward the electromagnetic in these systems. The change in the motion constants produces unexpected gravitomagnetic and nuclear affects.

Frank Znidarsic

2000-01-01

342

Queering Taiwan: in search of nationalism's other.  

PubMed

This article deals with the formation of Taiwan’s homosexual cultural politics in the 1990s, the impact and implications of which are yet to be examined within the larger context of Taiwan’s cultural and political development and ethnic relationships. It is argued that the rise of this cultural politics is both a reflection and a source of a growing sense of identity crisis on the island. By examining the configurations of “queer” in various discursive domains, this interdisciplinary study seeks to delineate the cross-referencing ideological network of this cultural movement and its entanglement with the complexity of Taiwan’s nationalism. At the same time, to the extent that this movement tends to present itself as a radical politics from a privileged epistemological and cultural standpoint, this claimed radicalism is also scrutinized for its problematics and ironies. PMID:21966703

Chen, Li-fen

2011-01-01

343

Current situation and industrialization of Taiwan nanotechnology  

Microsoft Academic Search

Nanotechnology is projected to be a very promising field, and the impact of nanotechnology on society is increasingly significant\\u000a as the research funding and manufactured goods increase exponentially. A clearer picture of Taiwan’s current and future nanotechnology\\u000a industry is an essential component for future planning. Therefore, this investigation studies the progress of industrializing\\u000a nanotechnology in Taiwan by surveying 150 companies.

Hsin-Ning Su; Pei-Chun Lee; Min-Hua Tsai; Kuo-Ming Chien

2007-01-01

344

Plate motion  

SciTech Connect

The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

Gordon, R.G. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

345

International Travelers from Taiwan  

Microsoft Academic Search

Taiwanese outbound travel market has been continuously growing but little in-depth research has investigated this market. This study uses discriminant analysis to examine Taiwanese outbound travelers whose travel philosophy is strongly oriented toward inclusive package vacations versus those who are not through their sociodemographics, travel characteristics, and benefits pursued variables. The results indicate that philosophy is a useful way to

Cheng-Te Lang; Joseph T. Oleary; Alastair M. Morrison

1997-01-01

346

Motion-based motion deblurring.  

PubMed

Motion blur due to camera motion can significantly degrade the quality of an image. Since the path of the camera motion can be arbitrary, deblurring of motion blurred images is a hard problem. Previous methods to deal with this problem have included blind restoration of motion blurred images, optical correction using stabilized lenses, and special cmos sensors that limit the exposure time in the presence of motion. In this paper, we exploit the fundamental trade off between spatial resolution and temporal resolution to construct a hybrid camera that can measure its own motion during image integration. The acquired motion information is used to compute a point spread function (psf) that represents the path of the camera during integration. This psf is then used to deblur the image. To verify the feasibility of hybrid imaging for motion deblurring, we have implemented a prototype hybrid camera. This prototype system was evaluated in different indoor and outdoor scenes using long exposures and complex camera motion paths. The results show that, with minimal resources, hybrid imaging outperforms previous approaches to the motion blur problem. We conclude with a brief discussion on how our ideas can be extended beyond the case of global camera motion to the case where individual objects in the scene move with different velocities. PMID:18579930

Ben-Ezra, Moshe; Nayar, Shree K

2004-06-01

347

The Taiwan Telemetered Seismographic Network  

Microsoft Academic Search

In 1972, the Taiwan Telemetered Seismographic Network (TTSN) was installed to monitor earthquakes occurring in an area from 21 to 26°N latitude and from 119 to 123°E longitude. The number of stations increased from six in 1972 to 24 in 1987. The stations are equipped with velocity-type seismometers with a natural frequency of 1 Hz. Since 1983, horizontal-component sensors have

Jeen Hwa Wang

1989-01-01

348

Applying environmental externalities to US Clean Coal Technologies for Taiwan  

SciTech Connect

During the period 1971 to 1980, electricity consumption in Taiwan increased remarkably at an average rate of 12.2% per year. Despite experiencing a record low in 1982 and 1983, electricity demand returned to double digit growth, reaching 11.6% and 10.2% in 1987 and 1988, respectively, due to a strong economic recovery. In 1988, 71.6 TWh of electricity was produced, 21.1 TWh of which was from coal-fired units (29%). The electricity demand for Taiwan is expected to continue to grow at a very rapid rate during the 1990--2006 time frame. The average load is expected to grow at an annual rate of 5.6% while the peak load is projected to increase at an annual rate of 6.0%. All new coal-fired power plants are expected to comply with government regulations on S0{sub 2}, NO{sub x}, and particulate emissions. Taper reports that all of its proposed coal-fired units will be equipped with modern flue gas emission reduction devices, such as electrostatic precipitators or baghouse filters, flue gas desulfurization and deco{sub x} devices, to reduce the pollutants to their minimum practical levels. New coal-based generation requirements in the sizes needed in Taiwan create an opportunity for several of the Cats currently under demonstration in the United States. Options to be considered are described.

Szpunar, C.B.; Gillette, J.L.

1992-01-01

349

Applying environmental externalities to US Clean Coal Technologies for Taiwan  

SciTech Connect

During the period 1971 to 1980, electricity consumption in Taiwan increased remarkably at an average rate of 12.2% per year. Despite experiencing a record low in 1982 and 1983, electricity demand returned to double digit growth, reaching 11.6% and 10.2% in 1987 and 1988, respectively, due to a strong economic recovery. In 1988, 71.6 TWh of electricity was produced, 21.1 TWh of which was from coal-fired units (29%). The electricity demand for Taiwan is expected to continue to grow at a very rapid rate during the 1990--2006 time frame. The average load is expected to grow at an annual rate of 5.6% while the peak load is projected to increase at an annual rate of 6.0%. All new coal-fired power plants are expected to comply with government regulations on S0{sub 2}, NO{sub x}, and particulate emissions. Taper reports that all of its proposed coal-fired units will be equipped with modern flue gas emission reduction devices, such as electrostatic precipitators or baghouse filters, flue gas desulfurization and deco{sub x} devices, to reduce the pollutants to their minimum practical levels. New coal-based generation requirements in the sizes needed in Taiwan create an opportunity for several of the Cats currently under demonstration in the United States. Options to be considered are described.

Szpunar, C.B.; Gillette, J.L.

1992-09-01

350

The Methane Sources and Flux in Offshore SW Taiwan  

NASA Astrophysics Data System (ADS)

The widely distributed BSRs imply the existence of potential gas hydrates in offshore southwestern Taiwan. The analyzed results reveal that sites with high methane concentrations are mainly distributed in the active margin and only few sites that composed of high methane concentrations in the passive margin. The carbon isotopic data show that most methane gases from offshore cored sediments are biogenic source in origin. However, some samples from active margin do also exhibit heavier carobn isotopic compositions, which range from -40 to -60 permil and are similar with the gas composition of inland mud volcanoes of SW Taiwan. It implies that there is also thermogetic gas source in this region. From some methane profiles, parallel methane gradients and different SMI depths could be found. This might be due to methane migrate to surface sediments from the same gas reservoir and with the same diffusive rates. Therefore, the methane flux could be estimated based on the sulfate reduction rate. Though BSRs are widely distributed both in the active margin and in the passive margin, most sites with high methane concentrations and flux have been discovered in the active margin. Therefore, we consider that different tectonic settings in offshore SW Taiwan might strongly control the stability of gas hydrates, and then affect the methane concentrations and fluxes of the cored sediments.

Yang, T. F.; Lin, S.; Wang, Y.

2009-12-01

351

Seismogenic Structures in Hualien Region, eastern Taiwan  

NASA Astrophysics Data System (ADS)

Due to extremely high seismicity and abundant tectonic-influenced geomorphic features, eastern Taiwan has long been known as a tectonically active region. The geological model of an on-going arc-continent collision was successfully proposed to explain the arrangement of the tectonic entities and their interaction. The convergent situation between Eurasia plate and Philippine Sea plate is believed still being existing because of no geomorphic evidence directly related to significant subsidence of the backbone mountain range. However, in the north of the Coastal Range, the Philippine Sea plate is moving northerly downward by the subduction mechanism. Accordingly the fault systems on-land and offshore should be significantly different. With an attempt to answer the puzzle mentioned above we therefore analyze the seismogenic structures in northern part of eastern Taiwan. We adopt the double difference (hypoDD) method to relocate earthquakes, apply the GOCAD (Geologic Computer Aided Design) to visually image the 3D subsurface structures, and determine the rupture plane by the Finite Dimension Source Model (FDSM) from first motion focal mechanisms. Selected earthquakes are (1) located within region between 121.2 ˜122° E and 23.5 ˜24.5° N; (2) M{ L }?3; (3) and showing clearly P or S arrived time at least 6 recorded stations. Additionally, we determine the M { L } ?4 focal mechanisms by using the first P wave polarities to examine the reliability of rupture planes determined above. A few of seismogenic structures are clearly identified in this study. Looking at the E-W profile, a major reverse fault dipping 60° to the east is found in depth of 20-40 km beneath the Coastal Range, which is probably the subsurface image of the plate boundary. On the other hand, within the Central Range several N-S oriented high-angle normal faults are found near the surface in the western part of the study area. The second one from the west reflects the subsurface extension of Lishan fault. In the eastern margin of the Central Range seismic clusters in depth of 10-20 km show high-angle reverse faults. Such a situation of compression down beneath but extension above may suggest a flower structure of the back-bone range. To the Hualien coast and offshore area no more mountains exist but we still found a west-dipping thrust in shallow depth, indicating the existence of the shortening. Further north, a complex seismic cluster is dominated by strike-slip and tensional earthquakes, but no fault plane can be recognized by spatial distribution.

Kuochen, H.; Wu, Y.; Chen, Y.; Chen, R.; Kuo, Y.

2004-12-01

352

Magical Motion  

NSDL National Science Digital Library

Students watch video clips from the October Sky and Harry Potter and the Sorcerer's Stone movies to see examples of projectile motion. Then they explore the relationships between displacement, velocity and acceleration, and calculate simple projectile motion. The objective of this activity is to articulate concepts related to force and motion through direct immersive interaction based on "The Science Behind Harry Potter" theme. Students' interest is piqued by the use of popular culture in the classroom.

University Of Houston

353

Animating Motion  

NSDL National Science Digital Library

This lesson challenges students to apply their knowledge of object motion by animating sequences of hand-rendered pictures that model a set of physical conditions. The challenges include animating the orbital motion of planets and satellites, the effects of gravity on a falling body, and motions of objects in inertial (moving) frames of reference. The lesson was created by a high school physics teacher to help learners build quantitative reasoning skills in preparation for understanding kinematics.

Latham, Ted

2004-07-16

354

Active tectonics of frontal thrust, southwestern Taiwan orogenic belt  

NASA Astrophysics Data System (ADS)

Thrust belts are characterized by great earthquakes, crustal shortening deformation, and extraordinary topographic relief and represent a fundamental manifestation of deformation in active orogenic belt. During the Quaternary period, Taiwan Orogen in arc-continent collisional convergent settings occurs as a result of the active thin-skin thrust belt which is displayed in the Western Foothills, western Taiwan. The Western Foothills represent a zone of ongoing convergence which shortening occurs in response to the thrusts westward movement. Recent geodetic studies indicate present shortening rates of ca. 40 mm/yr within the Western Foothills, southwestern Taiwan. It suggested high rates of deformation and is often considered to behave as a strong deformation within the southwestern Taiwan. In the study area is a ongoing deformation front which is dominated by a NE-SW trending structure fabric that consist of three active thrust faults. The geomorphic expression, which preserves a young surface features, is made up of five topographic and structural provinces of the Western Foothills, Chungchou Marine Terrace, Dawan Lowland, Tainan Tableland, and Chianan Coastal Plain from east to west which province due to the tectonic deformation were created during the late Pleistocene, that have been subsequently deformed by a major thrust of the Tainan fault and three imbricated faults of the Lungchuan, Meilin, and Chungchou faults. In this study we first use continuously cored boreholes to reconstruct the depositional architecture and 14C dating of the Holocene sediments, result of this analysis is able to assess the uplift rate and activity. The long-term vertical deformation rate of the Chianan Coastal Plain, Tainan Tableland, Dawan Lowland, Chungchou Marine Terrace, and Western Foothills was about -6 to 0, 0 to 5, -2 to 1, 1 to 4, and 6 to 7 mm/yr, respectively.

Chen, W.; Chou, F.; Yang, C.; Yang, H.

2009-04-01

355

Democratic Reforms in Taiwan: Issues for Congress.  

National Technical Information Service (NTIS)

Taiwan, which its government formally calls the Republic of China (ROC), is a success story for U.S. interests in the promotion of universal freedoms and democracy. Taiwan's people and their leaders transformed politics from rule imposed from the outside ...

S. A. Kan

2010-01-01

356

Management of scrap computer recycling in Taiwan  

Microsoft Academic Search

It is estimated that approximately 300,000 scrap personal computers are generated each year in Taiwan [S.-L. Chang, A Study on the Scrap Computer Treatment Cost, Environment Protection Administration of Taiwan, December 1998 (in Chinese)]. The disposal of such a huge number of scrap computers presents a difficult task for the island due to the scarcity of landfills and incineration facilities

Ching-Hwa Lee; Ssu-Li Chang; King-Min Wang; Lih-Chyi Wen

2000-01-01

357

Energy conservation of buildings in Taiwan  

Microsoft Academic Search

This paper highlights the research projects on building energy conservation studies conducted by the authors recently. These projects were all sponsored by the Energy Commission of Taiwan in an effort to promote research activities on building energy conservation and to obtain database specifically for the Taiwan area, so that appropriate energy-related policies can be made on a sound basis. The

Kuan-hsiung Yang; R. L. Hwang

1995-01-01

358

Foreign factors in Taiwan's economic transformation  

Microsoft Academic Search

This paper aims to explore the foreign influences on Taiwan's economic transformation over the past 40 years. While exports have always been important in sustaining Taiwan's economic growth, the driving force behind exports has changed from inward investment to outward investment. The analysis carried out is from an international political economy perspective and takes a historical overview. It argues that

Min-Hua Chiang; Bernard Gerbier

2010-01-01

359

ED overcrowding in Taiwan: Facts and strategies  

Microsoft Academic Search

The objective of this study was to quantity the extent of emergency department (ED) overcrowding in Taiwan and to identify possible solutions. The ED log was reviewed for all patients who presented to the National Taiwan University Hospital's ED from January 16, 1996 through February 15, 1996. Charts from patients held longer than 72 hours were reviewed. Among 5,810 patients,

Fuh-Yuan Shih; Matthew Huel-Ming; Shyr-Chyr Chen; Hsio-Po Wang; Cheng-Chung Fang; Ren-Shi Shyu; Guan-Tarn Huang; Shih-Ming Wang

1999-01-01

360

Development of surrogate organic contaminant parameters for source water quality standards in Taiwan, ROC  

Microsoft Academic Search

The objective of this research was to develop a rationale for selecting representative water quality parameters for organic contaminants and microorganisms and determining their respective contaminant level (or regulated value) for the source water quality standards in Taiwan. It was observed that chemical oxygen demand (COD) and total organic carbon (TOC) have strong correlation with UV254 in spite of the

E. E Chang; P. C. Chiang; T. F. Lin

1998-01-01

361

PROUD TO BE CHINESE: LITTLE LEAGUE BASEBALL AND NATIONAL IDENTITIES IN TAIWAN DURING THE 1970s  

Microsoft Academic Search

Defeated by the communists in 1949, the Chinese Nationalist Party (KMT) sought refuge in Taiwan under the conditions of war and aggression that produced strong defensive nationalism and an intensive struggle for national identification. The KMT faced a dual crisis of legitimacy during the 1970s, both domestically and internationally, after being expelled from the United Nations. The urgency of seeking

Junwei Yu; Alan Bairner

2008-01-01

362

Internationalization or Commodification? A Case Study of Internationalization Practices in Taiwan's Higher Education  

ERIC Educational Resources Information Center

|This article examines how commodification and consumerism have sharpened the discourse of internationalization in Taiwan's higher education. Given the strong sense of crisis in the less prestigious universities, this article argues that internationalization is only a means to survive instead of a pursuit of excellence to these universities. This…

Chen, Dorothy I-ru; Lo, William Yat Wai

2013-01-01

363

Present-day Crustal Deformation of Taiwan  

NASA Astrophysics Data System (ADS)

Taiwan, seated at the junction of the Manila and the Ryukyu subduction systems, is a classical case of the ongoing arc-continent collision due to convergence between the Eurasian and the Philippine Sea plates. We analyzed 601 GPS observations in Taiwan to understand the kinematics of present-day crustal deformation of the Taiwan mountain belt. Horizontal GPS velocities, relative to the Chinese continental margin station, S01R, represent a fan-shaped pattern and gradually decrease northwestward from ~82 mm/yr in SE Taiwan to nearly no deformation in NW coastal area. Directions of the horizontal velocities are dominantly toward NW in central Taiwan and the clockwise rotation and counterclockwise rotation are occurring in northern and southern Taiwan, respectively. For stations between the Chishan fault and the western flank of the southern Central Range in southern Taiwan, most station velocities are consistent (51.9 ± 6.6 mm/yr) and, from east to west, the azimuths change gradually from 277° to 247°. In northern Taiwan, magnitudes of northwestward velocities are 0.3-7.8 mm/yr in NW part of this area and vectors of 9.3-41.2 mm/yr from 53° to 146° occur in the Ilan area. Three significant features are characterized based on the analyses of velocities and 3-D block modeling results. First, tectonic block rotations are mostly concentrated on the northern Taiwan, which correspond to the transition from the Ryukyu subduction to the Taiwan collision zone. The roll-back of Ryukyu trench and the opening of Okinawa trough are probably superposed on the arc-continent collision-induced rotation in northern Taiwan mountain belt. Second, block translations are mainly occurred in southern Taiwan. The interaction between the Peikang basement high and the westward propagation of the accretionary wedge results in the material across southern Taiwan to move toward WSW, sub-parallel to the southern edge of the continental margin, via the strain partitioning along several major structures. Third, high slip rate deficits are mainly derived along the active faults in the Ilan area and along the northern Longitudinal Valley fault, which may correspond to the areas with high earthquake potential.

Ching, K.; Rau, R.; Hu, J.; Lee, J.; Johnson, K. M.

2009-12-01

364

Beam motions near separatrix  

SciTech Connect

Experimental data on particle motion near the separatrix of the one dimensional (1-D) fourth-integer islands are an-alyzed. When the beam bunch is initially kicked to the separatrix orbit, we observed a strong decoherence in the coherent betatron motion. We find that, through intensive particle tracking simulation analysis, the decoherence has resulted from the beam being split into beamlets in the beta-tron phase space. However, we also observe an unexpected recoherence of coherence signal, which may result form a modulated closed orbit or the homoclinic structure near the separatrix.

M. Ball et al.

1999-05-04

365

Southern Taiwan - an Evolving "Coastal Range"?  

NASA Astrophysics Data System (ADS)

As a part of the TAIGER research, existing tectonic concepts are continuously being reviewed in light of new data and for experimental design. One of the critical areas for understanding the tectonics of Taiwan is southern Taiwan. Seismicity and recent tomographic imaging confirm that the tectonics of Taiwan is controlled by the subduction and collision of two plates: the Philippine Sea plate (PSP) and the Eurasian plate (EUR). In northern and central Taiwan the PSP is in collision with EUR, and at the same time subducts northward under northern Taiwan [Wu et al., 2008]. Before the PSP subducts to sufficient depth, the collision of PSP and EUR produced the Foothills and the Central Range on the EUR and the Coastal Range on the PSP side. For southern Taiwan, with 22.7°N as a rough demarcation, the tectonic interpretation is at variance and still in debate. To the east of southern Taiwan the inactive andesitic volcanic islands of Lutao and Lanhsu mark the top of the Luzon arc, separated from Taiwan by a somewhat deformed fore-arc basin [McIntosh et al., 2005]. To its west the Manila Trench is the western limit of a series of trend-parallel small thrusts on the ocean floor [Lunberg et al., 1997]. As the Trench approaches the continental shelf from the south it gradually loses its bathymetric signature. Southern Taiwan itself is commonly viewed as a part of the accretionary prism, and yet is also considered a continuation of the Central Range, produced by the collision of the Luzon arc and continental shelf. Suppe [1981] and many others had long recognized the central Taiwan orogeny, as a result of the collision of the Luzon Arc with the EUR continental shelf and Central Range, is built from rocks of the continental shelf. Inspection of a map of bathymetry around Taiwan shows that the continental shelf turns noticeably westward offshore of southwestern Taiwan, and that southern Taiwan is situated off the continental shelf. The presence of the Benioff zone under southern Taiwan and the normal faulting earthquakes (M7) west of Hengchun in 2006 indicate that southern Taiwan is a part of the PSP that is moving over the subducting EUR. It appears that southern Taiwan has not yet fully engaged in collision with EUR. This interpretation implies that the high topography of southern Taiwan is not created in the same manner as the Central Range. But how was it created? Where is the boundary between the EUR and PSP on land? If southern Taiwan does move westward as a part of PSP then when it collides with the continental shelf it will become a part of a new coastal range. A reexamination is timely as new sea-land, local and teleseismic tomography, more detailed seismicity, and dense GPS data are becoming available, and when there are chances to enhance experiments early next year for testing ideas. References Lunberg et al., 1997. Tectonophysics 274, 5-23. McIntosh et al., 2005. Tectonophysics, 401,23-54. Suppe, J., 1981. Geol. Soc. China, Mem. 4, 67- 89. Wu et al., 2008. Manuscript submitted to JGR.

Wu, F. T.; McIntosh, K.; Lavier, L. L.

2008-12-01

366

Triggering Factor of Strong Earthquakes and Its Prediction Verification  

NASA Astrophysics Data System (ADS)

After 30 yearsS research, we have found that great earthquakes are triggered by tide- generation force of the moon. ItSs not the tide-generation force in classical view- points, but is a non-classical viewpoint tide-generation force. We call it as TGFR (Tide-Generation ForcesS Resonance). TGFR strongly depends on the tide-generation force at time of the strange astronomical points (SAP). The SAP mostly are when the moon and another celestial body are arranged with the earth along a straight line (with the same apparent right ascension or 180o difference), the other SAP are the turning points of the moonSs relatively motion to the earth. Moreover, TGFR have four different types effective areas. Our study indicates that a majority of earthquakes are triggering by the rare superimposition of TGFRsS effective areas. In China the great earthquakes in the plain area of Hebei Province, Taiwan, Yunnan Province and Sichuan province are trigger by the decompression TGFR; Other earthquakes are trig- gered by compression TGFR which are in Gansu Province, Ningxia Provinces and northwest direction of Beijing. The great earthquakes in Japan, California, southeast of Europe also are triggered by compression of the TGFR. and in the other part of the world like in Philippines, Central America countries, and West Asia, great earth- quakes are triggered by decompression TGFR. We have carried out examinational im- mediate prediction cooperate TGFR method with other earthquake impending signals such as suggested by Professor Li Junzhi. The successful ratio is about 40Key words: imminent prediction; triggering factor; TGFR (Tide-Generation ForcesS Resonance); TGFR compression; TGFR compression zone; TGFR decompression; TGFR decom- pression zone Triggering factor of strong earthquakes and its prediction verification

Ren, Z. Q.; Ren, S. H.

367

Motion sickness: a negative reinforcement model.  

PubMed

Theories pertaining to the "why" of motion sickness are in short supply relative to those detailing the "how." Considering the profoundly disturbing and dysfunctional symptoms of motion sickness, it is difficult to conceive of why this condition is so strongly biologically based in humans and most other mammalian and primate species. It is posited that motion sickness evolved as a potent negative reinforcement system designed to terminate motion involving sensory conflict or postural instability. During our evolution and that of many other species, motion of this type would have impaired evolutionary fitness via injury and/or signaling weakness and vulnerability to predators. The symptoms of motion sickness strongly motivate the individual to terminate the offending motion by early avoidance, cessation of movement, or removal of oneself from the source. The motion sickness negative reinforcement mechanism functions much like pain to strongly motivate evolutionary fitness preserving behavior. Alternative why theories focusing on the elimination of neurotoxins and the discouragement of motion programs yielding vestibular conflict suffer from several problems, foremost that neither can account for the rarity of motion sickness in infants and toddlers. The negative reinforcement model proposed here readily accounts for the absence of motion sickness in infants and toddlers, in that providing strong motivation to terminate aberrant motion does not make sense until a child is old enough to act on this motivation. PMID:19808080

Bowins, Brad

2010-01-15

368

Motion sickness: A negative reinforcement model  

Microsoft Academic Search

Theories pertaining to the “why” of motion sickness are in short supply relative to those detailing the “how.” Considering the profoundly disturbing and dysfunctional symptoms of motion sickness, it is difficult to conceive of why this condition is so strongly biologically based in humans and most other mammalian and primate species. It is posited that motion sickness evolved as a

Brad Bowins

2010-01-01

369

Fault Motion  

NSDL National Science Digital Library

This collection of animations provides elementary examples of fault motion intended for simple demonstrations. Examples include dip-slip faults (normal and reverse), strike-slip faults, and oblique-slip faults.

370

Wave Motion  

NSDL National Science Digital Library

This site from Carl Nave at Georgia State University presents a discussion of wave motion. The site explains the velocity of idealized ocean waves and details the measurement of large waves aboard the USS Ramapo.

Carl R. (Rod) Nave; University, Georgia S.

371

Motion Sickness  

MedlinePLUS

... senses movement by getting signals from your inner ears, eyes, muscles and joints. When it gets signals ... example, down below on a boat, your inner ear senses motion, but your eyes cannot tell you ...

372

Normal mode coupling due to azimuthal anisotropy in the transition zone: an example from Taiwan Island  

NASA Astrophysics Data System (ADS)

We investigate the effect of azimuthal anisotropy on coupling between spheroidal and toroidal modes at frequencies below 4 mHz after large earthquakes of Mw > 7.8, based on the seismic records from Broad-band Array in Taiwan for Seismology stations. Strong coupling of 0S25-0T25 is widely observed at Taiwan Island, but Earth's rotation cannot cause coupling between 0S25 and 0T25 according to coupling selection rules. Different from the Coriolis coupling, the anisotropic coupling of 0S25-0T25 becomes notable only when stations close to nodal lines of 0S25, and the coupling attenuates so rapidly that it is notable on the spectra of 18-24 hr vertical-component records. Modelling indicates that local azimuthal anisotropy is the most possible cause for the strong coupling. The abnormally strong coupling of 0S20-0T21 observed at Taiwan Island also shows similar characteristic of nodal nature and fast attenuation, suggesting local azimuthal anisotropy as the dominant factor for the coupling rather than the Earth's rotation, isotropy and transverse isotropy. Our estimation of sensitivity kernels indicates that the coupled modes 0S20-0T21 and 0S25-0T25 show peak sensitivity to azimuthal anisotropy at depth of 400-650 km, suggesting that the strong coupling may be explained by the presence of azimuthal anisotropy in the upper-mantle transition zone beneath Taiwan Island. The east-dipping Eurasian slab and the north-dipping Philippine Sea Plate beneath the Taiwan orogen are responsible for the formation of the anisotropy.

Hu, Xiao-Gang; Xue, Xiu-Xiu; Liu, Lin-Tao; Sun, He-Ping

2012-07-01

373

Climate and weather characteristics in association with the active fires in northern Southeast Asia and spring air pollution in Taiwan during 2010 7-SEAS/Dongsha Experiment  

NASA Astrophysics Data System (ADS)

Climatologically, the East Asian high merges with the westward expansion of the northwestern Pacific subtropical high in March. The local East–West cell/circulation is enhanced by a well-organized convergent center that forms over Indochina at 925 h Pa in March. This allows the emitted air pollutants from the biomass burning to be uplifted to the free troposphere and immediately transported downwind to the east. Using the data collected from the 2010 7-SEAS/Dongsha Experiment, six cases of long-range transport events involving air pollutants during March–April were identified at the Hengchun air quality monitoring station in southern Taiwan. These events were related to active burning phases over Indochina Peninsula. The air pollutants produced by these events were transported to Taiwan after a 2–3 day journey. A composite analysis for these identified six cases showed that the boundary layer of the southwesterly flow confluence coupled with a well-organized convergent center located over a thermal low under clear skies over the Indochina Peninsula may induce a distinct ascending motion to form the upward branch of the transient local East–West cell/circulation during the burning phase. This inferred upward motion together with the strong thermal buoyancy created by the active biomass burnings could carry the air pollutants to the lower free troposphere where they would effectively be conveyed downwind along the westerly flow above 850 h Pa level. The air pollutants were brought down to the surface by downward branch of the transient local East–West cell/circulation, which was induced by the subsidence of a cold surge anticyclone. Using continuous point sources, the six identified cases were simulated with the Hybrid Single-Particle Lagrangian-Integrated Trajectory (HYSPLIT) particle dispersion forward model to confirm our supposition regarding the mechanism for the long-range transport of Southeast Asian biomass burning pollutants that has a significant impact on the surface air quality of the downstream areas, particularly in Taiwan.

Yen, Ming-Cheng; Peng, Chi-Ming; Chen, Tsing-Chang; Chen, Ching-Sen; Lin, Neng-Huei; Tzeng, Ren-Yow; Lee, Yung-An; Lin, Cheng-Chih

2013-10-01

374

An overview of physical and biogeochemical processes and ecosystem dynamics in the Taiwan Strait  

NASA Astrophysics Data System (ADS)

The Taiwan Strait is an important channel in the west Pacific Ocean transporting water and chemical constituents between the East China Sea and the South China Sea. Due to its complex bottom topography, alternating monsoon forcing and conjunction of several current systems [such as the Zhejiang-Fujian (Zhe-Min) Coastal Current, the Kuroshio intrusion and the extension of the South China Sea Warm Current], the physical and biogeochemical processes and ecosystem dynamics in the Taiwan Strait vary significantly both in space and in time. Our recent interdisciplinary studies, combining in situ and remote sensing observations with numerical modeling, allow us to address several important issues concerning the Taiwan Strait. The temporal and spatial variation of circulation in the Taiwan Strait is modulated by strong monsoon forcing, complex topography and circulation in the northern South China Sea as well as coastal water input and the Kuroshio intrusion. The biogeochemical processes of carbon and nutrients in the Taiwan Strait depend largely on the physical forcing (external input) and the community structure (internal cycling). The primary producers in the Taiwan Strait are dominated by nano- and pico-phytoplankton, and the contribution of the microbial food web to the traditional food web is estimated to be about 30%, implying the fundamental significance of the microbial food web in this subtropical region. Upwelling is a predominant feature in the Taiwan Strait and shows dynamic short-term, seasonal and interannual variations. Combined hydrographic and satellite-derived information provides evidence on the teleconnection between the Taiwan Strait upwelling variation and the El Nino-Southern Oscillation (ENSO) climate variability. Upwelling has a tremendous impact on biogeochemical processes, biological productivity and ecosystem structure. Not only the biological productivity, but also dramatic changes in the phytoplankton community structure reveal the dynamic ecosystem responses to the variations in upwelling, which should have significant impact on the fishery resources. In this overview, we summarize the hydrographical features with an emphasis on upwelling, which is the key driver of biogeochemical processes and ecosystem dynamics in the Taiwan Strait.

Hong, Huasheng; Chai, Fei; Zhang, Caiyun; Huang, Bangqin; Jiang, Yiwu; Hu, Jianyu

375

Vection and induced visual motion  

NASA Astrophysics Data System (ADS)

When exposed to a large moving visual display, a person experiences illusory self motion (vection). Specialized devices were used to investigate the relation between illusory visual motion of stationary objects and illusory self motion induced by motion of a visual scene. In a first set of experiments, two distinct components of induced visual motion were measured: exocentric induced motion which causes a stationary object to appear to move with the self, and egocentric induced motion which causes an object to seem to move relative to the self. Another set of experiments was designed to reveal the extent to which vection depends on the presence of stationary objects in the field of view and to explore what types of relative motion between the moving display and the stationary objects most strongly induce vection. It was observed that when all stationary objects were removed, vection had a long latency and was very weak when it occurred. A third set of experiments was designed to reveal the extent to which illusory body tilt induced by viewing a tilted or rotating scene depends on the motion of a visual stimulus and on the geometrical features of the stimulus. The results reveal the relative contributions of visual polarity and visual motion to illusory body tilt and the extent to which visual stimuli can override conflicting stimuli arising from the otolith organs.

Howard, Ian P.

1991-12-01

376

Analysis of Single-Earthquake Sigma Using Taiwan Dataset  

NASA Astrophysics Data System (ADS)

The standard deviation of the logarithmic residuals in ground-motion prediction may directly influence the result of probabilistic seismic hazard analysis, especially in lower probability. "What method can reduce the sigma more?" is usually a hot issue in recent years. Now, we not only pay attention to this point, but also focus on "How the minimum variance of ground motion residuals from median attenuation can be got in nature". In this study, we used 23 Taiwan earthquakes, which have been recorded by more than 500 stations, to find out the facts. The single earthquake ground-motion attenuation form includes only propagation parameter and site parameter, because the source term is fixed. After regression using maximum likelihood method, we calculate a ground-motion residual for each station and plot the distribution. Even if the stations are very close to each other (the wave paths are very similar) or the stations are the same (the wave paths are the same), their residual still have difference. We also calculate a mean residual and a standard deviation for each 5km × 5km cell and evaluate the trend at different paths. The standard deviations of ln(PGA) for cells and earthquakes range from 0.2 to 0.6. We further analyze the single path sigma by using variogram method. We measure semi-variances at different distance bins (lags) and plot a semi-variogram. Nugget effect is commonly found in each single earthquake. This means even the distance between two stations is equal to zero; there still is significant difference in ground-motion residual. The single path sigma of ln(PGA) for earthquakes range from 0.32 to 0.56. The reduction of single path sigma (?sp) from the total sigma for earthquakes (?T) range from 20% to 40%.

SUNG, C.; Lee, C.

2011-12-01

377

Taiwan: Facing the future with nuclear power  

SciTech Connect

The republic of China on Taiwan is located approximately 100 miles off the southeast coast of mainland China, between Japan and the Philippines, and has an area of 13,970 square miles. The island nation has a population exceeding twenty million people, with over five million living in the capital of Taipei, making Taiwan the second most densely populated country in the world. The country also has one of the world`s fastest growing economies, with major industries that include electronics, textiles, food processing, chemicals and plastics. Annual growth of Taiwan`s gross national product (GNP) has averaged more than 7 percent for the past several years, and the small island is now the twelfth largest trading nation in the world, with a GNP exceeding US$200 billion.

NONE

1994-07-01

378

Antimicrobial Resistance in Streptococcus pneumoniae, Taiwan  

Microsoft Academic Search

Taiwan has one of the highest levels of antibiotic-resistant pneumococcus in the world. Pneumococcal iso- lates not susceptible to penicillin first appeared in Taiwan in 1986; in 1995 an increase in the prevalence of nonsusceptibility to penicillins, extended-spectrum cephalosporins, trimethoprim-sulfamethoxazole, and macrolides as well as multidrug resistance began to be recognized. With the persistence of antibiotic selective pressure, resistance in

Po-Ren Hsueh; Kwen-Tay Luh

2002-01-01

379

Predictive Distribution of Hynobiid Salamanders in Taiwan  

Microsoft Academic Search

Pei-Fen Lee, Kuang-Yang Lue, and Shan-Huah Wu (2006) Predictive distribution of hynobiid salamanders in Taiwan. Zoological Studies 45(2): 244-254. The distribution patterns of hynobiid salamanders in Taiwan, based on species and species complex, i.e., Hynobius arisanensis, the H. formosanus-sonani complex, and Hynobius sp. 1 (an undescribed species), were studied using a wildlife distribution database and an environmental factor database with

Pei-Fen Lee; Kuang-Yang Lue; Shan-Huah Wu

2006-01-01

380

Exploiting motion correlations in 3-D articulated human motion tracking.  

PubMed

In 3-D articulated human motion tracking, the curse of dimensionality renders commonly-used particle-filter-based approaches inefficient. Also, noisy image measurements and imperfect feature extraction call for strong motion prior. We propose to learn the correlation between the right-side and the left-side human motion using partial least square (PLS) regression. The correlation effectively constrains the sampling of the proposal distribution to portions of the parameter space that correspond to plausible human motions. The learned correlation is then used as motion prior in designing a Rao-Blackwellized particle filter algorithm, RBPF-PLS, which estimates only one group of state variables using the Monte Carlo method, leaving the other group being exactly computed through an analytical filter that utilizes the learned motion correlation. We quantitatively assessed the accuracy of the proposed algorithm with challenging HumanEva-I/II data set. Experiments with comparison with both the annealed particle filter and the standard particle filter show that the proposed method achieves lower estimation error in processing challenging real-world data of 3-D human motion. In particular, the experiments demonstrate that the learned motion correlation model generalizes well to motions outside of the training set and is insensitive to the choice of the training subjects, suggesting the potential wide applicability of the method. PMID:19369156

Xu, Xinyu; Li, Baoxin

2009-04-14

381

Taiwan: Biotechnology. Agrisure MIR604 Corn Receives Taiwan Approval, 2007. GAIN Report Number TW7037.  

National Technical Information Service (NTIS)

Taiwan grants an approval license to Agrisure MIR604 corn for food, feed and processing use. The license is valid for five years, effective October 22, 2007. Taiwan biotech regulations require a renewal process before the license expires. Licenses for RRS...

C. M. Perng

2007-01-01

382

Uniform Motion  

NSDL National Science Digital Library

The Video Analysis of Uniform Motion lab uses the Tracker video analysis tool to measure and analyze the motion of a steel ball rolling with constant velocity on an aluminum track. The zip file contains the lab handout, two videos (slower speed ball and faster speed ball), and the Tracker file. To open the Tracker file, download and run Tracker from http://www.cabrillo.edu/~dbrown/tracker/. Tracker is free. The videos can be used with other video analysis software; however, the handout has screen captures from Tracker and instructions specifically written for Tracker.

Titus, Aaron

2010-08-11

383

Evaluation of Regional Seismic Models in Taiwan by the TAIGER Active-Source Experiments  

NASA Astrophysics Data System (ADS)

In the Taiwan region, the complex geometry and mechanism in the collision and subduction zone between Eurasia and the Philippine Sea plates result in extremely complicated structure in the crust and uppermost mantle. As part of the TAiwan Integrated GEodynamics Research (TAIGER) project, a series of active-source experiments were conducted in the spring of 2008 providing high-quality records of a number of explosions at nearly 1000 recording sites distributed on the island of Taiwan and the surrounding seafloor. In this work, we use the TAIGER explosion records to examine the effect of three-dimensional (3D) crustal and uppermost mantle structure beneath Taiwan on the traveltimes of seismic waves and evaluate the performance of currently available 3D models for the Taiwan region in predicting seismic traveltimes. We measure the onset times of the first-motions from the records of the TAIGER explosions. The spatial distribution of the observed first-arrival times exhibits clearly the possible pattern in the lateral variations in the P-wave speed. We also calculate the synthetic seismograms in both 1D and 3D models using two different methods: the frequency-wavenumber (FK) and finite-difference (FD) methods. Both methods calculate the seismograms accurately, although the FK method can only be used for 1D models. We also measure the first-arrival times in all of the synthetic seismograms. Comparisons between the model-predicted first-arrival times and the observations demonstrate the improvement of the 3D models over the 1D model. Detailed examination of the differences in theoretical and observed first-arrival times also allows us to evaluate the relative strengths and weaknesses of the current 3D models in different parts of the region.

Lin, Y.; Zhao, L.; Hung, S.

2008-12-01

384

A High Frequency View of 1999 Chi-Chi, Taiwan, Source Rupture and Fault Mechanics  

NASA Astrophysics Data System (ADS)

High-frequency band-pass filtering of broadband strong-motion seismograms recorded immediately adjacent to the fault plane of the 1999 Chi-Chi, Taiwan earthquake reveals a sequence of distinct bursts, each of which can be considered as a sub-event from an asperity source of the Chi-Chi mainshock. These bursts collectively make up the entire mainshock accelerogram. Each burst may have released a significant portion of the total energy release of the Chi-Chi mainshock. Many of these bursts contain quasi-periodic sub-bursts with periods on the order of a few tenths of a second. Most bursts occur well behind the propagating rupture front. Detailed pictures of these asperity sources do not appear in conventional slip-map studies, presumably because of the low-pass filtering used in these waveform inversions. We directly used the high-frequency data to determine the origin times, locations and magnitudes of these sub-events. The first asperities to rupture in a given location follow the Chelungpu rupture propagation history at a velocity of about 2.0 km/s. Later asperity events at a given location can be interpreted as aftershocks that begin before the Chi-Chi rupture has terminated. Spatially these asperity sources appear in groups, most of which are located at shallow depth along the Chelungpu surface rupture and are consistent with the large asperities presented in source inversion studies. Asperities located at great depth suggest a non-planer rupture surface with dip increasing to the east. The frequency-magnitude distribution of these sub-events has b-value equal to 1.0. In space, the larger sub-events are located at greater depth, while the small sub-events are only located at shallower depths.

Chen, Y.; Sammis, C. G.; Teng, T.

2004-12-01

385

Quantum Motion  

NSDL National Science Digital Library

This resource illustrates the motion of a Gaussian wavepacket in one dimension scattering off of a barrier. The shape and size of the barrier can be changed, including creating a double barrier. The width, initial position, and total energy of the wavefunction can all be changed as well. Dimensionless units are used.

Group, Kansas S.; Zollman, Dean A.

2004-04-04

386

Projectile Motion  

NSDL National Science Digital Library

In this interactive simulation adapted from University of Colorado’s Physics Education Technology project, learn about projectile motion by firing various objects from a virtual cannon into the air. Experiment with the settings and try to hit a target.

Foundation, Wgbh E.

2007-04-19

387

A New Record of Ceratophyllid Flea (Siphonaptera) from Taiwan.  

National Technical Information Service (NTIS)

Twenty species of fleas hitherto recorded from Taiwan are listed. Nosopsyllus nicanus Jordan, 1937, is recorded for the first time from Rattus norvegicus and Rattus rattus tanezumi captured in the Taipei area, Taiwan. The male and female specimens are des...

J. C. Lien P. C. Fan

1971-01-01

388

New Dryinidae from Sulawesi and Taiwan (Hymenoptera: Chrysidoidea)  

Microsoft Academic Search

The following new species of Dryinidae are described: Anteon heppneri and martiale from Taiwan; Anteon cerberum, flaccum and subdignum; Thaumatodryinus noyesi; Dryinus alboniger and mansus from Sulawesi. The male of Lonchodryinus sinensis Olmi is described from Taiwan.

M. Olmi

1992-01-01

389

75 FR 15726 - Polyvinyl Alcohol From Taiwan; Determination  

Federal Register 2010, 2011, 2012, 2013

...Preliminary) (Remand)] Polyvinyl Alcohol From Taiwan; Determination...reason of imports from Taiwan of polyvinyl alcohol provided for in subheading 3905...of allegedly LTFV imports of polyvinyl alcohol from...

2010-03-30

390

Triggering Factor of Strong Earthquakes and Its Prediction Verification  

NASA Astrophysics Data System (ADS)

After 30 yearsS research, we have found that great earthquakes are triggered by tide- generation force of the moon. ItSs not the tide-generation force in classical view- points, but is a non-classical viewpoint tide-generation force. We call it as TGFR (Tide-Generation ForcesS Resonance). TGFR strongly depends on the tide-generation force at time of the strange astronomical points (SAP). The SAP mostly are when the moon and another celestial body are arranged with the earth along a straight line (with the same apparent right ascension or 180o difference), the other SAP are the turning points of the moonSs relatively motion to the earth. Moreover, TGFR have four different types effective areas. Our study indicates that a majority of earthquakes are triggering by the rare superimposition of TGFRsS effective areas. In China the great earthquakes in the plain area of Hebei Province, Taiwan, Yunnan Province and Sichuan province are trigger by the decompression TGFR; Other earthquakes are trig- gered by compression TGFR which are in Gansu Province, Ningxia Provinces and northwest direction of Beijing. The great earthquakes in Japan, California, southeast of Europe also are triggered by compression of the TGFR. and in the other part of the world like in Philippines, Central America countries, and West Asia, great earthquakes are triggered by decompression TGFR. We have carried out examinational immediate prediction cooperate TGFR method with other earthquake impending signals such as suggested by Professor Li Junzhi. The successful ratio is about 40%(from our fore- cast reports to the China Seismological Administration). Thus we could say the great earthquake can be predicted (include immediate earthquake prediction). Key words: imminent prediction; triggering factor; TGFR (Tide-Generation ForcesS Resonance); TGFR compression; TGFR compression zone; TGFR decompression; TGFR decom- pression zone

Ren, Z. Q.; Ren, S. H.

391

Taiwan Snowfall Activity and Its Association with Asian Dust Storm from 1995 to 2009  

NASA Astrophysics Data System (ADS)

While snowfall in the subtropical zone is rare, Yushan is the most famous snow spot in Taiwan. When it is snowing in mountains, people are experiencing unusually cold and wet weather in Taiwan. In this paper, snowfall activity from 1995 to 2009 and the related atmosphere circulation are examined with Taiwan CWB's weather station observations and the NCEP/DOE reanalysis atmospheric data. Also, Asian dust storm activity and PM10 concentration in Taiwan are examined with SYSNOP data and the EPA' s air quality monitoring station observation data. Our analyses show that snowfall activity is closely related to the position of EAT (East Asia Trough), strength of WPH (West Pacific High) and Asian dust storm active. Asian dust is a good ice nucleation for heterogenous freezing. Climatologically, the existence of a large-scale dry zone over mid-latitudes of Asia provides a favorable environment for the frequent occurrences of dust events and subsequent dust transport across Asia, which provides a huge amount of ice nucleation. In active year, when the EAT was shifted eastward and the strength of WPH was increased, an anticyclone anomalous occurred in the West Pacific. This anticyclone introduced anomalous southwesterly flows along the southeast cost of China and over Taiwan, resulting in a wetter-than-normal atmosphere and meanwhile the PM10 concentrations higher than usual which in favor of snowfall activity. Alternatively in inactive years, it resulted in a drier-than-normal atmosphere and a sluggish snowfall season. The SVD analysis has shown that the relation be tween the position of EAT and the anomalous pressure dipoles is rather robust, at least in those years that Asian dust storm activity is particularly strong while snowfall activity is weak (e.g., 1999, 2001, and 2002) or weak in dust storm activity and strong in snowfall activity (e.g., 19998, 2003, 2005 and 2008).

Tsai, L.; Wang, Z.; Liu, K.

2011-12-01

392

What University Governance Can Taiwan Learn from the United States?  

ERIC Educational Resources Information Center

Due to changes from centralization to marketization, Taiwan's university governance must increase its effectiveness. The purpose of this paper was to introduce trends in and issues of Taiwan's university governance, describe university governance in the United States, and draw implications that Taiwan's university governance needs to learn from…

Lee, Lung-Sheng; Land, Ming H.

2010-01-01

393

The development and regulation of occupational exposure limits in Taiwan  

Microsoft Academic Search

The occupational exposure limits (OELs) in Taiwan was promulgated in 1974 and has been revised five times since then. Many of the OELs were adopted from the most recent ACGIH TLVs and US OSHA PELs. A total of 483 chemicals were listed in the current Taiwan OELs Standard. The procedures of OELs development in Taiwan include the IOSH organized a

Tung-Sheng Shih; Kuen-Yuh Wu; Hong-I Chen; Cheng-Ping Chang; Ho-Yuan Chang; Yi-Shiao Huang; Saou-Hsing Liou

2006-01-01

394

A Study on School Leaders' Ethical Orientations in Taiwan  

Microsoft Academic Search

The purpose of this study is to explore the ethical orientations of Taiwan's school leaders by means of a questionnaire survey of 573 school leaders. A multidimensional ethical framework, including utilitarianism, justice, care, critique, and virtue, was used. The results demonstrate that the most frequent ethical orientation of Taiwan's school leaders is justice. Second, the ethical orientation of Taiwan's school

Feng Feng-I

2011-01-01

395

Combating cybercrime across the Taiwan Strait: investigation and prosecution issues  

Microsoft Academic Search

Reports have shown that Taiwan and China are attractive targets for cybercriminals. The special political situation between the two countries has encouraged numerous cyber-attacks across the Taiwan Strait. Establishing an efficient investigation and prosecution system is important to deter criminals from further exacerbating this unsatisfactory situation. This paper discusses issues of cybercrime investigation and prosecution across the Taiwan Strait. Based

Yao Chung Chang

2011-01-01

396

Combating cybercrime across the Taiwan Strait: investigation and prosecution issues  

Microsoft Academic Search

Reports have shown that Taiwan and China are attractive targets for cybercriminals. The special political situation between the two countries has encouraged numerous cyber-attacks across the Taiwan Strait. Establishing an efficient investigation and prosecution system is important to deter criminals from further exacerbating this unsatisfactory situation. This paper discusses issues of cybercrime investigation and prosecution across the Taiwan Strait. Based

Yao Chung Chang

2012-01-01

397

Large-scale seismic test program at Hualien Taiwan  

Microsoft Academic Search

The large scale seismic test (LSST) program at Hualien, Taiwan, is a follow-on to the soil-structure interaction (SSI) experiments at Lotung, Taiwan. The planned SSI studies are performed at a stiff soil site in Hualien, Taiwan, that historically has had slightly more destructive earthquakes in the past than Lotung. The objectives of the LSST program are as follows: to obtain

H. L. Graves; H. T. Tang; Y. C. Liao

1996-01-01

398

What Can Taiwan (and the United States) Expect from Japan?  

Microsoft Academic Search

In the 1990s and into the new century, increased Japanese sympathy toward Taiwan and antipathy toward mainland China led to a series of moves to improve treatment of Taiwan, including enhanced transporta- tion links, a higher level and frequency of official contacts, posting of a military attaché, and expressions of support for Taiwan's participation in regional and international organizations. Nevertheless,

Gregory W. Noble

2005-01-01

399

Taiwan's Capacity-bulding Program on Space Research and Applications  

NASA Astrophysics Data System (ADS)

The continuous buildup of the space program in Taiwan over the last decase has led to a series of scientific satellites with important applications in space study remotesensing and meteorology These include the plasma science instrument on the low-Earth orbiting satellite Formosat 1 the high-resoultion camera on Formosat 2 in sunsynchronous orbit and the GPS experiment for atmospheric study on the six microstatellites of the Formosat 3 COSMIC project Further new scientific projects are being planned The space science community in Taiwan therefore stands ready to work closely with COSPAR and its international partners in the promotion of the International Heliospheric Year IHY by providing advanced scientific observations of unique value At the same time the corresponding space research groups have established strong connections to the scientists in Southeast Asia over the last few years by organizing a series of capacity building workshops and international schools covering environmental monitoring land survey climate change atmospheric radar observations and space physics Some of these are sponsored by SARCS Southeast Asia Regional Committee of START and some by the SCOSTEP-CAWSES program In addition a vigorous IHY outreach program connecting high school students to the investigations of space weather and solar physics will be carried out by a consortium led by the Institute of Space Science of National Central University Such scientific infrastructure and experience will be of great value to future capacity-building activity in the serve of

Ip, W. H.; Chen, A. J.; Chu, Y. H.; Lee, L. C.; Liu, C. H.; Lyu, L. H.; Pan, C. J.; Su, S. Y.; Wang, J. T.; Yeh, H. C.

400

Typhoons enhancing northward transport through the Taiwan Strait  

NASA Astrophysics Data System (ADS)

Volume transport in the Taiwan Strait is usually northward for most of the year and varies seasonally because of the adjustment of the East Asian monsoon. Based on model simulations, the influence on this northward transport of every typhoon formed during the period 2005-2009 was examined. The results showed that there were four typhoons which enhanced northward transport during these five years. The current measurements, obtained from a buoy deployed in the Taiwan Strait, matched these events exactly. These typhoons had special moving tracks and life histories. They traveled westward in the area south of the strait or moved northward from the south to the north. Under the influence of such a typhoon, the prophase southward atmospheric forcing in the strait was weak and the anaphase northward atmospheric forcing (mainly along-strait wind stress) was strong, which is necessary and crucial in enhancing the northward transport. The ageostrophic process, another important driving factor in transport change, was generated mainly by local atmospheric forces inside the strait under the typhoon weather conditions and its effect on transport magnitude was comparable to that of direct atmospheric forcing. It first stored some energy from the atmospheric forcing to restrain the transport change, and then released the stored energy to prolong and even to intensify the enhanced northward transport.

Zhang, Wen-Zhou; Hong, Hua-Sheng; Yan, Xiao-Hai

2013-03-01

401

Management of scrap computer recycling in Taiwan.  

PubMed

It is estimated that approximately 300,000 scrap personal computers are generated each year in Taiwan [S.-L. Chang, A Study on the Scrap Computer Treatment Cost, Environment Protection Administration of Taiwan, December 1998 (in Chinese)]. The disposal of such a huge number of scrap computers presents a difficult task for the island due to the scarcity of landfills and incineration facilities available locally. Also, the hazardous materials contained (i.e., phosphor coatings of cathode ray tubes (CRTs), batteries, polychlorinated biphenyl capacitors, mercury-containing parts, liquid crystal display, high-lead content CRT funnel glass, and plastic containing flame-retardant bromine, etc.) in the scrap computers may seriously pollute the environment if they are not properly disposed of. Therefore, the EPA of Taiwan declared scrap personal computers the producer's recycling responsibility as of July 1997. Under this decree, the manufacturers, importers and sellers of personal computers have to properly recover and recycle the scrapped computers which they originally sell. On June 1, 1998, a producer responsibility recycling program for scrap computers was officially implemented in Taiwan. Under this program, consumers can bring their unwanted personal computers to the designated collection points and receive reward money. Currently, only six computer items are mandated to be recycled in this recycling program. They are notebooks, monitors, hard disks, power supplies, printed circuit boards and main frame shells. This article