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Sample records for taiwan strong motion

  1. Strong-motion data from the two Pingtung, Taiwan, earthquakes of 26 December 2006

    USGS Publications Warehouse

    Wu, C.-F.; Lee, W.H.K.; Boore, D.M.

    2008-01-01

    1016 strong-motion records at 527 free-field stations and 131 records at 42 strong-motion arrays at buildings and bridges were obtained for the Pingtung earthquake doublet from the Taiwan Central Weather Bureau's dense, digital strong-motion network. We carried out standard processing of these strong-motion records at free-field stations. A data set, including the originally recorded files, processed data files, and supporting software and information, is archived online http:// tecdc.earth.sinica.edu.tw/data/EQ2006Pingtung/. We have not yet completed the processing of the strong-motion array data at buildings and bridges. However, some preliminary results and the strong-motion array data recorded at the second nearest instrumented building to the Pingtung earthquake doublet are shown. This paper is intended to document our data processing procedures and the online archived data files, so that researchers can efficiently use the data. We also include two preliminary analyses: (1) a comparison of ground motions recorded by multiple accelerographs at a common site, the TAP 117 station in Taipei, and (2) attenuation of the horizontal ground motions (peak acceleration and response spectra at periods of 0.2, 1.0, and 3.0 s) with respect to distance. Our comparison study of multiple recordings at TAP 117 indicates that waveform coherence among 20- and 24-bit accelerograph records is much higher as compared to records from 16-bit or 12-bit accelerographs, suggesting that the former are of better quality. For the 20- and 24-bit accelerographs, waveform coherence is nearly 1 over the frequency range 1 to 8 Hz for all components, and is greater than about 0.9 from 8 to 20 Hz for the horizontal component, but only from 8 to 12 Hz for the vertical component. Plots of pseudo-acceleration response spectra (PSA) as a function of distance, however, show no clear indication for a difference related to the performance level of the accelerographs. The ground-motions of the first event (Mw = 7.0) are comparable, or even somewhat lower, than those from the smaller second event (Mw = 6.9), consistent with the relative difference of the local magnitudes (ML = 6.96 and 6.99 for the first and second events, respectively). The ground motions from the first event are generally lower than those predicted from equations based on other in-slab subduction earthquakes, whereas the ground motions from the second event are closer to the predictions. Ground-motions for soil sites are generally larger than those from rock sites.

  2. Strong ground motion in the Taipei basin from the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Fletcher, Joe B.; Wen, K.-L.

    2005-01-01

    The Taipei basin, located in northwest Taiwan about 160 km from the epicenter of the Chi-Chi earthquake, is a shallow, triangular-shaped basin filled with low-velocity fluvial deposits. There is a strong velocity contrast across the basement interface of about 600 m/sec at a depth of about 600-700 m in the deeper section of the basin, suggesting that ground motion should be amplified at sites in the basin. In this article, the ground-motion recordings are analyzed to determine the effect of the basin both in terms of amplifications expected from a 1D model of the sediments in the basin and in terms of the 3D structure of the basin. Residuals determined for peak acceleration from attenuation curves are more positive (amplified) in the basin (average of 5.3 cm/ sec2 compared to - 24.2 cm/sec2 for those stations outside the basin and between 75 and 110 km from the surface projection of the faulted area, a 40% increase in peak ground acceleration). Residuals for peak velocity are also significantly more positive at stations in the basin (31.8 cm/sec compared to 20.0 cm/sec out). The correlation of peak motion with depth to basement, while minor in peak acceleration, is stronger in the peak velocities. Record sections of ground motion from stations in and around the Taipei basin show that the largest long-period arrival, which is coherent across the region, is strongest on the vertical component and has a period of about 10-12 sec. This phase appears to be a Rayleigh wave, probably associated with rupture at the north end of the Chelungpu fault. Records of strong motion from stations in and near the basin have an additional, higher frequency signal: nearest the deepest point in the basin, the signal is characterized by frequencies of about 0.3 - 0.4 Hz. These frequencies are close to simple predictions using horizontal layers and the velocity structure of the basin. Polarizations of the S wave are mostly coherent across the array, although there are significant differences along the northwest edge that may indicate large strains across that edge of the basin. The length of each record after the main S wave are all longer at basin stations compared to those outside. This increase in duration of ground shaking is probably caused by amplification of ground motion at basin stations, although coda Q (0.67 - 1.30 Hz) is slightly larger inside the basin compared to those at local stations outside the basin. Durations correlate with depth to basement. These motions are in the range that can induce damage in buildings and may have contributed to the structural collapse of multistory buildings in the Taipei basin.

  3. Latest Development of Real-Time Strong-Motion Monitoring System in Taiwan

    NASA Astrophysics Data System (ADS)

    Hsiao, N.; Wu, Y.; Shin, T.; Teng, T.

    2003-12-01

    Based on the experience of the 1999 Chi-Chi Earthquake, the Central Weather Bureau (CWB) has made substantial improvements to the earthquake rapid report system. Besides the current use of digital lease phone line and internet transmission, the satellite link for station to center is setup for backup. The station is also equipped with UPS to prevent the failure of electricity power. This backup link system is designed as automatically switching in case of ground link interrupted. On the other hand, two real-time seismic sub-network are deployed stand alone at Hualein (East coast of Taiwan) and Tainan (south Taiwan) stations separately. The sub-network only manipulates real-time seismic data of nearby stations to shorten the procession time. The configuration and function of sub-network can be monitored and changed by Taipei center through computer link. Results from sub-network can be sent to Taipei center simultaneously. The collective use of these redundant systems significantly improves the capability and reliability of seismic emergency response. It will provide more robust foundation to develop earthquake early warning system. To safeguard train transportation from a disaster earthquake, the CWB assists Taiwan Railway Administration (TRA) to establish a seismic alert system including 44 3-component accelerographs along the track of the round-the-island Taiwan railway system. The configuration of the system is similar to the use of sub-network of CWB. It becomes the third backup of earthquake report system. In addition, ground vibration of a TRA instrument exceeds 180 gals, the power of the railway will be automatically cut-off to slow down the nearby train.

  4. Some observations on colocated and closely spaced strong ground-motion records of the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

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

    2003-01-01

    The digital accelerograph network installed in Taiwan produced a rich set of records from the 20 September 1999 Chi-Chi, Taiwan earthquake (Mw 7.6). Teledyne Geotech model A-800 and A-900A* digital accelerographs were colocated at 22 stations that recorded this event. Comparisons of the amplitudes, frequency content, and baseline offsets show that records from several of the A-800 accelerographs are considerably different than those from the colocated A-900A accelerographs. On this basis, and in view of the more thorough predeployment testing of the newer A-900A instruments, we recommend that the records from the A-800 instruments be used with caution in analyses of the mainshock and aftershocks. At the Hualien seismic station two A-900A and one A-800 instruments were colocated, along with a Global Positioning System instrument. Although the records from the two A-900A instruments are much more similar than those from a colocated A-800 instrument, both three-component records contain unpredictable baseline offsets, which produced completely unrealistic ground displacements derived from the accelerations by double integration, as do many of the strong-motion data from this event; the details of the baseline offsets differ considerably on the two three-component records. There are probably numerous sources of the baseline offsets, including sources external to the instruments, such as tilting or rotation of the ground, and sources internal to the instruments, such as electrical or mechanical hysteresis in the sensors. For the two colocated A-900A records at the Hualien seismic station, however, the differences in the baseline offsets suggest that the principal source is some transient disturbance within the instrument. The baseline offsets generally manifest themselves in the acceleration time series as pulses or steps, either singly or in combination. We find a 0.015-Hz low-cut filter can almost completely eliminate the effects of the baseline offsets, but then information regarding the permanent displacements is lost. The causative mechanisms of the baseline offsets are unknown presently. Hence, it is very difficult to recover the permanent displacements from the modern digital records, although for records close to large earthquakes, the signal-to-noise ratio should theoretically be adequate to obtain ground motions with periods of hundreds of seconds. This study reinforces our conclusion from previous studies that the sources of baseline offsets occurring in digital strong-motion records are very complex and often unpredictable, and that, therefore, it is difficult to remove the baseline effects to maximize the information content of the record. The baseline offsets only affect very long period motions (e.g., >20 sec), however, and therefore are of little or no engineering concern.

  5. Numerical earthquake models of the 2013 Nantou, Taiwan, earthquake series: Characteristics of source rupture processes, strong ground motions and their tectonic implication

    NASA Astrophysics Data System (ADS)

    Lee, Shiann-Jong; Yeh, Te-Yang

    2015-04-01

    On 27 March and 2 June in 2013, two moderate large earthquakes with magnitude ML 6.2 and ML 6.5, named the Nantou earthquake series, struck the Central Taiwan. These two events located in middle-to-deep crust at about 15-20 km and their epicenter were very close to the historic Nantou earthquake series which cause destructive damages in 1916-1917. These events indicate that the deep crust of Central Taiwan is an active seismogenic area even there is no evidence show a subsurface structure directly related to any faults at surface. In order to know the origins of Nantou earthquake series and their influence of strong ground shakings, we investigated the rupture processes and seismic wave propagations by using inverse and forward numerical simulation techniques. First, joint source inversions were performed by using teleseismic body wave, GPS coseismic displacements and near field ground motion data. A 3D seismic wave propagation simulation was then carrying out based on the inverted source model. Source inversion results indicate that the rupture characteristics of these two events are different. One ruptures from deep to shallow crust in northwest direction, while the other ruptures to the southwest. Three dimensional wave propagation simulation results show that the thrust movement on eastern dipping fault planes of the two events result in distinct rupture directivity effects with different amplified shaking patterns in western Taiwan. From results of the numerical earthquake models, we deduce that the occurrence of Nantou earthquake series might be related to stress releasing from the easternmost edge of a preexistent strong basement under middle-to-deep crust in Central Taiwan.

  6. GROUND MOTION ASSESSMENT BASED ON WEAK MOTION DATA IN TAIWAN Ground Motion Assessment Based on Weak Motion Data in Taiwan

    NASA Astrophysics Data System (ADS)

    Akinci, A.; D'Amico, S.; Malagnini, L.

    2010-12-01

    In this study, we characterize the scaling of the ground motions for frequencies ranging between 0.25 and 5 Hz, obtaining results for seismic attenuation, geometrical spreading, and source parameters in Taiwan. We regressed this large number of weak-motion data in order to characterize the regional propagation and the absolute source scaling. Stochastic simulations are generated for finite-fault ruptures using the obtained parameters to predict the absolute peaks of the ground acceleration and velocity for several magnitude and distance range, as well as beyond the magnitude range of the weak-motion data set on which they are calculated. The predictions are then compared with recorded strong motion data and empirical ground motion prediction equation obtained for the study region. We showed that our regional parameters, obtained from independent weak-motion database, may be applied for evaluation of ground motion parameters for earthquakes of magnitude up to 7.6.

  7. Strong motion seismology in Mexico

    NASA Astrophysics Data System (ADS)

    Singh, S. K.; Ordaz, M.

    1993-02-01

    Since 1985, digital accelerographs have been installed along a 500 km segment above the Mexican subduction zone, at some inland sites which form an attenuation line between the Guerrero seismic gap and Mexico City, and in the Valley of Mexico. These networks have recorded a few large earthquakes and many moderate and small earthquakes. Analysis of the data has permitted a significant advance in the understanding of source characteristics, wave propagation and attenuation, and site effects. This, in turn, has permitted reliable estimations of ground motions from future earthquakes. This paper presents a brief summary of some important results which are having a direct bearing on current earthquake engineering practice in Mexico.

  8. Seismic switch for strong motion measurement

    SciTech Connect

    Harben, Philip E.; Rodgers, Peter W.; Ewert, Daniel W.

    1995-01-01

    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.

  9. Seismic switch for strong motion measurement

    SciTech Connect

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

    1995-05-30

    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.

  10. Ground Motion Characteristic in the Kaohsiung Area, Taiwan

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

    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.

  11. Puerto Rico Strong Motion Seismic Network

    NASA Astrophysics Data System (ADS)

    Huerta-Lopez, C. I.; Martnez-Cruzado, J. A.; Martnez-Pagan, J.; Santana-Torres, E. X.; Torres-O, D. M.

    2014-12-01

    The Puerto Rico Strong Motion Seismic Network is currently in charge of the operation of: (i) free-field (ff) strong motion stations, (ii) instrumented structures (STR) (Dams, Bridges, Buildings), and (iii) the data acquisition/monitoring and analysis of earthquakes considered strong from the point of view of their intensity and magnitude. All these instruments are deployed in the Puerto Rico Island (PRI), US-, and British-Virgin Islands (BVI), and Dominican Republic (DR). The Puerto Rico Island and the Caribbean region have high potential to be affected by earthquakes that could be catastrophic for the area. The Puerto Rico Strong Motion Seismic Network (actually Puerto Rico Strong Motion Program, PRSMP) has grown since 1970's from 7 ff strong motion stations and one instrumented building with analog accelerographs to 111 ff strong motion stations and 16 instrumented buildings with digital accelerographs: PRI: 88 ff, 16 STR., DR: 13 ff, BVI: 5 ff, 2 STR collecting data via IP (internet), DU (telephone), and stand alone stations The current stage of the PRSMP seismic network, the analysis of moderate earthquakes that were recorded and/or occurred on the island, results of the intensity distribution of selected earthquakes, as well as results of dynamic parameter identification of some of the instrumented structures are here presented.

  12. Strong Motion Recording in the United States

    NASA Astrophysics Data System (ADS)

    Archuleta, R. J.; Fletcher, J. B.; Shakal, A. F.

    2014-12-01

    The United States strong motion program began in 1932 when the Coast and Geodetic Survey (C&GS) installed eight strong motion accelerographs in California. During the March 1933 Long Beach earthquake, three of these produced the first strong motion records. With this success the C&GS expanded the number of accelerographs to 71 by 1964. With development of less expensive, mass-produced accelerographs the number of strong motion accelerographs expanded to ~575 by 1972. Responsibilities for operating the network and disseminating data were transferred to the National Oceanic and Atmospheric Administration in 1970 and then to the U.S. Geological Survey in 1973. In 1972 the California Legislature established the California Strong Motion Instrumentation Program (CSMIP). CSMIP operates accelerographs at 812 ground stations, with multi-channel accelerographs in 228 buildings, 125 lifelines and 37 geotechnical arrays, in California. The USGS and the ANSS effort operate accelerographs at 1584 ground stations, 96 buildings, 14 bridges, 70 dams, and 15 multi-channel geotechnical arrays. The USC Los Angeles array has 78 ground stations; UCSB operates 5 geotechnical arrays; other government and private institutions also operate accelerographs. Almost all accelerographs are now digital with a sampling rate of 200 Hz. Most of the strong motion data can be downloaded from the Center for Engineering Strong Motion Data (http://strongmotioncenter.org). As accelerographs have become more sophisticated, the concept of what constitutes strong motion has blurred because small earthquakes (M ~3) are well recorded on accelerometers as well as seismometers. However, when accelerations are over ~10%g and velocities over ~1 cm/s, the accelerometers remain on scale, providing the unclipped data necessary to analyze the ground motion and its consequences. Strong motion data are essential to the development of ground motion prediction equations, understanding structural response, performance based engineering, soil response, and inversions for earthquake rupture parameters. While an important number of stations have been installed, many areas of the US are significantly deficient, e.g., recordings were obtained from only 2 stations within 60 km of the Mineral earthquake that damaged the nation's capital and other areas.

  13. Engineering applications of strong ground motion simulation

    NASA Astrophysics Data System (ADS)

    Somerville, Paul

    1993-02-01

    The formulation, validation and application of a procedure for simulating strong ground motions for use in engineering practice are described. The procedure uses empirical source functions (derived from near-source strong motion recordings of small earthquakes) to provide a realistic representation of effects such as source radiation that are difficult to model at high frequencies due to their partly stochastic behavior. Wave propagation effects are modeled using simplified Green's functions that are designed to transfer empirical source functions from their recording sites to those required for use in simulations at a specific site. The procedure has been validated against strong motion recordings of both crustal and subduction earthquakes. For the validation process we choose earthquakes whose source models (including a spatially heterogeneous distribution of the slip of the fault) are independently known and which have abundant strong motion recordings. A quantitative measurement of the fit between the simulated and recorded motion in this validation process is used to estimate the modeling and random uncertainty associated with the simulation procedure. This modeling and random uncertainty is one part of the overall uncertainty in estimates of ground motions of future earthquakes at a specific site derived using the simulation procedure. The other contribution to uncertainty is that due to uncertainty in the source parameters of future earthquakes that affect the site, which is estimated from a suite of simulations generated by varying the source parameters over their ranges of uncertainty. In this paper, we describe the validation of the simulation procedure for crustal earthquakes against strong motion recordings of the 1989 Loma Prieta, California, earthquake, and for subduction earthquakes against the 1985 Michoacn, Mexico, and Valparaiso, Chile, earthquakes. We then show examples of the application of the simulation procedure to the estimatation of the design response spectra for crustal earthquakes at a power plant site in California and for subduction earthquakes in the Seattle-Portland region. We also demonstrate the use of simulation methods for modeling the attenuation of strong ground motion, and show evidence of the effect of critical reflections from the lower crust in causing the observed flattening of the attenuation of strong ground motion from the 1988 Saguenay, Quebec, and 1989 Loma Prieta earthquakes.

  14. The Italian Strong Motion Network (RAN)

    NASA Astrophysics Data System (ADS)

    Costa, Giovanni; Ammirati, Alfredo; de Nardis, Rita; Filippi, Luisa; Gallo, Antonella; Lavecchia, Giusy; Sirignano, Sebastiano; Zambonelli, Elisa; Nicoletti, Mario

    2014-05-01

    A network for the strong motion monitoring of the territory allows recording data that provide an excellent opportunity to study the source, path, and site effects on the ground motions, specifically in near source area, for updating seismic hazard map and consequently construction codes and earthquake resistant design. Strong motion data also help to increase the effective preparation and response to seismic emergencies and the ability of a community to quickly recover from the damages of an earthquake contributes to lower the seismic risk usually measured in term of casualties and economic losses. The Italian network for monitoring the strong movement of the national territory (RAN) is the result of a fruitful cooperation over the last 16 years between the Italian government, the regions and local authorities and now counts more than 500 stations. Over the years, as a priority the DPC has focused mainly on the expansion of the network in terms of the number of measurement points and technological improvement of instrumentation as well as the data transmission system. A data acquisition centre was implemented in which the Antelope software collects, processes and archives, automatically, the data of the RAN and of the external strong motion networks that contribute to the database of the RAN. Recently the DPC has dedicated specific resources to improve the response of the network, in particular, in case of emergency. The efficiency of the network on a daily basis is not less than 95% and temporary networks were installed in the epicentral area within 24 hours after the earthquake and connected to the data acquisition centre in Rome. A fast seismic data analysis is essential to provide useful information to Authorities which make decisions immediately after a strong earthquake occurrence. During a strong earthquake, the modern accelerometers are the only instruments which can provide near source high-quality data that are important both for scientific and for civil protection purposes. Automatic and fast techniques have been developed by the University of Trieste for the automatic real-time strong motion data analysis. These techniques have been installed and customized in the data acquisition centre of the Department of Civil Protection of Italy (DPC) to process the quasi real-time data of the Italian Strong Motion Network (RAN) and to exploit information from RAN stations during seismic emergences for Civil protection purposes. RAN counts more than 500 stations covering all the Italian territory. Two local networks, the Friuli Venezia Giulia Accelerometric Network (RAF), located in NE Italy, and the Irpinia Seismic Network (ISNet), contribute their data into the RAN data acquisition system. The performance of the network and of the fast automatic strong motion data analysis during the Emilia 2012 sequence is analyzed.

  15. Strong ground motion prediction using virtual earthquakes.

    PubMed

    Denolle, M A; Dunham, E M; Prieto, G A; Beroza, G C

    2014-01-24

    Sedimentary basins increase the damaging effects of earthquakes by trapping and amplifying seismic waves. Simulations of seismic wave propagation in sedimentary basins capture this effect; however, there exists no method to validate these results for earthquakes that have not yet occurred. We present a new approach for ground motion prediction that uses the ambient seismic field. We apply our method to a suite of magnitude 7 scenario earthquakes on the southern San Andreas fault and compare our ground motion predictions with simulations. Both methods find strong amplification and coupling of source and structure effects, but they predict substantially different shaking patterns across the Los Angeles Basin. The virtual earthquake approach provides a new approach for predicting long-period strong ground motion. PMID:24458636

  16. Stochastic Ground Motion Simulation with Site Correction in Ilan Area, Northeastern Taiwan

    NASA Astrophysics Data System (ADS)

    NFN, Megawati; Kuo-Liang, Wen

    2015-04-01

    Earthquake waveform is controlled by three factors - source properties, path characteristics, and local site effects. The local site effect is the important factor participate strong ground motion prediction. In this study, we used stochastic point-source method for simulating ground motion (Boore, 2005). This method has been widely used in the development of ground-motion prediction equation and in modeling the parameters that controls observed ground motion (Atkinson et al., 2009). The shallow earthquake events which recorded by Taiwan Strong Motion Instrumentation Program (TSMIP) from 1992 to 2012 are simulated with the stochastic point-source method (Boore, 1983; Boore, 2003). The earthquake records are selected with the depth from 0 to 30 km and the magnitude (Mw) from 4 to 6.5. The study area is situated in Ilan area which is located in the northeastern Taiwan. There are 70 TSMIP stations which based on the Vs30 consist of site class B, C, D, and E. Seismic parameters for stochastic method were selected based on previous studies (Sokolov et al., 2006; 2009). The crustal amplification parameter is set to the halfspace. The empirical transfer functions from 0.2 Hz to 10 Hz for each station in Ilan area will be calculated by H/H method between observed and simulated spectra (Borcheret, 1970). Ground motion prediction is calculated by selecting several target events for stochastic point-source simulating to the halfspace. The prediction of peak ground acceleration (PGA) is estimated after doing the site correction with the empirical transfer function. Finally, the simulated ground motion was compared in time domain (PGA) and frequency domain (Degree of spectrum difference, DSPD) to show the goodness of the simulation. Keywords : Stochastic point-source method, Site effect, Empirical transfer function

  17. Strong motion duration and earthquake magnitude relationships

    SciTech Connect

    Salmon, M.W.; Short, S.A.; Kennedy, R.P.

    1992-06-01

    Earthquake duration is the total time of ground shaking from the arrival of seismic waves until the return to ambient conditions. Much of this time is at relatively low shaking levels which have little effect on seismic structural response and on earthquake damage potential. As a result, a parameter termed ``strong motion duration`` has been defined by a number of investigators to be used for the purpose of evaluating seismic response and assessing the potential for structural damage due to earthquakes. This report presents methods for determining strong motion duration and a time history envelope function appropriate for various evaluation purposes, for earthquake magnitude and distance, and for site soil properties. There are numerous definitions of strong motion duration. For most of these definitions, empirical studies have been completed which relate duration to earthquake magnitude and distance and to site soil properties. Each of these definitions recognizes that only the portion of an earthquake record which has sufficiently high acceleration amplitude, energy content, or some other parameters significantly affects seismic response. Studies have been performed which indicate that the portion of an earthquake record in which the power (average rate of energy input) is maximum correlates most closely with potential damage to stiff nuclear power plant structures. Hence, this report will concentrate on energy based strong motion duration definitions.

  18. Earthquake Scaling and Development of Ground Motion Prediction for Earthquake Hazard Mitigation in Taiwan

    NASA Astrophysics Data System (ADS)

    Ma, K.; Yen, Y.

    2011-12-01

    For earthquake hazard mitigation toward risk management, integration study from development of source model to ground motion prediction is crucial. The simulation for high frequency component ( > 1 Hz) of strong ground motions in the near field was not well resolved due to the insufficient resolution in velocity structure. Using the small events as Green's functions (i.e. empirical Green's function (EGF) method) can resolve the problem of lack of precise velocity structure to replace the path effect evaluation. If the EGF is not available, a stochastic Green's function (SGF) method can be employed. Through characterizing the slip models derived from the waveform inversion, we directly extract the parameters needed for the ground motion prediction in the EGF method or the SGF method. The slip models had been investigated from Taiwan dense strong motion and global teleseismic data. In addition, the low frequency ( < 1 Hz) can obtained numerically by the Frequency-Wavenumber (FK) method. Thus, broadband frequency strong ground motion can be calculated by a hybrid method that combining a deterministic FK method for the low frequency simulation and the EGF or SGF method for high frequency simulation. Characterizing the definitive source parameters from the empirical scaling study can provide directly to the ground motion simulation. To give the ground motion prediction for a scenario earthquake, we compiled the earthquake scaling relationship from the inverted finite-fault models of moderate to large earthquakes in Taiwan. The studies show the significant involvement of the seismogenic depth to the development of rupture width. In addition to that, several earthquakes from blind fault show distinct large stress drop, which yield regional high PGA. According to the developing scaling relationship and the possible high stress drops for earthquake from blind faults, we further deploy the hybrid method mentioned above to give the simulation of the strong motion in displacement, velocity and acceleration. We now give this exercise to the high stress drop event, and the events, which might have potential seismic hazard to a specific site to give further estimation on seismic hazard evaluation.

  19. A hybrid method of simulating broadband ground motion : A case study of the 2006 Pingtung earthquake, Taiwan

    NASA Astrophysics Data System (ADS)

    Yen, Y.; Ma, K.; Cheng, C.; Shao, K.; Lin, P.

    2011-12-01

    For the demand of engineering, the time-history of ground motions which consider the reliability and earthquake physical characters have been provided for earthquake resistant design of important building structures. However, the high frequency portion ( > 1 Hz) of near-fault ground motions was restricted by the insufficient resolution of velocity structure. Considering the relative small events which contain path and site effect in waveforms as Green's functions (i.e. empirical Green's function (EGF) method) can resolve the problem of lack of precise velocity structure to replace the path effect evaluation. Alternatively, a stochastic Green's function (SGF) method can be employed when the EGF is unavailable. Further, the low frequency ( < 1 Hz) can be obtained numerically by the Frequency-Wavenumber (FK) method. Thus, broadband frequency strong ground motion can be calculation by a hybrid method that combining a deterministic FK method for the low frequency simulation and the EGF or SGF method for high frequency simulation. The slip models had been investigated from Taiwan dense strong motion and global teleseismic data. Characterizing the slip models derived from the waveform inversion can directly extract the source parameters needed for the ground motion prediction in the EGF method or the SGF method. The nuclear power plant in southern tip of Taiwan was experienced a strong shaking by the 26 December 2006 Pingtung, Taiwan offshore earthquake. The closest strong motion station of the Central Weather Bureau, KAU082, recorded the peak acceleration value (PGA) of 0.24 g. We considered the adjacent stations to be the case study for possibility evaluation of predicting ground motion utilizing the EGF method or SGF method. The possible damage impact toward nuclear power plant for specific sites can be estimated and verified according to the simulation results

  20. The Athens Acropolis Strong Motion Array

    NASA Astrophysics Data System (ADS)

    Kalogeras, I. S.; Evangelidis, C. P.; Melis, N. S.; Boukouras, K.

    2012-04-01

    During the last decades, extensive restoration works through a dedicated "Acropolis Restoration Service" (YSMA) take place in the Acropolis, the greatest sanctuary of ancient Athens. Since 2008, a permanent strong motion array was deployed by the Institute of Geodynamics, National Observatory of Athens (NOA-IG) in collaboration with YSMA. Free field installations were decided at sites showing various characteristics, aiming to investigate differences in geotechnical properties as well as the structure response of Parthenon itself. The installation phase is presented, with the techniques used to overcome difficulties (i.e. extreme weather conditions, power and communication limitations, restoration works and visitors) and the special care taken for the specific archaeological site. Furthermore, indicative examples of seismic events recorded by the array are analyzed and the complexity of the hill and the monument is made apparent. Among them, the long distance events of Tohoku, Japan 2010 and Van, Turkey 2011, some regional moderate earthquakes in Greece and some weak earthquakes from the vicinity. Continuous ambient noise monitoring using PQLX software gives some first indicative results, showing a variety of characteristics at installation sites. Finally, further developments and future steps are presented such as: the extension of the array, the integration of seismic data within the GIS platform of YSMA at the site and the use of strong motion records, in conjunction with data from other monitoring systems operating in Acropolis for the study of specific monuments.

  1. Towards Integrated Marmara Strong Motion Network

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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) - Sleymaniye 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 Ataky in Istanbul.

  2. Ground Motion Characteristic in the Kaohsiung & Pingtung Area, Taiwan

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

    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.

  3. Strong Motion Seismograph Based On MEMS Accelerometer

    NASA Astrophysics Data System (ADS)

    Teng, Y.; Hu, X.

    2013-12-01

    The MEMS strong motion seismograph we developed used the modularization method to design its software and hardware.It can fit various needs in different application situation.The hardware of the instrument is composed of a MEMS accelerometer,a control processor system,a data-storage system,a wired real-time data transmission system by IP network,a wireless data transmission module by 3G broadband,a GPS calibration module and power supply system with a large-volumn lithium battery in it. Among it,the seismograph's sensor adopted a three-axis with 14-bit high resolution and digital output MEMS accelerometer.Its noise level just reach about 99?g/?Hz and 2g to 8g dynamically selectable full-scale.Its output data rates from 1.56Hz to 800Hz. Its maximum current consumption is merely 165?A,and the device is so small that it is available in a 3mm3mm1mm QFN package. Furthermore,there is access to both low pass filtered data as well as high pass filtered data,which minimizes the data analysis required for earthquake signal detection. So,the data post-processing can be simplified. Controlling process system adopts a 32-bit low power consumption embedded ARM9 processor-S3C2440 and is based on the Linux operation system.The processor's operating clock at 400MHz.The controlling system's main memory is a 64MB SDRAM with a 256MB flash-memory.Besides,an external high-capacity SD card data memory can be easily added.So the system can meet the requirements for data acquisition,data processing,data transmission,data storage,and so on. Both wired and wireless network can satisfy remote real-time monitoring, data transmission,system maintenance,status monitoring or updating software.Linux was embedded and multi-layer designed conception was used.The code, including sensor hardware driver,the data acquisition,earthquake setting out and so on,was written on medium layer.The hardware driver consist of IIC-Bus interface driver, IO driver and asynchronous notification driver. The application program layer mainly concludes: earthquake parameter module, local database managing module, data transmission module, remote monitoring, FTP service and so on. The application layer adopted multi-thread process. The whole strong motion seismograph was encapsulated in a small aluminum box, which size is 80mm120mm55mm. The inner battery can work continuesly more than 24 hours. The MEMS accelerograph uses modular design for its software part and hardware part. It has remote software update function and can meet the following needs: a) Auto picking up the earthquake event; saving the data on wave-event files and hours files; It may be used for monitoring strong earthquake, explosion, bridge and house health. b) Auto calculate the earthquake parameters, and transferring those parameters by 3G wireless broadband network. This kind of seismograph has characteristics of low cost, easy installation. They can be concentrated in the urban region or areas need to specially care. We can set up a ground motion parameters quick report sensor network while large earthquake break out. Then high-resolution-fine shake-map can be easily produced for the need of emergency rescue. c) By loading P-wave detection program modules, it can be used for earthquake early warning for large earthquakes; d) Can easily construct a high-density layout seismic monitoring network owning remote control and modern intelligent earthquake sensor.

  4. 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)

    Liu, K.

    2009-12-01

    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.

  5. The Commercial TREMOR Strong-Motion Seismograph

    NASA Astrophysics Data System (ADS)

    Evans, J. R.; Hamstra, R. H.; Kuendig, C.; Camina, P.

    2001-12-01

    The emergence of major seismological and earthquake-engineering problems requiring large, dense instrument arrays led several of us to investigate alternate solutions. Evans and Rogers (USGS Open File Report 95-555, 1995) and Evans (USGS Open File Report 98-109, 1998) demonstrated the efficacy of low-cost robust silicon accelerometers in strong-motion seismology, making possible a vast increase in the spatial density of such arrays. The 1998 design displays true 16-bit performance and excellent robustness and linearity---13 of these prototype near-real-time instruments are deployed in Oakland, California, and have recorded data from seven small events (up to 5.7 %g). Since this technology is a radical departure from past efforts, it was necessary for the USGS to develop the sensor and demonstrate its efficacy thoroughly. Since it is neither practical nor appropriate for the USGS to produce instrumentation beyond a demonstration phase, the US Geological Survey and GeoSIG Ltd undertook a collaborative effort (a ``CRAD'') to commercialize the new technology. This effort has resulted in a fully temperature-compensated 16-bit system, the GeoSIG GT-316, announced in April, 2001, combining the ICS-3028 TM-based USGS sensor, temperature compensation technique, and peak ground velocity (PGV) computation with a highly customized 16-bit GeoSIG recorder. The price has not been set but is likely to be around \\2000 in large quantities. The result is a near-real-time instrument telemetering peak ground acceleration (PGA) and PGV about 90 s after onset of the P wave, then minutes later transmitting the waveform. The receiving software, ``HomeBase()'', also computes spectral acceleration, S_{a}. PGA, PGV, S_{a}, and waveforms are forwarded immediately by HomeBase() for ShakeMap generation and other uses. Shaking metrics from the prototypes in Oakland are consistently among the first to arrive for the northern California ShakeMap. For telemetry we use a low-cost always-connected cell-phone-based Internet technology (CDPD), but any RS-232 connected telemetry system is a viable candidate (spread spectrum, CDMA, GSM, POT). The instruments can be synchronized via CDPD to a few tenths of a second, or to full precision with an optional GPS receiver. Sensor RMS noise is 33 \\mathrm \\mu g over the band 0.1 to 35 Hz, 11 \\mathrm \\mu g$ over the band 0.1 to 1.0 Hz; the sensor is extremely linear (far better than 1% of full scale); temperature compensation is to better than 1% of full scale. TREMOR-class instruments are intended to fill the niche of high spatial resolution with an economical low-maintenance device, while conventional instruments continue to pursue maximum amplitude resolution. The TREMOR instrument also has applications in areas where budget or access limitations require lower purchase, installation, or maintenance cost (commercial ANSS partners, remote sites, on-call aftershock arrays, extremely dense arrays, and organizations with limited budgets). However, we primarily envision large, mixed arrays of conventional and TREMOR instruments in urban areas, the former providing better early information from small events and the TREMOR instruments guaranteeing better spatial resolution and more near-field recording of large events. Together, they would meet the ANSS goal of dense near-real-time urban monitoring and the collection of requisite data for risk mitigation.

  6. Strong motion instrumentation of an RC building structure

    USGS Publications Warehouse

    Li, H.-J.; Celebi, M.

    2001-01-01

    The strong-motion instrumentation scheme of a reinforced concrete building observed by California Strong-Motion Instrumentation Program (CSMIP) is introduced in this paper. The instrumented building is also described and the recorded responses during 1994 Northridge earthquake are provided.

  7. Towards an integrated European strong motion data distribution

    NASA Astrophysics Data System (ADS)

    Luzi, Lucia; Clinton, John; Cauzzi, Carlo; Puglia, Rodolfo; Michelini, Alberto; Van Eck, Torild; Sleeman, Reinhoud; Akkar, Sinan

    2013-04-01

    Recent decades have seen a significant increase in the quality and quantity of strong motion data collected in Europe, as dense and often real-time and continuously monitored broadband strong motion networks have been constructed in many nations. There has been a concurrent increase in demand for access to strong motion data not only from researchers for engineering and seismological studies, but also from civil authorities and seismic networks for the rapid assessment of ground motion and shaking intensity following significant earthquakes (e.g. ShakeMaps). Aside from a few notable exceptions on the national scale, databases providing access to strong motion data has not appeared to keep pace with these developments. In the framework of the EC infrastructure project NERA (2010 - 2014), that integrates key research infrastructures in Europe for monitoring earthquakes and assessing their hazard and risk, the network activity NA3 deals with the networking of acceleration networks and SM data. Within the NA3 activity two infrastructures are being constructed: i) a Rapid Response Strong Motion (RRSM) database, that following a strong event, automatically parameterises all available on-scale waveform data within the European Integrated waveform Data Archives (EIDA) and makes the waveforms easily available to the seismological community within minutes of an event; and ii) a European Strong Motion (ESM) database of accelerometric records, with associated metadata relevant to earthquake engineering and seismology research communities, using standard, manual processing that reflects the state of the art and research needs in these fields. These two separate repositories form the core infrastructures being built to distribute strong motion data in Europe in order to guarantee rapid and long-term availability of high quality waveform data to both the international scientific community and the hazard mitigation communities. These infrastructures will provide the access to strong motion data in an eventual EPOS seismological service. A working group on Strong Motion data is being created at ORFEUS in 2013. This body, consisting of experts in strong motion data collection, processing and research from across Europe, will provide the umbrella organisation that will 1) have the political clout to negotiate data sharing agreements with strong motion data providers and 2) manage the software during a transition from the end of NERA to the EPOS community. We expect the community providing data to the RRSM and ESM will gradually grow, under the supervision of ORFEUS, and eventually include strong motion data from networks from all European countries that can have an open data policy.

  8. Integration of strong motion networks and accelerometric data in Europe

    NASA Astrophysics Data System (ADS)

    Luzi, L.; Clinton, J. F.; Akkar, S.; Sleeman, R.; Van Eck, T.

    2014-12-01

    Efforts for an organized collection of strong motion data in Europe started during the Fourth Framework Program granted by the European Union, with the first release of the European Strong Motion database. Subsequently other attempts were made, but the initiatives were carried out within a project by a single or few institutions, often isolated from data providers. During the Seventh Framework Program, in the context of the project NERA, parallel to the establishment of infrastructures, major efforts were devoted on the improvement of networking among strong-motion data providers in the broader European countries. Two major infrastructures for storing and disseminating accelerometric data and metadata were built: a. The Rapid-Raw Strong Motion (RRSM) database that automatically delivers strong motion products in near-real time. The system collects and uses all relevant, unrestricted waveform data from the European Integrated waveform Data Archive (EIDA) within minutes after an earthquake (M>=3.5) in the European- Mediterranean region. The RRSM web interface is available at http://orfeusdev.knmi.nl:8080/opencms/rrsm b. A prototype of strong-motion database (Engineering Strong Motion database, ESM) that contains an initial core formed by the accelerograms recorded by Italian and Turkish strong-motion data providers. ESM is structured to contain not only the data available in EIDA but also off-line data; earthquake and strong-motion metadata contain more detailed information than the corresponding metadata in RRSM. A Working Group (WG5 - acceleration and strong motion data), operating under ORFEUS, has been created to build the basis for the sustainable integrated pan-European accelerometric data distribution. The responsibilities and duties of the WG5 are envisaged as follows: 1. Setting rules for data dissemination; 2. Establishing MoU's with data providers; 3. Collaborating with the European project EPOS for the preparation of projects; 4. Contacting similar establishments in the other parts of the world; 5. Ensure quality of metadata and waveforms; 6. Ensure IT development improvements. The steps made in two years towards the Integration of strong motion networks in Europe are illustrated and the major results of this initiative discussed.

  9. Strong-Motion Program report, January-December 1985

    USGS Publications Warehouse

    Porcella, R. L., (Edited By)

    1989-01-01

    This Program Report contains preliminary information on the nature and availability of strong-motion data recorded by the U.S. Geological Survey (USGS). The Strong-Motion Program is operated by the USGS in cooperation with numerous Federal, State, and local agencies and private organizations. Major objective of this program are to record both strong ground motion and the response of various types of engineered structures during earthquakes, and to disseminate this information and data to the international earthquake-engineering research and design community. This volume contains a summary of the accelerograms recovered from the USGS National Strong-Motion Instrumentation Network during 1985, summaries of recent strong-motion publications, notes on the availability of digitized data, and general information related to the USGS and other strong-motion programs. The data summary in table 1 contains information on all USGS accelerograms recovered (though not necessarily recorded) during 1985; event data are taken from "Preliminary Determination of Epicenters," published by the USGS.

  10. Rrsm: The European Rapid Raw Strong-Motion Database

    NASA Astrophysics Data System (ADS)

    Cauzzi, C.; Clinton, J. F.; Sleeman, R.; Domingo Ballesta, J.; Kaestli, P.; Galanis, O.

    2014-12-01

    We introduce the European Rapid Raw Strong-Motion database (RRSM), a Europe-wide system that provides parameterised strong motion information, as well as access to waveform data, within minutes of the occurrence of strong earthquakes. The RRSM significantly differs from traditional earthquake strong motion dissemination in Europe, which has focused on providing reviewed, processed strong motion parameters, typically with significant delays. As the RRSM provides rapid open access to raw waveform data and metadata and does not rely on external manual waveform processing, RRSM information is tailored to seismologists and strong-motion data analysts, earthquake and geotechnical engineers, international earthquake response agencies and the educated general public. Access to the RRSM database is via a portal at http://www.orfeus-eu.org/rrsm/ that allows users to query earthquake information, peak ground motion parameters and amplitudes of spectral response; and to select and download earthquake waveforms. All information is available within minutes of any earthquake with magnitude ? 3.5 occurring in the Euro-Mediterranean region. Waveform processing and database population are performed using the waveform processing module scwfparam, which is integrated in SeisComP3 (SC3; http://www.seiscomp3.org/). Earthquake information is provided by the EMSC (http://www.emsc-csem.org/) and all the seismic waveform data is accessed at the European Integrated waveform Data Archive (EIDA) at ORFEUS (http://www.orfeus-eu.org/index.html), where all on-scale data is used in the fully automated processing. As the EIDA community is continually growing, the already significant number of strong motion stations is also increasing and the importance of this product is expected to also increase. Real-time RRSM processing started in June 2014, while past events have been processed in order to provide a complete database back to 2005.

  11. An Improved Approach for Nonstationary Strong Ground Motion Simulation

    NASA Astrophysics Data System (ADS)

    Li, Yanan; Wang, Guoxin

    2015-10-01

    A new stochastic ground motion model for generating a suite of ground motion time history with both temporal and frequency nonstationarities for specified earthquake and site characteristics is proposed based on the wavelet method. This new model is defined in terms of 6 key parameters that characterize the duration, evolving intensity, predominant frequency, bandwidth and frequency variation of the ground acceleration process. All parameters, except for peak ground acceleration (PGA), are identified manually from a database of 2444 recorded horizontal accelerations. The two-stage regression analysis method is used to investigate the inter- and intra-event residuals. For any given earthquake and site characteristics in terms of the fault mechanism, moment magnitude, Joyner and Boore distance and site shear-wave velocity, sets of the model parameters are generated and used, in turn, by the stochastic model to generate strong ground motion accelerograms, which can capture and properly embody the primary features of real strong ground motions, including the duration, evolving intensity, spectral content, frequency variation and peak values. In addition, it is shown that the characteristics of the simulated and observed response spectra are similar, and the amplitude of the simulated response spectra are in line with the predicted values from the published seismic ground motion prediction equations (SGMPE) after a systematic comparison. The proposed method can be used to estimate the strong ground motions as inputs for structural seismic dynamic analysis in engineering practice in conjunction with or instead of recorded ground motions.

  12. Strong ground motion from the michoacan, Mexico, earthquake.

    PubMed

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

    1986-09-01

    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 potenial 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 descripton of the ground motions that caused the disaster. PMID:17746576

  13. Strong Ground Motion from the Michoacan, Mexico, Earthquake

    NASA Astrophysics Data System (ADS)

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

    1986-09-01

    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 caused the disaster.

  14. Optimum strong-motion array geometry for source inversion - II

    USGS Publications Warehouse

    Iida, M.

    1990-01-01

    Optimum strong-motion array geometry for source inversions is determined for each of three types of earthquake faults: strike-slip, dip-slip and offshore subduction thrust. It is found that the complete Green's function is capable of stabilizing the accuracy of an inversion solution obtained using theoretical seismograms, regardless of the differences in array configuration. The optimum strong-motion array for a strike-slip fault is characterized by stations well distributed in azimuth, while the optimum array for a dip-slip event has stations arranged in a grid-shaped form. -from Author

  15. Update on the Center for Engineering Strong Motion Data

    NASA Astrophysics Data System (ADS)

    Haddadi, H. R.; Shakal, A. F.; Stephens, C. D.; Oppenheimer, D. H.; Huang, M.; Leith, W. S.; Parrish, J. G.; Savage, W. U.

    2010-12-01

    The U.S. Geological Survey (USGS) and the California Geological Survey (CGS) established the Center for Engineering Strong-Motion Data (CESMD, Center) to provide a single access point for earthquake strong-motion records and station metadata from the U.S. and international strong-motion programs. The Center has operational facilities in Sacramento and Menlo Park, California, to receive, process, and disseminate records through the CESMD web site at www.strongmotioncenter.org. The Center currently is in the process of transitioning the COSMOS Virtual Data Center (VDC) to integrate its functions with those of the CESMD for improved efficiency of operations, and to provide all users with a more convenient one-stop portal to both U.S. and important international strong-motion records. The Center is working with COSMOS and international and U.S. data providers to improve the completeness of site and station information, which are needed to most effectively employ the recorded data. The goal of all these and other new developments is to continually improve access by the earthquake engineering community to strong-motion data and metadata world-wide. The CESMD and its Virtual Data Center (VDC) provide tools to map earthquakes and recording stations, to search raw and processed data, to view time histories and spectral plots, to convert data files formats, and to download data and a variety of information. The VDC is now being upgraded to convert the strong-motion data files from different seismic networks into a common standard tagged format in order to facilitate importing earthquake records and station metadata to the CESMD database. An important new feature being developed is the automatic posting of Internet Quick Reports at the CESMD web site. This feature will allow users, and emergency responders in particular, to view strong-motion waveforms and download records within a few minutes after an earthquake occurs. Currently the CESMD and its Virtual Data Center provide selected strong-motion records from 17 countries. The Center has proved to be significantly useful for providing data to scientists, engineers, policy makers, and emergency response teams around the world.

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

    USGS Publications Warehouse

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

    2005-01-01

    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.

  17. A simple model for strong ground motions and response spectra

    USGS Publications Warehouse

    Safak, Erdal; Mueller, Charles; Boatwright, John

    1988-01-01

    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.

  18. Strong Ground Motion Database System for the Mexican Seismic Network

    NASA Astrophysics Data System (ADS)

    Perez-Yanez, C.; Ramirez-Guzman, L.; Ruiz, A. L.; Delgado, R.; Macías, M. A.; Sandoval, H.; Alcántara, L.; Quiroz, A.

    2014-12-01

    A web-based system for strong Mexican ground motion records dissemination and archival is presented. More than 50 years of continuous strong ground motion instrumentation and monitoring in Mexico have provided a fundamental resource -several thousands of accelerograms- for better understanding earthquakes and their effects in the region. Lead by the Institute of Engineering (IE) of the National Autonomous University of Mexico (UNAM), the engineering strong ground motion monitoring program at IE relies on a continuously growing network, that at present includes more than 100 free-field stations and provides coverage to the seismic zones in the country. Among the stations, approximately 25% send the observed acceleration to a processing center in Mexico City in real-time, and the rest require manual access, remote or in situ, for later processing and cataloguing. As part of a collaboration agreement between UNAM and the National Center for Disaster Prevention, regarding the construction and operation of a unified seismic network, a web system was developed to allow access to UNAM's engineering strong motion archive and host data from other institutions. The system allows data searches under a relational database schema, following a general structure relying on four databases containing the: 1) free-field stations, 2) epicentral location associated with the strong motion records available, 3) strong motion catalogue, and 4) acceleration files -the core of the system. In order to locate and easily access one or several records of the data bank, the web system presents a variety of parameters that can be involved in a query (seismic event, region boundary, station name or ID, radial distance to source or peak acceleration). This homogeneous platform has been designed to facilitate dissemination and processing of the information worldwide. Each file, in a standard format, contains information regarding the recording instrument, the station, the corresponding earthquake, the record itself, and the numerical data. The standard format used was designed and preserved by many institutions in Mexico. At this stage, only cataloged accelerograms (M>=5) from IE are integrated. Institutions expected to become part of the unified network of Mexico, will make available data through the platform described in this paper.

  19. Strong motion observations and recordings from the great Wenchuan Earthquake

    USGS Publications Warehouse

    Li, X.; Zhou, Z.; Yu, H.; Wen, R.; Lu, D.; Huang, M.; Zhou, Y.; Cu, J.

    2008-01-01

    The National Strong Motion Observation Network System (NSMONS) of China is briefly introduced in this paper. The NSMONS consists of permanent free-field stations, special observation arrays, mobile observatories and a network management system. During the Wenchuan Earthquake, over 1,400 components of acceleration records were obtained from 460 permanent free-field stations and three arrays for topographical effect and structural response observation in the network system from the main shock, and over 20,000 components of acceleration records from strong aftershocks occurred before August 1, 2008 were also obtained by permanent free-field stations of the NSMONS and 59 mobile instruments quickly deployed after the main shock. The strong motion recordings from the main shock and strong aftershocks are summarized in this paper. In the ground motion recordings, there are over 560 components with peak ground acceleration (PGA) over 10 Gal, the largest being 957.7 Gal. The largest PGA recorded during the aftershock exceeds 300 Gal. ?? 2008 Institute of Engineering Mechanics, China Earthquake Administration and Springer-Verlag GmbH.

  20. Enhancement of the national strong-motion network in Turkey

    USGS Publications Warehouse

    Gulkan, Polat; 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

    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.

  1. Source Characteristics of Shallow Intraslab Earthquakes from Strong Motion Data

    NASA Astrophysics Data System (ADS)

    Asano, K.; Iwata, T.; Irikura, K.

    2002-12-01

    Large shallow intraslab earthquakes, occurring within subducting slabs at 30-100km depths, generate earthquake damages by strong ground motions (e.g. the 1993 Kushiro-oki earthquake, the 2001 Geiyo earthquake, and the 2001 Nisqually earthquake). Source characteristics of intraslab earthquakes have been pointed out to have some different features compared to those of inland crustal earthquakes and interplate earthquakes by some researchers. We examined six shallow intraslab earthquakes that recently occurred around Japan (MJMA 5.1-7.0) using dense strong motion network data. The observed peak ground accelerations at K-NET stations for the 2001 Geiyo earthquake in near distance are about 3 times larger than those expected from the attenuation relation based on inland crustal earthquakes proposed by Fukushima and Tanaka (1992). For other intraslab events, the observed peak ground accelerations are also larger than the expected values. These seem to be related with high stress drop in source as well as low attenuation along the propagation path in case of intraslab earthquakes. We carried out strong motion simulation based on the empirical Green's function method to investigate the source characteristics of intraslab earthquakes. Using the empirical Green's function method, we can construct the source model to explain observed waveforms in broadband frequency range (Irikura, 1986; Miyake et al., 1999). We used the observed waveforms of a small event occurring at each source region as the empirical Green's function, and estimated the number, size, and location of asperity (strong motion generation area), rise time, and rupture propagation velocity of target events by forward modeling. Since the combined area of asperities obtained for each earthquake is about 14-66% of values predicted by the empirical relation for inland crustal earthquakes proposed by Somerville et al. (1999), the stress drops on asperity of shallow intraslab earthquakes are higher than those of inland crustal earthquakes. The ratios between the combined area of asperities obtained in this study and the value predicted from the empirical relation decrease with focal depth. The stress drops on asperity of shallow intraslab earthquakes increase with focal depth. We used the strong motion data from K-NET, KiK-net, and F-net operated by the National Research Institute for Earth Science and Disaster Prevention (NIED) and the CMT solutions by F-net and Harvard University. We also used the hypocentral information provided by the Japan Meteorological Agency (JMA).

  2. Establishment of Antakya Basin Strong Ground Motion Monitoring System

    NASA Astrophysics Data System (ADS)

    Durukal, E.; zel, O.; Bikce, M.; Gene?, M. C.; Kac?n, S.; Erdik, M.; Safak, E.; ver, S.

    2009-04-01

    Turkey is located in one of the most active earthquake zones of the world. The cities located along the North Anatolian Fault (NAF) and the East Anatolian Fault (EAF) are exposed to significant earthquake hazard. The Hatay province near the southern terminus of the EAF has always experienced a significant seismic activity, since it is on the intersection of the northernmost segment of Dead Sea Fault Zone coming from the south, with the Cyprean Arc approaching from south-west. Historical records extending over the last 2000 years indicate that Antakya, founded in the 3rd century B.C., is effected by intensity IX-X earthquakes every 150 years. In the region, the last destructive earthquake occurred in 1872. Destructive earthquakes should be expected in the region in the near future similar to the ones that occurred in the past. The strong response of sedimentary basins to seismic waves was largely responsible for the damage produced by the devastating earthquakes of 1985 Michoacan Earthquake which severely damaged parts of Mexico City, and the 1988 Spitak Earthquake which destroyed most of Leninakan, Armenia. Much of this devastating response was explained by the conversion of seismic body waves to surface waves at the sediment/rock contacts of sedimentary basins. "Antakya Basin Strong Ground Motion Monitoring System" is set up with the aim of monitoring the earthquake response of the Antakya Basin, contributing to our understanding of basin response, contributing to earthquake risk assessment of Antakya, monitoring of regional earthquakes and determining the effects of local and regional earthquakes on the urban environment of Antakya. The soil properties beneath the strong motion stations (S-Wave velocity structure and dominant soil frequency) are determined by array measurements that involve broad-band seismometers. The strong motion monitoring system consists of six instruments installed in small buildings. The stations form a straight line along the short axis of Antakya basin passing through the city center. They are equipped with acceleration sensors, GPS and communication units and operate in continuous recording mode. For on-line data transmission the EDGE mode of available GSM systems are employed. In the array measurements for the determination of soil properties beneath the stations two 4-seismometer sets have been utilized. The system is the first monitoring installment in Turkey dedicated to understanding basin effects. The records obtained will allow for the visualization of the propagation of long-period ground motion in the basin and show the refraction of surface waves at the basin edge. The records will also serve to enhance our capacity to realistically synthesize the strong ground motion in basin-type environments.

  3. Weather-related Ground Motions Recorded by Taiwan Broadband Seismic Network Stations

    NASA Astrophysics Data System (ADS)

    Yang, C. F.; Chi, W. C.

    2014-12-01

    Broadband seismometers record ground motions, which can be induced by weather-related processes. Analyzing such signals might help to better understand those natural processes. Previously, abnormal seismic signals have been detected during rainfall and snowmelt events. The amplitudes of those seismic signals correlated with the variations of the discharge in a nearby river and scientists have proposed that such signals were generated by bed load transport. Here, we used the continuous seismic data from the Broadband Array in Taiwan for Seismology (BATS) to analyze the weather-related ground motions during rainfall events. The sampling rate for seismic data is 100 samples per second. We compared the seismic data with the precipitation data from the rain gauge stations in Taiwan in three select rainfall periods, Typhoon Kalmaegi in 2008, Typhoon Morakot in 2009 and the East Asian rainy season in 2012. During raining, the Power Spectral Density (PSD) of high frequency (> 1 Hz) seismic noises is apparently high, and the amplitude of the seismic noise also correlates with the local precipitation, especially at the stations in the drainage basins, and the PSD decreased gradually after peaks of precipitation. At some seismic stations, we observed vertical ground motions at several bands of frequencies: 0-1 Hz, 1-5 Hz, and 5-45 Hz. However, on horizontal components we found the 5-45 Hz energy splits into two bands: 5-25 Hz and 30-45 Hz. For stations near the ridge tops or on the coastal plain, the 30-45 Hz band energy is weaker or missing. Preliminary results show that the amplitudes of the seismic waves correlate with the stream flow discharge. Next, we plan to study the sources of the different bands of energy to examine if we can monitor and quantify natural processes, like precipitation and river discharge, using seismic signals.

  4. Can mobile phones used in strong motion seismology?

    NASA Astrophysics Data System (ADS)

    D'Alessandro, Antonino; D'Anna, Giuseppe

    2013-04-01

    Micro Electro-Mechanical Systems (MEMS) accelerometers are electromechanical devices able to measure static or dynamic accelerations. In the 1990s MEMS accelerometers revolutionized the automotive-airbag system industry and are currently widely used in laptops, game controllers and mobile phones. Nowadays MEMS accelerometers seems provide adequate sensitivity, noise level and dynamic range to be applicable to earthquake strong motion acquisition. The current use of 3 axes MEMS accelerometers in mobile phone maybe provide a new means to easy increase the number of observations when a strong earthquake occurs. However, before utilize the signals recorded by a mobile phone equipped with a 3 axes MEMS accelerometer for any scientific porpoise, it is fundamental to verify that the signal collected provide reliable records of ground motion. For this reason we have investigated the suitability of the iPhone 5 mobile phone (one of the most popular mobile phone in the world) for strong motion acquisition. It is provided by several MEMS devise like a three-axis gyroscope, a three-axis electronic compass and a the LIS331DLH three-axis accelerometer. The LIS331DLH sensor is a low-cost high performance three axes linear accelerometer, with 16 bit digital output, produced by STMicroelectronics Inc. We have tested the LIS331DLH MEMS accelerometer using a vibrating table and the EpiSensor FBA ES-T as reference sensor. In our experiments the reference sensor was rigidly co-mounted with the LIS331DHL MEMS sensor on the vibrating table. We assessment the MEMS accelerometer in the frequency range 0.2-20 Hz, typical range of interesting in strong motion seismology and earthquake engineering. We generate both constant and damped sine waves with central frequency starting from 0.2 Hz until 20 Hz with step of 0.2 Hz. For each frequency analyzed we generate sine waves with mean amplitude 50, 100, 200, 400, 800 and 1600 mg0. For damped sine waves we generate waveforms with initial amplitude of 2 g0. Our tests show as, in the frequency and amplitude range analyzed (0.2-20 Hz, 10-2000 mg0), the LIS331DLH MEMS accelerometer have excellent frequency and phase response, comparable with that of some standard FBA accelerometer used in strong motion seismology. However, we found that the signal recorded by the LIS331DLH MEMS accelerometer slightly underestimates the real acceleration (of about 2.5%). This suggests that may be important to calibrate a MEMS sensor before using it in scientific applications. A drawback of the LIS331DLH MEMS accelerometer is its low sensitivity. This is an important limitation of all the low cost MEMS accelerometers; therefore nowadays they are desirable to use only in strong motion seismology. However, the rapid development of this technology will lead in the coming years to the development of high sensitivity and low noise digital MEMS sensors that may be replace the current seismic accelerometer used in seismology. Actually, the real main advantage of these sensors is their common use in the mobile phones.

  5. Overview of SMIP (Strong Motion Instrumentation Program) strong motion records from the Loma Prieta earthquake 17 October 1989

    SciTech Connect

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

    1990-01-01

    A total of 125 strong-motion records were recovered from 93 stations of the California Strong Motion Instrumentation Program (CSMIP). The 93 stations include 53 ground-response stations and 40 extensively instrumented structures. The most distant stations were approximately 175 km (105 miles) from the epicenter. Twenty-five records were obtained within 40 km (24 miles) of the epicenter. The closest SMIP station is Corralitos, located very close to the San Andreas fault and near the center of the aftershock zone. A peak horizontal acceleration of 65 percent g was recorded at this station. This is the first record from the nearfield of a magnitude 7 earthquake in California. Three other stations, Santa Cruz, Capitola, and Watsonville, within 20 km (12 miles) of the epicenter, recorded the shaking in the heavily damaged coastal area. Peak horizontal accelerations ranged from 40 percent g at Watsonville to 54 percent g at Capitola. All four of these stations recorded high vertical accelerations ranging from 40 percent g at Santa Cruz to 60 percent g at Capitola. Nine SMIP stations recorded the ground motion in the City of San Francisco with peak horizontal accelerations ranging from 9 percent to 21 percent g. Stations located on Yerba Buena Island and Treasure Island form a rock/soil pair that recorded peak horizontal accelerations of 6 percent and 16 percent g, respectively. In Oakland two stations recorded the ground motion of 26 percent and 29 percent g suggesting a similar level of shaking at the I-880 Freeway and at the east end of the damaged San Francisco-Oakland Bay Bridge.

  6. Database for earthquake strong motion studies in Italy

    USGS Publications Warehouse

    Scasserra, G.; Stewart, J.P.; Kayen, R.E.; Lanzo, G.

    2009-01-01

    We describe an Italian database of strong ground motion recordings and databanks delineating conditions at the instrument sites and characteristics of the seismic sources. The strong motion database consists of 247 corrected recordings from 89 earthquakes and 101 recording stations. Uncorrected recordings were drawn from public web sites and processed on a record-by-record basis using a procedure utilized in the Next-Generation Attenuation (NGA) project to remove instrument resonances, minimize noise effects through low- and high-pass filtering, and baseline correction. The number of available uncorrected recordings was reduced by 52% (mostly because of s-triggers) to arrive at the 247 recordings in the database. The site databank includes for every recording site the surface geology, a measurement or estimate of average shear wave velocity in the upper 30 m (Vs30), and information on instrument housing. Of the 89 sites, 39 have on-site velocity measurements (17 of which were performed as part of this study using SASW techniques). For remaining sites, we estimate Vs30 based on measurements on similar geologic conditions where available. Where no local velocity measurements are available, correlations with surface geology are used. Source parameters are drawn from databanks maintained (and recently updated) by Istituto Nazionale di Geofisica e Vulcanologia and include hypocenter location and magnitude for small events (M< ??? 5.5) and finite source parameters for larger events. ?? 2009 A.S. Elnashai & N.N. Ambraseys.

  7. On pads and filters: Processing strong-motion data

    USGS Publications Warehouse

    Boore, D.M.

    2005-01-01

    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.

  8. Probabilistic Motion Planning of Balloons in Strong, Uncertain Wind Fields

    NASA Technical Reports Server (NTRS)

    Wolf, Michael T.; Blackmore, Lars; Kuwata, Yoshiaki; Fathpour, Nanaz; Elfes, Alberto; Newman, Claire

    2010-01-01

    This paper introduces a new algorithm for probabilistic motion planning in arbitrary, uncertain vector fields, with emphasis on high-level planning for Montgolfiere balloons in the atmosphere of Titan. The goal of the algorithm is to determine what altitude--and what horizontal actuation, if any is available on the vehicle--to use to reach a goal location in the fastest expected time. The winds can vary greatly at different altitudes and are strong relative to any feasible horizontal actuation, so the incorporation of the winds is critical for guidance plans. This paper focuses on how to integrate the uncertainty of the wind field into the wind model and how to reach a goal location through the uncertain wind field, using a Markov decision process (MDP). The resulting probabilistic solutions enable more robust guidance plans and more thorough analysis of potential paths than existing methods.

  9. Development of three-dimensional basement structure in Taiwan deduced from past plate motion: Consistency with the present seismicity

    NASA Astrophysics Data System (ADS)

    Takada, Youichiro; Fukahata, Yukitoshi; Hashima, Akinori; Terakawa, Toshiko; Fukui, Kenji; Yanagisawa, Takatoshi; Ikeda, Yasutaka; Kimura, Gaku; Matsu'Ura, Mitsuhiro

    2007-06-01

    Using colored clay, we examined geometrical evolution of the three-dimensional basement structure in Taiwan due to relative plate motion under the following assumptions: the motion of the Philippine Sea plate relative to the Eurasian plate has been constant during the last 15 Myr, the Ryukyu and Manila trenches had been connected by a transform fault before the collision between the Luzon arc and Eurasian continental margin, and the collision started at 5 Ma. The basement structure obtained from the clay model was fully consistent with observed deep seismicity, which led us to the following conclusions. There are no oceanic slabs beneath central Taiwan. Instead, the Eurasian continental margin is underthrusting beneath it. The Philippine Sea slab extends northwestward from the Ryukyu trench, while the South China Sea slab extends southeastward from the Manila trench. The downdip length of the South China Sea slab becomes shorter from south to north.

  10. Another Look at Strong Ground Motion Accelerations and Stress Drop

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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.

  11. High-frequency filtering of strong-motion records

    USGS Publications Warehouse

    Douglas, J.; Boore, D.M.

    2011-01-01

    The influence of noise in strong-motion records is most problematic at low and high frequencies where the signal to noise ratio is commonly low compared to that in the mid-spectrum. The impact of low-frequency noise (5 Hz) on computed pseudo-absolute response spectral accelerations (PSAs). In contrast to the case of low-frequency noise our analysis shows that filtering to remove high-frequency noise is only necessary in certain situations and that PSAs can often be used up to 100 Hz even if much lower high-cut corner frequencies are required to remove the noise. This apparent contradiction can be explained by the fact that PSAs are often controlled by ground accelerations associated with much lower frequencies than the natural frequency of the oscillator because path and site attenuation (often modelled by Q and ?, respectively) have removed the highest frequencies. We demonstrate that if high-cut filters are to be used, then their corner frequencies should be selected on an individual basis, as has been done in a few recent studies.

  12. Nonlinear attenuation and rock damage during strong seismic ground motions

    NASA Astrophysics Data System (ADS)

    Sleep, Norman H.; Hagin, Paul

    2008-10-01

    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 number depth of the incident waves, 30 m, for the 10 s-1 dominant angular frequency on a velocity seismogram. The low-amplitude S wave velocity gradually recovered with the logarithm of time. The attenuation of strong waves in general depends nonlinearly on their amplitude. High dynamic stress triggered small, very shallow earthquakes, at sites including Parkfield. The theoretical frictional behavior of a fractured medium with heterogeneous prestress relates these phenomena. Failure occurs in the highly prestressed domains causing small earthquakes and opening-mode cracks. The energy to dilate the cracks dissipates a significant fraction of the incoming seismic energy. The local high-porosity domains close with the logarithm of time, as expected from the aging law of rate and state friction, increasing the S wave velocity. The domain model indicates that nonlinear effects increase gradually over a range of dynamic Coulomb stresses as observed and as included in the widely used Masing rules. The Linker and Dieterich (1992) relationship provides the maximum sustainable dynamic coefficient of friction needed to utilize the Masing rules. This parameter is the coefficient of friction at a laboratory normal traction plus a constant 0.15 times the logarithm of the ratio of field normal traction to the laboratory normal traction. It is helpful to relate S wave velocity to starting frictional strength, as coefficient of friction near the quarter-wavelength depth determines nonlinear behavior. Then the dynamic coefficient of friction and equivalently the maximum sustainable acceleration at the dominant frequency depend weakly on S wave velocity. For example, the coefficient of friction at an angular frequency of 10 s-1 is less than 1.5 for rocks ranging from Parkfield sandstone to intact granite.

  13. Perceptual Training Strongly Improves Visual Motion Perception in Schizophrenia

    ERIC Educational Resources Information Center

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

    2011-01-01

    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…

  14. Perceptual Training Strongly Improves Visual Motion Perception in Schizophrenia

    ERIC Educational Resources Information Center

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

    2011-01-01

    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

  15. Strong ground motions generated by earthquakes on creeping faults

    USGS Publications Warehouse

    Harris, Ruth A.; Abrahamson, Norman A.

    2014-01-01

    A tenet of earthquake science is that faults are locked in position until they abruptly slip during the sudden strain-relieving events that are earthquakes. Whereas it is expected that locked faults when they finally do slip will produce noticeable ground shaking, what is uncertain is how the ground shakes during earthquakes on creeping faults. Creeping faults are rare throughout much of the Earth's continental crust, but there is a group of them in the San Andreas fault system. Here we evaluate the strongest ground motions from the largest well-recorded earthquakes on creeping faults. We find that the peak ground motions generated by the creeping fault earthquakes are similar to the peak ground motions generated by earthquakes on locked faults. Our findings imply that buildings near creeping faults need to be designed to withstand the same level of shaking as those constructed near locked faults.

  16. Validation of Predicted Strong Ground Motion Based on Energy Index of Seismic Wave

    NASA Astrophysics Data System (ADS)

    Hirai, Toshiyuki; Sawada, Sumio

    A model fault is supposed and strong ground motions are predicted around the fault by stochastic Green's function method to compare indexes such as PGA, PGV and energy index named IED(Incident Energy Density). It is necessary to show the validity of the predicted motions but the indexes such as PGA and PGV should not be enough to represent the characteristics of earthquake ground motions. In this study, we study the applicability of IED of a seismic wave to estimate validity of the predicted strong ground motion. IED of a predicted strong ground motion has good relation to magnitude of earthquake. The variation of IED due to the phase characteristics of element seismic waves used in stochastic Green's function method or the difference of soil characteristics is less than PGA and PGV. It can be concluded that if IED is added to evaluation indexes, it is possible to estimate more rationally the validity of a predicted strong ground motion.

  17. Strong ground motion prediction for southwestern China from small earthquake records

    NASA Astrophysics Data System (ADS)

    Tao, Z. R.; Tao, X. X.; Cui, A. P.

    2015-09-01

    For regions lack of strong ground motion records, a method is developed to predict strong ground motion by small earthquake records from local broadband digital earthquake networks. Sichuan and Yunnan regions, located in southwestern China, are selected as the targets. Five regional source and crustal medium parameters are inversed by micro-Genetic Algorithm. These parameters are adopted to predict strong ground motion for moment magnitude (Mw) 5.0, 6.0 and 7.0. Strong ground motion data are compared with the results, most of the result pass through ideally the data point plexus, except the case of Mw 7.0 in Sichuan region, which shows an obvious slow attenuation. For further application, this result is adopted in probability seismic hazard assessment (PSHA) and near-field strong ground motion synthesis of the Wenchuan Earthquake.

  18. Site Characterization of Italian Strong Motion Recording Stations

    SciTech Connect

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

    2008-07-08

    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 (V{sub s30}) is estimated using a hybrid approach. For young Quaternary alluvium, V{sub s30} 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 V{sub s30} are developed using the available data. This work is also presented in Scasserra et al. (2008: JEE, in review)

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

    SciTech Connect

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

    2008-07-08

    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, V{sub s30}, etc) as well as ground motion characteristics (e.g. peak ground acceleration, peak ground velocity, peak ground displacement, Arias intensity, etc.)

  20. Predicting Strong Motions for Seismic Hazard Assessments in Seattle, Washington

    NASA Astrophysics Data System (ADS)

    Delorey, Andrew A.

    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.

  1. Synthetic strong ground motions for engineering design utilizing empirical Green`s functions

    SciTech Connect

    Hutchings, L.J.; Jarpe, S.P.; Kasameyer, P.W.; Foxall, W.

    1996-04-11

    We present a methodology for developing realistic synthetic strong ground motions for specific sites from specific earthquakes. We analyzed the possible ground motion resulting from a M = 7.25 earthquake that ruptures 82 km of the Hayward fault for a site 1.4 km from the fault in the eastern San Francisco Bay area. We developed a suite of 100 rupture scenarios for the Hayward fault earthquake and computed the corresponding strong ground motion time histories. We synthesized strong ground motion with physics-based solutions of earthquake rupture and applied physical bounds on rupture parameters. By having a suite of rupture scenarios of hazardous earthquakes for a fixed magnitude and identifying the hazard to the site from the statistical distribution of engineering parameters, we introduce a probabilistic component into the deterministic hazard calculation. Engineering parameters of synthesized ground motions agree with those recorded from the 1995 Kobe, Japan and the 1992 Landers, California earthquakes at similar distances and site geologies.

  2. Implications of the Northridge earthquake for strong ground motions from thrust faults

    USGS Publications Warehouse

    Somerville, P.; Saikia, C.; Wald, D.; Graves, R.

    1996-01-01

    The peak accelerations recorded on alluvial sites during the Northridge earthquake were about 50% larger than the median value predicted by current empirical attenuation relations at distances less than about 30 km. This raises the question of whether the ground motions from the Northridge earthquake are anomalous for thrust events or are representative of ground motions expected in future thrust earthquakes. Since the empirical data base contains few strong-motion records close to large-thrust earthquakes, it is difficult to assess whether the Northridge ground motions are anomalous based on recorded data alone. For this reason, we have used a broadband strong-motion simulation procedure to help assess whether the ground motions were anomalous. The simulation procedure has been validated against a large body of strong-motion data from California earthquakes, and so we expect it to produce accurate estimates of ground motions for any given rupture scenario, including blind-thrust events for which no good precedent existed in the strong-motion data base until the occurrence of the Northridge earthquake. The ground motions from the Northridge earthquake and our simulations of these ground motions have a similar pattern of departure from empirical attenuation relations for thrust earthquakes: the peak accelerations are at about the 84th percentile level for distances within 20 to 30 km and follow the median level for larger distances. This same pattern of departure from empirical attenuation relations was obtained in our simulations of the peak accelerations of an Elysian Park blind-thrust event prior to the occurrence of the Northridge earthquake. Since we are able to model this pattern with broadband simulations, and had done so before the Northridge earthquake occurred, this suggests that the Northridge strong-motion records are not anomalous and are representative of ground motions close to thrust faults. Accordingly, it seems appropriate to include these recordings in strong-motion data sets that are used to develop empirical ground-motion attenuation relations for thrust faults and to use this augmented data set as the basis for evaluating the need for modifications in design coefficients in the seismic provisions of building codes.

  3. Disaster Mitigation by Quick Response Against Strong Earthquake Motion

    NASA Astrophysics Data System (ADS)

    Nakamura, Y.

    2007-12-01

    The concept of EEW, earthquake early warning, was reported on San Francisco Daily Evening Bulletin on 3rd November 1868 by Dr. Cooper first for San Francisco area. According to him this idea was triggered by a failure of earthquake prediction. It is impressive that the thinking way is same as present. In 1982 more than 100 years later, the warning system for Tohoku Shinkansen realized the Cooper's idea for the first time on the world. After that, SAS for Mexico City started operating in 1991, and UrEDAS for Tokaido Shinkansen, an evolutional P-wave detection/warning system, began to operate in 1992. The UrEDAS technology is based on new concepts and methods to realize a real time system for estimating the earthquake parameters as magnitude, location and depth. In Japan at 1992, a new information service using UrEDAS technology had been prepared, but it was not born due to objection of JMA, Japan Meteorological Agency. By the same JMA, an information service, so called "Kinkyu Jishin Sokuho", will be broadcasted in nation wide from the first of October 2007. This implies that our UrEDAS Information Service plan has been correct, and it is my pleasure. However, it shall be rare case in Japan that JMA's information will reach faster than arriving of M7 class or less earthquake at the possible damaged areas, because it takes a time relatively long for processing and transmitting. Only for M8 class earthquakes of which the occurrence probability is about once in ten years in Japan, it is possible to receive the information before arriving of strong shaking in a possible damaged area far from the epicenter. JMA should popularize "Kinkyu Jishin Sokuho" after understandable explanation of these facts. I'm afraid that it will mislead people to broadcast a film on an evacuation training in unbelievable condition which is assuming an earthquake of seismic intensity 7 (corresponding to MMI scale XII) arriving 20 seconds later. Anyway, we can rely only on the onsite alarm in focal area. Accurate and quick earthquake information just after shaking is more useful than the late early warning. And I hope public organizations to make best effort that they can announce the earthquake information not only for main shock but also aftershocks, because these information is quite important for the quick response.

  4. Strong motion deficits in dyslexia associated with DCDC2 gene alteration.

    PubMed

    Cicchini, Guido Marco; Marino, Cecilia; Mascheretti, Sara; Perani, Daniela; Morrone, Maria Concetta

    2015-05-27

    Dyslexia is a specific impairment in reading that affects 1 in 10 people. Previous studies have failed to isolate a single cause of the disorder, but several candidate genes have been reported. We measured motion perception in two groups of dyslexics, with and without a deletion within the DCDC2 gene, a risk gene for dyslexia. We found impairment for motion particularly strong at high spatial frequencies in the population carrying the deletion. The data suggest that deficits in motion processing occur in a specific genotype, rather than the entire dyslexia population, contributing to the large variability in impairment of motion thresholds in dyslexia reported in the literature. PMID:26019324

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

    USGS Publications Warehouse

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

    1989-01-01

    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.

  6. Damage assessment of RC buildings subjected to the different strong motion duration

    NASA Astrophysics Data System (ADS)

    Mortezaei, Alireza; mohajer Tabrizi, Mohsen

    2015-07-01

    An earthquake has three important characteristics; namely, amplitude, frequency content and duration. Amplitude and frequency content have a direct impact but not necessarily the sole cause of structural damage. Regarding the duration, some researchers show a high correlation between strong motion duration and structural damage whereas some others find no relation. This paper focuses on the ground motion durations characterized by Arias Intensity (AI). High duration may increase the damage state of structure for the damage accumulation. This paper investigates the response time histories (acceleration, velocity and displacement) of RC buildings under the different strong motion durations. Generally, eight earthquake records were selected from different soil type, and these records were grouped according to their PGA and frequency ranges. Maximum plastic rotation and drift response was chosen as damage indicator. In general, there was a positive correlation between strong motion duration and damage; however, in some PGA and frequency ranges input motions with shorter durations might cause more damage than the input motions with longer durations. In soft soils, input motions with longer durations caused more damage than the input motions with shorter durations.

  7. Strong Ground Motion Data from the October 23 and November 9, 2011 Van, Turkey Earthquakes

    NASA Astrophysics Data System (ADS)

    Harmandar, E.; Erdik, M.

    2012-04-01

    An earthquake of Mw = 7.2 on 23 October 2011 occured in the Van region of Eastern Turkey at 10:41 GMT. The epicenter of the earthquake is reported by the Kandilli Observatory and Earthquake Research Institute (KOERI) as 38.7578N-43.3602E. This earthquake have caused 604 life losses and around 1 billion USD damage mainly due to total collapse of about 200 residential buildings and other lesser damaged buildings. Shortly after this earthquake, the November 9, 2011 earthquake (ML = 5.6) took place at 19:23 GMT in the Edremit subprovince. KOERI reported the epicenter as 38.4295N -43.2342E. 40 people have died after the second damaging earthquake. After the first earthquake by the end of October, the Strong Motion Data Base of Turkey provides data from 22 stations, most of them at large distances beyond 100 km. After the second earthquake, six stations of KOERI and three statios of National Strong Motion network provides strong motion data. We have complemented this strong motion data base through conversion of broad-band seismographic data. We have also simulated strong ground motion in the epicentral area of these two earthquakes. A comparative analysis using ground motion prediction equations is also included.

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

    USGS Publications Warehouse

    Fedock, Joseph J.

    1986-01-01

    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.

  9. Strong-motion observations of the M 7.8 Gorkha, Nepal, earthquake sequence and development of the N-shake strong-motion network

    USGS Publications Warehouse

    Dixit, Amod; Ringler, Adam; Sumy, Danielle F.; Cochran, Elizabeth S.; Hough, Susan E.; Martin, Stacey; Gibbons, Steven; Luetgert, James H.; Galetzka, John; Shrestha, Surya; Rajaure, Sudhir; McNamara, Daniel E.

    2015-01-01

    We present and describe strong-motion data observations from the 2015 M 7.8 Gorkha, Nepal, earthquake sequence collected using existing and new Quake-Catcher Network (QCN) and U.S. Geological Survey NetQuakes sensors located in the Kathmandu Valley. A comparison of QCN data with waveforms recorded by a conventional strong-motion (NetQuakes) instrument validates the QCN data. We present preliminary analysis of spectral accelerations, and peak ground acceleration and velocity for earthquakes up to M 7.3 from the QCN stations, as well as preliminary analysis of the mainshock recording from the NetQuakes station. We show that mainshock peak accelerations were lower than expected and conclude the Kathmandu Valley experienced a pervasively nonlinear response during the mainshock. Phase picks from the QCN and NetQuakes data are also used to improve aftershock locations. This study confirms the utility of QCN instruments to contribute to ground-motion investigations and aftershock response in regions where conventional instrumentation and open-access seismic data are limited. Initial pilot installations of QCN instruments in 2014 are now being expanded to create the NepalShaking Hazard Assessment for Kathmandu and its Environment (N-SHAKE) network.

  10. An evaluation of the strong ground motion recorded during the May 1, 2003 Bingol Turkey, earthquake

    USGS Publications Warehouse

    Akkar, Sinan; Boore, David M.; Gulkan, Polat

    2005-01-01

    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 9 km, respectively, was obtained at a station near the city of Bingöl, Turkey. The maximum peak ground values of 0.55g 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.

  11. Strong ground-motion prediction from Stochastic-dynamic source models

    USGS Publications Warehouse

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

    2003-01-01

    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.

  12. 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

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

    2004-01-01

    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.

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

    SciTech Connect

    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

    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.

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

    SciTech Connect

    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

    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.

  15. Coupled cavities for motional ground-state cooling and strong optomechanical coupling

    NASA Astrophysics Data System (ADS)

    Liu, Yong-Chun; Xiao, Yun-Feng; Luan, Xingsheng; Gong, Qihuang; Wong, Chee Wei

    2015-03-01

    Motional ground-state cooling and quantum-coherent manipulation of mesoscopic mechanical systems are crucial goals in both fundamental physics and applied science. We demonstrate that the motional ground state can be achieved in the highly unresolved sideband regime, through coherent auxiliary cavity interferences. We further illustrate coherent strong Rabi coupling between indirectly coupled and individually optimized mechanical resonators and optical cavities through effective dark-mode interaction. The proposed approach provides a platform for quantum manipulation of mesoscopic mechanical devices beyond the resolved sideband limit.

  16. Designed microtremor array based actual measurement and analysis of strong ground motion at Palu city, Indonesia

    SciTech Connect

    Thein, Pyi Soe; Pramumijoyo, Subagyo; Wilopo, Wahyu; Setianto, Agung; Brotopuspito, Kirbani Sri; Kiyono, Junji; Putra, Rusnardi Rahmat

    2015-04-24

    In this study, we investigated the strong ground motion characteristics under Palu City, Indonesia. The shear wave velocity structures evaluated by eight microtremors measurement are the most applicable to determine the thickness of sediments and average shear wave velocity with Vs ≤ 300 m/s. Based on subsurface underground structure models identified, earthquake ground motion was estimated in the future Palu-Koro earthquake by using statistical green’s function method. The seismic microzonation parameters were carried out by considering several significant controlling factors on ground response at January 23, 2005 earthquake.

  17. New Hybridized Surface Wave Approach for Geotechnical Modeling of Shear Wave Velocity at Strong Motion Recording Stations

    NASA Astrophysics Data System (ADS)

    Kayen, R.; Carkin, B.; Minasian, D.

    2006-12-01

    Strong motion recording (SMR) networks often have little or no shear wave velocity measurements at stations where characterization of site amplification and site period effects is needed. Using the active Spectral Analysis of Surface Waves (SASW) method, and passive H/V microtremor method we have investigated nearly two hundred SMR sites in California, Alaska, Japan, Australia, China and Taiwan. We are conducting these studies, in part, to develop a new hybridized method of site characterization that utilizes a parallel array of harmonic-wave sources for active-source SASW, and a single long period seismometer for passive-source microtremor measurement. Surface wave methods excel in their ability to non-invasively and rapidly characterize the variation of ground stiffness properties with depth below the surface. These methods are lightweight, inexpensive to deploy, and time-efficient. They have been shown to produce accurate and deep soil stiffness profiles. By placing and wiring shakers in a large parallel circuit, either side-by-side on the ground or in a trailer-mounted array, a strong in-phase harmonic wave can be produced. The effect of arraying many sources in parallel is to increase the amplitude of waves received at far-away spaced seismometers at low frequencies so as to extend the longest wavelengths of the captured dispersion curve. The USGS system for profiling uses this concept by arraying between two and eight electro-mechanical harmonic-wave shakers. With large parallel arrays of vibrators, a dynamic force in excess of 1000 lb can be produced to vibrate the ground and produce surface waves. We adjust the harmonic wave through a swept-sine procedure to profile surface wave dispersion down to a frequency of 1 Hz and out to surface wave-wavelengths of 200-1000 meters, depending on the site stiffness. The parallel-array SASW procedure is augmented using H/V microtremor data collected with the active source turned off. Passive array microtremor data reveal the natural and resonance characteristics of the ground by capturing persistent natural vibrations. These microtremors are the result of the interaction of surface waves arriving from distant sources and the stiffness structure of the site under investigation. As such, these resonance effects are effective in constraining the layer thicknesses of the SASW shear wave velocity structure and aid in determining the depth of the deepest layer. Together, the hybridized SASW and H/V procedure provides a complete data set for modeling the geotechnical aspects of ground amplification of earthquake motions. Data from these investigations are available at http://walrus.wr.usgs.gov/geotech.

  18. Comparison of damping in buildings under low-amplitude and strong motions

    USGS Publications Warehouse

    Celebi, M.

    1996-01-01

    This paper presents a comprehensive assessment of damping values and other dynamic characteristics of five buildings using strong-motion and low-amplitude (ambient vibration) data. The strong-motion dynamic characteristics of five buildings within the San Francisco Bay area are extracted from recordings of the 17 October 1989 Loma Prieta earthquake (LPE). Ambient vibration response characteristics for the same five buildings were inferred using data collected in 1990 following LPE. Additional earthquake data other than LPE for one building and ambient vibration data collected before LPE for two other buildings provide additional confirmation of the results obtained. For each building, the percentages of critical damping and the corresponding fundamental periods determined from low-amplitude test data are appreciably lower than those determined from strong-motion recordings. These differences are attributed mainly to soil-structure interaction and other non-linear behavior affecting the structures during strong shaking. Significant contribution of radiation damping to the effective damping of a specific building is discussed in detail.

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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.

  20. Before and after retrofit - response of a building during ambient and strong motions

    USGS Publications Warehouse

    Celebi, M.; Liu, Huaibao P.

    1998-01-01

    This paper presents results obtained from ambient vibration and strong-motion responses of a thirteen-story, moment-resisting steel framed Santa Clara County Office Building (SCCOB) before being retrofitted by visco-elastic dampers and from ambient vibration response following the retrofit. Understanding the cumulative structural and site characteristics that affect the response of SCCOB before and after the retrofit is important in assessing earthquake hazards to other similar buildings and decision making in retrofitting them. The results emphasize the need to better evaluate structural and site characteristics in developing earthquake resisting designs that avoid resonating effects. Various studies of the strong-motion response records from the SCCOB during the 24 April 1984 (MHE) Morgan Hill (MS = 6.1), the 31 March 1986 (MLE) Mt. Lewis (MS = 6.1) and the 17 October 1989 (LPE) Loma Prieta (MS = 7.1) earthquakes show that the dynamic characteristics of the building are such that it (a) resonated (b) responded with a beating effect due to close-coupling of its translational and torsional frequencies, and (c) had a long-duration response due to low-damping. During each of these earthquakes, there was considerable contents damage and the occupants felt the rigorous vibration of the building. Ambient tests of SCCOB performed following LPE showed that both translational and torsional periods of the building are smaller than those derived from strong motions. Ambient tests performed following the retrofit of the building with visco-elastic dampers show that the structural fundamental mode frequency of the building has increased. The increased frequency implies a stiffer structure. Strong-motion response of the building during future earthquakes will ultimately validate the effectiveness of the retrofit method.This paper presents results obtained from ambient vibration and strong-motion responses of a thirteen-story, moment-resisting steel framed Santa Clara County Office Building (SCCOB) before being retrofitted by visco-elastic dampers and from ambient vibration response following the retrofit. Understanding the cumulative structural and site characteristics that affect the response of SCCOB before and after the retrofit is important in assessing earthquake hazards to other similar buildings and decision making in retrofitting them. The results emphasize the need to better evaluate structural and site characteristics in developing earthquake resisting designs that avoid resonating effects. Various studies of the strong-motion response records from the SCCOB during the 24 April 1984 (MHE) Morgan Hill (Ms = 6.1), the 31 March 1986 (MLE) Mt. Lewis (Ms = 6.1) and the 17 October 1989(LPE) Loma Prieta (Ms = 7.1) earthquakes show that the dynamic characteristics of the building are such that it (a) resonated (b) responded with a beating effect due to close-coupling of its translational and torsional frequencies, and (c) had a long-duration response due to low-damping. During each of these earthquakes, there was considerable contents damage and the occupants felt the rigorous vibration of the building. Ambient tests of SCCOB performed following LPE showed that both translational and torsional periods of the building are smaller than those derived from strong motions. Ambient tests performed following the retrofit of the building with visco-elastic dampers show that the structural fundamental mode frequency of the building has increased. The increased frequency implies a stiffer structure. Strong-motion response of the building during future earthquakes will ultimately validate the effectiveness of the retrofit method.

  1. Vision for the Future of the US National Strong-Motion Program

    USGS Publications Warehouse

    Committee for the Future of the US National Strong-Motion Program

    1997-01-01

    This document provides the requested vision for the future of the National Strong-Motion Program operated by the US Geological Survey. Options for operation of the program are presented in a companion document. Each of the three major charges of the EHRP, program council pertaining to the vision document is addressed here. The 'Vision Summary' through a series of answers to specific questions is intended to provide a complete synopsis of the committees response to program council charges. The Vision for the Future of the NSMP is presented as section III of the Summary. Analysis and detailed discussion supporting the answers in the summary are presented as sections organized according to the charges of the program council. The mission for the program is adopted from that developed at the national workshop entitled 'Research Needs for Strong Motion Data to Support Earthquake Engineering' sponsored by the National Science Foundation.

  2. Strong Ground Motion Simulation of the 2008 MS 8.0 Wenchuan, China, Earthquake

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Yao, X.; Yu, X.

    2014-12-01

    The near source strong ground motions of the 2008 MS 8.0 Wenchuan, China, earthquake are simulated using empirical Green's function (EFG) method. At first, we estimate the locations of strong motion generation areas (SMGA) based on the teleseismic data inversion results by some other researchers. Then, preliminarily determine the total areas of SMGA referring to the scaling law introduced by Somerville et al. (1999). Finally, we implement the genetic algorithm searching for the optimized source parameters. Based on the source models, we synthetize the waveforms for the 18 stations located near the source region. Our results show that the comparison between the synthetic waveforms and the observed records agree each other very well. We find that there are five obvious SMGAs on the fault. The locations of the two of them are similar with the asperities from the teleseismic data inversion. However, the combined strong motion generation areas and the rise time we obtained are smaller than those values predicted by the extension value of the scaling law by Somerville et al. (1999).

  3. Relativistic electron motion in cylindrical waveguide with strong guiding magnetic field and high power microwave

    SciTech Connect

    Wu, Ping; Sun, Jun; Cao, Yibing

    2015-06-15

    In O-type high power microwave (HPM) devices, the annular relativistic electron beam is constrained by a strong guiding magnetic field and propagates through an interaction region to generate HPM. Some papers believe that the E × B drift of electrons may lead to beam breakup. This paper simplifies the interaction region with a smooth cylindrical waveguide to research the radial motion of electrons under conditions of strong guiding magnetic field and TM{sub 01} mode HPM. The single-particle trajectory shows that the radial electron motion presents the characteristic of radial guiding-center drift carrying cyclotron motion. The radial guiding-center drift is spatially periodic and is dominated by the polarization drift, not the E × B drift. Furthermore, the self fields of the beam space charge can provide a radial force which may pull electrons outward to some extent but will not affect the radial polarization drift. Despite the radial drift, the strong guiding magnetic field limits the drift amplitude to a small value and prevents beam breakup from happening due to this cause.

  4. The Engineering Strong Ground Motion Network of the National Autonomous University of Mexico

    NASA Astrophysics Data System (ADS)

    Velasco Miranda, J. M.; Ramirez-Guzman, L.; Aguilar Calderon, L. A.; Almora Mata, D.; Ayala Hernandez, M.; Castro Parra, G.; Molina Avila, I.; Mora, A.; Torres Noguez, M.; Vazquez Larquet, R.

    2014-12-01

    The coverage, design, operation and monitoring capabilities of the strong ground motion program at the Institute of Engineering (IE) of the National Autonomous University of Mexico (UNAM) is presented. Started in 1952, the seismic instrumentation intended initially to bolster earthquake engineering projects in Mexico City has evolved into the largest strong ground motion monitoring system in the region. Today, it provides information not only to engineering projects, but also to the near real-time risk mitigation systems of the country, and enhances the general understanding of the effects and causes of earthquakes in Mexico. The IE network includes more than 100 free-field stations and several buildings, covering the largest urban centers and zones of significant seismicity in Central Mexico. Of those stations, approximately one-fourth send the observed acceleration to a processing center in Mexico City continuously, and the rest require either periodic visits for the manual recovery of the data or remote interrogation, for later processing and cataloging. In this research, we document the procedures and telecommunications systems used systematically to recover information. Additionally, we analyze the spatial distribution of the free-field accelerographs, the quality of the instrumentation, and the recorded ground motions. The evaluation criteria are based on the: 1) uncertainty in the generation of ground motion parameter maps due to the spatial distribution of the stations, 2) potential of the array to provide localization and magnitude estimates for earthquakes with magnitudes greater than Mw 5, and 3) adequacy of the network for the development of Ground Motion Prediction Equations due to intra-plate and intra-slab earthquakes. We conclude that the monitoring system requires a new redistribution, additional stations, and a substantial improvement in the instrumentation and telecommunications. Finally, we present an integral plan to improve the current network's monitoring capabilities.

  5. A strong-motion network in Northern Italy (RAIS): data acquisition and processing

    NASA Astrophysics Data System (ADS)

    Augliera, Paolo; Ezio, D'alema; Simone, Marzorati; Marco, Massa

    2010-05-01

    The necessity of a dense network in Northern Italy started from the lack of available data after the occurrence of the 24th November 2004, Ml 5.2, Sal earthquake. Since 2006 many efforts have been made by the INGV (Italian National Institute for Geophysics and Volcanology), department of Milano-Pavia (hereinafter INGV MI-PV), to improve the strong-motion monitoring of the Northern Italy regions. At the end of 2007, the RAIS (Strong-Motion Network in Northern Italy) included 19 stations equipped with Kinemetrics Episensor FBA ES-T coupled with 5 20-bits Lennartz Mars88/MC and 14 24-bits Reftek 130-01 seismic recorders. In this step, we achieved the goal to reduce the average inter-distances between strong-motion stations, installed in the area under study, from about 40 km to 15 km. In this period the GSM-modem connection between the INGV MI-PV acquisition center and the remote stations was used. Starting to 2008, in order to assure real-time recordings, with the aim to integrate RAIS data in the calculation of the Italian ground-shaking maps, the main activity was devoted to update the data acquisition of the RAIS strong-motion network. Moreover a phase that will lead to replace the original recorders with 24-bits GAIA2 systems (directly produced by INGV-CNT laboratory, Rome) has been starting. Today 11 out of the 22 stations are already equipped by GAIA2 and their original GSM-modem acquisition system were already replaced with real-time connections, based on TCP/IP or Wi-Fi links. All real time stations storage data using the MiniSEED format. The management and data exchange are assured by the SEED-Link and Earthworm packages. The metadata dissemination is achieved through the website, where the computed strong motion parameters, together the amplification functions, for each recording station are available for each recorded events. The waveforms, for earthquake with local magnitude higher than 3.0 are now collected in the ITalian ACcelerometric Archive (http://itaca.mi.ingv.it).

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

    USGS Publications Warehouse

    Peng, K.; Xie, Lingtian; Li, S.; Boore, D.M.; Iwan, W.D.; Teng, T.L.

    1985-01-01

    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 gain ranging, a specified dynamic range of 102 dB, a 2.5 s pre-event memory, programmable triggering, and are equipped with TCG-1B Time Code Generators with a stability of 3 parts in 107 over a range of 0-50??C. In 2 y of operation beginning July, 1982 a total of 603 near-source 3-component accelerograms were gathered from 243 earthquakes of magnitude ML = 1.2-5.3. Most of these accelerograms have recorded the initial P-wave. The configuration of the experimental array and a representative set of near-source strong-motion accelerograms are presented in this paper. The set of accelerograms exhibited were obtained during the ML = 5.3 Lulong earthquake of October 19, 1982, when digital event recorders were triggered. The epicentral distances ranged from 4 to 41 km and the corresponding range of peak horizontal accelerations was 0.232g to 0.009g. A preliminary analysis of the data indicates that compared to motions in the western United States, the peak acceleration attenuates much more rapidly in the Tangshan area. The scaling of peak acceleration with magnitude, however, is similar in the two regions. Data at more distant sites are needed to confirm the more rapid attenuation. ?? 1985.

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

    SciTech Connect

    Wong, I.G. ); Silva, W.J.; Stark, C.L. ); Jackson, S.; Smith, R.P. )

    1991-01-01

    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.

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

    SciTech Connect

    Wong, I.G.; Silva, W.J.; Stark, C.L.; Jackson, S.; Smith, R.P.

    1991-12-31

    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.

  9. Source complexity of the 1987 Whittier Narrows, California, earthquake from the inversion of strong motion records

    USGS Publications Warehouse

    Hartzell, S.; Iida, M.

    1990-01-01

    Strong motion records for the Whittier Narrows earthquake are inverted to obtain the history of slip. Both constant rupture velocity models and variable rupture velocity models are considered. The results show a complex rupture process within a relatively small source volume, with at least four separate concentrations of slip. Two sources are associated with the hypocenter, the larger having a slip of 55-90 cm, depending on the rupture model. These sources have a radius of approximately 2-3 km and are ringed by a region of reduced slip. The aftershocks fall within this low slip annulus. Other sources with slips from 40 to 70 cm each ring the central source region and the aftershock pattern. All the sources are predominantly thrust, although some minor right-lateral strike-slip motion is seen. The overall dimensions of the Whittier earthquake from the strong motion inversions is 10 km long (along the strike) and 6 km wide (down the dip). The preferred dip is 30?? and the preferred average rupture velocity is 2.5 km/s. Moment estimates range from 7.4 to 10.0 ?? 1024 dyn cm, depending on the rupture model. -Authors

  10. Rapid magnitude estimation for moderate to large earthquakes using strong motion records in the Iranian plateau

    NASA Astrophysics Data System (ADS)

    Babaei, P.; Sadeghi, H.; Rahimi, B.; Sadeghi Bagherabadi, A.

    2010-12-01

    Rapid estimation of earthquake magnitude has an effective role in emergency response operation. A fast determination of the earthquake magnitude is important to produce ground shaking and damage distribution maps in a short time after an event occurring. Iran Strong Motion Network (ISMN) has more than 1100 stations distributed in the Iranian plateau. The availability of a relatively large number of strong-motion records motivated us to do a study on rapid magnitude estimation. Three-component accelerograms of earthquakes with moment magnitude of 5 and greater are used. We calculated the parameter of total effective shaking by time integration of the absolute amplitude values of the three components over the strong shaking duration. There is an attenuation relation of total effective shaking with magnitude and hypocentral distance. We estimated coefficients of this attenuation relation through a least square regression analysis, and obtained a series of attenuation curves of total effective shaking in the moment magnitude range of 5 to 7. The estimated moment magnitudes match closely with reported values. This magnitude determination could be done, just after the waveforms have completed.

  11. Attenuation Characteristics of Strong Ground Motions during the Mw 6.1 South Napa Earthquake

    NASA Astrophysics Data System (ADS)

    Si, H.; Koketsu, K.; Miyake, H.; Ibrahim, R.

    2014-12-01

    The 2014 South Napa earthquake (Mw 6.1, GCMT) occurred near the American Canyon, California, at 3:20 on 24 August 2014. The earthquake is the largest damaging earthquakes in the area since the 1989 Mw 6.9 Loma Prieta earthquake. A large number of strong ground motions were recorded during this earthquake. We discuss the attenuation characteristics of the strong ground motions of the earthquake.The data used in this study are PGAs compiled by the Center for Engineering Strong Motion Data (CESMD), while the records derived at the stations located in a building were excluded. PGA is defined as the larger one among the PGAs of two horizontal components. We use a source model derived based on the waveform inversion by Dreger (2014). Based on the source model, we calculated the fault distance (FD) and the median distance (MED) which defined as the closest distance from a station to the middle line of the fault plane. We compared the observed PGAs with the GMPEs developed both in US (Boore et al., 2014) and Japan (Si and Midorikawa, 1999; Koketsu et al., 2013), as shown in Figure 1 (left, and center). The predictions by the GMPEs are generally consistent with the observations in near-field area, but overestimated at stations farther than about 10 km in fault distance. The reasons of the overestimates are assumed as follows: (1) the backward propagation effects since many far stations are located in bay area, (2) the energy loss when the seismic waves pass through the sharp discontinuities in the shear wave velocity structure. The second reason are taken into account for the case using MED based on the methods used in Si et al. (2012, 15WCEE). The corrected predictions are significantly improved (Figure 1, right).

  12. Crack-like rupture processes observed in near-fault strong motion data

    NASA Astrophysics Data System (ADS)

    Yomogida, Kiyoshi

    1988-10-01

    Strong motion data observed directly above a rupture zone of the Michoacan, Mexico, earthquake in 1985 provide, for the first time, clear evidence for crack-like rupture process in a major earthquake. The observed simple ramp-function type displacements cannot be explained by dislocation models such as a step-function dislocation, but require a crack-like slip function which grossly satisfies stress conditions on the fault (i.e., stress drops to some finite level after a passage of rupture front). This conclusion is required because the records contain sufficient near-field terms to distinguish between the two models.

  13. The Quake-Catcher Network: Improving Earthquake Strong Motion Observations Through Community Engagement

    NASA Astrophysics Data System (ADS)

    Cochran, E. S.; Lawrence, J. F.; Christensen, C. M.; Chung, A. I.; Neighbors, C.; Saltzman, J.

    2010-12-01

    The Quake-Catcher Network (QCN) involves the community in strong motion data collection by utilizing volunteer computing techniques and low-cost MEMS accelerometers. Volunteer computing provides a mechanism to expand strong-motion seismology with minimal infrastructure costs, while promoting community participation in science. Micro-Electro-Mechanical Systems (MEMS) triaxial accelerometers can be attached to a desktop computer via USB and are internal to many laptops. Preliminary shake table tests show the MEMS accelerometers can record high-quality seismic data with instrument response similar to research-grade strong-motion sensors. QCN began distributing sensors and software to K-12 schools and the general public in April 2008 and has grown to roughly 1500 stations worldwide. We also recently tested whether sensors could be quickly deployed as part of a Rapid Aftershock Mobilization Program (RAMP) following the 2010 M8.8 Maule, Chile earthquake. Volunteers are recruited through media reports, web-based sensor request forms, as well as social networking sites. Using data collected to date, we examine whether a distributed sensing network can provide valuable seismic data for earthquake detection and characterization while promoting community participation in earthquake science. We utilize client-side triggering algorithms to determine when significant ground shaking occurs and this metadata is sent to the main QCN server. On average, trigger metadata are received within 1-10 seconds from the observation of a trigger; the larger data latencies are correlated with greater server-station distances. When triggers are detected, we determine if the triggers correlate to others in the network using spatial and temporal clustering of incoming trigger information. If a minimum number of triggers are detected then a QCN-event is declared and an initial earthquake location and magnitude is estimated. Initial analysis suggests that the estimated locations and magnitudes are similar to those reported in regional and global catalogs. As the network expands, it will become increasingly important to provide volunteers access to the data they collect, both to encourage continued participation in the network and to improve community engagement in scientific discourse related to seismic hazard. In the future, we hope to provide access to both images and raw data from seismograms in formats accessible to the general public through existing seismic data archives (e.g. IRIS, SCSN) and/or through the QCN project website. While encouraging community participation in seismic data collection, we can extend the capabilities of existing seismic networks to rapidly detect and characterize strong motion events. In addition, the dense waveform observations may provide high-resolution ground shaking information to improve source imaging and seismic risk assessment.

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

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    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.

  15. Liquefaction and strong motion during the 2010-2011 Canterbury earthquake sequence

    NASA Astrophysics Data System (ADS)

    Chamberlain, M.; Wang, C. Y.; Dreger, D. S.; Cox, S.

    2014-12-01

    Liquefaction is a major seismic hazard for engineered structures; thus improved ability to predict the potential for liquefaction in seismically active regions is badly needed. The 2010 Mw 7.1 Darfield event and its associated aftershock sequence caused numerous occurrences of liquefaction in the Canterbury region of New Zealand, providing an excellent opportunity to study the occurrence of liquefaction in coastal plains near an active mountain belt. In this study we utilize strong motion data from over 100 stations in the New Zealand region and examine a number of major liquefaction events associated with the Canterbury earthquake sequence. These data are used to construct empirical attenuation relationships of ground motion as functions of hypocentral distance. The attenuation relationships so derived for the Canterbury region are similar to those developed for Southern California. This similarity suggests some generality of ground motion attenuation in sedimentary basins, even between geographically disparate regions. These relationships are used to estimate the seismic energy density at each liquefaction site in the Canterbury region, which is compared with a global database of liquefaction occurrences. Some liquefaction sites in the Canterbury region experienced seismic energy densities near the lower threshold for liquefaction established for the global dataset, suggesting high sensitivity to liquefaction.

  16. WHITTIER NARROWS, CALIFORNIA EARTHQUAKE OF OCTOBER 1, 1987-PRELIMINARY ASSESSMENT OF STRONG GROUND MOTION RECORDS.

    USGS Publications Warehouse

    Brady, A.G.; Etheredge, E.C.; Porcella, R.L.

    1988-01-01

    More than 250 strong-motion accelerograph stations were triggered by the Whittier Narrows, California earthquake of 1 October 1987. Considering the number of multichannel structural stations in the area of strong shaking, this set of records is one of the more significant in history. Three networks, operated by the U. S. Geological Survey, the California Division of Mines and Geology, and the University of Southern California produced the majority of the records. The excellent performance of the instruments in these and the smaller arrays is attributable to the quality of the maintenance programs. Readiness for a magnitude 8 event is directly related to these maintenance programs. Prior to computer analysis of the analog film records, a number of important structural resonant modes can be identified, and frequencies and simple mode shapes have been scaled.

  17. A strong-motion database from the Central American subduction zone

    NASA Astrophysics Data System (ADS)

    Arango, Maria Cristina; Strasser, Fleur O.; Bommer, Julian J.; Hernndez, Douglas A.; Cepeda, Jose M.

    2011-04-01

    Subduction earthquakes along the Pacific Coast of Central America generate considerable seismic risk in the region. The quantification of the hazard due to these events requires the development of appropriate ground-motion prediction equations, for which purpose a database of recordings from subduction events in the region is indispensable. This paper describes the compilation of a comprehensive database of strong ground-motion recordings obtained during subduction-zone events in Central America, focusing on the region from 8 to 14 N and 83 to 92 W, including Guatemala, El Salvador, Nicaragua and Costa Rica. More than 400 accelerograms recorded by the networks operating across Central America during the last decades have been added to data collected by NORSAR in two regional projects for the reduction of natural disasters. The final database consists of 554 triaxial ground-motion recordings from events of moment magnitudes between 5.0 and 7.7, including 22 interface and 58 intraslab-type events for the time period 1976-2006. Although the database presented in this study is not sufficiently complete in terms of magnitude-distance distribution to serve as a basis for the derivation of predictive equations for interface and intraslab events in Central America, it considerably expands the Central American subduction data compiled in previous studies and used in early ground-motion modelling studies for subduction events in this region. Additionally, the compiled database will allow the assessment of the existing predictive models for subduction-type events in terms of their applicability for the Central American region, which is essential for an adequate estimation of the hazard due to subduction earthquakes in this region.

  18. Nonlinear Site Response Validation Studies Using KIK-net Strong Motion Data

    NASA Astrophysics Data System (ADS)

    Asimaki, D.; Shi, J.

    2014-12-01

    Earthquake simulations are nowadays producing realistic ground motion time-series in the range of engineering design applications. Of particular significance to engineers are simulations of near-field motions and large magnitude events, for which observations are scarce. With the engineering community slowly adopting the use of simulated ground motions, site response models need to be re-evaluated in terms of their capabilities and limitations to 'translate' the simulated time-series from rock surface output to structural analyses input. In this talk, we evaluate three one-dimensional site response models: linear viscoelastic, equivalent linear and nonlinear. We evaluate the performance of the models by comparing predictions to observations at 30 downhole stations of the Japanese network KIK-Net that have recorded several strong events, including the 2011 Tohoku earthquake. Velocity profiles are used as the only input to all models, while additional parameters such as quality factor, density and nonlinear dynamic soil properties are estimated from empirical correlations. We quantify the differences of ground surface predictions and observations in terms of both seismological and engineering intensity measures, including bias ratios of peak ground response and visual comparisons of elastic spectra, and inelastic to elastic deformation ratio for multiple ductility ratios. We observe that PGV/Vs,30 as measure of strain is a better predictor of site nonlinearity than PGA, and that incremental nonlinear analyses are necessary to produce reliable estimates of high-frequency ground motion components at soft sites. We finally discuss the implications of our findings on the parameterization of nonlinear amplification factors in GMPEs, and on the extensive use of equivalent linear analyses in probabilistic seismic hazard procedures.

  19. Site effects by generalized inversion technique using strong motion recordings of the 2008 Wenchuan earthquake

    NASA Astrophysics Data System (ADS)

    Ren, Yefei; Wen, Ruizhi; Yamanaka, Hiroaki; Kashima, Toshihide

    2013-06-01

    The generalized inversion of S-wave amplitude spectra from the free-field strong motion recordings of the China National Strong Motion Observation Network System (NSMONS) are used to evaluate the site effects in the Wenchuan area. In this regard, a total of 602 recordings from 96 aftershocks of the Wenchuan earthquake with magnitudes of M3.7- M6.5 were selected as a dataset. These recordings were obtained from 28 stations at a hypocenter distance ranging from 30 km to 150 km. The inversion results have been verified as reliable by comparing the site response at station 62WUD using the Generalized Inversion Technique (GIT) and the Standard Spectral Ratio method (SSR). For all 28 stations, the site predominant frequency F p and the average site amplification in different frequency bands of 1.0-5.0 Hz, 5.0-10.0 Hz and 1.0-10.0 Hz have been calculated based on the inversion results. Compared with the results from the horizontal-to-vertical spectral ratio (HVSR) method, it shows that the HVSR method can reasonably estimate the site predominant frequency but underestimates the site amplification. The linear fitting between the average site amplification for each frequency band and the V s20 (the average uppermost-20 m shear wave velocity) shows good correlation. A distance measurement called the asperity distance D Aspt is proposed to reasonably characterize the source-to-site distance for large earthquakes. Finally, the inversed site response is used to identify the soil nonlinearity in the main shock and aftershocks of Wenchuan earthquake. In ten of the 28 stations analyzed in the main shock, the soil behaved nonlinearly, where the ground motion level is apparently beyond a threshold of PGA > 300 cm/s2 or PGV > 20 cm/s, and only one station coded 51SFB has evidence of soil nonlinear behavior in the aftershocks.

  20. The SCEC Broadband Platform: A Collaborative Open-Source Software Package for Strong Ground Motion Simulation and Validation

    NASA Astrophysics Data System (ADS)

    Silva, F.; Maechling, P. J.; Goulet, C.; Somerville, P.; Jordan, T. H.

    2013-12-01

    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 SCEC Broadband Platform is open-source scientific software that can generate broadband (0-100Hz) ground motions for earthquakes, integrating complex scientific modules that implement rupture generation, low and high-frequency seismogram synthesis, non-linear site effects calculation, and visualization into a software system that supports easy on-demand computation of seismograms. The Broadband Platform operates in two primary modes: validation simulations and scenario simulations. In validation mode, the Broadband Platform runs earthquake rupture and wave propagation modeling software to calculate seismograms of a historical earthquake for which observed strong ground motion data is available. Also in validation mode, the Broadband Platform calculates a number of goodness of fit measurements that quantify how well the model-based broadband seismograms match the observed seismograms for a certain event. Based on these results, the Platform can be used to tune and validate different numerical modeling techniques. During the past year, we have modified the software to enable the addition of a large number of historical events, and we are now adding validation simulation inputs and observational data for 23 historical events covering the Eastern and Western United States, Japan, Taiwan, Turkey, and Italy. In scenario mode, the Broadband Platform can run simulations for hypothetical (scenario) earthquakes. In this mode, users input an earthquake description, a list of station names and locations, and a 1D velocity model for their region of interest, and the Broadband Platform software then calculates ground motions for the specified stations. By establishing an interface between scientific modules with a common set of input and output files, the Broadband Platform facilitates the addition of new scientific methods, which are written by earth scientists in a number of languages such as C, C++, Fortran, and Python. The Broadband Platform's modular design also supports the reuse of existing software modules as building blocks to create new scientific methods. Additionally, the Platform implements a wrapper around each scientific module, converting input and output files to and from the specific formats required (or produced) by individual scientific codes. Working in close collaboration with scientists and research engineers, the SCEC software development group continues to add new capabilities to the Broadband Platform and to release new versions as open-source scientific software distributions that can be compiled and run on many Linux computer systems. Our latest release includes the addition of 3 new simulation methods and several new data products, such as map and distance-based goodness of fit plots. Finally, as the number and complexity of scenarios simulated using the Broadband Platform increase, we have added batching utilities to substantially improve support for running large-scale simulations on computing clusters.

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

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

    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.

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

    USGS Publications Warehouse

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

    2002-01-01

    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.

  3. NetQuakes - A new approach to urban strong-motion seismology

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    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.

  4. Calibration of strong motion models for Central America region and its use in seismic hazard assessment

    NASA Astrophysics Data System (ADS)

    Climent, A.; Benito, M. B.; Piedra, R.; Lindholm, C.; Gaspar-Escribano, J.

    2013-05-01

    We present the results of a study aimed at choosing the more suitable strong-motion models for seismic hazard analysis in the Central America (CA) Region. After a careful revision of the state of the art, different models developed for subduction and volcanic crustal zones, in tectonic environment similar to those of CA, were selected. These models were calibrated with accelerograms recorded in Costa Rica, Nicaragua and El Salvador. The peak ground acceleration PGA and Spectral Acceleration SA (T) derived from the records were compared with the ones predicted by the models in similar conditions of magnitude, distance and soil. The type of magnitude (Ms, Mb, MW), distance (Rhyp, Rrup, etc) and ground motion parameter (maximum horizontal component, geometrical mean, etc ) was taken into account in the comparison with the real data. As results of the analysis, the models which present a best fit with the local data were identified. These models have been applied for carrying out seismic hazard analysis in the region, in the frame of the RESIS II project financed by the Norwegian Foreign Department and also by the Spanish project SISMOCAES. The methodology followed is based on the direct comparison between PGA and SA 5 % damped response values extracted from actual records with the corresponding acceleration values predicted by the selected ground-motion models for similar magnitude, distance and soil conditions. Residuals between observed and predicted values for PGA, and SA (1sec) are calculated and plotted as a function of distance and magnitude, analyzing their deviation from the mean value. Besides and most important, a statistical analysis of the normalized residuals was carry out using the criteria proposed by Scherbaum et al. (2004), which consists in categorizing ground motion models based in a likelihood parameter that reflects the goodness-of-fit of the median values as well as the shape of the underlying distribution of ground motion residuals. Considering the results of the both analysis the conclusions can be drawn in the following paragraphs. Analyses of residuals show that in some cases the best adjustments of PGA and SA values do not always favor the same equation. Consequently, the following equations that present reasonable adjustments for both parameters are finally selected: Schmidt (2010) and Zhao et al (2006) for shallow crustal sources; Schmidt (2010), Zhao et al (2006), Youngs et al. (1997) and Lin & Lee (2008) for subduction interface and Schmidt (2010), Youngs et al (1997), Zhao et al (2006) and Garcia et al (2005) for inslab subduction sources. Finally, to improve the development of proper models of attenuation of the region, it is recommended to the governmental and private institutions, to support the implementation of permanent strong ground motion networks in all Central America countries, especially in Guatemala, Honduras, Nicaragua and Panama, including free field stations. In case of Costa Rica and El Salvador to strengthen the networks that already they operate.

  5. On the Effects of Non-Planar Fault Geometry on Strong Ground Motion

    NASA Astrophysics Data System (ADS)

    Olsen, K. B.; Aochi, H.

    2002-12-01

    We quantify the effects of complex fault geometry on low-frequency (<1 Hz) strong ground motion using numerical modeling of dynamic rupture. Our tests include the computation of synthetic seismograms for several simple rupture scenarios with planar and curved fault approximations of the 1994 Northridge and the 1992 Landers earthquakes. We use the boundary integral equation method (BIEM) to compute the dynamic rupture process, which includes the normal stress effects along the curved fault geometries. The wave propagation and computation of synthetic seismograms are modeled using a fourth-order finite-difference method (FDM). The near-field ground motion is significantly affected by the acceleration, deceleration and arrest of rupture due to fault bending, as well as the the variation in directivity of the rupture. We compare 1-Hz near-fault peak velocities for 40o-dipping, thrust faults buried 5 km with dimensions 24 km by 16 km. Compared to that for a planar fault, such as most approximations of the Northridge earthquake, a 6-km-long hanging-wall or footwall splay with a maximum offset of 1 km can change peak velocities by up to a factor of 2-3 above the fault. This change is caused in part by a variation in directivity, in part by differences in the rupture dynamics for the scenarios. In particular, the curved faults cause a gradual arrest of rupture, while the planar fault rupture stops abruptly with a resulting increase in moment. Our tests suggest that the differences in waveform are larger on the hanging wall compared to those on the footwall. The results imply that kinematic ground motion estimates and slip inversion may be significantly biased by the omission of dynamic rupture effects and of relatively gentle variation in fault geometry, even for long-period waves.

  6. Strong ground motion in the Kathmandu Valley during the 2015 Gorkha, Nepal, earthquake

    NASA Astrophysics Data System (ADS)

    Takai, Nobuo; Shigefuji, Michiko; Rajaure, Sudhir; Bijukchhen, Subeg; Ichiyanagi, Masayoshi; Dhital, Megh Raj; Sasatani, Tsutomu

    2016-01-01

    On 25 April 2015, a large earthquake of Mw 7.8 occurred along the Main Himalayan Thrust fault in central Nepal. It was caused by a collision of the Indian Plate beneath the Eurasian Plate. The epicenter was near the Gorkha region, 80 km northwest of Kathmandu, and the rupture propagated toward east from the epicentral region passing through the sediment-filled Kathmandu Valley. This event resulted in over 8000 fatalities, mostly in Kathmandu and the adjacent districts. We succeeded in observing strong ground motions at our four observation sites (one rock site and three sedimentary sites) in the Kathmandu Valley during this devastating earthquake. While the observed peak ground acceleration values were smaller than the predicted ones that were derived from the use of a ground motion prediction equation, the observed peak ground velocity values were slightly larger than the predicted ones. The ground velocities observed at the rock site (KTP) showed a simple velocity pulse, resulting in monotonic-step displacements associated with the permanent tectonic offset. The vertical ground velocities observed at the sedimentary sites had the same pulse motions that were observed at the rock site. In contrast, the horizontal ground velocities as well as accelerations observed at three sedimentary sites showed long duration with conspicuous long-period oscillations, due to the valley response. The horizontal valley response was characterized by large amplification (about 10) and prolonged oscillations. However, the predominant period and envelope shape of their oscillations differed from site to site, indicating a complicated basin structure. Finally, on the basis of the velocity response spectra, we show that the horizontal long-period oscillations on the sedimentary sites had enough destructive power to damage high-rise buildings with natural periods of 3 to 5 s.

  7. An improved method for tight integration of GPS and strong-motion records: Complementary advantages

    NASA Astrophysics Data System (ADS)

    Tu, Rui; Zhang, Qin; Wang, Li; Liu, Zhanke; Huang, Guanwen

    2015-12-01

    The complementary nature of GPS and seismic sensors for station ground motion estimation is well recognized and many studies have proposed the integrated processing of the two datasets for obtaining more accurate and reliable seismic waves (displacement, velocity and acceleration). There are two critical issues in the integrated processing; one is the precise correction of the strong-motion's baseline shifts which are caused by tilting and/or rotation of the seismic sensors, the other is the suitable constraint of the high resolution accelerations to get more reliable seismic waves. In this contribution, we present an improved approach for the integration estimation in two steps. First, proper introduction of the baseline-corrected acceleration into the Precise Point Positioning (PPP)'s state equation and treatment of the baseline shifts as unknown parameters to be estimated for each epoch. Second, after correction of these baseline shifts, use of the high resolution acceleration for constraint of the GPS solution and ambiguity resolution. The efficiency of the improved approach was validated using an experimental dataset which was recorded by a pair of collocated GPS antenna and an accelerometer, and it shows that the advantages of each sensor are complementary.

  8. City of Bingl in May 2003: Assessment of strong ground motion records

    NASA Astrophysics Data System (ADS)

    eken, U.; Beyhan, G.; Selim, H. H.

    2014-03-01

    The main shock of Bingl earthquake ( M W = 6.4) recorded by six accelerometers in the area occurred at 03:27 local time on May 1, 2003. The largest acceleration value of north-south component was recorded as 545.5 cm/s2 at the nearest station which it is 12 km away from the epicenter of earthquake. Especially, 0.15 s short period was observed when high spectral acceleration value occurred. An acceleration value greater than 50 gal was recorded at the BNG (Bingl) station and structural damage occurred within 6.5 s was very important for the near source and strong ground motion seismology. The recorded peak acceleration values were greater than the estimated empirical acceleration values. However, the structural damage was not as high and widespread as expected. This occurrence was explained by considering the factors of earthquake source, frequency content, effective duration, effective acceleration value, local soil conditions, rupture direction and attenuation.

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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.

  10. Options for the Future of the US National Strong-Motion Program

    USGS Publications Warehouse

    Committee for the Future of the US National Strong-Motion Program

    1997-01-01

    This report constitutes the requested 'Options Document'. This report considers three options. Option I assumes a constant level of financial support for Operating Expenses (OE) with not additional personnel support. Option II assumes a slight increase in OE support of $150K for FY 99 and beyond. Option III considers the role that a NSMP must play if the nation's urgent need to record the main earthquake at locations of significance for society is to be met. Two parts of Option III are considered. The first part of this option, termed Option III A, considers the role that strong-motion recording in and near man-made structures must play if a near-real time hazard initiative is to be implemented in the United States; The second part of Option III; termed Option III B, considers the scope of a NSMP needed to address society's needs to record the main earthquake in locations of significance for future public earthquake safety.

  11. Real-Time Baseline Error Estimation and Correction for GNSS/Strong Motion Seismometer Integration

    NASA Astrophysics Data System (ADS)

    Li, C. Y. N.; Groves, P. D.; Ziebart, M. K.

    2014-12-01

    Accurate and rapid estimation of permanent surface displacement is required immediately after a slip event for earthquake monitoring or tsunami early warning. It is difficult to achieve the necessary accuracy and precision at high- and low-frequencies using GNSS or seismometry alone. GNSS and seismic sensors can be integrated to overcome the limitations of each. Kalman filter algorithms with displacement and velocity states have been developed to combine GNSS and accelerometer observations to obtain the optimal displacement solutions. However, the sawtooth-like phenomena caused by the bias or tilting of the sensor decrease the accuracy of the displacement estimates. A three-dimensional Kalman filter algorithm with an additional baseline error state has been developed. An experiment with both a GNSS receiver and a strong motion seismometer mounted on a movable platform and subjected to known displacements was carried out. The results clearly show that the additional baseline error state enables the Kalman filter to estimate the instrument's sensor bias and tilt effects and correct the state estimates in real time. Furthermore, the proposed Kalman filter algorithm has been validated with data sets from the 2010 Mw 7.2 El Mayor-Cucapah Earthquake. The results indicate that the additional baseline error state can not only eliminate the linear and quadratic drifts but also reduce the sawtooth-like effects from the displacement solutions. The conventional zero-mean baseline-corrected results cannot show the permanent displacements after an earthquake; the two-state Kalman filter can only provide stable and optimal solutions if the strong motion seismometer had not been moved or tilted by the earthquake. Yet the proposed Kalman filter can achieve the precise and accurate displacements by estimating and correcting for the baseline error at each epoch. The integration filters out noise-like distortions and thus improves the real-time detection and measurement capability. The system will return precise and accurate displacements at a high rate for real-time earthquake monitoring.

  12. Deterministic earthquake scenario for the Basel area: Simulating strong motions and site effects for Basel, Switzerland

    NASA Astrophysics Data System (ADS)

    OprAl, Ivo; FH, Donat; Mai, P. Martin; Giardini, Domenico

    2005-04-01

    The Basel earthquake of 18 October 1356 is considered one of the most serious earthquakes in Europe in recent centuries (I0 = IX, M ? 6.5-6.9). In this paper we present ground motion simulations for earthquake scenarios for the city of Basel and its vicinity. The numerical modeling combines the finite extent pseudodynamic and kinematic source models with complex local structure in a two-step hybrid three-dimensional (3-D) finite difference (FD) method. The synthetic seismograms are accurate in the frequency band 0-2.2 Hz. The 3-D FD is a linear explicit displacement formulation using an irregular rectangular grid including topography. The finite extent rupture model is adjacent to the free surface because the fault has been recognized through trenching on the Reinach fault. We test two source models reminiscent of past earthquakes (the 1999 Athens and the 1989 Loma Prieta earthquake) to represent Mw ? 5.9 and Mw ? 6.5 events that occur approximately to the south of Basel. To compare the effect of the same wave field arriving at the site from other directions, we considered the same sources placed east and west of the city. The local structural model is determined from the area's recently established P and S wave velocity structure and includes topography. The selected earthquake scenarios show strong ground motion amplification with respect to a bedrock site, which is in contrast to previous 2-D simulations for the same area. In particular, we found that the edge effects from the 3-D structural model depend strongly on the position of the earthquake source within the modeling domain.

  13. Attenuation Tomography Based on Strong Motion Data: Case Study of Central Honshu Region, Japan

    NASA Astrophysics Data System (ADS)

    Kumar, Parveen; Joshi, A.; Verma, O. P.

    2013-12-01

    Three-dimensional frequency dependent S-wave quality factor (Qβ(f)) value for the central Honshu region of Japan has been determined in this paper using an algorithm based on inversion of strong motion data. The method of inversion for determination of three-dimensional attenuation coefficients is proposed by H ashida and S himazaki (J Phys Earth. 32, 299-316, 1984) and has been used and modified by J oshi (Curr Sci. 90, 581-585, 2006; Nat Hazards. 43, 129-146, 2007) and J oshi et al. (J. Seismol. 14, 247-272, 2010). Twenty-one earthquakes digitally recorded on strong motion stations of Kik-net network have been used in this work. The magnitude of these earthquake ranges from 3.1 to 4.2 and depth ranging from 5 to 20 km, respectively. The borehole data having high signal to noise ratio and minimum site effect is used in the present work. The attenuation structure is determined by dividing the entire area into twenty-five three-dimensional blocks of uniform thickness having different frequency-dependent shear wave quality factor. Shear wave quality factor values have been determined at frequencies of 2.5, 7.0 and 10 Hz from record in a rectangular grid defined by 35.4°N to 36.4°N and 137.2°E to 138.2°E. The obtained attenuation structure is compared with the available geological features in the region and comparison shows that the obtained structure is capable of resolving important tectonic features present in the area. The proposed attenuation structure is compared with the probabilistic seismic hazard map of the region and shows that it bears some remarkable similarity in the patterns seen in seismic hazard map.

  14. 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

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

    2012-04-01

    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

  15. Importance of bimaterial interfaces for earthquake dynamics and strong ground motion

    NASA Astrophysics Data System (ADS)

    Brietzke, Gilbert B.; Cochard, Alain; Igel, Heiner

    2009-08-01

    We perform a numerical investigation of dynamic ruptures on a bimaterial interface in 3-D with regularized slip-weakening friction and a heterogeneous initial shear stress and discuss the resulting strong ground motion. To isolate effects introduced by the material contrast, we perform pairs of simulations with opposite material orientations. We show that for many parameter sets the dynamics of rupture propagation are significantly influenced by the broken symmetry due to the material contrast during rupture propagation. The resulting slip histories of two events with reversed orientations of the material contrast can deviate such that the emanating waves lead to large differences in peak ground motion (peak ground velocity and peak ground acceleration), even when slip-distribution of the individual events are very similar, and therefore their moment magnitudes are basically identical. We also show that the wrinkle-like slip pulse specific to the bimaterial mechanism can be nucleated naturally from an initially crack-like mode of rupture, when the initial stress allows for large propagation distances. Once such a pulse has been nucleated, it travels at a dominant propagation speed close to the generalized Rayleigh velocity. The dynamic weakening of the fault due to the normal stress alteration during slip allows nucleating ruptures to overcome asperities of low initial shear stress in the preferred direction, which is the direction of displacement on the seismically slower side of the fault. In such situations, the orientation of the material contrast determines rupture extent and therefore the size of the earthquake, potentially by orders of magnitude.

  16. Hybrid k-squared source model for strong ground motion simulations: Introduction

    NASA Astrophysics Data System (ADS)

    Gallovi?, Frantiek; Brokeov, Johana

    2007-01-01

    Common kinematic strong motion modeling techniques can be divided into integral and composite according to the source representation. In the integral approach, we usually consider the rupture propagating in the form of a slip pulse, creating the k-squared final slip distribution. Such a model is acceptable on large scales where the faulting process is assumed to be deterministic, which is also supported by low-frequency slip inversions. Nevertheless, on small scales the real rupture is rather disorganized (chaotic) and requires a stochastic description. This is involved in the composite approach, in which the source acts as a discrete sequence of individually rupturing subevents. However, this model usually leads to incorrect spectral amplitudes in the low-frequency band (as compared to the integral model). The purpose of this study is to propose a hybrid kinematic k-squared source model based on a set of subsources, scaled to provide the k-squared slip distribution. The modeling combines: (1) the integral approach at low frequencies, based on the representation theorem and the k-squared slip distribution (obtained by composing subsources slip contributions), and (2) the composite approach at high frequencies, based on the summation of ground motion contributions from the subsources, treated as individual point sources. The same set of subsources is used in both the approaches, i.e. for both the frequency ranges. The hybrid method is numerically efficient, while minimizing the above-mentioned problems of both the techniques. The source model is applied to two events: 1999 Athens ( Mw=5.9) and 1997 Kagoshima ( Mw=6.1) earthquake examples. In the first example, the simulated PGAs are examined with respect to the attenuation relation for Greece. In the second example, synthetic velocigrams are compared with observed data showing that, despite the neglected site-effects, the complexities of measured waveforms are relatively well reproduced.

  17. Effects of 2D small-scale sedimentary basins on strong ground motion characteristics

    NASA Astrophysics Data System (ADS)

    Movahedasl, R.; Ghayamghamian, M. R.

    2015-08-01

    A lot of research on the 2D or 3D effects of large-scale basins (within several kilometers depth) have been conducted in the past. However, different 2D aspects of small-scale sedimentary basins (within tens of meters depth) remain in the developing stage. Here, an attempt is made to analyze different aspects of small-scale basins using both numerical and empirical investigations. In the first step, the 2D effects of small-scale basins on strong motion characteristics are numerically examined both in the time and frequency domains. In addition, the effects of input motion are also explained by the results of model excitation in different orthogonal directions. Then, the numerical outcomes are verified by the analysis of actual earthquake data recorded at a downhole array in the Fujisawa small basin, Japan. In the second step, since available recorded earthquake data in small basins with a clear understanding of subsurface geology are very limited, different 2D aspects of the small basin are parametrically investigated. For this purpose, extensive parametrical studies are carried out on the main features of a small basin such as slope angle, shape, infill soil properties, and basin thickness by using the finite difference numerical method. The horizontal and vertical peak ground accelerations of 2D with respect to 1D ones are defined as the horizontal and vertical aggravation factors (AGH and AGV). The AGH and AGV factors show large sensitivity to infill soil properties, shape and thickness, and small sensitivity to slope angle. The values of AGH and AGV factors vary in the range of 0.5-2 with large variations around small basin edges due to wave coupling, conversion, scattering and focusing in the vicinity of small basin edges. These cause a complicated pattern of 2D de-amplification and amplification, which mostly affect the motion in the high frequency range (>1?Hz). Finally, the outcomes provide numerical and field evidence on the 2D effects of small basins, and give some recommendations for design codes.

  18. Emission and its back-reaction accompanying electron motion in relativistically strong and QED-strong pulsed laser fields

    SciTech Connect

    Sokolov, Igor V.; Nees, John A.; Yanovsky, Victor P.; Naumova, Natalia M.; Mourou, Gerard A.

    2010-03-15

    The emission from an electron in the field of a relativistically strong laser pulse is analyzed. At pulse intensities of J>=2x10{sup 22} W/cm{sup 2} the emission from counterpropagating electrons is modified by the effects of quantum electrodynamics (QED), as long as the electron energy is sufficiently high: E>=1 GeV. The radiation force experienced by an electron is for the first time derived from the QED principles and its applicability range is extended toward the QED-strong fields.

  19. Analysis of strong-motion data from the New Hampshire earthquake of 18 January 1982

    SciTech Connect

    Chang, F.K.

    1983-09-01

    This report provides a permanent record and presents an analysis of the strong-motion data from the New Hampshire earthquake of 18 January 1982 which occurred at latitude 43.5 degrees N. longtitude 71.6 degrees W. Thirty-six accelerograms were recorded and digitized. The raw digitized accelerograms were processed by the US Geological Survey, Seismic Engineering Branch, to provide baseline correction and integrals are presented in tabular and graphic form. The integrated velocities and displacements are presented in graphic form. The attenuation curves of the three orthogonal components for peak acceleration, peak velocity, peak displacement, and velocity spectrum intensity on the crest, abutment, and downstream sites of the five US Army Corps of Engineers earth dams were plotted and compared. The transverse component shows the highest energy at the Franklin Falls Dam. However, its attenuation rate is faster than the vertical and longitudinal components. The transverse component of the accelerograph located on the right abutment of Franklin Falls Dam (8 km from the epicenter) recorded a maximum acceleration of 0.55 g's, which is the highest acceleration ever recorded in the eastern United States. The integrated maximum velocity is 5.59 cm/sec, which is very low in comparison with other earthquake records in the western United States or other earthquake regions. 8 references, 6 figures, 3 tables.

  20. Characteristics of strong ground motions in the 2014 M s 6.5 Ludian earthquake, Yunnan, China

    NASA Astrophysics Data System (ADS)

    Hu, J. J.; Zhang, Q.; Jiang, Z. J.; Xie, L. L.; Zhou, B. F.

    2015-10-01

    The 2014 M s 6.5 (M w6.1) Ludian earthquake occurred in the eastern Sichuan-Yunnan border region of western China. This earthquake caused much more severe engineering damage than the usual earthquakes with the same magnitude in China. The National Strong Motion Network obtained large set of ground motion recordings during the earthquake. To investigate the engineering interested characteristics of ground motion from Ludian earthquake and compare it with the M w 7.9 Wenchuan and the M w 6.6 Lushan earthquakes in western China, studies on the ground motion field, attenuation relationship, distance dependence of significant duration, and site amplification were carried out. Some conclusion is drawn. Specifically, the ground motion field reveals a directional feature, and the distribution characteristics of the two horizontal components are similar. The attenuation relationship for Ludian earthquake is basically consistent with the ground motion prediction equation (GMPE) for western China, except the slight smaller than the GMPE predicted at short periods. The distance dependences of ground motion duration are different in Sichuan and Yunnan regions due to the local physical dispersion and Q value. The site amplification factors are dominated by linear site response for lower reference ground motion, but the nonlinearity becomes notable for higher reference ground motion. This feature is basically consistent with the empirical model for western China. All the results indicate that the spatial distribution of ground motion, the attenuation characteristics, and the site amplification effect should be considered in characterization of near-field ground motion.

  1. Characteristics of strong ground motions in the 2014 M s 6.5 Ludian earthquake, Yunnan, China

    NASA Astrophysics Data System (ADS)

    Hu, J. J.; Zhang, Q.; Jiang, Z. J.; Xie, L. L.; Zhou, B. F.

    2016-01-01

    The 2014 M s 6.5 ( M w6.1) Ludian earthquake occurred in the eastern Sichuan-Yunnan border region of western China. This earthquake caused much more severe engineering damage than the usual earthquakes with the same magnitude in China. The National Strong Motion Network obtained large set of ground motion recordings during the earthquake. To investigate the engineering interested characteristics of ground motion from Ludian earthquake and compare it with the M w 7.9 Wenchuan and the M w 6.6 Lushan earthquakes in western China, studies on the ground motion field, attenuation relationship, distance dependence of significant duration, and site amplification were carried out. Some conclusion is drawn. Specifically, the ground motion field reveals a directional feature, and the distribution characteristics of the two horizontal components are similar. The attenuation relationship for Ludian earthquake is basically consistent with the ground motion prediction equation (GMPE) for western China, except the slight smaller than the GMPE predicted at short periods. The distance dependences of ground motion duration are different in Sichuan and Yunnan regions due to the local physical dispersion and Q value. The site amplification factors are dominated by linear site response for lower reference ground motion, but the nonlinearity becomes notable for higher reference ground motion. This feature is basically consistent with the empirical model for western China. All the results indicate that the spatial distribution of ground motion, the attenuation characteristics, and the site amplification effect should be considered in characterization of near-field ground motion.

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

    SciTech Connect

    Stevenson, J.D.

    1995-11-01

    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.

  3. Scaling Relation of Mega-fault Systems for Strong Ground Motion Prediction

    NASA Astrophysics Data System (ADS)

    Irikura, K.; Awata, Y.; Miyake, H.; Kagawa, T.; Miyakoshi, K.; Sato, T.; Dan, K.; Matsushima, S.

    2006-12-01

    We are studying scaling relations between fault length (L) and seismic moment (Mo) for mega-fault systems such as the 1906 San Francisco earthquake and the 2002 Denali earthquake. Scholz (2002) proposed an idea that the scaling relation changes from L-model to W-model for extra large earthquakes. According to the idea, Ikikura et al. (2004) proposed three-stage scaling relations between fault rupture area (S) and seismic moment; i.e., Mo is in proportion with S^{2/3} for Mo<7.5x1018Nm, S^{1/2} for Mo <7.5x1020, S for extra large earthquakes. Meanwhile, Somerville et al. (1999) proposed an uniform scaling, Mo is in proportion with S^{2/3}, even for larger earthquakes. We consider that the difference of the two scaling relations causes from their treatments of fault width (W). Irikura et al. (2004) introduces saturation of fault width considering thickness of seismogenic zone. However, fault widths are not observed values but estimated from aftershock distributions. We have to carefully evaluate S-Mo relationship considering uncertainty of fault widths. We try to estimate fault width from two empirical relationships, fault length vs. fault displacement (D) and seismic moment Mo vs fault length (L). The relationship L vs D is from certain data based on geological and geomorphological investigations. As for fault displacement, Awata (2006) proposes liner relationship between behavioral fault segment length and its maximum displacement. He also proposed saturation of fault displacement in case of mega-fault system. We here propose and demonstrate new scaling relations between fault length and seismic moment for mega-fault systems compiling past earthquake data (introducing field data about behavioral fault segments). We compare the derived fault width with carefully validated fault width from waveform and geodetic inversions to develop scaling relation for strong ground motion estimation. ACKNOWLEDGEMENT: A portion of this study was supported by the JNES research topic 'Ground Motion Prediction for Mega-fault Systems Based on Dynamic Source Modeling' (P.I.: Kojiro Irikura). REFERENCES: Somerville et al. (1999), SRL. Irikura et al. (2004), 13WCEE. Scholz(2002),Cambridge University Press. Awata (2006), AGU 2006 Fall Meeting.

  4. Seismic Intensity Maps for North Anatolian Fault Zone (Turkey) using Local Felt Intensity and Strong Motion Datasets

    NASA Astrophysics Data System (ADS)

    Askan, A.

    2014-12-01

    Seismic intensity maps indicate the spatial distribution of ground shaking levels in the meizoseismal area affected from an earthquake. Intensity maps provide guidance for the rapid assessment of shaking intensity and consequently the physical damage involved with an earthquake. Local correlations between the instrumental ground motion parameters and shaking intensity values are used to prepare these maps. There are several correlations derived using data from different regions in the world. However, since local damage characteristics of the built environment affect the felt-intensity values directly, different felt-intensity values may be reported in two different regions subjected to ground motions with similar amplitude and frequency contents. Thus such relationships should be derived based on regional strong motion and intensity datasets. Despite the intense seismic activity, as of now there are no such local correlations for the North Anatolian Fault Zone. In this study, we use the recently-compiled Turkish strong motion dataset along with the corresponding felt intensity data from past earthquakes to derive local relationships between MMI and a selected ground motion parameter (PGA, PGV, and SA at selected periods). We provide two sets of predictive equations: first group expresses the intensity values as a function of a selected ground motion parameter while the second set is more refined involving the event magnitude, distance and site class terms as independent variables. We present intensity maps of selected past events against the observed maps. We conclude that regional data from seismic networks is crucial for preparing realistic maps for use disaster management purposes.

  5. Development of Ocean Bottom Accelerometer for Observation of Strong Motion on Sea Floor

    NASA Astrophysics Data System (ADS)

    Shinohara, Masanao; Yamada, Tomoaki; Kanazawa, Toshihiko

    To understand characteristics of large earthquakes occurring in a subduction zone, it is necessary to study an asperity where large earthquakes occur repeatedly. Because observation near an asperity is needed for studies of earthquake generation, ocean bottom seismometer (OBS) is essential to observe seismic waves from earthquakes in subduction areas. Since a conventional OBS is designed for high-sensitivity observation, OBS records of large earthquake occurring near an OBS are often saturated. An accelerometer is suitable to record large amplitude seismic waves. Recently a compact accelerometer with a large dynamic range and low-power consumption is being developed. In addition, a pressure vessel of an OBS can contain much more batteries by using a large size titanium sphere. Therefore we developed new OBSs to obtain low-sensitivity (strong motion) accelerograms on the sea floor by installation of a small three-component accelerometer to a conventional long-term OBS. Three types of the OBS with accelerometer were developed. First type has a compact three-component accelerometer and the conventional 4.5 Hz velocity seismometers and used the sea floor observation of aftershocks of the 2004 Sumatra-Andaman Earthquake. Recording period of the first type is limited to two month due to capacities of batteries and a storage device. Second type has accelerometers only, however a recording period reaches one year by using a large pressure vessel. Third type records both high-sensitivity seismogram and low-sensitivity accelerograms with a recording period of one year. Both the second type and third type were used for the earthquake observation off Ibaraki. From these observations, we could obtain low-sensitivity accelerograms on sea floor with a good S/N ratio. Especially, records near the epicenter of the earthquake with magnitude of 7 off Ibaraki in 2008 were recorded without saturation. The developed OBSs with accelerometers are useful for location and studies of source process of large earthquakes.

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

    SciTech Connect

    Hutchings, L.; Foxall, W.; Kasameyer, P.; Wu, F.T.; Rau, R.-J.; Jarpe, S.

    1997-01-01

    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.

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

    SciTech Connect

    Bucksbaum, Philip H

    2011-04-13

    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.

  8. Modelling of Strong Ground Motions from 1991 Uttarkashi, India, Earthquake Using a Hybrid Technique

    NASA Astrophysics Data System (ADS)

    Kumar, Dinesh; Teotia, S. S.; Sriram, V.

    2011-10-01

    We present a simple and efficient hybrid technique for simulating earthquake strong ground motion. This procedure is the combination of the techniques of envelope function (M idorikawa et al. Tectonophysics 218:287-295, 1993) and composite source model (Z eng et al. Geophys Res Lett 21:725-728, 1994). The first step of the technique is based on the construction of the envelope function of the large earthquake by superposition of envelope functions for smaller earthquakes. The smaller earthquakes (sub-events) of varying sizes are distributed randomly, instead of uniform distribution of same size sub-events, on the fault plane. The accelerogram of large event is then obtained by combining the envelope function with a band-limited white noise. The low-cut frequency of the band-limited white noise is chosen to correspond to the corner frequency for the target earthquake magnitude and the high-cut to the Boore's f max or a desired frequency for the simulation. Below the low-cut frequency, the fall-off slope is 2 in accordance with the ?2 earthquake source model. The technique requires the parameters such as fault area, orientation of the fault, hypocenter, size of the sub-events, stress drop, rupture velocity, duration, source-site distance and attenuation parameter. The fidelity of the technique has been demonstrated by successful modeling of the 1991 Uttarkashi, Himalaya earthquake (Ms 7). The acceptable locations of the sub-events on the fault plane have been determined using a genetic algorithm. The main characteristics of the simulated accelerograms, comprised of the duration of strong ground shaking, peak ground acceleration and Fourier and response spectra, are, in general, in good agreement with those observed at most of the sites. At some of the sites the simulated accelerograms differ from observed ones by a factor of 2-3. The local site geology and topography may cause such a difference, as these effects have not been considered in the present technique. The advantage of the technique lies in the fact that detailed parameters such as velocity-Q structures and empirical Green's functions are not required or the records of the actual time history from the past earthquakes are not available. This method may find its application in preparing a wide range of scenarios based on simulation. This provides information that is complementary to the information available in probabilistic hazard maps.

  9. Observations and stochastic modelling of strong ground motions for the 2011 October 23 Mw 7.1 Van, Turkey, earthquake

    NASA Astrophysics Data System (ADS)

    Akinci, Aybige; Antonioli, Andrea

    2013-03-01

    The 2011 October 23 Van earthquake occurred at 13:41 local time in Eastern Turkey with an epicentre at 43.36oE, 38.76oN (Kandilli Observatory Earthquake Research Institute (KOERI)), 16 km north-northeast of the city of Van, killing around 604 people and leaving thousands homeless. This work presents an overview of the main features of the seismic ground shaking during the Van earthquake. We analyse the ground motion characteristics of the mainshock in terms of peak ground acceleration (PGA), peak ground velocity (PGV) and spectral accelerations (SA, 5 per cent of critical damping). In order to understand the characteristics of the ground motions induced by the mainshock, we also study the site response of the strong motion stations that recorded the seismic sequence. The lack of seismic recordings in this area imposes major constraints on the computation of reliable seismic hazard estimates for sites in this part of the country. Towards this aim, we have used a stochastic method to generate high frequency ground motion synthetics for the Mw 7.1 Van 2011 earthquake. The source mechanism of the Van event and regional wave propagation parameters are constrained from the available and previous studies. The selected model parameters are then validated against recordings. We also computed the residuals for the ground motion parameters in terms of PGA and PGV at each station and the model parameter bias by averaging the residuals over all the stations. The attenuation of the simulated ground motion parameters is compared with recent global and regional ground motion prediction equations. Finally, since it has been debated whether the earthquake of November 9 was an aftershock of the October 23 earthquake, we examine whether static variation of Coulomb stress could contribute to the observed aftershock triggering during the 2011 Van Lake sequence. Comparison with empirical ground motion prediction illustrated that the observed PGA data decay faster than the global empirical ground motion equations, both at moderate and larger distance; this feature is captured by the AC10 model that is derived from Turkish earthquake database. Faster attenuation of ground motion due to the high attenuation of seismic waves in the Eastern Anatolian plateau is in agreement with our stochastic simulations of strong ground motions of the 2011 October 23 Van earthquake. This highlights the importance of retrieving specific regional seismic parameters for the ground motion predictive equations. The stress redistribution computation indicates that the October sequence had an active role in promoting the November aftershocks, being the Coulomb stress variation positive in the entire region of interest. Furthermore, the Van events enhanced the stress level on the Caldiran fault.

  10. Extension of Characterized Source Model for Broadband Strong Ground Motion Simulations (0.1-50s) of M9 Earthquake

    NASA Astrophysics Data System (ADS)

    Asano, K.; Iwata, T.

    2014-12-01

    After the 2011 Tohoku earthquake in Japan (Mw9.0), many papers on the source model of this mega subduction earthquake have been published. From our study on the modeling of strong motion waveforms in the period 0.1-10s, four isolated strong motion generation areas (SMGAs) were identified in the area deeper than 25 km (Asano and Iwata, 2012). The locations of these SMGAs were found to correspond to the asperities of M7-class events in 1930's. However, many studies on kinematic rupture modeling using seismic, geodetic and tsunami data revealed that the existence of the large slip area from the trench to the hypocenter (e.g., Fujii et al., 2011; Koketsu et al., 2011; Shao et al., 2011; Suzuki et al., 2011). That is, the excitation of seismic wave is spatially different in long and short period ranges as is already discussed by Lay et al.(2012) and related studies. The Tohoku earthquake raised a new issue we have to solve on the relationship between the strong motion generation and the fault rupture process, and it is an important issue to advance the source modeling for future strong motion prediction. The previous our source model consists of four SMGAs, and observed ground motions in the period range 0.1-10s are explained well by this source model. We tried to extend our source model to explain the observed ground motions in wider period range with a simple assumption referring to the previous our study and the concept of the characterized source model (Irikura and Miyake, 2001, 2011). We obtained a characterized source model, which have four SMGAs in the deep part, one large slip area in the shallow part and background area with low slip. The seismic moment of this source model is equivalent to Mw9.0. The strong ground motions are simulated by the empirical Green's function method (Irikura, 1986). Though the longest period limit is restricted by the SN ratio of the EGF event (Mw~6.0) records, this new source model succeeded to reproduce the observed waveforms and Fourier amplitude spectra in the period range 0.1-50s. The location of this large slip area seems to overlap the source regions of historical events in 1793 and 1897 off Sanriku area. We think the source model for strong motion prediction of Mw9 event could be constructed by the combination of hierarchical multiple asperities or source patches related to histrorical events in this region.

  11. North Anna Nuclear Power Plant Strong Motion Records of the Mineral, Virginia Earthquake of August 23, 2011

    NASA Astrophysics Data System (ADS)

    Graizer, V.

    2012-12-01

    The MW 5.8 Mineral, Virginia earthquake was recorded at a relatively short epicentral distance of about 18 km at the North Anna Nuclear Power Plant (NPP) by the SMA-3 magnetic tape digital accelerographs installed inside the plant's containment at the foundation and deck levels. The North Anna NPP is operated by the Virginia Electric and Power Company (VEPCO) and has two pressurized water reactors (PWR) units that began operation in 1978 and 1980, respectively. Following the earthquake, both units were safely shutdown. The strong-motion records were processed to get velocity, displacement, Fourier and 5% damped response spectra. The basemat record demonstrated relatively high amplitudes of acceleration of 0.26 g and velocity of 13.8 cm/sec with a relatively short duration of strong motion of 2-3 sec. Recorded 5% damped Response Spectra exceed Design Basis Earthquake for the existing Units 1 and 2, while comprehensive plant inspections performed by VEPCO and U.S. Nuclear Regulatory Commission have concluded that the damage to the plant was minimal not affecting any structures and equipment significant to plant operation. This can be explained in part by short duration of the earthquake ground motion at the plant. The North Anna NPP did not have free-field strong motion instrumentation at the time of the earthquake. Since the containment is founded on rock there is a tendency to consider basemat record as an approximation of the free-field recording. However, comparisons of deck and basemat records demonstrate that the basemat recording is also affected by structural resonance frequencies higher than 3 Hz. Structural resonances in the frequency range of 3-4 Hz can at least partially explain significant exceedance of observed motions relative to ground motion calculated using ground motion prediction equations.cceleration, velocity and displacement at the North Anna NPP basemat level. Amplitudes of acceleration, velocity and displacement at basemat and deck levels

  12. Slip history of the 1995 Kobe, Japan, earthquake determined from strong motion, teleseismic, and geodetic data

    USGS Publications Warehouse

    Wald, D.J.

    1996-01-01

    Near-source ground motions, teleseismic body waveforms, and geodetic displacements produced by the 1995 Kobe, Japan, earthquake have been used to determine the spatial and temporal dislocation pattern on the faulting surfaces. Analysis of the slip model indicates that the ground motions recorded within the severely damaged region of Kobe originated from the region of relatively low slip (about 1 m) deep beneath Kobe and not from the shallow, higher slip regions (about 3 m) beneath Aqaji Island. Although the slip was relatively low beneath Kobe, the combined effects of source rupture directivity, a short slip duration, and site amplification conspired to generate very damaging ground motions within the city.

  13. Long-Period Strong Ground Motions Having Fired Large Oil Storage Tanks During the 2003 Tokachi-Oki, Japan, Earthquake

    NASA Astrophysics Data System (ADS)

    Hatayama, K.

    2005-12-01

    The 2003 Tokachi-oki, Japan, earthquake (Mw8.0; Japan Meteorological Agency, 2003) generated large-amplitude long-period (5 to 8 sec) strong ground motions in the Yufutsu plain, Hokkaido, Japan that is about 200 km away from the epicenter. Those motions excited big sloshing in many large oil storage tanks located on the plain and the sloshing caused two tank fires and several floating roofs to sink. Japanese nation-wide strong-motion observation networks have provided us with the first data set consisting of densely sampled strong ground motions that are rich in long-period components. This data set clearly showed that the large long-period motions were not observed before the waves entering the plain, i.e. the Yufutsu plain grew the long-period ground motions (Koketsu et al., 2005). The high density of spatial sampling can also show the spatial distribution of strength of long-period motions in the plain and their propagation there. We show by some contour maps of velocity responses that the strongest long-period shaking in the Yufutsu plain was observed around the downtown area of the Tomakomai city where the damage to oil tanks was more severe than any other areas. The isochrone of peaks of envelopes suggests a possibility that the long-period wave trains were focusing into the downtown from different directions. In order to study the excitation and the propagation process of long-period motions in the Yufutsu plain, an attempt was made to explore its deep sediment-bedrock structure by means of long-period microtremor array observations (Kanno et al., 2005). Relying on their resultant S-wave velocity profiles, we try to reproduce the features of the long-period motions observed there during the 2003 Tokachi-oki earthquake by making numerical simulations of 2-D seismic wave-fields by means of the finite difference method. To date we have succeeded in reproducing qualitatively the observed phenomena that the amplitude of long-period motions in the downtown area of the Tomakomai city was larger than any other areas in the Yufutsu plain.

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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.

  15. Application of the 'Recipe for Strong Ground Motion Evaluation' to the 2003 Tokachi-oki, Japan, Earthquake

    NASA Astrophysics Data System (ADS)

    Morikawa, N.; Aoi, S.; Honda, R.; Senna, S.; Hayakawa, Y.; Fujiwara, H.

    2004-12-01

    The National Research Institute for Earth Science and Disaster Prevention has carried on the special research project 'National Seismic Hazard Mapping Project of Japan'. In this project, strong ground motion evaluations for scenario earthquakes have been carried out based on the 'Recipe for strong ground motion evaluation' proposed by Irikura et al. (2004). Here we simulate strong ground motions during the 2003 Tokachi-oki earthquake (Mw=8.0) by applying the 'Recipe', and examine its validity. A simplified source model consists of some rectangular-shaped asperities on a fault plane is constructed following the method in the 'Recipe'. A 3D velocity structure model in and around Hokkaido, which is the target area for the simulation, is also constructed based on boreholes, reflection and refraction surveys, and geological data. Waveforms are calculated by the hybrid Green's function method (Kamae et al., 1998). We use the 3D finite-difference method and the stochastic Green's function method for low (< 0.2 Hz) and high frequency content, respectively. As an overall feature, the peak ground velocity and seismic intensity distributions of simulated strong ground motions agree well with the observed ones. However, some problems become clear. The first is the underestimations in the frequency range of 0.2-1 Hz at sites located on deep basins. This may be a lack in the evaluation on the effects of 3D structure in the calculations using the stochastic Green's function. The second is the overestimations in high frequency range (> 2 Hz) at sites located on back-arc side. This may be caused by the existence of low-Q zone beneath the volcanic front, which is not considered in this simulation. In addition, the non-linear site effects also should be considered in strong motion evaluations, especially for soft soil sites near source region.

  16. Acceleration and volumetric strain generated by the Parkfield 2004 earthquake on the GEOS strong-motion array near Parkfield, California

    USGS Publications Warehouse

    Borcherdt, Rodger D.; Johnston, Malcolm J.S.; Dietel, Christopher; Glassmoyer, Gary; Myren, Doug; Stephens, Christopher

    2004-01-01

    An integrated array of 11 General Earthquake Observation System (GEOS) stations installed near Parkfield, CA provided on scale broad-band, wide-dynamic measurements of acceleration and volumetric strain of the Parkfield earthquake (M 6.0) of September 28, 2004. Three component measurements of acceleration were obtained at each of the stations. Measurements of collocated acceleration and volumetric strain were obtained at four of the stations. Measurements of velocity at most sites were on scale only for the initial P-wave arrival. When considered in the context of the extensive set of strong-motion recordings obtained on more than 40 analog stations by the California Strong-Motion Instrumentation Program (Shakal, et al., 2004 http://www.quake.ca.gov/cisn-edc) and those on the dense array of Spudich, et al, (1988), these recordings provide an unprecedented document of the nature of the near source strong motion generated by a M 6.0 earthquake. The data set reported herein provides the most extensive set of near field broad band wide dynamic range measurements of acceleration and volumetric strain for an earthquake as large as M 6 of which the authors are aware. As a result considerable interest has been expressed in these data. This report is intended to describe the data and facilitate its use to resolve a number of scientific and engineering questions concerning earthquake rupture processes and resultant near field motions and strains. This report provides a description of the array, its scientific objectives and the strong-motion recordings obtained of the main shock. The report provides copies of the uncorrected and corrected data. Copies of the inferred velocities, displacements, and Psuedo velocity response spectra are provided. Digital versions of these recordings are accessible with information available through the internet at several locations: the National Strong-Motion Program web site (http://agram.wr.usgs.gov/), the COSMOS Virtual Data Center Web site (http://www.cosmos-eq.org), and the CISN Engineering and Berkeley data centers (http://www.quake.ca.gov/cisn-edc). They are also accessible together with recordings on the GEOS Strong-motion Array near Parkfield, CA since its installation in 1987 through the USGS GEOS web site ( http://nsmp.wr.usgs.gov/GEOS).

  17. PG&E's Seismic Network Goes Digital With Strong Motion: Successes and Challenges

    NASA Astrophysics Data System (ADS)

    Stanton, M. A.; Cullen, J.; McLaren, M. K.

    2008-12-01

    Pacific Gas and Electric Company (PG&E) is in year 3 of a 5-year project to upgrade the Central Coast Seismic Network (CCSN) from analog to digital. Located along the south-central California coast, the CCSN began operation in 1987, with 20 analog stations; 15 vertical component and 5 dual gain 3-component S-13 sensors. The analog signals travel over FM radio telemetry links and voice channels via PG&E's microwave network to our facility in San Francisco (SF), where the A/D conversion is performed on a computer running Earthworm v7.1, which also transmits the data to the USGS in Menlo Park. At the conversion point the dynamic ranges of the vertical and dual-gain sensors are 40-50dB and 60-70dB, respectively. Dynamic range exceedance (data clipping) generally occurs for a M2.5 or greater event within about 40 km of a station. The motivations to upgrade the seismic network were the need for higher dynamic range and to retire obsolete analog transmission equipment. The upgraded digital stations consist of the existing velocity sensors, a 131A-02/3 accelerometer and a Reftek 130-01 Broadband Seismic Recorder for digital data recording and transmission to SF. Vertical only stations have one component of velocity and 3 components of acceleration. Dual gain sites have 3 components of velocity and 3 of acceleration. To date we have successfully upgraded 6 sites; 3 more will be installed by the end of 2008. Some of the advantages of going digital are 1) data is recorded at each site and in SF, 2) substantially increased dynamic range of the velocity sensors to 120dB, as observed by on scale, close-by recordings from a M3.9 San Simeon aftershock on 04/29/2008, 3) accelerometers for on scale recording of large earthquakes, and 4) ability to contribute our strong motion data to USGS ShakeMaps. A significant challenge has been consistent radio communications. To resolve this issue we are installing point-to-multipoint Motorola Canopy spread spectrum radios at the stations and communication towers.

  18. The strong ground motion in Mexico City: array and borehole data analysis.

    NASA Astrophysics Data System (ADS)

    Roull, A.; Chvez-Garca, F. J.

    2003-04-01

    Site response at Mexico City has been intensively studied for the last 15 years, since the disastrous 1985 earthquakes. After those events, more than 100 accelerographs were installed, and their data have been extremely useful in quantifying amplification and in the subsequent upgrading of the building code. However, detailed analysis of the wavefield has been hampered by the lack of absolute time in the records and the large spacing between stations in terms of dominant wavelengths. In 2001, thanks to the support of CONACYT, Mexico, a new dense accelerographic network was installed in the lake bed zone of Mexico City. The entire network, including an existing network of 3 surface and 2 borehole stations operated by CENAPRED, consists in 12 surface and 4 borehole stations (at 30, 102 and 50 meters). Each station has a 18 bits recorder and a GPS receiver so that the complete network is a 3D array with absolute time. The main objective of this array is to provide data that can help us to better understand the wavefield that propagates in Mexico City during large earthquakes. Last year, a small event of magnitude 6.0 was partially recorded by 6 of the 12 surface stations and all the borehole stations. We analysed the surface data using different array processing techniques such as f-k methods and MUSIC algorithm and the borehole ones using a cross-correlation method. For periods inferior to the site resonance period, the soft clay layer with very low propagation velocities (less than 500 m/s) and a possible multipathing rule the wavefield pattern. For the large period range, the dominant surface wave comes from the epicentral direction and propagates with a quicker velocity (more than 1500 m/s) that corresponds to the velocity of deep layers. The analysis of borehole data shows the presence of different quick wavetrains in the short period range that could correspond to the first harmonic modes of Rayleigh waves. To complete this study, four others events recorded in 1994 by a temporal dense network installed in the firm rock zone of Mexico City were analysed using the same techniques. The results confirm the presence of a diffracting zone south of the valley. These results confirm the hypothesis of a possible interaction between the soft clay layers resonance and diffracted wavetrains of Rayleigh waves to explain both the amplification and the long duration of strong ground motion in Mexico City.

  19. Clastic Pipes: Proxies of High Water Tables and Strong Ground Motion, Jurassic Carmel Formation, Southern Utah

    NASA Astrophysics Data System (ADS)

    Wheatley, David; Chan, Marjorie

    2015-04-01

    Multiple soft sediment deformation features from bed-scale to basin-scale are well preserved within the Jurassic Carmel Formation of Southern Utah. Field mapping reveals thousands of small-scale clastic injectite pipes (10 cm to 10 m diameter, up to 20 m tall) in extremely high densities (up to 500+ pipes per 0.075 square kilometers). The pipes weather out in positive relief from the surrounding host strata of massive sandstone (sabkha) and crossbedded sands with minor conglomerate and shale (fluvial) deposits. The host rock shows both brittle and ductile deformation. Reverse, normal, and antithetical faulting is common with increased frequency, including ring faults, surrounding the pipes. The pipes formed from liquefaction and subsequent fluidization induced by strong ground motion. Down-dropped, graben blocks and ring faults surrounding pipes indicate initial sediment volume increase during pipe emplacement followed by sediment volume decrease during dewatering. Complex crosscutting relationships indicate several injection events where some pipe events reached the surface as sand blows. Multiple ash layers provide excellent stratigraphic and temporal constraints for the pipe system with the host strata deposited between 166 and 164 Ma. Common volcanic fragments and rounded volcanic cobbles occur within sandstone and conglomerate beds, and pipes. Isolated volcanic clasts in massive sandstone indicate explosive volcanic events that could have been the exogenic trigger for earthquakes. The distribution of pipes are roughly parallel to the Middle Jurassic paleoshoreline located in marginal environments between the shallow epicontinental Sundance Sea and continental dryland. At the vertical stratigraphic facies change from dominantly fluvial sediments to dominantly massive sabkha sediments, there is a 1-2 m-thick floodplain mudstone that was a likely seal for underlying, overpressurized sediments. The combination of loose porous sediment at a critical depth of water saturation made the system extremely susceptible to liquefaction. Fluid inclusions of carbonate nodules present on the pipe margins indicate salinity, temperature, and character of possible early diagenetic fluids before significant burial. These inclusions can reveal information about brines from point sources or fed via groundwater. Overall, the combination of clastic pipes and their related soft deformation structures in the host rock provide proxies for the existence of high water table conditions within arid climate regimes and transitional paleoenvironments previously assumed to be devoid of significant amounts of water. The pipe distribution and evidence of multiple injectite events paralleling an ancient paleoshoreline provides basin-scale insights on repeated paleoseismicity and volcanism along the convergent boundary of the Cordilleran.

  20. Characteristics of strong motions and damage implications of M S6.5 Ludian earthquake on August 3, 2014

    NASA Astrophysics Data System (ADS)

    Xu, Peibin; Wen, Ruizhi; Wang, Hongwei; Ji, Kun; Ren, Yefei

    2015-02-01

    The Ludian County of Yunnan Province in southwestern China was struck by an M S6.5 earthquake on August 3, 2014, which was another destructive event following the M S8.0 Wenchuan earthquake in 2008, M S7.1 Yushu earthquake in 2010, and M S7.0 Lushan earthquake in 2013. National Strong-Motion Observation Network System of China collected 74 strong motion recordings, which the maximum peak ground acceleration recorded by the 053LLT station in Longtoushan Town was 949 cm/s2 in E-W component. The observed PGAs and spectral ordinates were compared with ground-motion prediction equation in China and the NGA-West2 developed by Pacific Earthquake Engineering Researcher Center. This earthquake is considered as the first case for testing applicability of NGA-West2 in China. Results indicate that the observed PGAs and the 5 % damped pseudo-response spectral accelerations are significantly lower than the predicted ones. The field survey around some typical strong motion stations verified that the earthquake damage was consistent with the official isoseismal by China Earthquake Administration.

  1. Simulation of Strong Ground Motion During the 1950 Great Assam Earthquake

    NASA Astrophysics Data System (ADS)

    Raghukanth, S. T. G.

    2008-10-01

    In this paper, ground motion during the Independence Day earthquake of August 15, 1950 (Mw 8.6, B en-M enahem et al., 1974) in the northeastern part of India is estimated by seismological approaches. A hybrid simulation technique which combines the low frequency ground motion simulated from an analytical source mechanism model with the stochastically simulated high-frequency components is used for obtaining the acceleration time histories. A series of ground motion simulations are carried out to estimate the peak ground acceleration (PGA) and spectral accelerations at important cities and towns in the epicentral region. One sample PGA distribution in the epicentral region encompassing the epicenter is also obtained. It is found that PGA in the epicentral region has exceeded 1 g during this earthquake. The estimated PGA’s are validated to the extent possible using the MMI values. The simulated acceleration time histories can be used for the assessment of important engineering structures in northeastern India.

  2. Estimation of slip scenarios of mega-thrust earthquakes and strong motion simulations for Central Andes, Peru

    NASA Astrophysics Data System (ADS)

    Pulido, N.; Tavera, H.; Aguilar, Z.; Chlieh, M.; Calderon, D.; Sekiguchi, T.; Nakai, S.; Yamazaki, F.

    2012-12-01

    We have developed a methodology for the estimation of slip scenarios for megathrust earthquakes based on a model of interseismic coupling (ISC) distribution in subduction margins obtained from geodetic data, as well as information of recurrence of historical earthquakes. This geodetic slip model (GSM) delineates the long wavelength asperities within the megathrust. For the simulation of strong ground motion it becomes necessary to introduce short wavelength heterogeneities to the source slip to be able to efficiently simulate high frequency ground motions. To achieve this purpose we elaborate "broadband" source models constructed by combining the GSM with several short wavelength slip distributions obtained from a Von Karman PSD function with random phases. Our application of the method to Central Andes in Peru, show that this region has presently the potential of generating an earthquake with moment magnitude of 8.9, with a peak slip of 17 m and a source area of approximately 500 km along strike and 165 km along dip. For the strong motion simulations we constructed 12 broadband slip models, and consider 9 possible hypocenter locations for each model. We performed strong motion simulations for the whole central Andes region (Peru), spanning an area from the Nazca ridge (16^o S) to the Mendana fracture (9^o S). For this purpose we use the hybrid strong motion simulation method of Pulido et al. (2004), improved to handle a general slip distribution. Our simulated PGA and PGV distributions indicate that a region of at least 500 km along the coast of central Andes is subjected to a MMI intensity of approximately 8, for the slip model that yielded the largest ground motions among the 12 slip models considered, averaged for all assumed hypocenter locations. This result is in agreement with the macroseismic intensity distribution estimated for the great 1746 earthquake (M~9) in central Andes (Dorbath et al. 1990). Our results indicate that the simulated PGA and PGV for all scenario slips for central Andes, and for an average soil condition, exhibit similar amplitudes and attenuation characteristics with distance as the PGA and PGV values observed during the 2010 Maule (Mw 8.8), and 2011 Tohoku-oki (Mw 9.0) earthquakes. Our results clearly indicate that the simulated ground motions for scenarios with deep rupture nucleations (~40 km) are consistently smaller than the ground motions obtained for shallower rupture nucleations. We also performed strong ground motion simulations in metropolitan Lima by using the aforementioned slip scenarios, and incorporating site amplifications obtained from several microtremors array surveys conducted at representative geotechnical zones in this city. Our simulated PGA and PGV in Lima reach values of 1000 cm/s^2 and 80 cm/s. Our results show that the largest values of PGA (at Puente Piedra district, Northern Lima) are related with short period site effects, whereas the largest values of PGV are related with large site amplifications for periods from 1s to 1.5s (at Callao, Villa el Salvador and La Molina districts). Our results also indicate that the simulated PGA and PGV in central Lima (Parque de la Reserva) are in average 2~3 times larger than the values recorded by a strong motion instrument installed at this location, during the 1974 (Mw8.0) and 1966 (Mw8.0) earthquakes off-shore Lima.

  3. Modeling of strong ground motion during the 1992 Cairo earthquake in the urban area northern Greater of Cairo, Egypt

    NASA Astrophysics Data System (ADS)

    Omar, Khaled; Attia, Mohsen; Fergany, El Sayed; Hassoup, Awad; Elkhashab, Hussein

    2013-06-01

    The 1992 Cairo earthquake originated from Dahshour seismic zone at an epicentral distance of about 25 km southwest of Cairo. Regardless of its relatively moderate magnitude (Mb = 5.8), it caused extensive property damage besides injuries and loss of lives. The significant damage of this earthquake was probably associated with amplification of seismic waves due to local site effects. Liquefaction was observed at many sites near the epicenter. There are no records of strong ground motion at the damaged area during this earthquake. The main shock was recorded only by the local Kattamya station (KEG) constructed in limestone rock site at about 46-48 km east of Cairo. In the present work, the strong ground motion during 1992 Cairo earthquake was analyzed and the possible causes of damage and structural failure were discussed. The study area is located at the southern part of Cairo city, holding heavy population and many public structures and strategic buildings. The ground motion parameters in terms of peak ground acceleration (PGA), peak ground velocity (PGV), and pseudo-spectral acceleration (PSA) were estimated for each site in the study area and in the KEG site. The site-dependent spectral models together with the stochastic technique were applied for this purpose, using the Fourier amplitude spectrum (FAS) source scaling, attenuation model, and the site amplification functions. The peak ground acceleration of the studied area, comprising 89 sites in northern great of Cairo (Qalyoub city) was calculated. The calculated peak ground acceleration values indicate the sites of high values of peak ground acceleration which are also characterized by high ground motion amplification factors. The ground motion, which is presented in this study, is highly amplified by the soil layer covering the area. Otherwise, the surface layer must be totally removed before construction of the buildings to avoid its large amplification to the ground motion.

  4. Self-noise models of five commercial strong-motion accelerometers

    USGS Publications Warehouse

    Ringler, Adam; Evans, John R.; Hutt, Charles R.

    2015-01-01

    To better characterize the noise of a number of commonly deployed accelerometers in a standardized way, we conducted noise measurements on five different models of strong‐motion accelerometers. Our study was limited to traditional accelerometers (Fig. 1) and is in no way exhaustive.

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

    NASA Astrophysics Data System (ADS)

    Houston, Heidi; Kanamori, Hiroo

    1990-08-01

    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.

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

    USGS Publications Warehouse

    Ji, C.; Larson, K.M.; Tan, Y.; Hudnut, K.W.; Choi, K.

    2004-01-01

    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 rupture initiated at a depth of 8.5 km and propagated southeastwards with a speed ???3.0 km/sec, with rake vectors forming a fan structure around the hypocenter. We obtained a peak slip of 2.8 m and total seismic moment of 6.2 ?? 1018 Nm. We interpret the slip distribution as indicating that the hanging wall rotates relative to the footwall around the hypocenter, in a sense that appears consistent with the shape of the mapped fault trace. Copyright 2004 by the American Geophysical Union.

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

    USGS Publications Warehouse

    Joyner, William B.; Boore, David M.

    1981-01-01

    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.

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

    USGS Publications Warehouse

    Celebi, M.

    2000-01-01

    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.

  9. Spin-orbit interaction in bremsstrahlung and its effect on the electron motion in a strong Coulomb field

    NASA Astrophysics Data System (ADS)

    Kovtun, Oleksiy; Tioukine, Valeri; Surzhykov, Andrey; Yerokhin, Vladimir A.; Cederwall, Bo; Tashenov, Stanislav

    2015-12-01

    Linear polarization of bremsstrahlung x rays produced in collisions of longitudinally polarized 2.1-MeV electrons with gold atoms was studied using the Compton scattering technique. We observed that the angle of x-ray polarization is strongly correlated with the incoming electron polarization. This correlation reveals the dominance of the spin-orbit interaction in bremsstrahlung and indicates a striking effect of the electron spin on the electron motion in a strong Coulomb field. The results confirm the validity of the theoretical predictions in a computationally challenging energy regime.

  10. Equations of motion for natural orbitals of strongly driven two-electron systems

    NASA Astrophysics Data System (ADS)

    Rapp, J.; Brics, M.; Bauer, D.

    2014-07-01

    Natural orbital theory is a computationally useful approach to the few- and many-body quantum problems. While natural orbitals have been known and applied for many years in electronic structure applications, their potential for time-dependent problems started being investigated only recently. Correlated two-particle systems are of particular importance because the structure of the two-body reduced density matrix expanded in natural orbitals is known exactly in this case. However, in the time-dependent case the natural orbitals carry time-dependent phases that allow for certain time-dependent gauge transformations of the first kind. Different phase conventions will, in general, lead to different equations of motion for the natural orbitals. A particular phase choice allows us to derive the exact equations of motion for the natural orbitals of any (laser-) driven two-electron system explicitly, i.e., without any dependence on quantities that, in practice, require further approximations. For illustration, we solve the equations of motion for a model helium system. Besides calculating the spin-singlet and spin-triplet ground states, we show that the linear response spectra and the results for resonant Rabi flopping are in excellent agreement with the benchmark results obtained from the exact solution of the time-dependent Schrdinger equation.

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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.

  12. Calculation of broadband time histories of ground motion: Comparison of methods and validation using strong-ground motion from the 1994 Northridge earthquake

    USGS Publications Warehouse

    Hartzell, S.; Harmsen, S.; Frankel, A.; Larsen, S.

    1999-01-01

    This article compares techniques for calculating broadband time histories of ground motion in the near field of a finite fault by comparing synthetics with the strong-motion data set for the 1994 Northridge earthquake. Based on this comparison, a preferred methodology is presented. Ground-motion-simulation techniques are divided into two general methods: kinematic- and composite-fault models. Green's functions of three types are evaluated: stochastic, empirical, and theoretical. A hybrid scheme is found to give the best fit to the Northridge data. Low frequencies ( 1 Hz) are calculated using a composite-fault model with a fractal subevent size distribution and stochastic, bandlimited, white-noise Green's functions. At frequencies below 1 Hz, theoretical elastic-wave-propagation synthetics introduce proper seismic-phase arrivals of body waves and surface waves. The 3D velocity structure more accurately reproduces record durations for the deep sedimentary basin structures found in the Los Angeles region. At frequencies above 1 Hz, scattering effects become important and wave propagation is more accurately represented by stochastic Green's functions. A fractal subevent size distribution for the composite fault model ensures an ??-2 spectral shape over the entire frequency band considered (0.1-20 Hz).

  13. A source model of the 2014 South Napa Earthquake by the EGF broad-band strong ground motion simulation

    NASA Astrophysics Data System (ADS)

    Iwata, T.; Asano, K.; Kubo, H.

    2014-12-01

    The source model of the 2014 South Napa earthquake (Mw6.0) is estimated using broad band strong ground motion simulation by the empirical Green's function method (Irikura, 1986, Irikura et al., 1997). We used the CESMD strong motion data. Aftershock ground motion records of Mw3.6 which occurred at 05:33 on 24th August (PDT), are used as an empirical Green's function. We refer to the finite source model by Dreger et al. (2014) for setting the geometry of the source fault plane and the rupture velocity. We assume a single rectangular strong motion generation area (e.g. Miyake et al., 2003; Asano and Iwata, 2012). The seismic moment ratio between the target and EGF events is fixed from the moment magnitudes. As only five station data are available for the aftershock records, the size of SMGA area, rupture starting point, and the rise time on the SMGA are determined by the trial and error.?Preliminary SMGA model is 6x6km2 and the rupture mainly propagates WNW and shallower directions. The SMGA size we obtained follows the empirical relationship of Mw and SMGA size for the inland crustal events (Irikura and Miyake, 2011). Waveform fittings are fairly well at the near source station NHC (Huichica creek) and 68150 (Napa Collage), where as the fitting is not good at the south-side stations, 68206 (Crockett - Carquinez Br. Geotech Array) and 68310 (Vallejo - Hwy 37/Napa River E Geo. Array). Particularly, we did not succeed in explaining the high PGA at the 68206 surface station. We will try to improve our SMGA model and will discuss the origin of the high PGA observed at that station.

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

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    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.

  15. Strong motion simulation at Abu Zenima city, Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    Khalil, Amin Esmail

    2013-06-01

    Earthquake hazard assessments are an important task for the design of earthquake resistant structures and insurance industry. Such assessments get more importance when the site of interest is located near an active earthquake zone. Such situation is present for the location of Abu Zenima city. The city is characterized by the presence of industrial and Maritime platform in addition to other Oil production facilities. These industrial facilities motivated the present work. The simulated earthquake ground motion time histories are conducted using stochastic technique. The magnitude used for simulation is obtained using both probabilistic and deterministic approaches. An analysis using both approaches shows that moderate earthquakes in the vicinity of the site could have the largest effects on the area. Thus an earthquake of magnitude 4.5 at a distance of 21 km is chosen as design earthquake. The simulated ground motions are presented in terms of acceleration, velocity, and displacement time histories. In addition the response spectra are also presented that may be used for engineering purposes.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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;

  17. Extracting the Building Response with QCN-Taiwan Sensor Data: Application to the building of Science Education Center, National Taiwan Normal University

    NASA Astrophysics Data System (ADS)

    Liang, W.; Lee, W.; Chen, K. H.; Yen, E. H.; Lawrence, J. F.; Lin, C.; Chang, C.

    2013-12-01

    We have taken advantage of strong motion sensor data collected from the Taiwan Quake Catcher Network (QCN-Taiwan) in 2012 to extract the building response of the Science Education Center, National Taiwan Normal University. The QCN-Taiwan project is mainly aimed to construct a school seismic network with low-cost sensors for the purpose of earthquake science education in Taiwan. So far there are more than 60 volunteer QCN sites deployed island-wide in the campus of Taiwan. There were 10 MEMS sensors deployed in the basement and every story from 1 to 8 in the building. We analyze the acceleration data generated from 3 moderate to strong earthquakes (6.4?ML?5.2) to study the characteristic frequencies and responses of the building. Both deconvolution and H/V spectral ratio methods are used to characterize the building response. The dominant frequency in the NS direction is 1.7-1.9 Hz, which is slightly higher than recorded in the EW direction of 1.65-1.8 Hz. In addition, the amplification is much significant in levels higher than the 3rd floor in the frequency range of 1-3 Hz as shown in the H/V spectral ratio diagrams. We deconvolve all waveforms with both the motions in the ground and top floors to derive the building responses, respectively. Results show that the 1.6 Hz resonance is dominant in levels higher than the 4th floor for waveforms deconvolved with the basement data. On the other hand, both the up-going and down-going shear waves are clearly seen in the waveforms deconvoled with top floor data, which tells a shear velocity of ~190 m/s. We have proven that the strong motion data collected by the low-cost QCN MEMS sensors during large earthquakes is useful for extracting the building response.

  18. Modeling Strong Ground Motion during the February 22 2011 M6.3 Christchurch, New Zealand, Earthquake

    NASA Astrophysics Data System (ADS)

    Benites, R. A.; Fry, B.; Kaiser, A. E.

    2012-12-01

    We present a simple, kinematic model of the rupture of the M6.3 February 22 2011 earthquake in the city of Christchurch, New Zealand, that provides insights into the factors influencing observed ground motions. The model is based on a rectangular 8 x 9 km fault dipping 75o, striking 64o and rupturing with a thrust mechanism. The fault is embedded in a velocity model consisting of one layer over a uniform half-space representing the stiffest soil deposit and the bedrock underneath, respectively (Brown, L.J.; Weeber, J.H. 1992). The free-surface of the soil layer is assumed to be flat, however, the bedrock interface (initially at 900 m depth) pinches out as a 3-D cosine shaped free-surface topography up to 250 m high, representing Bank's Peninsula. The base of the topography is elliptical, with principle axes of 9 km and 4.5 km. Numerical modeling of the rupture shows that the observed corresponding strong ground motion is mainly due to two factors: the coherent rupture of a section of the fault, of 25 km2 area, with 116o rake and 3.1 km/s rupture velocity, and the presence of the sediments immediately overlying the fault. The discretization of the whole fault into several subfaults each with prescribed values of slip in the range 0.4-3.0 m, and rise time, allows the parametric study of the ground motion using several rupture scenarios. The model with the coherent rupture described above best reproduces the high (1.2 g -1.8 g) accelerations observed at stations in the footwall of the fault. The incidence upon the topography appears to produce Rayleigh waves propagating away from it. This is in agreement with particle motion surface wave analysis of the measured seismograms that reveals the contribution of Rayleigh wave energy to the observed long-period ground motions. Furthermore, arrival times of the Rayleigh wave energy are consistent with predicted travel times from our basin velocity model. We reproduce prominent near-surface effects at many Christchurch strong motion stations through the addition of a shallow, thin (6m thick) layer with a high S-wave attenuation factor. The resulting seismograms exhibit about 40% less frequency content in the horizontal motion than in the vertical motion, as observed at stations located on water saturated soils. Given that no suitable rock reference station recordings were available with which to estimate site effects in the Christchurch metropolitan area, we used computed synthetic seismograms from our rupture model at the base of the soft soil column to calculate site transfer functions that describe the observed site effects at each of the strong ground motion stations.

  19. Particle acceleration by a wave in a strong magnetic field - Regular and stochastic motion

    NASA Technical Reports Server (NTRS)

    Karimabadi, H.; Akimoto, K.; Omidi, N.; Menyuk, C. R.

    1990-01-01

    A general theory for the acceleration of a charged particle by a coherent wave of arbitrary polarization, propagation angle, and phase velocity in the presence of a uniform and strong magnetic field is presented. It is shown that the Hamiltonian surfaces are topologically open for waves with parallel phase velocity, equal to or larger than the speed of light. The trapping width is found to be a strong function of the index of refraction (N), and for N = 1 the trapping width increases as a function of the harmonic number. A novel mechanism for coherently accelerating particles to unlimited energies is presented.

  20. Experimental investigation of strong ground motion due to thrust fault earthquakes

    NASA Astrophysics Data System (ADS)

    Gabuchian, Vahe; Rosakis, Ares J.; Lapusta, Nadia; Oglesby, David D.

    2014-02-01

    Thrust fault earthquakes are studied in a laboratory earthquake setup previously used to investigate analog strike-slip seismic events. Dynamic mode II ruptures are generated along preexisting faults in an analog material, Homalite H-100, and their interaction with the free surface is studied for both sub-Rayleigh and supershear rupture speeds. High-speed digital photography and laser velocimeter diagnostics are used synergistically to identify and study the ground velocity signatures caused by the various features of the generated ruptures. The obtained surface-normal motions of both sub-Rayleigh and supershear ruptures show substantial asymmetry between the hanging and footwall, with the hanging wall experiencing much larger velocity amplitudes. The main features of the surface velocity traces at various stations can be explained by the calculated arrivals of various waves and frontsMach cones, Pand S waves, and sub-Rayleigh features. In both the sub-Rayleigh and supershear cases, the arrival of the rupture tip generates a prominent Rayleigh wave traveling along the simulated Earth's surface. Supershear events feature larger amplitudes of ground shaking profiles. All signatures in the surface motion records attenuate and broaden with increasing distance from the fault trace. The signatures corresponding to the arrival of the Mach fronts attenuate with distance at a slower rate than those from sub-Rayleigh ruptures. The arrival of the updip supershear rupture at the free surface creates a downdip propagating slip feature with its own Mach cone. These additional Mach fronts further amplify ground shaking on the hanging and footwalls.

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

    USGS Publications Warehouse

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

    2002-01-01

    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.

  2. Resolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 1. Strong motions

    USGS Publications Warehouse

    Graves, R.W.; Wald, D.J.

    2001-01-01

    We develop a methodology to perform finite fault source inversions from strong motion data using Green's functions (GFs) calculated for a three-dimensional (3-D) velocity structure. The 3-D GFs are calculated numerically by inserting body forces at each of the strong motion sites and then recording the resulting strains along the target fault surface. Using reciprocity, these GFs can be recombined to represent the ground motion at each site for any (heterogeneous) slip distribution on the fault. The reciprocal formulation significantly reduces the required number of 3-D finite difference computations to at most 3NS, where NS is the number of strong motion sites used in the inversion. Using controlled numerical resolution tests, we have examined the relative importance of accurate GFs for finite fault source inversions which rely on near-source ground motions. These experiments use both 1-D and 3-D GFs in inversions for hypothetical rupture models in order (1) to analyze the ability of the 3-D methodology to resolve trade-offs between complex source phenomena and 3-D path effects, (2) to address the sensitivity of the inversion results to uncertainties in the 3-D velocity structure, and (3) to test the adequacy of the 1-D GF method when propagation effects are known to be three-dimensional. We find that given "data" from a prescribed 3-D Earth structure, the use of well-calibrated 3-D GFs in the inversion provides very good resolution of the assumed slip distribution, thus adequately separating source and 3-D propagation effects. In contrast, using a set of inexact 3-D GFs or a set of hybrid 1-D GFs allows only partial recovery of the slip distribution. These findings suggest that in regions of complex geology the use of well-calibrated 3-D GFs has the potential for increased resolution of the rupture process relative to 1-D GFs. However, realizing this full potential requires that the 3-D velocity model and associated GFs should be carefully validated against the true 3-D Earth structure before performing the inverse problem with actual data. Copyright 2001 by the American Geophysical Union.

  3. The Geophysical Database Management System in Taiwan

    NASA Astrophysics Data System (ADS)

    Pu, H.; Shin, T.; Chang, C.; Leu, P.

    2013-12-01

    The Geophysical Database Management System (GDMS) is an integrated and web-based open data service which has been developed by the Central Weather Bureau (CWB), Taiwan, R.O.C. since 2005. This service went online on Aug. 1, 2008. The GDMS provides six types of geophysical data acquired from the Short-period Seismographic System, Broadband Seismographic System, Free-field Strong-motion Station, Strong-motion Building Array, Global Positioning System, and Groundwater Observation System. When utilizing the GDMS website, users can download seismic event data and continuous geophysical data. At present, many researchers have accessed this public platform to obtain geophysical data. Clearly, the establishment of GDMS is a significant improvement in data sorting for interested researchers. The geophysical monitoring network in CWB. (a) The Short-period Seismographic System. (b) The Broadband Seismographic System. (c) The Free-field Strong-motion Seismographic System. (d) The Strong-motion Building Array. (e) The Global Positioning System. (f) The Groundwater Observation System.

  4. Engineering Analysis of Strong-motion Data Recorded During German Task Force Missions To Turkey (1998-2000)

    NASA Astrophysics Data System (ADS)

    Schwarz, J.; Ende, C.; Habenberger, J.; Lang, D. H.; Raschke, M.

    Obviously, structural damage caused by strong earthquakes can not only be attributed to defects in design or construction, but rather the widely discussed phenomenon of local site effects has to be considered as well. In the last decade extensive strong-motion measurements were carried out by the reconnaissance team of the German TaskForce for Earthquakes. Missions to Turkey in 1998 (Adana, Ceyhan) and in 1999 (Izmit/Kocaeli and Duezce) provided a unique database of recorded aftershocks at sites where building damage occurred. To gain more insight into the effect of local site conditions post-earthquake investigations were initiated in Adana and Kocaeli (October 2000). Microtremors were recorded at sites of the previously installed strong-motion accelerographs and locations of evident concentration or variation of building damage spreaded over the area of main shaking effects. The predominant frequencies and amplification potential at recording sites were identified by H/V spectral ratio method. On the basis of H/V-spectra the sites were classified (into soft soil, stiff soil, rock-type conditions) enabling more detailed studies of recorded strong motion data which were obtained by previous TaskForce missions. Attenuation laws for spectral and peak ground acceleration were statistically determined similar to the approach by Ambraseys et al. (1996). As it can be concluded, the differences between ground motion on soft and stiff soil are less pronounced and of a similar level of amplitudes. It has to be emphasized that the studies are supported by different data types referring to an unique and consistent data-set. Thus, conclusions concerning the reliability of recently applied site response estimation techniques will be derived in dependence on soil conditions. Finally, it will be discussed to which extent subsoil conditions are responsible for the enforcement of building damage. For this purpose and in relation to geological features, a macroseismic map of shaking effects (intensity) was prepared taking into consideration the results of a damage survey undertaken immediately after the 1999 Izmit/Kocaeli earthquake as well as meanwhile presented intensity assignments of other research groups. As a result, instrumentally investigated (micro)sites are correlated with macroseismic shaking effects.

  5. Strong correlation of atomic thermal motion in the first coordination shell of a Cu-Zr metallic glass

    SciTech Connect

    Zhang, Y.; Mattern, N.; Eckert, J.; Institut fuer Werkstoffwissenschaft, Technische Universitaet Dresden, D-01062 Dresden

    2013-02-25

    We demonstrate a strong correlation of atomic thermal motions in the first coordination shell of Cu{sub 50}Zr{sub 50} metallic glass using molecular dynamics simulations, which explains directly the small thermal expansion coefficient calculated by the first maxima of pair correlation functions. The vibrational anisotropy in the glass is found to be even higher than in crystalline copper. The parallel-perpendicular anisotropy gradually decreases upon heating. The anisotropy in Zr-Zr is the strongest bonds among all the interatomic bonds, which is also very stable near the glass transition at 700 K. Structurally, the anisotropy can be correlated to Cu-centered (0 2 8 1) clusters.

  6. Strong correlation of atomic thermal motion in the first coordination shell of a Cu-Zr metallic glass

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Mattern, N.; Eckert, J.

    2013-02-01

    We demonstrate a strong correlation of atomic thermal motions in the first coordination shell of Cu50Zr50 metallic glass using molecular dynamics simulations, which explains directly the small thermal expansion coefficient calculated by the first maxima of pair correlation functions. The vibrational anisotropy in the glass is found to be even higher than in crystalline copper. The parallel-perpendicular anisotropy gradually decreases upon heating. The anisotropy in Zr-Zr is the strongest bonds among all the interatomic bonds, which is also very stable near the glass transition at 700 K. Structurally, the anisotropy can be correlated to Cu-centered (0 2 8 1) clusters.

  7. Strong ground motion inferred from liquefaction caused by the 1811-1812 New Madrid, Missouri, earthquakes

    USGS Publications Warehouse

    Holzer, Thomas L.; Noce, Thomas E.; Bennett, Michael J.

    2015-01-01

    Peak ground accelerations (PGAs) in the epicentral region of the 18111812 New Madrid, Missouri, earthquakes are inferred from liquefaction to have been no greater than ?0.35g. PGA is inferred in an 11,380??km2area in the Lower Mississippi Valley in Arkansas and Missouri where liquefaction was extensive in 18111812. PGA was inferred by applying liquefaction probability curves, which were originally developed for liquefaction hazard mapping, to detailed maps of liquefaction byObermeier (1989). The low PGA is inferred because both a shallow (1.5m deep) water table and a large moment magnitude (M7.7) earthquake were assumed in the analysis. If a deep (5.0m) water table and a small magnitude (M6.8) earthquake are assumed, the maximum inferred PGA is 1.10g. Both inferred PGA values are based on an assumed and poorly constrained correction for sand aging. If an aging correction is not assumed, then the inferred PGA is no greater than 0.22g. A low PGA value may be explained by nonlinear site response. Soils in the study area have an averageVS30of 22015??m/s. A low inferred PGA is consistent with PGA values estimated from ground?motion prediction equations that have been proposed for the New Madrid seismic zone when these estimates are corrected for nonlinear soil site effects. This application of liquefaction probability curves demonstrates their potential usefulness in paleoseismology.

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

    NASA Astrophysics Data System (ADS)

    Ugurhan, B.; Askan, A.

    2010-12-01

    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.

  9. Site-dependent spectra from the 1999 Turkey earthquakes considering different sets of strong-motion data

    NASA Astrophysics Data System (ADS)

    Schwarz, J.; Ende, C.; Habenberger, J.; Lang, D. H.

    2003-04-01

    In the last decade extensive strong-motion measurements were carried out by the reconnaissance team of the German TaskForce for Earthquakes. Aftershocks were recorded by a mesh of temporarily installed strong-motion recorders during the field surveys to Turkey in 1998 (Adana/Ceyhan), 1999 (Izmit/Kocaeli and Duezce/Bolu) and 2002 (Sultandagi/Afyon). Particularly the two missions in 1999 provided a unique and comprehensive database of recorded aftershocks at sites where building damage occurred. In addition, post-earthquake investigations were initiated around the provinces Adana and Kocaeli in October 2000 to gain more insight into the effect of local site conditions. Therefore, microtremors were recorded at sites of the previously installed strong-motion accelerographs and locations of evident concentration or remarkable scatter of building damage. By applying H/V-spectral ratio method on microtremor data, a classification of the recording sites (into soft soil, stiff soil, rock-type conditions) was performed. For the derivation of attenuation laws different databases were applied. In addition to the aftershock records of the strong-motion stations of German TaskForce for Earthquakes (Schwarz et al., 2002), a small dataset of main- and aftershocks from the 1999 Turkey earthquakes provided by the Kandilli Observatory (KOERI, 2002) and the General Directorate of Disaster Affairs (AFET) could be implied. The magnitude-distance composition of both datasets are quite different in terms of the covered magnitude and distance range. While the dataset of the German TaskForce mainly consists of small magnitude aftershocks (at the present state of elaboration: Ml <= 4.9) being recorded in epicentral distances Re < 70 km, the KOERI dataset is featured by larger magnitudes (Ml = 4.8-7.2) and by a distance range of about 10--250 km. The aftershock database of German TaskForce consists of 538 triaxial acceleration records (rock 53, stiff 52, soft 433), while that of KOERI comprises 145 triaxial acceleration records (rock 6, stiff 36, soft 103). On this basis, three sets of strong motion records were investigated by an one-step as well as a two-step regression analysis (similar to the approach by Ambraseys et al., 1996). Furthermore, parametric studies with respect to the lower bounds of magnitude and source depth were performed. Results indicate that the composition of the dataset and in particular the decision on the lower bound magnitude significantly determine the qualitative spectrum shape. In comparison to the spectra determined by Ambraseys et al. (1996) attenuation functions, the recorded data lead to significant lower accelerations for the borizontal as well as for the vertical components. Furthermore, no significant differences between data from soft and stiff soil recording sites can be observed, supporting the authors opinion that the severity of ground motion during earthquakes is less responsible for the high extent of building damage than the vulnerability of the building stock (which seem to be quite different for one particular building type in dependence on the date of construction). Therefore more attention should be attributed to the investigation of the building inventory.

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

    SciTech Connect

    Munguia-Orozco, L.

    1983-01-01

    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.

  11. A Web-Based Borehole Strong-motion Data Dissemination Portal

    NASA Astrophysics Data System (ADS)

    Steidl, J. H.; Seale, S.; Ratzesberger, H.; Civilini, F.; Vaughan, N.

    2009-12-01

    Accelerometric and pore pressure data from instrumented boreholes in southern California are producing very interesting observations from a large data set that includes 100’s of earthquake observations each month. While the majority of these are very small events, they provide the control data that represents the linear behavior of the site. In addition, the largest motions recorded to date, ~10%g, are getting to the regime where nonlinear soil behavior effects become important. In order to make these data more accessible to the seismology and earthquake engineering research community, software development of a web-based data dissemination portal has taken place under the George E. Brown Jr., Network for Earthquake Engineering (NEES) program. This development includes processing and analysis tools, and web-based data dissemination available through the NEES@UCSB website [http://nees.ucsb.edu]. Of interest to the research community are the tools developed to provide search, waveform viewing, and download capabilities for access to data acquired through the various borehole-monitoring programs at UC Santa Barbara. Researchers interested in obtaining data recorded at the various field sites can use the map-based search tool to select a particular station and instrument(s). The user is then provided another map-based interface that allows the user to select events with choice of magnitude, distance, and time period. Once the user has selected an event of interest, the ability to view the data is provided, along with some waveform parameters like peak velocity and acceleration. The records can then be downloaded in a number of common formats, including MSEED, SAC, and an ASCII text-based real-time data viewer (RDV) format. The last format allows the data to be viewed in the NEES RDV tool, a platform independent JAVA program developed to display both real-time streaming data, or playback data that has been downloaded through the web-based event search tool.

  12. The September 19, 1985 Michoacan Earthquake: Aftershock acceleration data recorded by a temporary installation of strong motion instruments

    NASA Astrophysics Data System (ADS)

    Mungua, Luis; Simila, Gerry W.; McNally, Karen C.; Thompson, Howard

    1986-06-01

    We describe acceleration signals recorded for nine aftershocks of the September 19, 1985 Michoacan earthquake. To obtain this data set, three A-700 Teledyne-Geotech digital strong-motion instruments were operated temporarily at two sites on the Jos Mara Morelos (La Villita) Dam, and at a site located at about 12 km to the west of the town of Zihuatanejo. Peak horizontal accelerations of 0.005 g to 0.031 g were recorded at epicentral distances between 10 and 75 km, for earthquakes with magnitude (mb) between 4.5 and 5.3. It was observed that the peak accelerations recorded at a site on the embankment of the dam (near the crest ) are approximately three times those recorded on the abutment bedrock portion of the dam. Although these sites were spatially separated by no more than 300 m, differences among their records are also significant. Waveforms recorded at the embankment site look more complex than those from the abutment site. This fact, as well as the higher peak accelerations on the embankment, provides evidence of a strong influence of the structure of the dam on the ground motion at the embankment site.

  13. Executive Summary of Vision and Options for the Future of the US National Strong-Motion Program

    USGS Publications Warehouse

    Committee for the Future of the US National Strong-Motion Program

    1997-01-01

    These reports are presented in response to a charge of the Earthquake Hazards Reduction Program (EHRP) Program Council of the U.S. Geological Survey to 'define the future of the USGS National Strong-Motion Program (NSMP)' (Appendix A). The council requested that a 'Vision Paper' and an 'Options Document' be prepared. Each of these reports is a separate document. The 'Executive Summary' of both reports is presented here under separate cover. The content of the reports and the executive summary is organized to the extent possible according to the main charges of the EHRP Program Council. Detailed evaluation of charges and questions posed by the Council with the benefit of modern GIS tools and the recent deliberations of three national workshops have yielded substantial new insight regarding the status of strong-motion measurement in the US. These reports are intended as an objective evaluation of the nation's need and capability to record the next major earthquake at locations of most significance for public safety.

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

    USGS Publications Warehouse

    Coordinated by Holzer, Thomas L.

    1992-01-01

    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.

  15. Kinematic inversion of strong motion data using a Gaussian parameterization of the slip: application to the Iwate-Miyagi earthquake.

    NASA Astrophysics Data System (ADS)

    Lucca, Ernestina; Festa, Gaetano; Emolo, Antonio

    2010-05-01

    We present a non linear technique to invert strong motion records with the aim of obtaining the final slip and the rupture velocity distributions on the fault plane. Kinematic inversion of strong motion data is an ill-conditioned inverse problem, with several solutions available also in the case of noise-free synthetic data (Blind test on earthquake source inversion,http://www.seismo.ethz.ch/staff/martin/BlindTest.html).On the other hand, complete dynamic inversion still looks impracticable, because of an unclear understanding of the physical mechanisms controlling the energy balance at the rupture tip and a strong correlation between the initial stress field and the parameters of the constitutive law. Hence a strong effort is demanded to increase the robustness of the inversion, looking at the details of the slip and rupture velocity parameterization, at the global exploration techniques, at the efficiency of the cost-function in selecting solutions, at the synthesis process in retrieving the stable features of the rupture. In this study, the forward problem, i.e. the ground motion simulation, is solved evaluating the representation integral in the frequency domain by allowing possible rake variation along the fault plane. The Green's tractions on the fault are computed using the discrete wave-number integration technique that provides the full wave-field in a 1D layered propagation medium. The representation integral is computed through a finite elements technique on a Delaunay triangulation of the fault plane. The rupture velocity is finally defined on a coarser regular grid and rupture times are computed by integration of the eikonal equation. For the inversion, the slip distribution is parameterized by 2D overlapping Gaussian functions, which can easily relate the spectrum of the possible solutions with the minimum resolvable wavelength, related to source-station distribution and data processing. The inverse problem is solved by a two-step procedure aimed at separating the computation of the rupture velocity from the evaluation of the slip distribution, the latter being a linear problem, when the rupture velocity is fixed. The non-linear step is solved by optimization of an L2 misfit function between synthetic and real seismograms, and solution is searched by the use of the Neighbourhood Algorithm. The conjugate gradient method is used to solve the linear step instead. The developed methodology has been applied to the M7.2, Iwate Nairiku Miyagi, Japan, earthquake that was recorded by the K-net and Kik-net accelerometric networks.

  16. Effects of fault dip and slip rake angles on near-source ground motions: Why rupture directivity was minimal in the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Aagaard, B.T.; Hall, J.F.; Heaton, T.H.

    2004-01-01

    We study how the fault dip and slip rake angles affect near-source ground velocities and displacements as faulting transitions from strike-slip motion on a vertical fault to thrust motion on a shallow-dipping fault. Ground motions are computed for five fault geometries with different combinations of fault dip and rake angles and common values for the fault area and the average slip. The nature of the shear-wave directivity is the key factor in determining the size and distribution of the peak velocities and displacements. Strong shear-wave directivity requires that (1) the observer is located in the direction of rupture propagation and (2) the rupture propagates parallel to the direction of the fault slip vector. We show that predominantly along-strike rupture of a thrust fault (geometry similar in the Chi-Chi earthquake) minimizes the area subjected to large-amplitude velocity pulses associated with rupture directivity, because the rupture propagates perpendicular to the slip vector; that is, the rupture propagates in the direction of a node in the shear-wave radiation pattern. In our simulations with a shallow hypocenter, the maximum peak-to-peak horizontal velocities exceed 1.5 m/sec over an area of only 200 km2 for the 30??-dipping fault (geometry similar to the Chi-Chi earthquake), whereas for the 60??- and 75??-dipping faults this velocity is exceeded over an area of 2700 km2 . These simulations indicate that the area subjected to large-amplitude long-period ground motions would be larger for events of the same size as Chi-Chi that have different styles of faulting or a deeper hypocenter.

  17. Motion.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    2002-01-01

    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…

  18. Motion.

    ERIC Educational Resources Information Center

    Gerhart, James B.; Nussbaum, Rudi H.

    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

  19. Motion.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    2002-01-01

    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

  20. The Quake-Catcher Network: A Community-Led, Strong-Motion Network with Implications for Earthquake Advanced Alert

    NASA Astrophysics Data System (ADS)

    Cochran, E. S.; Lawrence, J. F.; Christensen, C. M.; Jakka, R. S.; Chung, A. I.

    2009-12-01

    The goal of the Quake-Catcher Network (QCN) is to dramatically increase the number of strong-motion observations by exploiting recent advances in sensing technologies and cyberinfrastructure. Micro-Electro-Mechanical Systems (MEMS) triaxial accelerometers are very low cost (50-100), interface to any desktop computer via USB cable, and provide high-quality acceleration data. Preliminary shake table tests show the MEMS accelerometers can record high-fidelity seismic data and provide linear phase and amplitude response over a wide frequency range. Volunteer computing provides a mechanism to expand strong-motion seismology with minimal infrastructure costs, while promoting community participation in science. Volunteer computing also allows for rapid transfer of metadata, such as that used to rapidly determine the magnitude and location of an earthquake, from participating stations. QCN began distributing sensors and software to K-12 schools and the general public in April 2008 and has grown to roughly 1000 stations. Initial analysis shows metadata are received within 1-14 seconds from the observation of a trigger; the larger data latencies are correlated with greater server-station distances. Currently, we are testing a series of triggering algorithms to maximize the number of earthquakes captured while minimizing false triggers. We are also testing algorithms to automatically detect P- and S-wave arrivals in real time. Trigger times, wave amplitude, and station information are currently uploaded to the server for each trigger. Future work will identify additional metadata useful for quickly determining earthquake location and magnitude. The increased strong-motion observations made possible by QCN will greatly augment the capability of seismic networks to quickly estimate the location and magnitude of an earthquake for advanced alert to the public. In addition, the dense waveform observations will provide improved source imaging of a rupture in near-real-time. These same observations will provide new images of the subsurface, which will improve earthquake hazard scenarios by predicting shaking outcomes from a dynamic rupture through the earth. QCN has the potential to produce wide-reaching outcomes for: earthquake advanced alert, improved seismic safety, and increased public knowledge of earthquakes.

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

    SciTech Connect

    JAMES N. BRUNE AND ABDOLRASOOL ANOOSHEHPOOR

    1998-02-23

    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.

  2. Strong vortical flows generated by the collective motion of magnetic particle chains rotating in a fluid cell.

    PubMed

    Gao, Yang; Beerens, Jasper; van Reenen, Alexander; Hulsen, Martien A; de Jong, Arthur M; Prins, Menno W J; den Toonder, Jaap M J

    2015-01-01

    Magnetic microparticles, assembled into chains that are actuated with rotating magnetic fields, can be used as microstirrers to promote fluid transport and biochemical reactions in microfluidic systems. We show that, within a certain range of magnetic field rotation frequency, the microstirrers exhibit a coherent collective motion: the rotating magnetic particle chains move throughout the volume of a flat fluid cell and generate very strong (~1 mm s(-1)) and global (9 mm) vortical fluid flows, with many eddy-type substructures that fluctuate continuously in time, resembling turbulent flow. The collective motion makes the microstirrers not only defy gravity, but also move against magnetic field gradients. The induced fluid flow is directly related to the stirring rate and the amount of magnetic particle chains. The observed behavior is caused by the magnetic and hydrodynamic interactions between the magnetic microparticles and the fluid. We utilized the phenomenon of swarming particles to enhance biochemical assays with magnetic capture particles (4000 ?L(-1)) and IgG targets (500 pM). When compared to a reference system of sedimented magnetic capture particles, magnetic actuation leads to both a ~9 times increase in the initial assay kinetics as well as a ~7 times increase of target capture signal after 30 minutes. PMID:25380482

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

    USGS Publications Warehouse

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

    2002-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    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.

  5. Installation of a digital, wireless, strong-motion network for monitoring seismic activity in a western Colorado coal mining region

    SciTech Connect

    Peter Swanson; Collin Stewart; Wendell Koontz

    2007-01-15

    A seismic monitoring network has recently been installed in the North Fork Valley coal mining region of western Colorado as part of a NIOSH mine safety technology transfer project with two longwall coal mine operators. Data recorded with this network will be used to characterize mining related and natural seismic activity in the vicinity of the mines and examine potential hazards due to ground shaking near critical structures such as impoundment dams, reservoirs, and steep slopes. Ten triaxial strong-motion accelerometers have been installed on the surface to form the core of a network that covers approximately 250 square kilometers (100 sq. miles) of rugged canyon-mesa terrain. Spread-spectrum radio networks are used to telemeter continuous streams of seismic waveform data to a central location where they are converted to IP data streams and ported to the Internet for processing, archiving, and analysis. 4 refs.

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

    USGS Publications Warehouse

    Evans, J.R.

    1998-01-01

    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.

  7. Three-Dimensional Attenuation Structure of the Kumaon Himalayas, India, Based on Inversion of Strong Motion Data

    NASA Astrophysics Data System (ADS)

    Kumar, Parveen; Joshi, A.; Sandeep; Kumar, Ashvini

    2015-02-01

    Three-dimensional attenuation structure based on frequency-dependent shear wave quality factor, Q β ( f), has been determined for the Kumaon region of the Himalayas. An algorithm based on inversion of strong motion data developed by J oshi (Curr Sci 90:581-585, 2006a) and later modified by K umar et al. (Pure Appl Geophys, doi: 10.1007/s00024-013-0658-x, 2013) was used for determination of three-dimensional attenuation coefficients. The input of this algorithm is the spectral acceleration of the S phase of the accelerogram and the outcome is the attenuation coefficient and the source acceleration spectra. A dense network monitoring strong ground motion in the Kumaon region of the Uttarakhand Himalayas has been operating since 2006. This network recorded 287 earthquakes up to July, 2013, of which 18 were used for this work. Shear-wave quality-factors were estimated for frequencies of 1.0, 5.0, and 10.0 Hz for two rectangular blocks of surface of dimensions 85 × 55 and 90 × 30 km2 in the Kumaon region of the Himalayas. Both blocks were divided into 25 three-dimensional blocks of uniform thickness with different Q β ( f) values. The spatial distribution of frequency-dependent shear-wave quality factors in two different blocks reveal the attenuation properties of the region. The profiles of the contours of shear-wave quality factors observed were comparable with those of major tectonic units present in the region.

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

    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.

  10. Analytical investigations of seismic responses for reinforced concrete bridge columns subjected to strong near-fault ground motion

    NASA Astrophysics Data System (ADS)

    Su, Chin-Kuo; Sung, Yu-Chi; Chang, Shuenn-Yih; Huang, Chao-Hsun

    2007-09-01

    Strong near-fault ground motion, usually caused by the fault-rupture and characterized by a pulse-like velocity-wave form, often causes dramatic instantaneous seismic energy (Jadhav and Jangid 2006). Some reinforced concrete (RC) bridge columns, even those built according to ductile design principles, were damaged in the 1999 Chi-Chi earthquake. Thus, it is very important to evaluate the seismic response of a RC bridge column to improve its seismic design and prevent future damage. Nonlinear time history analysis using step-by-step integration is capable of tracing the dynamic response of a structure during the entire vibration period and is able to accommodate the pulsing wave form. However, the accuracy of the numerical results is very sensitive to the modeling of the nonlinear load-deformation relationship of the structural member. FEMA 273 and ATC-40 provide the modeling parameters for structural nonlinear analyses of RC beams and RC columns. They use three parameters to define the plastic rotation angles and a residual strength ratio to describe the nonlinear load-deformation relationship of an RC member. Structural nonlinear analyses are performed based on these parameters. This method provides a convenient way to obtain the nonlinear seismic responses of RC structures. However, the accuracy of the numerical solutions might be further improved. For this purpose, results from a previous study on modeling of the static pushover analyses for RC bridge columns (Sung et al. 2005) is adopted for the nonlinear time history analysis presented herein to evaluate the structural responses excited by a near-fault ground motion. To ensure the reliability of this approach, the numerical results were compared to experimental results. The results confirm that the proposed approach is valid.

  11. Source parameters of the 2013 Lushan, Sichuan, Ms7.0 earthquake and estimation of the near-fault strong ground motion

    NASA Astrophysics Data System (ADS)

    Meng, L.; Zhou, L.; Liu, J.

    2013-12-01

    Abstract: The April 20, 2013 Ms 7.0 earthquake in Lushan city, Sichuan province of China occurred as the result of east-west oriented reverse-type motion on a north-south striking fault. The source location suggests the event occurred on the Southern part of Longmenshan fault at a depth of 13km. The Lushan earthquake caused a great of loss of property and 196 deaths. The maximum intensity is up to VIII to IX at Boxing and Lushan city, which are located in the meizoseismal area. In this study, we analyzed the dynamic source process and calculated source spectral parameters, estimated the strong ground motion in the near-fault field based on the Brune's circle model at first. A dynamical composite source model (DCSM) has been developed further to simulate the near-fault strong ground motion with associated fault rupture properties at Boxing and Lushan city, respectively. The results indicate that the frictional undershoot behavior in the dynamic source process of Lushan earthquake, which is actually different from the overshoot activity of the Wenchuan earthquake. Based on the simulated results of the near-fault strong ground motion, described the intensity distribution of the Lushan earthquake field. The simulated intensity indicated that, the maximum intensity value is IX, and region with and above VII almost 16,000km2, which is consistence with observation intensity published online by China Earthquake Administration (CEA) on April 25. Moreover, the numerical modeling developed in this study has great application in the strong ground motion prediction and intensity estimation for the earthquake rescue purpose. In fact, the estimation methods based on the empirical relationship and numerical modeling developed in this study has great application in the strong ground motion prediction for the earthquake source process understand purpose. Keywords: Lushan, Ms7.0 earthquake; near-fault strong ground motion; DCSM; simulated intensity

  12. Simulation of Strong Ground Motion Based on Conventional Empirical Green s Functions In the Michoacn State, Mexico

    NASA Astrophysics Data System (ADS)

    Vazquez Rosas, R.; Aguirre Gonzalez, J. J.; Mijares Arellano, H. H.

    2012-12-01

    In the present work, we study the state of Michoacn, one of the most important seimogenic zones in Mexico. Three kinds of sources exist in the state, producing tectonic earthquakes, volcanic earthquakes, and events due to local faults in the region. For this reason, it is of vital importance the study of source parameters in the Michoacn state. In this work in particular we applied the simulation of strong ground motions by the conventional empirical Green s functions proposed by Irikura (1986). We installed a temporary network consisting of 6 accelerograph stations across the state, at the following locations: Faro de Bruceras, Aguililla, Apatzingn, Ptzcuaro, Morelia, and Maravato. The stations form a line that is perpendicular to the coastline and has a total length of 366 km, while the distance between neighboring stations varies from 60 to 80 km. Among all the seismic events recorded at this temporary network, we select 2 events originated along the coastline of Michoacn (May the 2007), with moment magnitudes of 4.3 and 5.1 Mw. In order to calibrate the model, the earthquake of May 31, 2007 (M 5.1) was simulated using the aftershock of May 27 of that year (M 4.3) with satisfactory results, following the same method and considering the ?2 spectral model with constant stress drop. Later, we calculated six scenarios for a postulate earthquake of M 7.4. From the six scenarios the largest peak ground accelerations for each station were, 83 cm/s2 in Faro de Bruceras , 15.4 cm/s2 in Apatzingn, 23 cm/s2 in Ptzcuaro, 3.7 cm/s2 in Morelia and Maravatio con 3.0 cm/s2 . One limitation of this study is that we used relatively small-magnitude earthquakes. This was a consequence of the relatively short operation period of the temporary network, which had to be limited to 3 months. To improve these simulations it is necessary to have more information about rupture processes of the recorded earthquakes. And likewise, information of future earthquakes in the region is needed in order to improve prediction models as the one presented in this work. That information will be useful to minimize uncertainty and to better understand the parameters involved in the strong-motion simulations.

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

    USGS Publications Warehouse

    Harmsen, S.C.

    1997-01-01

    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.

  14. An estimation of sediment thickness using Sp converted phases in Kaoping, Taiwan

    NASA Astrophysics Data System (ADS)

    Chuang, M.; Wu, Y.; Wei, J.; Chang, C.

    2011-12-01

    The Kaoping area is a triangle alluvial plain, located in the southwestern Taiwan. Accelerograms recorded from 1991 to 2010 by the Taiwan Strong Motion Instrumentation Program (TSMIP) stations are used to study the thickness variations of the Quaternary alluviums beneath Kaoping area by examining the Sp converted phase. Travel-time difference of S and Sp phases is used to estimate the sediment thickness. With highly seismicity activities and dense strong motion array, this technique has been used in Lan-Yang Plain and Chia-Nan Plain. In this study we focus on Kaoping region in order to discuss the underground structures in the study region. The major targets are to determine the location of Chaochou fault and Sp phase is converted from which formation boundary. Results show that the thickness become thicker toward the west in Kaohsiung area, and the thickness become thinner toward east. Details will be presented in this study.

  15. Strong motion characteristics of the M w 6.6 Lushan earthquake, Sichuan, China an insight into the spatial difference of a typical thrust fault earthquake

    NASA Astrophysics Data System (ADS)

    Hu, Jinjun; Zhang, Wenbo; Xie, Lili; Zhang, Qi; Jiang, Zhijun

    2015-06-01

    Near-field strong ground motions are useful for engineering seismology studies and seismic design, but dense observation networks of damaging earthquakes are still rare. In this study, based on the strong-motion data from the M w 6.6 Lushan earthquake, the ground motion parameters in different spatial regions are systematically analyzed, and the contributions from different effects, like the hanging-wall effect, directivity effect, and attenuation effect are separated to the extent possible. Different engineering parameters from the observed ground motions are compared with the local design response spectra and a new attenuation relation of Western China. General results indicate that the high frequency ground motion, like the peak ground acceleration, on two sides of the fault plane is sensitive to the hanging-wall effect, whereas the low frequency ground motion, like the long period spectral acceleration, in the rupture propagation direction is affected by the directivity effect. Moreover, although the M w 6.6 Lushan earthquake is not a large magnitude event, the spatial difference of ground motion is still obvious; thus, for a thrust faulting earthquake, in addition to the hanging effect, the directivity effect should also be considered.

  16. Robust features of the source process for the 2004 Parkfield, California, earthquake from strong-motion seismograms

    NASA Astrophysics Data System (ADS)

    Twardzik, C.; Madariaga, R.; Das, S.; Custdio, S.

    2012-12-01

    We explore a recently developed procedure for kinematic inversion based on an elliptical subfault approximation. In this method, the slip is modelled by a small set of elliptical patches, each ellipse having a Gaussian distribution of slip. We invert near-field strong ground motion for the 2004 September 28 Mw 6.0 Parkfield, California, earthquake. The data set consists of 10 digital three-component 18-s long displacement seismograms. The best model gives a moment of 1.21 1018 N m, with slip on two distinct ellipses, one with a high-slip amplitude of 0.91 m located 20 km northwest of the hypocentre. The average rupture speed of the rupture process is 2.7 km s-1. We find no slip in the top 5 km. At this depth, a lineation of small aftershocks marks the transition from creeping above to locked below, in the interseismic period. The high-slip patch coincides spatially with the hypocentre of the 1966 Mw6.0 Parkfield, California, earthquake. The larger earthquakes prior to the 2004 Parkfield earthquake and the aftershocks of the 2004 earthquake (Mw > 3) also lie around this high-slip patch, where our model images a sharp slip gradient. This observation suggests the presence of a permanent asperity that breaks during large earthquakes, and has important implications for the slip deficit observed on the Parkfield segment, which is necessary for reliable seismic hazard assessment.

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

    USGS Publications Warehouse

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

    2004-01-01

    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.

  18. Numerical Simulation of Strong Ground Motion at Mexico City:A Hybrid Approach for Efficient Evaluation of Site Amplification and Path Effects for Different Types of Earthquakes

    NASA Astrophysics Data System (ADS)

    Cruz, H.; Furumura, T.; Chavez-Garcia, F. J.

    2002-12-01

    The estimation of scenarios of the strong ground motions caused by future great earthquakes is an important problem in strong motion seismology. This was pointed out by the great 1985 Michoacan earthquake, which caused a great damage in Mexico City, 300 km away from the epicenter. Since the seismic wavefield is characterized by the source, path and site effects, the pattern of strong motion damage from different types of earthquakes should differ significantly. In this study, the scenarios for intermediate-depth normal-faulting, shallow-interplate thrust faulting, and crustal earthquakes have been estimated using a hybrid simulation technique. The character of the seismic wavefield propagating from the source to Mexico City for each earthquake was first calculated using the pseudospectral method for 2D SH waves. The site amplifications in the shallow structure of Mexico City are then calculated using the multiple SH wave reverberation theory. The scenarios of maximum ground motion for both inslab and interplate earthquakes obtained by the simulation show a good agreement with the observations. This indicates the effectiveness of the hybrid simulation approach to investigate the strong motion damage for future earthquakes.

  19. Stochastic strong ground motion simulations for the intermediate-depth earthquakes of the south Aegean subduction zone

    NASA Astrophysics Data System (ADS)

    Kkallas, Harris; Papazachos, Konstantinos; Boore, David; Margaris, Vasilis

    2015-04-01

    We have employed the stochastic finite-fault modelling approach of Motazedian and Atkinson (2005), as described by Boore (2009), for the simulation of Fourier spectra of the Intermediate-depth earthquakes of the south Aegean subduction zone. The stochastic finite-fault method is a practical tool for simulating ground motions of future earthquakes which requires region-specific source, path and site characterizations as input model parameters. For this reason we have used data from both acceleration-sensor and broadband velocity-sensor instruments from intermediate-depth earthquakes with magnitude of M 4.5-6.7 that occurred in the south Aegean subduction zone. Source mechanisms for intermediate-depth events of north Aegean subduction zone are either collected from published information or are constrained using the main faulting types from Kkallas et al. (2013). The attenuation parameters for simulations were adopted from Skarladoudis et al. (2013) and are based on regression analysis of a response spectra database. The site amplification functions for each soil class were adopted from Klimis et al., (1999), while the kappa values were constrained from the analysis of the EGELADOS network data from Ventouzi et al., (2013). The investigation of stress-drop values was based on simulations performed with the EXSIM code for several ranges of stress drop values and by comparing the results with the available Fourier spectra of intermediate-depth earthquakes. Significant differences regarding the strong-motion duration, which is determined from Husid plots (Husid, 1969), have been identified between the for-arc and along-arc stations due to the effect of the low-velocity/low-Q mantle wedge on the seismic wave propagation. In order to estimate appropriate values for the duration of P-waves, we have automatically picked P-S durations on the available seismograms. For the S-wave durations we have used the part of the seismograms starting from the S-arrivals and ending at the 95%-energy limit of the Husid plots. After appropriate calibration of all parameters involved in the simulations we generated separate stochastic waveforms for both P- and S-waves, and produce the final synthetics by appropriate merging of the two stochastic waveforms. This work has been partly supported by the 3D-SEGMENTS project #1337 funded by EC European Social Fund and the Operational Programme "Education and Lifelong Learning" of the ARISTEIA-I call of the Greek Secretariat of Research and Technology.

  20. Strong Erosion-Driven Nongravitational Effects in Orbital Motions of the Kreutz Sungrazing Systems Dwarf Comets

    NASA Astrophysics Data System (ADS)

    Sekanina, Zdenek; Kracht, Rainer

    2015-03-01

    We investigate the relationships among the angular orbital elementsthe longitude of the ascending node ?, the inclination i, and the argument of perihelion ?of the Kreutz systems faint, dwarf sungrazers observed only with the Solar and Heliospheric Observatory/STEREO coronagraphs; their published orbits were derived using a parabolic, purely gravitational approximation. In a plot of i against ? the bright Kreutz sungrazers (such as C/1843 D1, C/1882 R1, C/1963 R1, etc.) fit a curve of fixed apsidal orientation, whereas the dwarf members are distributed along a curve that makes with the apsidal curve an angle of 15. The dwarf sungrazers perihelion longitude is statistically invariable, but their perihelion latitude increases systematically with ?. We find that this trend can be explained by a strong erosion-driven nongravitational acceleration normal to the orbit plane, confirmed for several test dwarf Kreutz sungrazers by orbital solutions with nongravitational terms incorporated directly in the equations of motion on a condition of fixed apsidal orientation. Proceeding in three steps, we first apply Marsden et al.'s standard formalism, solving for the normal acceleration only, and eventually relax additional constraints on the nongravitational law and the accelerations radial and transverse components. The resulting nongravitational accelerations on the dwarf sungrazers exceed the maximum for cataloged comets in nearly parabolic orbits by up to three orders of magnitude, topping in exceptional cases the Suns gravitational acceleration! A mass-loss model suggests that the dwarf sungrazers nuclei fragment copiously and their dimensions diminish rapidly near the Sun, implying the objects imminent demise shortly before they reach perihelion.

  1. The July 12, 1993, Hokkaido-Nansei-Oki, Japan, earthquake: Coseismic slip pattern from strong-motion and teleseismic recordings

    USGS Publications Warehouse

    Mendoza, C.; Fukuyama, E.

    1996-01-01

    We employ a finite fault inversion scheme to infer the distribution of coseismic slip for the July 12, 1993, Hokkaido-Nansei-Oki earthquake using strong ground motions recorded by the Japan Meteorological Agency within 400 km of the epicenter and vertical P waveforms recorded by the Global Digital Seismograph Network at teleseismic distances. The assumed fault geometry is based on the location of the aftershock zone and comprises two fault segments with different orientations: a northern segment striking at N20??E with a 30?? dip to the west and a southern segment with a N20??W strike. For the southern segment we use both westerly and easterly dip directions to test thrust orientations previously proposed for this portion of the fault. The variance reduction is greater using a shallow west dipping segment, suggesting that the direction of dip did not change as the rupture propagated south from the hypocenter. This indicates that the earthquake resulted from the shallow underthrusting of Hokkaido beneath the Sea of Japan. Static vertical movements predicted by the corresponding distribution of fault slip are consistent with the general pattern of surface deformation observed following the earthquake. Fault rupture in the northern segment accounts for about 60% of the total P wave seismic moment of 3.4 ?? 1020 N m and includes a large circular slip zone (4-m peak) near the earthquake hypocenter at depths between 10 and 25 km. Slip in the southern segment is also predominantly shallower than 25 km, but the maximum coseismic displacements (2.0-2.5 m) are observed at a depth of about 5 km. This significant shallow slip in the southern portion of the rupture zone may have been responsible for the large tsunami that devastated the small offshore island of Okushiri. Localized shallow faulting near the island, however, may require a steep westerly dip to reconcile the measured values of ground subsidence.

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

    SciTech Connect

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

    1998-01-01

    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.

  3. Analysis of landslide damage caused by the 2008 Wenchuan earthquake using strong motion data: A case study in the Beichuan county town

    NASA Astrophysics Data System (ADS)

    Wang, Xiuying; Nie, Gaozhong; Wang, Song

    2012-08-01

    The county town of Beichuan county, China, experienced catastrophic destruction due to landslides induce by the 2008 Wenchuan earthquake. In consideration of the special location of the county town, this paper selected the landslides induced in the town as representative of large-scale near-rupture landslides, and quantitatively analyzed why the landslide damage was so destructive in the town by using strong motion data obtained from the Wenchuan earthquake in the Longmenshan area. Three methods were employed to estimate the landslide damage using strong motion data. (1) Peak ground accelerations (PGAs) on the hanging wall were used to evaluate the PGAs on the landslide sites in the town. The evaluated average PGAs were all greater than 1 g, indicating that the ground motion intensity was very strong during the earthquake. (2) Acceleration time histories, from another station with similar geological conditions to the town, were used to evaluate the critical acceleration changing range, and the estimated values showed the geological conditions were very susceptible to earthquakes. (3) Acceleration time histories, from two stations on the hanging and foot walls of the rupture, and near the town, were used to calculate the Newmark displacements, and all the evaluated displacements indicated that landslides were very likely. The results show that the slopes, susceptible to earthquakes in the Beichuan county town, were easily triggered under such strong ground-motion intensity and developed into large-scale catastrophic events.

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

    SciTech Connect

    Stevenson, J.D.

    1995-11-01

    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.

  5. Developing a generalized pseudo-dynamic source model of Mw 6.5-7.0 to simulate strong ground motions

    NASA Astrophysics Data System (ADS)

    Song, Seok Goo

    2016-02-01

    Accurate prediction of ground motion intensity and its variability is an important element in seismic hazard assessment. Simulation-based ground motion prediction has become popular in light of earthquake rupture and wave-propagation modelling methods and the rapid growth in computing power. Earthquake rupture modelling needs to be physics-based and also computationally efficient. It also requires the ability to quantify the variability of finite source models for future scenario events. A generalized pseudo-dynamic source model (e.g. earthquake source statistics model) for Mw 6.5-7.0 has been constructed by analysing a number of dynamic rupture models based on 1-point and 2-point statistics of kinematic source parameters. Synthetic broad-band ground motions derived from the pseudo-dynamic source model are validated against empirical ground motion prediction equations (GMPEs). The pseudo-dynamic source model produces ground motion intensities mostly compatible with the empirical GMPEs in the broad frequency range. The perturbation analysis of 1-point and 2-point statistics helps to elucidate the effect of source statistics on ground motions in a systematic way. The constructed pseudo-dynamic source model may be used to generate a feasible range of rupture scenarios for future events and to simulate expected ground motions for seismic hazard assessment.

  6. Microtremor Array Measurement Survey and Strong Ground Motion Observation Activities of The MarDiM (SATREPS) Project

    NASA Astrophysics Data System (ADS)

    Ozgur Citak, Seckin; Karagoz, Ozlem; Chimoto, Kosuke; Ozel, Oguz; Yamanaka, Hiroaki; Aksahin, Bengi; Arslan, Safa; Hatayama, Ken; Ohori, Michihiro; Hori, Muneo

    2015-04-01

    Since 1939, devastating earthquakes with magnitude greater than seven ruptured North Anatolian Fault (NAF) westward, starting from 1939 Erzincan (Ms=7.9) at the eastern Turkey and including the latest 1999 Izmit-Golcuk (Ms=7.4) and the Duzce (Ms=7.2) earthquakes in the eastern Marmara region, Turkey. On the other hand, the west of the Sea of Marmara an Mw7.4 earthquake ruptured the NAF' s Ganos segment in 1912. The only un-ruptured segments of the NAF in the last century are within the Sea of Marmara, and are identified as a "seismic gap" zone that its rupture may cause a devastating earthquake. In order to unravel the seismic risks of the Marmara region a comprehensive multidisciplinary research project The MarDiM project "Earthquake And Tsunami Disaster Mitigation in The Marmara Region and Disaster Education in Turkey", has already been started since 2003. The project is conducted in the framework of "Science and Technology Research Partnership for Sustainable Development (SATREPS)" sponsored by Japan Science and Technology Agency (JST) and Japan International Cooperation Agency (JICA). One of the main research field of the project is "Seismic characterization and damage prediction" which aims to improve the prediction accuracy of the estimation of the damages induced by strong ground motions and tsunamis based on reliable source parameters, detailed deep and shallow velocity structure and building data. As for detailed deep and shallow velocity structure microtremor array measurement surveys were conducted in Zeytinburnu district of Istanbul and Tekirdag province at about 81 sites on October 2013 and September 2014. Also in September 2014, 11 accelerometer units were installed mainly in public buildings in both Zeytinburnu and Tekirdag area and are currently in operation. Each accelerometer unit compose of a Network Sensor (CV-374A2) by Tokyo Sokushin, post processing PC for data storage and power supply unit. The Network Sensor (CV-374A2) consist of three servo type accelerometers for two horizontal and one vertical component combined with 24 bit AD converter. In the presentation current achievements and activities of research group, preliminary results of microtremor array measurement surveys and recorded data by the newly installed stations will be introduced.

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

    USGS Publications Warehouse

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

    2006-01-01

    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.

  8. 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)

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

    2007-12-01

    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).

  9. 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

    Stevenson, J.D.

    1995-02-01

    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.

  10. Evaluation of P- and S- Wave Velocities at CGS Geotechnical Arrays Using Wave Propagation Analysis of Strong Ground-Motion Records

    NASA Astrophysics Data System (ADS)

    Haddadi, H. R.; Shakal, A. F.; Hagos, L. Z.

    2014-12-01

    The average compressional and shear wave velocities of ground layers at the California Geological Survey's instrumented geotechnical arrays are evaluated by analyzing the strong ground-motion records of the earthquakes. The Normalized Input-Output Minimization Method (NIOM) has been employed to correlate the ground motion waveforms recorded at various depths of the geotechnical arrays, and to calculate the P- and S- wave travel times and velocities between the depths at which the seismic sensors have been installed. As of August 2014, the California Geological Survey's Strong-Motion Instrumentation Program (CGS CSMIP) operates 35 geotechnical arrays, a large number of them with cooperation of the California Department of Transportation (Caltrans). As of this date, 140 records from 68 earthquakes with magnitude 3.5 and larger have been recorded at 28 geotechnical arrays. The records are available for download through the Center for Engineering Strong Motion Data (CESMD), the joint center of the U.S. Geological Survey and the California Geological Survey. The velocities obtained in this study for the cases of weak and strong shaking are compared with the measured velocities at the geotechnical array sites obtained using geophysical methods such as SASW, PS suspension logging and downhole methods. The average shear wave velocities in the upper 30 m of the geotechnical arrays from this study are compared with the Vs30 values from geophysical investigations. Application of wave propagation analysis is especially important in studying the dynamic characteristics of ground layers during high stress ground shaking and yields average values for a larger area under a site as opposed to the area in the very close vicinity of the geotechnical array.

  11. A Study of the Seismotomography in Tatun Volcano Region, Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, Y.; Wu, Y.; Chang, C.; Lin, C.; Huang, B.

    2008-12-01

    Tatun volcano region is close to Taipei city, so it is very important to realize the volcanic activity and seismotectonic structures of this region. P arrivals, S-P times and polarities of the first motions from two local temporary seismic networks located in Taipei and Tatun region, Central Weather Bureau Seismic Network (CWBSN) and Taiwan Strong Motion Instrumentation Program (TSMIP) are used to determine Vp and Vp/Vs structures as well as focal mechanisms. By the combination of data from those networks, the coverage of ray paths is improved. According to our results, we found most of micro-earthquakes were relocated above the region with high Vp and high Vp/Vs beneath Tatun volcano region and focal mechanisms of those earthquakes are strike-slip type. Based on the relocated hypocenters distribution, we suggest that those micro-earthquakes might correlate to the Chinshan fault.

  12. Strong ground motion simulation for the Mw6.6 Lushan Earthquake, Sichuan, China, base on the inverted and synthetic slip models

    NASA Astrophysics Data System (ADS)

    Shen, W.; Zhong, Q.; Shi, B.

    2013-12-01

    As we know, the estimation of slip distributions on the fault surface is one of the most important issues for the source inversion of earthquake fault rupturing process. The characteristics of slip distribution on the mainfault play an important role to control strong ground motion pattern. Wang et al., and Zhang et al., published the fast inversion for the rupturing process soon after the 20 April 2013 Lushan, Ya'an earthquake in Sichuan, China. A large amount of works has suggested that variable slip models derived from longer-period ground motion recording are relevant for the prediction of higher-frequency ground motions. The k square model and crack model are well known to describe the slip distribution on the rupture surface. In this study, first we synthesize two forward models: the value of maximum slip, fault dimension, corner wave number derived from Wang model is used to constrain the production of k square model; also, the value of maximum slip, the dimension of asperities from Wang model is used to produce the crack model. Calculation shows that the value of corner wave number of these two synthetic slip models and the inverted models are much the same, and these four slip models are then used to simulate the ground motions for the Lushan earthquake base on the stochastic finite-fault method. Furthermore, a stochastic slip model is also employed for the simulation of strong ground motion for the Lushan event. The simulated results characterized by PGA and PGV show that the source models base on the inverted and synthetic slip distributions could capture most of the basic features of the ground motion. Moreover, the simulated MMI distributions reflect the obvious rupture directivity effect and the influence of the shallow velocity structure well. While the simulation of stochastic slip model is apparently higher than observed MMI. In addition, our simulation result shows that the higher-frequency ground is strongly sensitive to the degree of slip roughness, therefore, we suggest that, for a realistic ground motion simulations due to future earthquake, it is imperative to properly estimate the slip roughness distribution.

  13. Comparing Action Gestures and Classifier Verbs of Motion: Evidence from Australian Sign Language, Taiwan Sign Language, and Nonsigners' Gestures without Speech

    ERIC Educational Resources Information Center

    Schembri, Adam; Jones, Caroline; Burnham, Denis

    2005-01-01

    Recent research into signed languages indicates that signs may share some properties with gesture, especially in the use of space in classifier constructions. A prediction of this proposal is that there will be similarities in the representation of motion events by sign-naive gesturers and by native signers of unrelated signed languages. This

  14. Comparing Action Gestures and Classifier Verbs of Motion: Evidence from Australian Sign Language, Taiwan Sign Language, and Nonsigners' Gestures without Speech

    ERIC Educational Resources Information Center

    Schembri, Adam; Jones, Caroline; Burnham, Denis

    2005-01-01

    Recent research into signed languages indicates that signs may share some properties with gesture, especially in the use of space in classifier constructions. A prediction of this proposal is that there will be similarities in the representation of motion events by sign-naive gesturers and by native signers of unrelated signed languages. This…

  15. Investigation of the Local Soil Effects at the New Strong-Motion Array (MATNet) in Hatay-K.Maras Region, Turkey

    NASA Astrophysics Data System (ADS)

    Polat, O.; eken, U.

    2014-12-01

    The national strong-motion network in Turkey (TR-KYH) is owned and operated by the Prime Ministry, Disaster and Emergency Management Presidency Earthquake Department (AFAD). All TR-KYH stations generates real-time continuous data. A new dense strong-motion array (MATNet) has been installed near Hatay-K.Maras areas. It is at the SW corner of the East Anatolia Fault Zone (EAFZ). Primary target of MATNet is to investigate local site effects. Other important goal is to evaluate them as a part of early warning and preliminary damage estimate system. We also aim to develop a new attenuation relationship in the future from records including this new array. Most recorders are deployed as free-field and mounted in the container which is designed and produced for specific purposes. Hatay, Iskenderun and K.Maras cities have residential, industrial and dense populated areas. New stations are installed on different geological units in 1-3 km or 5-15 km intervals in city centers. Distances increase up to 30 km at the outside of settlements. The MATNet contains 55 triaxial force-balance accelerometers and capable to record explosions. A recent earthquake (Mw=4.5) occurred in the Gulf of Iskenderun on 14 February 2014, and triggered the MATNet and other regional accelerographs (80 triaxial strong-motion stations in total). Location of MATNet strong-motion stations in Hatay-K.Maras Region, Turkey, and distribution of triggered accelerometers during the recent earthquake (Mw=4.5), have been shown in the figure as a- and b-. In the present study, we analyzed to estimate the site response in the frequency range 0.5-10.0 Hz using the reference site (SSR) and HVSR techniques. The site response values thus obtained at each strong-motion sites were observed to be associated with the Quaternary formations. The maximum site amplifications at 0.5-1.8 Hz are detected as 10 around Hatay city, 6-8 (for 0.8-2.3 Hz) near K.Maras and Iskenderun areas. It is apparent that in both 0.5-1.8 and 0.8-2.3 Hz frequency bands, presence of geological contacts and sediment thicknesses controls the site responses in the study areas. It is also inferred that larger site response (~10) value in the 0.5 Hz frequency band could be indicating the probable presence of soil class C (360

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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.), before pushing it to the NA5 portal, for user notification.

  17. Rupture processes of the 2010 Canterbury earthquake and the 2011 Christchurch earthquake inferred from InSAR, strong motion and teleseismic datasets

    NASA Astrophysics Data System (ADS)

    Yun, S.; Koketsu, K.; Aoki, Y.

    2014-12-01

    The September 4, 2010, Canterbury earthquake with a moment magnitude (Mw) of 7.1 is a crustal earthquake in the South Island, New Zealand. The February 22, 2011, Christchurch earthquake (Mw=6.3) is the biggest aftershock of the 2010 Canterbury earthquake that is located at about 50 km to the east of the mainshock. Both earthquakes occurred on previously unrecognized faults. Field observations indicate that the rupture of the 2010 Canterbury earthquake reached the surface; the surface rupture with a length of about 30 km is located about 4 km south of the epicenter. Also various data including the aftershock distribution and strong motion seismograms suggest a very complex rupture process. For these reasons it is useful to investigate the complex rupture process using multiple data with various sensitivities to the rupture process. While previously published source models are based on one or two datasets, here we infer the rupture process with three datasets, InSAR, strong-motion, and teleseismic data. We first performed point source inversions to derive the focal mechanism of the 2010 Canterbury earthquake. Based on the focal mechanism, the aftershock distribution, the surface fault traces and the SAR interferograms, we assigned several source faults. We then performed the joint inversion to determine the rupture process of the 2010 Canterbury earthquake most suitable for reproducing all the datasets. The obtained slip distribution is in good agreement with the surface fault traces. We also performed similar inversions to reveal the rupture process of the 2011 Christchurch earthquake. Our result indicates steep dip and large up-dip slip. This reveals the observed large vertical ground motion around the source region is due to the rupture process, rather than the local subsurface structure. To investigate the effects of the 3-D velocity structure on characteristic strong motion seismograms of the two earthquakes, we plan to perform the inversion taking 3-D velocity structure of this region into account.

  18. Shear-wave velocity characterization of the USGS Hawaiian strong-motion network on the Island of Hawaii and development of an NEHRP site-class map

    USGS Publications Warehouse

    Wong, I.G.; Stokoe, K.H., II; Cox, B.R.; Yuan, J.; Knudsen, K.-L.; Terra, F.; Okubo, P.; Lin, Y.-C.

    2011-01-01

    To assess the level and nature of ground shaking in Hawaii for the purposes of earthquake hazard mitigation and seismic design, empirical groundmotion prediction models are desired. To develop such empirical relationships, knowledge of the subsurface site conditions beneath strong-motion stations is critical. Thus, as a first step to develop ground-motion prediction models for Hawaii, spectralanalysis-of-surface-waves (SASW) profiling was performed at the 22 free-field U.S. Geological Survey (USGS) strong-motion sites on the Big Island to obtain shear-wave velocity (VS) data. Nineteen of these stations recorded the 2006 Kiholo Bay moment magnitude (M) 6.7 earthquake, and 17 stations recorded the triggered M 6.0 Mahukona earthquake. VS profiling was performed to reach depths of more than 100 ft. Most of the USGS stations are situated on sites underlain by basalt, based on surficial geologic maps. However, the sites have varying degrees of weathering and soil development. The remaining strong-motion stations are located on alluvium or volcanic ash. VS30 (average VS in the top 30 m) values for the stations on basalt ranged from 906 to 1908 ft/s [National Earthquake Hazards Reduction Program (NEHRP) site classes C and D], because most sites were covered with soil of variable thickness. Based on these data, an NEHRP site-class map was developed for the Big Island. These new VS data will be a significant input into an update of the USGS statewide hazard maps and to the operation of ShakeMap on the island of Hawaii.

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

    PubMed

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

    2010-11-01

    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

  20. Taiwan: Background Notes Series.

    ERIC Educational Resources Information Center

    Reams, Joanne Reppert

    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

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

    SciTech Connect

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

    2005-04-22

    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.

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

    USGS Publications Warehouse

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

    2000-01-01

    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.

  3. Kinematic Source Rupture Process of the 2008 Iwate-Miyagi Nairiku Earthquake, a MW6.9 thrust earthquake in northeast Japan, using Strong Motion Data

    NASA Astrophysics Data System (ADS)

    Asano, K.; Iwata, T.

    2008-12-01

    The 2008 Iwate-Miyagi Nairiku earthquake (MJMA7.2) on June 14, 2008, is a thrust type inland crustal earthquake, which occurred in northeastern Honshu, Japan. In order to see strong motion generation process of this event, the source rupture process is estimated by the kinematic waveform inversion using strong motion data. Strong motion data of the K-NET and KiK-net stations and Aratozawa Dam are used. These stations are located 3-94 km from the epicenter. Original acceleration time histories are integrated into velocity and band- pass filtered between 0.05 and 1 Hz. For obtaining the detailed source rupture process, appropriate velocity structure model for Green's functions should be used. We estimated one dimensional velocity structure model for each strong motion station by waveform modeling of aftershock records. The elastic wave velocity, density, and Q-values for four sedimentary layers are assumed following previous studies. The thickness of each sedimentary layer depends on the station, which is estimated to fit the observed aftershock's waveforms by the optimization using the genetic algorithm. A uniform layered structure model is assumed for crust and upper mantle below the seismic bedrock. We succeeded to get a reasonable velocity structure model for each station to give a good fit of the main S-wave part in the observation of aftershocks. The source rupture process of the mainshock is estimated by the linear kinematic waveform inversion using multiple time windows (Hartzell and Heaton, 1983). A fault plane model is assumed following the moment tensor solution by F-net, NIED. The strike and dip angle is 209 and 51, respectively. The rupture starting point is fixed at the hypocenter located by the JMA. The obtained source model shows a large slip area in the shallow portion of the fault plane approximately 6 km southwest of the hypocenter. The rupture of the asperity finishes within about 9 s. This large slip area corresponds to the area with surface break reported by the field survey group (e.g., AIST/GSJ, 2008), which supports the existence of the large slip close to the ground surface. But, most of surface offset found by the field survey are less than 0.5 m whereas the slip amount of the shallow asperity of the source inversion result is 3-4 m. In north of the hypocenter, the estimated slip amount is small. Slip direction is almost pure dip-slip for the entire fault (Northwest side goes up against southeast side). Total seismic moment is 2.6 1019 Nm (MW 6.9). Acknowledgments: Strong motion data of K-NET and KiK-net operated by the National Research Institute for Earth Science and Disaster Prevention are used. Strong motion data of Aratozawa Dam obtained by Miyagi prefecture government is also used in the study.

  4. Rupture history of the 2008 Mw 7.9 Wenchuan, China, earthquake: Evaluation of separate and joint inversions of geodetic, teleseismic, and strong-motion data

    USGS Publications Warehouse

    Hartzell, Stephen; Mendoza, Carlos; Ramírez-Guzmán, Leonardo; Zeng, Yuesha; Mooney, Walter

    2013-01-01

    An extensive data set of teleseismic and strong-motion waveforms and geodetic offsets is used to study the rupture history of the 2008 Wenchuan, China, earthquake. A linear multiple-time-window approach is used to parameterize the rupture. Because of the complexity of the Wenchuan faulting, three separate planes are used to represent the rupturing surfaces. This earthquake clearly demonstrates the strengths and limitations of geodetic, teleseismic, and strong-motion data sets. Geodetic data (static offsets) are valuable for determining the distribution of shallower slip but are insensitive to deeper faulting and reveal nothing about the timing of slip. Teleseismic data in the distance range 30°–90° generally involve no modeling difficulties because of simple ray paths and can distinguish shallow from deep slip. Teleseismic data, however, cannot distinguish between different slip scenarios when multiple fault planes are involved because steep takeoff angles lead to ambiguity in timing. Local strong-motion data, on the other hand, are ideal for determining the direction of rupture from directivity but can easily be over modeled with inaccurate Green’s functions, leading to misinterpretation of the slip distribution. We show that all three data sets are required to give an accurate description of the Wenchuan rupture. The moment is estimated to be approximately 1.0 × 1021 N · m with the slip characterized by multiple large patches with slips up to 10 m. Rupture initiates on the southern end of the Pengguan fault and proceeds unilaterally to the northeast. Upon reaching the cross-cutting Xiaoyudong fault, rupture of the adjacent Beichuan fault starts at this juncture and proceeds bilaterally to the northeast and southwest.

  5. The SCEC Broadband Platform: A Collaborative Open-Source Software Package for Strong Ground Motion Simulation and Validation

    NASA Astrophysics Data System (ADS)

    Silva, F.; Maechling, P. J.; Goulet, C. A.; Somerville, P.; Jordan, T. H.

    2014-12-01

    The Southern California Earthquake Center (SCEC) Broadband Platform is a collaborative software development project involving geoscientists, earthquake engineers, graduate students, and the SCEC Community Modeling Environment. The SCEC Broadband Platform (BBP) is open-source scientific software that can generate broadband (0-100Hz) ground motions for earthquakes, integrating complex scientific modules that implement rupture generation, low and high-frequency seismogram synthesis, non-linear site effects calculation, and visualization into a software system that supports easy on-demand computation of seismograms. The Broadband Platform operates in two primary modes: validation simulations and scenario simulations. In validation mode, the Platform runs earthquake rupture and wave propagation modeling software to calculate seismograms for a well-observed historical earthquake. Then, the BBP calculates a number of goodness of fit measurements that quantify how well the model-based broadband seismograms match the observed seismograms for a certain event. Based on these results, the Platform can be used to tune and validate different numerical modeling techniques. In scenario mode, the Broadband Platform can run simulations for hypothetical (scenario) earthquakes. In this mode, users input an earthquake description, a list of station names and locations, and a 1D velocity model for their region of interest, and the Broadband Platform software then calculates ground motions for the specified stations. Working in close collaboration with scientists and research engineers, the SCEC software development group continues to add new capabilities to the Broadband Platform and to release new versions as open-source scientific software distributions that can be compiled and run on many Linux computer systems. Our latest release includes 5 simulation methods, 7 simulation regions covering California, Japan, and Eastern North America, the ability to compare simulation results against GMPEs, and several new data products, such as map and distance-based goodness of fit plots. As the number and complexity of scenarios simulated using the Broadband Platform increases, we have added batching utilities to substantially improve support for running large-scale simulations on computing clusters.

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

    NASA Astrophysics Data System (ADS)

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

    2001-12-01

    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 total fault length of 112 km with four segments. We assumed that the characterized fault model consisted of two regions: asperity and background (Somerville et al., 1999; Irikura, 2000; Dan et al., 2000). The main differences in the four fault models were 1) how to determine a seismic moment Mo from a fault rupture area S, 2) number of asperities N, 3) how to determine a stress parameter ? , and 4) fmax. We calculated broadband strong motions at three stations near the fault by a hybrid method of the semi-empirical and theoretical approaches. A comparison between the results from the hybrid method and those from empirical attenuation relations showed that the hybrid method using the characterized fault model could evaluate near-fault rupture directivity effects more reliably than the empirical attenuation relations. We also discussed the characterized fault models and the strong motion characteristics. The Mo extrapolated from the empirical Mo-S relation by Somerville et al. (1999) was a half of that determined from the mean value of the Wells and Coppersmith (1994) data. The latter Mo was consistent with that for the 1891 Nobi, Japan, earthquake whose fault length was almost the same as the length of the target earthquake. In addition, the fault model using the latter Mo produced a slip amount of about 6 m on the largest asperity, which was consistent with the displacement of 6 m to 9 m per event obtained from a trench survey. High-frequency strong motions were greatly influenced by the ? for the asperities (188 bars, 246 bars, 108 bars, and 134 bars) and fmax (13.5 Hz and 6 Hz). Irikura (2000) determined the ? based on a circular crack theory on the condition that the combined area of asperities was constant. So, in estimating ? , the evaluation of N became important. Dan et al. (2000) determined the ? based on the empirical relation between Mo and high-frequency level A of acceleration source spectrum. In order to interpret A physically, a further investigation of the relationship between A and N is needed. A more investigation of fmax, especially for M8 inland earthquakes, is also needed. Acknowledgment : During the course of this study, we were indebted to Drs. Mori, Hirata, and Komaru, Earthquake Research Division, Research and Development Bureau, the Ministry of Education, Scince and Technology, Japan.

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

    USGS Publications Warehouse

    Hartzell, S.; Mendoza, C.

    1991-01-01

    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

  8. Strong ground motion generated by controlled blasting experiments and mining induced seismic events recorded underground at deep level mines in South Africa

    NASA Astrophysics Data System (ADS)

    Milev, A.; Selllers, E.; Skorpen, L.; Scheepers, L.; Murphy, S.; Spottiswoode, S. M.

    2011-12-01

    A number of simulated rockbursts were conducted underground at deep level gold mines in South Africa in order to estimate the rock mass response when subjected to strong ground motion. The rockbursts were simulated by means of large blasts detonated in solid rock close to the sidewall of a tunnel. The simulated rockbursts involved the design of the seismic source, seismic observations in the near and far field, high-speed video filming, a study of rock mass conditions such as fractures, joints, rock strength etc. Knowledge of the site conditions before and after the simulated rockbursts was also gained. The numerical models used in the design of the simulated rockbursts were calibrated by small blasts taking place at each experimental site. A dense array of shock type accelerometers was installed along the blasting wall to monitor the attenuation of the strong ground motion as a function of the distance from the source. The attenuation of peak particle velocities, was found to be proportional to R^-1.7. Special investigations were carried out to evaluate the mechanism and the magnitude of damage, as well as the support behaviour under excessive dynamic loading. The strong ground motion generated by mining induced seismic events was studied, as part of this work, not only to characterize the rock mass response, but also to estimate the site effect on the surface of the underground excavations. A stand-alone instrument especially designed for recording strong ground motions was used to create a large database of peak particle velocities measured on stope hangingwalls. A total number of 58 sites located in stopes where the Carbon Leader Reef, Ventersdorp Contact Reef, Vaal Reef and Basal Reef are mined, were monitored. The peak particle velocities were measured at the surface of the excavations to identify the effect of the free surface and the fractures surrounding the underground mining. Based on these measurements the generally accepted velocity criterion of 3 m/s was found to be an adequate value to meet the requirements of support systems during a rockburst. The data recorded on the skin of the excavations were compared to the data recorded by the mine seismic networks to determine the site response, defined as the ratio of the measured peak ground velocity to the peak ground velocity inferred from the mine seismic data. The site response measured at all mines studied was found to be 9 ± 3 times larger on average.

  9. 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)

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

    2013-12-01

    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 1 g. In the present analysis, Bhatwari and Uttarkashi can expect ground accelerations in excess of 1 g. 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.

  10. Fault rupture process and strong ground motion simulation of the 2014/04/01 Northern Chile (Pisagua) earthquake (Mw8.2)

    NASA Astrophysics Data System (ADS)

    Pulido Hernandez, N. E.; Suzuki, W.; Aoi, S.

    2014-12-01

    A megathrust earthquake occurred in Northern Chile in April 1, 2014, 23:46 (UTC) (Mw 8.2), in a region that had not experienced a major earthquake since the great 1877 (~M8.6) event. This area had been already identified as a mature seismic gap with a strong interseismic coupling inferred from geodetic measurements (Chlieh et al., JGR, 2011 and Metois et al., GJI, 2013). We used 48 components of strong motion records belonging to the IPOC network in Northern Chile to investigate the source process of the M8.2 Pisagua earthquake. Acceleration waveforms were integrated to get velocities and filtered between 0.02 and 0.125 Hz. We assumed a single fault plane segment with an area of 180 km by 135 km, a strike of 357, and a dip of 18 degrees (GCMT). We set the starting point of rupture at the USGS hypocenter (19.610S, 70.769W, depth 25km), and employed a multi-time-window linear waveform inversion method (Hartzell and Heaton, BSSA, 1983), to derive the rupture process of the Pisagua earthquake. Our results show a slip model characterized by one large slip area (asperity) localized 50 km south of the epicenter, a peak slip of 10 m and a total seismic moment of 2.36 x 1021Nm (Mw 8.2). Fault rupture slowly propagated to the south in front of the main asperity for the initial 25 seconds, and broke it by producing a strong acceleration stage. The fault plane rupture velocity was in average 2.9 km/s. Our calculations show an average stress drop of 4.5MPa for the entire fault rupture area and 12MPa for the asperity area. We simulated the near-source strong ground motion records in a broad frequency band (0.1 ~ 20 Hz), to investigate a possible multi-frequency fault rupture process as the one observed in recent mega-thrust earthquakes such as the 2011 Tohoku-oki (M9.0). Acknowledgments Strong motion data was kindly provided by Chile University as well as the IPOC (Integrated Plate boundary Observatory Chile).

  11. Respiratory motion compensation for simultaneous PET/MR based on a 3D-2D registration of strongly undersampled radial MR data: a simulation study

    NASA Astrophysics Data System (ADS)

    Rank, Christopher M.; Heußer, Thorsten; Flach, Barbara; Brehm, Marcus; Kachelrieß, Marc

    2015-03-01

    We propose a new method for PET/MR respiratory motion compensation, which is based on a 3D-2D registration of strongly undersampled MR data and a) runs in parallel with the PET acquisition, b) can be interlaced with clinical MR sequences, and c) requires less than one minute of the total MR acquisition time per bed position. In our simulation study, we applied a 3D encoded radial stack-of-stars sampling scheme with 160 radial spokes per slice and an acquisition time of 38 s. Gated 4D MR images were reconstructed using a 4D iterative reconstruction algorithm. Based on these images, motion vector fields were estimated using our newly-developed 3D-2D registration framework. A 4D PET volume of a patient with eight hot lesions in the lungs and upper abdomen was simulated and MoCo 4D PET images were reconstructed based on the motion vector fields derived from MR. For evaluation, average SUVmean values of the artificial lesions were determined for a 3D, a gated 4D, a MoCo 4D and a reference (with ten-fold measurement time) gated 4D reconstruction. Compared to the reference, 3D reconstructions yielded an underestimation of SUVmean values due to motion blurring. In contrast, gated 4D reconstructions showed the highest variation of SUVmean due to low statistics. MoCo 4D reconstructions were only slightly affected by these two sources of uncertainty resulting in a significant visual and quantitative improvement in terms of SUVmean values. Whereas temporal resolution was comparable to the gated 4D images, signal-to-noise ratio and contrast-to-noise ratio were close to the 3D reconstructions.

  12. An initial model of seismic microzonation of Sikkim Himalaya through thematic mapping and GIS integration of geological and strong motion features^*

    NASA Astrophysics Data System (ADS)

    Nath, Sankar Kumar

    2005-05-01

    Seismic microzonation and hazard mapping was undertaken in the Sikkim Himalaya with local site conditions and strong ground motion attributes incorporated into a geographic information system. A strong motion network in Sikkim consisting of 9 digital accelerographs recorded more than 100 events during 1998-2002, of which 72 events are selected with signal-to-noise ratios ?3 for the estimation of site response (SR), peak ground acceleration (PGA) and resonance frequency (RF) at all stations. With these data and inputs from IRS-1C LISS III digital data, topo-sheets, geographical boundary of the State of Sikkim, surface geological maps, soil taxonomy map at 1:50,000 scale and seismic refraction profiles, the seismological and geological thematic maps, namely, SR, PGA, RF, lithology, soil class, slope, drainage, and landslide layers were generated. The geological and seismological layers are assigned normalized weights and feature ranks following a pair-wise comparison hierarchical approach and later integrated through GIS to create the microzonation map of the region. The overall SR, PGA and resonance frequency show an increasing trend in a NW-SE direction, peaking at Singtam in the lesser Himalaya. Six major hazard zones are demarcated with different percentages of probability index values in the geological, seismological hazard and microzonation maps. The maximum risk is attached to a probability greater than 78% in the Singtam and adjoining area. These maps offer generally better spatial representation of seismic hazards including site-specific analysis as a first level microzonation attempt.

  13. Automatic Imaging the Rupture Process of the 2014 South Napa Earthquake by Iterative Deconvolution and Stacking the Strong-motion Data

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Wang, R.

    2014-12-01

    The 2014 South Napa earthquake was well recorded by a densely distributed strong-motion network. By using the automatic iterative deconvolution and stacking (IDS) method, we invert data of strong-motion networks with different apertures and station spacings for rupture processes, in order to examine the influences of networks on the rupture models. By performing a series of inversions, we have found that networks, with apertures more than 60 km and station spacings less than 10 km, are sufficient to imaging the rupture process of the South Napa earthquake. The automatically estimated rupture models of different networks are consistent with each other; all of them suggest that the ruptures mainly propagated to the north and to shallow depths, and formed a unilateral rupture event. The peak slip of this earthquake is about 0.5-0.7 m, located near the ground surface and about 5 km to the north of the epicenter. This work suggests that, with the IDS method, it is feasible in principle to automatically estimate the earthquake rupture process after the earthquake occurrence. This would be beneficial to the earthquake emergency responses, such as earthquake relief and disaster mitigations.

  14. Site correction of stochastic simulation in southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Lun Huang, Cong; Wen, Kuo Liang; Huang, Jyun Yan

    2014-05-01

    Peak ground acceleration (PGA) of a disastrous earthquake, is concerned both in civil engineering and seismology study. Presently, the ground motion prediction equation is widely used for PGA estimation study by engineers. However, the local site effect is another important factor participates in strong motion prediction. For example, in 1985 the Mexico City, 400km far from the epicenter, suffered massive damage due to the seismic wave amplification from the local alluvial layers. (Anderson et al., 1986) In past studies, the use of stochastic method had been done and showed well performance on the simulation of ground-motion at rock site (Beresnev and Atkinson, 1998a ; Roumelioti and Beresnev, 2003). In this study, the site correction was conducted by the empirical transfer function compared with the rock site response from stochastic point-source (Boore, 2005) and finite-fault (Boore, 2009) methods. The error between the simulated and observed Fourier spectrum and PGA are calculated. Further we compared the estimated PGA to the result calculated from ground motion prediction equation. The earthquake data used in this study is recorded by Taiwan Strong Motion Instrumentation Program (TSMIP) from 1991 to 2012; the study area is located at south-western Taiwan. The empirical transfer function was generated by calculating the spectrum ratio between alluvial site and rock site (Borcheret, 1970). Due to the lack of reference rock site station in this area, the rock site ground motion was generated through stochastic point-source model instead. Several target events were then chosen for stochastic point-source simulating to the halfspace. Then, the empirical transfer function for each station was multiplied to the simulated halfspace response. Finally, we focused on two target events: the 1999 Chi-Chi earthquake (Mw=7.6) and the 2010 Jiashian earthquake (Mw=6.4). Considering the large event may contain with complex rupture mechanism, the asperity and delay time for each sub-fault is to be concerned. Both the stochastic point-source and the finite-fault model were used to check the result of our correction.

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

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    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.

  16. Rupture process of the Ms 6.6 Superstition Hills, California, earthquake determined from strong-motion recordings: application of tomographic source inversion

    USGS Publications Warehouse

    Frankel, A.; Wennerberg, L.

    1989-01-01

    We analyze strong-motion recordings of the Ms6.6 Superstition Hills earthquake to determine the timing, location, spatial extent, and rupture velocity of the subevents that produced the bulk of the high-frequency (0.5 to 4Hz) seismic energy radiated by this shock. The earthquake can be characterized by three principal subevents, the largest ones occurring about 3 and 10sec after initiation of rupture. Timing relationships between pulses on the seismograms indicate that the three subevents are located within 8km of each other along the northern portion of the Superstition Hills fault. The two largest subevents display different directivity effects. We apply a tomographic source inversion to the integrated accelerograms to determine the slip acceleration on the fault as a function of time and distance, based on a one-dimensional fault model. -from Authors

  17. K-NET and KiK-net strong-motion data of the 2011 Tohoku-Oki earthquake (M9.0)

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    The 11 March 2011 Tohoku-Oki earthquake is the largest instrumentally recorded earthquake in Japan to date (M9.0, JMA). The vibration from this devastating earthquake was felt almost all over Japan and severe shaking of JMA seismic intensity of "6 lower" or higher was recorded from Kanto to Tohoku districts, in East Japan. The earthquake generated a huge tsunami, which caused catastrophic damages to the Pacific coast of the Honshu Island, particularly to Iwate, Miyagi, and Fukushima prefectures. The National Research Institute for Earth Science and Disaster Prevention (NIED) operates two nation-wide strong-motion observation networks K-NET and KiK-net, which succeeded in recording the strong-motion accelerograms at more than one thousand stations almost all over Japan. The earthquake and the associated tsunami directly affected facilities and operation of K-NET and KiK-net. The tsunami damaged 5 stations in Iwate and Miyagi prefectures. The data center of K-NET and KiK-net in Tsukuba, Ibaraki prefecture was also damaged by the strong motion of main shock and major aftershocks, and a blackout lasted for almost 1 day. Tens of communication lines of stations were not available immediately after the earthquake. Some of them had not been available during several weeks or months. In the noon of March 12, electric power of the data center was restored. After a stable electric power supply was secured, we restarted the data center system operations, and subsequently started to retrieve records from the stations. On March 15 we released the first version of K-NET and KiK-net data set of the main shock on our web sites. The data set consisted of accelerograms from 388 stations. We updated the data set three times as retrieval of the records progressed. The latest version was published on July 13. That release consisted of accelerograms from 1212 stations including 19 stations where peak ground accelerations above 1000 gals were recorded. Although we tried to retrieve records by on-site operations at the stations where wiring was unavailable, records of the 2 stations in Fukushima prefecture have not been yet retrieved because the stations are located in an exclusion zone around the Fukushima Daiichi nuclear power plant. Moreover, we lost records of 2 stations close to the coast in Iwate prefecture, since the stations were completely swept away by the tsunami. In this presentation, we will introduce our response to the emergency situation of data retrieval, publishing data, and system operation of K-NET and KiK-net after the 2011 Tohoku-Oki earthquake. Strong-motion data of K-NET and KiK-net are available on the following web sites (http://www.k-net.bosai.go.jp/, http://www.kik.bosai.go.jp/ )

  18. Taiwan: country profile.

    PubMed

    Spain, D

    1984-03-01

    This discussion of Taiwan focuses on population growth, regions and cities, ethnicity and religion, households and families, housing, education, labor force, income, communication, and sources of information. Taiwan, founded in 1949, took a census in 1980. Its household registration system is efficient and provides population data on a yearly basis. In 1981 the population totaled 18.1 million, an increase of about 20% from the 1971 total of 15 million. Taiwan's population grew 1.9% in 1981, a decline from the 2.2% growth rate of 1971. The birthrate is 23 births/1000 population and the death rate is 5/1000. Taiwan's birthrate is similar to that of China's and both are higher than those of Japan or Hong Kong. Almost 1/3 of Taiwan's population is under 15. Only 4% of the population is aged 65 or over. The entire country is divided into 48 commuting rings associated with specific central cities. The capital city of Taipei and Kaohsiung are special municipalities, and certain offshore islands of Fukien Province are included in population totals. The country is further divided into 5 administrative districts for the household registration system. The Han Chinese constitute 98% of Taiwan's population. Approximately 250,000 aborigines (less than 2% of the population) live in the mountainous central and eastern parts of the island. They are believed to be of Malayan stock. Taiwan's predominant religion is a mixture of Buddhism and Taoism, introduced centuries ago by the original settlers. The family household is composed mainly of family members, including lodgers and hired workers living in the same place under the same household head. Between 1971 and 1980, the number of households in Taiwan increased from 2.6 million to 3.7 million. In 1980, 99% of all households were family households. Average was 4.8 persons for family households and 26.5 persons for nonfamily households. There were 3.7 million housing units in Taiwan in 1980. Taiwan's literacy rate was 86% in 1980, up from 78% in 1970. Men's literacy rates are higher than women's. In June 1982, 6.9 million persons were in Taiwan's labor force, or 58% of all persons aged 15 and over. The largest category of workers in Taiwan are salaried employees and wage earners (47% of all workers in 1980). Taiwan's per capita grossnational product in 1981 was US$2360. Wages are highest in petroleum and coal manufacturing. Taiwan produces a large number of books, newspapers, and magazines for a country of its size. There is no shortage of demographic information in Taiwan. PMID:12279790

  19. Kinematic rupture process of the 2014 Chile Mw 8.1 earthquake constrained by strong-motion, GPS static offsets and teleseismic data

    NASA Astrophysics Data System (ADS)

    Liu, Chengli; Zheng, Yong; Wang, Rongjiang; Xiong, Xiong

    2015-08-01

    On 2014 April 1, a magnitude Mw 8.1 interplate thrust earthquake ruptured a densely instrumented region of Iquique seismic gap in northern Chile. The abundant data sets near and around the rupture zone provide a unique opportunity to study the detailed source process of this megathrust earthquake. We retrieved the spatial and temporal distributions of slip during the main shock and one strong aftershock through a joint inversion of teleseismic records, GPS offsets and strong motion data. The main shock rupture initiated at a focal depth of about 25 km and propagated around the hypocentre. The peak slip amplitude in the model is 6.5 m, located in the southeast of the hypocentre. The major slip patch is located around the hypocentre, spanning 150 km along dip and 160 km along strike. The associated static stress drop is 3 MPa. Most of the seismic moment was released within 150 s. The total seismic moment of our preferred model is 1.72 1021 N m, equivalent to Mw 8.1. For the strong aftershock on 2014 April 3, the slip mainly occurred in a relatively compact area, and the major slip area surrounded the hypocentre with the peak amplitude of 2.5 m. There is a secondary slip patch located downdip from the hypocentre with the peak slip of 2.1 m. The total seismic moment is about 3.9 1020 N m, equivalent to Mw 7.7. Between the rupture areas of the main shock and the 2007 November 14 Mw 7.7 Antofagasta, Chile earthquake, there is an earthquake vacant zone with a total length of about 150 km. Historically, if there is no big earthquake or obvious aseismic creep occurring in this area, it has a great potential of generating strong earthquakes with magnitude larger than Mw 7.0 in the future.

  20. A Study Of The Tomography And Seismicity In Taipei Basin And Tatun Volcano Regions, Taiwan And Their Structural Implications

    NASA Astrophysics Data System (ADS)

    Lin, Y.; Wu, Y.; Lin, C.; Zhao, L.; Chang, C.

    2007-12-01

    The Taipei Basin with soft deposit in the north of Taiwan has been produced by the motion of the Sanchiao fault. Taipei, the capital of Taiwan, is located at the Taipei Basin and the Tatun volcano group which have volcanism is located adjacent to it. The local seismicity is very low, however, it is a very important topic to understand the seismotectonics of the Taipei Basin and Tatun volcano regions. We combined the seismic data from the records of the Central Weather Bureau Seismic Network (CWBSN) and Taiwan Strong Motion Instrumentation Program (TSMIP) to establish the tomography of Taiwan and then relocated those earthquakes in the study region. Totally, 17,548 events from 1974 to 2006 in the North Taiwan were used for Vp and Vp/Vs tomography. We focus our study on Taipei region that is bounded in latitude 24.91 to 25.31N and longitude 121.3 to 121.8E. A total of 339 seismic events with depth less than 100 km from 1977 to 2006 were relocated to study the seismotectonic structures. The pattern of high Vp/Vs ratio coincides with the Sanchiao fault which has made the Taipei Basin, and reveals that the effects of basin amplification affects about several kilometers. There is a zone with high Vp/Vs ratio beneath the Tatun volcano group at the depth of 5~10 kilometer and the strata with low Vp/Vs ratio above this zone appears like an arch. Besides, there are some earthquakes occurred surrounding the high Vp/Vs ratio zone. It may imply that there is a potential region for being full of fluid. It is worth to further analysis about the formation of these earthquakes.

  1. Maternity Leave in Taiwan

    ERIC Educational Resources Information Center

    Feng, Joyce Yen; Han, Wen-Jui

    2010-01-01

    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

  2. Maternity Leave in Taiwan

    ERIC Educational Resources Information Center

    Feng, Joyce Yen; Han, Wen-Jui

    2010-01-01

    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…

  3. A Study of the Influence of Organizational Knowledge Ability and Knowledge Absorptive Capacity on Organization Performance in Taiwan`s Hi-Tech Enterprises

    NASA Astrophysics Data System (ADS)

    Chen, Ching-Piao; Liu, Pang-Lo; Tsai, Chih-Hung

    In recent years, business operation tends to be internationalized and the production cost increases day by day, the technology promotion of Taiwan`s hi-tech enterprises met its bottleneck; lots of industries have introduced Knowledge Management (KM) and emphasized the knowledge absorptive capacity of the employees to promote the organizational business performance under this competition environment. This research studied the influence of organizational knowledge ability and knowledge absorptive capacity on organization performance in Taiwan`s hi-tech enterprises. The research found that: the industry with strong organizational knowledge ability has positive influence on organization performance; the industry with strong organizational knowledge ability has positive influence on knowledge absorptive capacity and the industry with strong knowledge absorptive capacity has positive influence on organization performance. Therefore, the organizational knowledge ability and knowledge absorption capacity of Taiwan`s high-tech enterprises have positive influence on the promotion of their organization performance.

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

    USGS Publications Warehouse

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

    2002-01-01

    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.

  5. Strong Ground Motion Simulation in Fukuoka Region (Japan) Using Finite-fault Stochastic Simulation Method of the March 20, 2005 Earthquake.

    NASA Astrophysics Data System (ADS)

    Moustafa, S. S.; Ohshima, M.; Takenaka, H.; Kawase, H.

    2005-12-01

    Stochastic finite-fault simulation (Beresnev and Atkinson, 1998) is used to simulate the acceleration records of West off Fukuoka earthquake which took place on March 20, 2005, at 10:53 (JST) with Mw 6.6 at a depth of 10 km off-shore west of Fukuoka prefecture, Japan. Stochastic simulations are generated for finite-fault ruptures, in order to define the shape and amplitude level of the Fourier spectrum. The orientation of the fault model used in the present study is assumed to be strike of N 304 E with the dip angle of 87 degree (Takenaka et. al., 2005). The dimensions of the fault are chosen based on the spatial distribution of the aftershocks and the fault plane modeled with an array of subfaults. A slip distribution model, derived from previous studies of this earthquake, is used to specifically account for the source effect. The radiation from each subfault is modeled as Brune`s point source using the Omega square stochastic model approach. The earthquake rupture initiates at the hypocenter, and propagates in all directions along the fault plane. Simulations are generated for an observation point by summing the subfault time series, appropriately lagged in time. This approach is expedient and therefore cost-effective, and has been extensively used in the past by engineers (using empirical spectra) and recently by seismologists (using spectra derived from physical models of the source). The method is calibrated against its ability of reproducing the main shock recordings at 27 stations from K- and Kik-nets, NIED strong-motion stations, at epicentral distances ranging from 23 to 92 km. The intent of this presentation is to capture the essential characteristics of high-frequency motion at each site. The results show a satisfactory match between simulated and observed peak ground accelerations and Fourier spectra except some stations which suffered strong effects of the forward rupture directivity. Large differences between the synthetics and recordings are basically limited to the low-frequency part of the spectrum (less than 2 Hz) which imply that the discrepancies patterns between observed and recorded time histories of the 2005 West off Fukuoka earthquake may be explained by the destructive combination of the source directivity and the site effects.

  6. Rupture process of the two main 2014 Pisagua earthquakes (Mw 8.1 and 7.6) from strong motion, geodetic and global seismic data

    NASA Astrophysics Data System (ADS)

    Vallee, M.; Grandin, R.; Ruiz, S.; Delouis, B.; Vigny, C.; Rivera, E.; Aissaoui, E. M.; Allgeyer, S.; Satriano, C.; Poiata, N.; Bernard, P.; Vilotte, J. P.; Schurr, B.

    2014-12-01

    The 2014 seismic sequence in Northern Chile culminated with the Mw8.1 Pisagua earthquake (2014/04/01), rapidly followed by a large aftershock close to Iquique (Mw=7.6, 2014/04/03). A detailed analysis of these two earthquakes is required to better relate these major events with their preparatory phase, and in particular with the intense activity of the area between March 16th and April 1st. This area has been densely instrumented by several international and Chilean projects, including strong motion and broadband sensors as well as high-rate GPS stations. In this study, we make an extensive use of the seismo-geodetic data collected by the IPOC/CSN (http://www.ipoc-network.org/) and ONEMI networks. In a first step, we model several of the foreshocks with magnitudes in the range [5.5 6.5] in order to determine a seismic velocity model able to reproduce the observations up to 0.1Hz. This velocity model is then used to analyze the rupture process of the two main shocks. Besides the use of the local displacement waveforms (coming from strong motion sensors and high-rate GPS), the inversion procedure also includes the static GPS displacements and the teleseismic P and SH waves. The source models are finally validated with other geophysical information not included in the inversion, such as InSAR or surface waves analysis through an empirical Green function approach. These data consistently show that most of the coseismic slip of the 1st April main shock is located in a 50km long zone (along strike), close and South from the hypocenter. In the time domain, this large slip patch has been activated 15-20s after origin time and lasted about 30s. Before this activation, seismic moment release was low and rupture remained in the hypocentral region. Differences and relations between the two shocks, as well as their interpretation in the 2014 seismic sequence, will be discussed.

  7. Taiwan Regulation of Biobanks.

    PubMed

    Fan, Chien-Te; Hung, Tzu-Hsun; Yeh, Chan-Kun

    2015-12-01

    This paper introduces legal framework and governance structure in relation to the management and development of biobanks in Taiwan. At first, we briefly describe Taiwan's population, political system and health care system. Secondly, this research introduces biobanking framework of Taiwan including 25 biobanks established with the approval of the Ministry of Health and Welfare. In those biobanks, "Taiwan Biobank" is the first and the largest government-supported biobank which comprises population-based cohort study and disease- oriented study. Since the collection of information, data, and biological specimen of biobanks often involve highly sensitive personal information, in the legal framework of Taiwan, there is a specific regulation, "Human Biobank Management Act" (HBMA), which plays an important role in regulating biobanks in Taiwan. HBMA, the Personal Information Act and other regulations constitute a comprehensive legal and regulatory privacy framework of biobanks. Through the introduction and analysis of the current legal framework applicable to biobanks, we found that there are several challenges that need to be solved appropriately that involve duplicate review systems, the obstacles in the international collaboration, and data sharing between biobanks in Taiwan. PMID:26711420

  8. Rupture history of the 2013 Mw 6.6 Lushan earthquake constrained with local strong motion and teleseismic body and surface waves

    NASA Astrophysics Data System (ADS)

    Hao, J.; Ji, C.; Wang, W.; Yao, Z.

    2013-12-01

    The rupture history of the April 20, 2013 Mw 6.6 Lushan (China) earthquake is constrained by inverting waveforms of local strong motion, teleseismic broadband body waves, and long period surface waves. This earthquake ruptured a blind thrust fault oriented N210E (along the Longmenshan fault zone) and dipping 40 to the NW. The inverted slip distribution is heterogeneous, dominated by a slip patch with a roughly right triangular shape, which spans a depth range of 5-20 km and accounts for two-thirds of the total seismic moment (8.9x10**18 Nm). The rupture initiated roughly at the middle of the triangles hypotenuse and, during the first 4 s, propagated mainly in along-strike and down-dip directions, towards a peak slip of 1.2 m. Despite a large number of fatalities and economic loss, the estimated static and apparent stress drops of the Lushan earthquake are 1.5 MPa and 0.35 MPa, considerably low with respect to other similar intra-plate earthquakes.

  9. Taiwan: growing, growing, gone.

    PubMed

    Hanson, R

    1979-10-01

    Accommodation between Taiwan and the People's Republic of China may not be inconceivable as trade contacts (though officially disallowed) grow. Because of Taiwan's well-established success and the pressing need in China to industrialize, it appears, however, that such an accommodation will occur only after China becomes more like Taiwan. Taiwan owes its success, first, to land reform and then, in the 1960s, to steady industrialization. Besides broad controls over money supply and capital designed to ward off inflationary pressures when needed, and the grand outlines for development, another factor in the island's economic success is that the government has interfered little with private enterprise. The economy has an underpinning of small to medium size businesses. There are more than 10,000 trading companies. This diverse foundation has given the economy as a whole a flexible buffer on which more sophisticated industires can be formed. PMID:12278253

  10. ARRA-funded VS30 measurements using multi-technique approach at strong-motion stations in California and central-eastern United States

    USGS Publications Warehouse

    Yong, Alan; Martin, Antony; Stokoe, Kenneth; Diehl, John

    2013-01-01

    Funded by the 2009 American Recovery and Reinvestment Act (ARRA), we conducted geophysical site characterizations at 191 strong-motion stations: 187 in California and 4 in the Central-Eastern United States (CEUS). The geophysical methods used at each site included passive and active surface-wave and body-wave techniques. Multiple techniques were used at most sites, with the goal of robustly determining VS (shear-wave velocity) profiles and VS30 (the time-averaged shear-wave velocity in the upper 30 meters depth). These techniques included: horizontal-to-vertical spectral ratio (HVSR), two-dimensional (2-D) array microtremor (AM), refraction microtremor (ReMi™), spectral analysis of surface wave (SASW), multi-channel analysis of surface waves (Rayleigh wave: MASRW; and Love wave: MASLW), and compressional- and shear-wave refraction. Of the selected sites, 47 percent have crystalline, volcanic, or sedimentary rock at the surface or at relatively shallow depth, and 53 percent are of Quaternary sediments located in either rural or urban environments. Calculated values of VS30 span almost the full range of the National Earthquake Hazards Reduction Program (NEHRP) Site Classes, from D (stiff soils) to B (rock). The NEHRP Site Classes based on VS30 range from being consistent with the Class expected from analysis of surficial geology, to being one or two Site Classes below expected. In a few cases where differences between the observed and expected Site Class occurred, it was the consequence of inaccurate or coarse geologic mapping, as well as considerable degradation of the near-surface rock. Additionally, several sites mapped as rock have Site Class D (stiff soil) velocities, which is due to the extensive weathering of the surficial rock.

  11. Rupture process of 2011 Mw7.1 Van, Eastern Turkey earthquake from joint inversion of strong-motion, high-rate GPS, teleseismic, and GPS data

    NASA Astrophysics Data System (ADS)

    Konca, A. Ozgun

    2015-10-01

    We analyzed the rupture process of the 2011 Mw7.1 Van, Eastern Turkey earthquake using teleseismic, strong-motion, 1-Hz GPS waveforms and static GPS displacement measurements. We performed data sensitivity analyses using four different rupture scenarios. Overall, when geodetic and seismic datasets are modeled jointly, slip distribution is well-constrained and rupture velocity can be obtained. The 2011 Van earthquake is a case where none of the available datasets are sufficient to constrain the slip distribution and the rupture kinematics on their own. This study confirms that rather than fitting one dataset perfectly, using multiple datasets jointly leads to a better-constrained slip distribution. The kinematic model obtained from the joint inversion of all the available data shows a 45-km-long bilateral rupture with two sub-events; one larger slip patch propagating up-dip and toward west of the hypocenter and a smaller second slip patch toward the east. The highest slip is to the west of the hypocenter with a peak value of 4.5 m. The slip is confined to the depths of 7.5 to 20 km and the shallower part of the fault remains unbroken. The average rupture velocity is around 3 km/s, close the Rayleigh wave velocity. The rupture is faster with shorter rise times for the larger sub-event toward the west, while the rise times are longer for the smaller sub-event to the east. This difference in seismic behavior might be related to the segmentation of the fault.

  12. Broad-band strong motion simulations coupling k-square kinematic source models with empirical Green's functions: the 2009 L'Aquila earthquake

    NASA Astrophysics Data System (ADS)

    Del Gaudio, Sergio; Causse, Mathieu; Festa, Gaetano

    2015-10-01

    The use of simulated accelerograms may improve the evaluation of the seismic hazard when an accurate modelling of both source and propagation is performed. In this paper, we performed broad-band simulations of the 2009, M 6.3 L'Aquila earthquake, coupling a k-2 kinematic model for the seismic source with empirical Green's functions (EGFs) as propagators. We extracted 10 EGFs candidates from a database of aftershocks satisfying quality criteria based on signal-to-noise ratio, fault proximity, small magnitude, similar focal mechanism and stress drop. For comparison with real observations, we also derived a low-frequency kinematic model, based on inversion of ground displacement as integrated from strong motion data. Kinematic properties of the inverted model (rupture velocity, position of the rupture nucleation, low-frequency slip and roughness degree of slip heterogeneity) were used as constraints in the k-2 model, to test the use of a single specific EGF against the use of the whole set of EGFs. Comparison to real observations based on spectral and peak ground acceleration shows that the use of all available EGFs improves the fit of simulations to real data. Moreover the epistemic variability related to the selection of a specific EGF is significantly larger (two to three times) than recent observations of between event variability, that is the variability associated with the randomness of the rupture process. We finally performed `blind' simulations releasing all the information on source kinematics and only considering the fault geometry and the magnitude of the target event as known features. We computed peak ground acceleration, acceleration Fourier and response spectra. Simulations follow the same trend with distance as real observations. In most cases these latter fall within one sigma from predictions. Predictions with source parameters constrained at low frequency do not perform better than `blind' simulations, showing that extrapolation of the low-frequency description of the rupture front as inferred by the kinematic inversion may introduce some bias in the final simulations.

  13. Philippine Sea Slab and South-Ryukyu Arc Sliver Accommodation of Arc-Continent Collision East of Taiwan

    NASA Astrophysics Data System (ADS)

    Lallemand, S.; Theunissen, T.; Font, Y.; Schnurle, P.; Lee, C.; Liu, C.

    2011-12-01

    The southern termination of the Ryukyu arc-trench system underwent a complex polyphased and extremely rapid tectonic evolution during the last 5 to 8 My. At first, the relative motion of the Philippine Sea plate (PSP) has changed about 5 My ago from a northward to a northwestward motion relative to Eurasia. Secondly, the Ryukyu trench has propagated from east to west during the same time period resulting in a tectonic inversion along the former passive margin of the South China Sea into the active margin of the S-Ryukyu trench. Thirdly, the convergence rate along the neo-formed S-Ryukyu trench dramatically increased from 8 to 13 cm/yr since at least 2 My when the Southern Okinawa Trough (SOT) started to rift. At the same time, the oceanic subduction of the South China Sea beneath the northern Manila arc progressively evolved into a continental subduction of the Chinese platform at the origin of the Taiwan orogen. The timing of these various kinematic and tectonic events should have been recorded in the deformed sedimentary basins and fold-and-thrust belts in the region. Unfortunately, a large part is now below the sea-level and no or a few age constraints are available. The recent joint project between Taiwan-USA & France (TAIGER & ACTS) gave us the opportunity to considerably increase the resolution of the seismic imagery around the island and especially in the most highly deformed area east of Taiwan along the S-Ryukyu forearc. We already knew that the seismic activity focussed in this region but we ignored how the converging plates deformed. We can now argue that the PSP strongly deforms in the vicinity of its deep interaction with the root of the Taiwan orogen. The north-dipping PSP slab buckles and tears along two diverging directions with a down-faulted part subducting beneath the SOT.

  14. Seismic Site Characterizations At 25 ANSS/PNSN Stations and Compilation Of Site-Specific Data For The Entire Strong-Motion Network In Washington And Oregon

    NASA Astrophysics Data System (ADS)

    Cakir, R.; Walsh, T. J.; Ypma, A.; Pileggi, D.

    2011-12-01

    Site specific velocity information generated using seismic methods can be used to improve the seismic hazard maps of urban areas. With United States Geological Survey (USGS)-External grant program awards, Washington State Department of Natural Resources- Division of Geology and Earth Resources has conducted shallow seismic surveys at 60 station sites operated by Pacific Northwest Seismic Network (PNSN) and the USGS-National Strong Motion Program (NSMP) in Washington and Oregon to characterize these sites through estimation of S-wave (Vs) and P-wave (Vp) velocity profiles. We are currently conducting shallow seismic surveys at 25 ANSS/PNSN station sites in western Washington and Oregon. Active (Multichannel Analysis of Surface Waves, MASW, P-wave and S-wave refractions) and passive (Microtremor Array Measurements, MAM, and Horizontal-to-Vertical Spectral Ratio, HVSR) seismic methods were used to estimate the Vs and Vp profiles at the station sites. Subsequently, for each site Vp/Vs and Poisson's ratio profiles along with Vs30m values were calculated and geologic interpretations were made. Deep sediment layers (>30 meters up to~1km) were characterized using a joint inversion of the HVSR and MASW methods. Deep sediment Vs estimates were also constrained using available geology and borehole information. Available resistance tests (i.e., standard penetration test, SPT) and other borehole soil information (where available) were used to estimate and correlate shear-wave velocities. Various agencies in the region provide borehole, geology and other valuable subsurface data that can be directly or indirectly used in seismic site characterization processes. For this reason, we are generating an interactive mapping environment through the Washington State Geology Portal (http://www.dnr.wa.gov/ResearchScience/Topics/GeosciencesData/Pages/geology_portal.aspx) to link and/or provide these data online for the entire Pacific Northwest Seismic Network (PNSN) stations in Washington and Oregon. This interactive site-specific information mapping may help better constrain Vs estimates, better interpret subsurface layers obtained from seismic surveys and provide background geologic and geotechnical data for seismologists and earthquake engineers. Results of the active and passive seismic site characterizations for shallow and deep Vs and shallow Vp estimates, and examples of interactive mapping of the site-specific information will be shown. Our Vs profiles in terms of NEHRP soil classifications based on average Vs values at top 30 meters (Vs30m) can be directly used for ShakeMap products, HAZUS-MH applications, seismic hazard mapping, and building code developments in the region.

  15. On the similarity of strong ground motions from a deep-focus earthquake (01/01/2012, Mj7.0) and the 2011 Tohoku earthquake - possible effects of specific propagation path

    NASA Astrophysics Data System (ADS)

    Wakai, A.; Nozu, A.

    2013-12-01

    On 1st January, 2012, there was a deep-focus earthquake (Mj7.0) at the depth of 397km close to the Izu-Ogasawara Trench, south of Japan. It is well known that, for such a deep-focus earthquake, anomalous seismic intensity distribution is obtained because of the propagation of seismic waves through the high-Q subducting plate (in this case, The Pacific plate). According to our analysis, such a specific propagation path may have significant effects, not only for intensity distribution but also for the characteristics of strong ground motions. For this earthquake, records of ground motions were obtained at permanent strong motion stations in a wide area. We focused on the records in the Kanto region, where largest ground motions were observed. We analyzed the Fourier phase characteristics of the records, using the method of substituting the Fourier phase characteristics of the records with those from other earthquakes at the same station [Nozu and Irikura, 2008; Wakai and Nozu, 2012]. It was surprising to find that the Fourier phase characteristics of the deep-focus event were similar to those of the 2011 Tohoku earthquake. In the past study, such similarities were observed for two or more closely-located earthquakes, because, for the closely-located earthquakes, the path and site effects are shared between the two events [Nozu and Irikura, 2008; Wakai and Nozu, 2012]. However, for the current earthquake pair, the earthquakes are not closely-located at all. Our interpretation is as follows. In this case, seismic waves radiated from the deep-focus event can propagate with little attenuation through the Pacific plate until they approach to the plate boundary close to the Kanto region. Then they can propagate through the landside plate, toward the observation sites, being affected by the existence of the sedimentary basin. By the way, the seismic waves from the Tohoku earthquake also propagate from the plate boundary to the observation sites, being affected by the sedimentary basin. The sedimentary basin has similar effects for the two events because the incident angles are similar. This should be the reason why strong ground motions from the two events are so similar. Thus, we concluded that the specific propagation path for the deep-focus event contributed to the similarity of strong ground motions of the two events. The permanent strong-motion stations (black triangles), the rupture starting point of the 2011 mainshock by JMA (red star), epicentres of a deep-focus events (blue star), the SPGAs of the 2011 main shock (orange cross and circle) [Nozu, 2011] .

  16. Preliminary study on soil to rock spectral ratio method of microtremor measurement in Taipei Basin, Taiwan

    NASA Astrophysics Data System (ADS)

    Huang, Jyun Yan; Wen, Kuo Liang; Te Chen, Chun; Chang, Shun Chiang

    2014-05-01

    Taipei city is the capital of Taiwan which located in Taipei basin and covered with hundreds meter of alluvial layer that might cause serious damage during huge earthquake. Prediction of possible strong motion levels occurred in the basin then became popular. Engineers most like to use Ground Motion Prediction Equation (GMPEs) as common tool for seismic hazard calculation but GMPEs were usually debated that it can only give one prediction value (PGA, PGV, Sa etc.) rather than time history or spectrum. Seismologists tried theoretical simulation (1D, 2D, 3D method) but could only give low frequency (usually less than 1 Hz) results restricted to that the shallow structures were not clear enough. Resent years, wide frequency simulation techniques such as empirical green's function added stochastic simulation method (hybrid method) were applied to several different purposes but site effect still plays an important role that need to be considered. Traditionally soil to rock spectral ratio of shear wave (denoted as S/R) was widely applied to check basin effect for decades but the technique needs lots of permanent stations and several years to get enough records. If some site located within strong motion network but not close enough to the strong motion stations, interpolate or extrapolate results needed to be used. Wen and Huang (2012) conducted a dense microtremor measurement network in whole Taiwan and applied microtremor H/V to discuss dominant frequency with traditional transfer functions from earthquake shear wave and found good agreement between them. Furthermore, in this study, the ability of soil to rock spectral ratio of microtremor (denoted as MS/R) measurement was tested in Taipei basin. The preliminary results showed MS/R had good agreement with S/R between 0.2 to 5 Hz. And distance from soil site to reference rock site should no greater than 8 to 10 km base on degree of spectrum difference (DSPD) calculation. If the MS/R works that site effect study from this technique could be applied for some region which distribution of strong motion stations were not dense enough after all.

  17. 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

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

    1991-06-01

    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.

  18. The EL Mayor-Cucapah Earthquake of April 4, 2010 (mw 7.2): Main Shock and Aftershocks Relocation and Relevant Aspects of the Strong Motion Data Recorded in the Epicenter Region. (Invited)

    NASA Astrophysics Data System (ADS)

    Munguia, L.

    2010-12-01

    The El Mayor-Cucapah earthquake (Mw = 7.2) was the largest earthquake to occur in northeastern Baja California since February 1892, when an earthquake of slightly lower magnitude occurred at the northwestern end of the Laguna Salada fault. This event, with epicenter located ~ 40 km south of the city of Mexicali, occurred on April 4, 2010 at 15:40 local time or 22:40 UTC. Thirteen strong motion stations of a network operated by CICESE in Baja California were triggered by the main shock. Those stations are located at distances of 12 to 140 km from the epicenter. Six of them are located on sediments of the Mexicali Valley, at less than 40 km from the epicenter; the other seven stations recorded at larger distances, on granitic rocks of the peninsular ranges of Baja California. In this study, we analyze the digital accelerograms produced by the main shock and by most of the larger aftershocks. At first, the P-wave arrival times measured on the accelerograms were combined with time readings from the closer-to-the-source weak-motion stations to relocate the hypocenters. With this, we attempted to improve the hypocenter locations obtained on the basis of more regional data sets. Due to lack of station coverage to the south of the main-shocks epicenter, this task was particularly important for those aftershocks occurring along the SE extension of the ruptured area. Our located hypocenters had smaller location errors and provide a better insight about the extent of the main-shock rupture to southeast. Concerning the strong motion data, we noted that on sediments the recorded peak ground accelerations (PGA) varied from 0.148 to 0.815 g, while on the rock sites the PGA were in the range 0.013 to 0.074 g. The largest peak acceleration recorded was observed on the vertical component of the MDO station, sited on sediments. For ground velocity and displacement, the peak values from sedimentary sites are between 14 and 61 cm/sec and 9 and 52 cm, respectively. In such instances the larger values were always observed on the horizontal components of ground motion. From these comparisons, an immediate conclusion is that peak strong motion parameters from sediment sites were, on average, up to ten times higher than those from rock sites. Finally, and in addition to a general description of the recorded ground motions, other aspects of the earthquake, like PGA attenuation with distance, spectral composition of the ground motions, nonlinearity features and preliminary estimations of the radiated seismic energy and stress drop will also be briefly addressed in our technical presentation.

  19. Broadband strong motion simulation coupling K-2 kinematic source model with empirical Green's functions: application to the 2009 L'Aquila earthquake

    NASA Astrophysics Data System (ADS)

    Del Gaudio, Sergio; Causse, Mathieu; Festa, Gaetano

    2014-05-01

    We perform 'blind' broadband ground-motion simulations using empirical Green's functions (EGF) summed up according to a k-2 kinematic source model. Source parameters (roughness degree of slip heterogeneity, nucleation point, rupture velocity) are defined as a priori random variables, so as to compute the expected median and variability of the ground-motion. The method is used to predict ground-motion of the 2009 L'Aquila earthquake (Mw = 6.3), one of the best recorded events in Europe. A large database of aftershocks is available, providing a large number of potential EGFs. Moreover the main shock and the aftershocks have been recorded at various distances from the epicenter, and hence simulations have been performed both in near-field and far-field conditions. We first selected aftershocks in the magnitude range 3.5 - 3.7, located approximately on the fault plane of the main shock, with a similar focal mechanism and with a high signal to noise ratio (> 3) in the frequency range of interest (0.2 Hz to 20 Hz). All these aftershocks (~15) can be considered as 'good' candidates for EGF ground-motion prediction. We then analyze how the choice of the EGF affect the simulation results. We also show that the use of several EGF distributed over the fault plane significantly improves the results in comparison to predictions performed using a single EGF, especially for the near source stations. Finally we analyze how different degree of a priori knowledge on the source parameters (fixed low frequency slip distribution, roughness degree of slip heterogeneity, rupture velocity, nucleation point) may affect the simulations. Comparison between synthetics and real data are shown in terms of Fourier amplitude spectra and response spectra.

  20. Seismotectonic characteristics of the northernmost part of the Longitudinal Valley suture, eastern Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, C.-F.; Shyu, J. B. H.; Wu, Y.-M.

    2012-04-01

    The island of Taiwan is located at the collisional boundary between the Philippine Sea and the Eurasian plates. In eastern Taiwan, the Longitudinal Valley between the Central Range and the Coastal Range is generally considered as the suture zone. The Ryukyu subduction system, on the other hand, extends southwestward from offshore eastern Taiwan, and intersects with the northernmost Longitudinal Valley suture. As a result, this area is characterized by frequent earthquakes and complex geological structures. Although there have been several tectonic investigations in this area, detailed knowledge of seismotectonic characteristics of this complicated region is still very limited. Recently, we have obtained high resolution earthquake data by combining records from seismic stations of the Japan Meteorological Agency (JMA) and data from Taiwan Central Weather Bureau Seismic Network (CWBSN) and Taiwan Strong Motion Instrumentation Program (TSMIP). Therefore, we attempted to analyze this area in detail using these high resolution seismic data, together with tectonic geomorphic investigations. The distribution of background seismicity shows that many earthquakes occurred at about 10 km deep in this area, and a linear seismicity cluster extends to the surface west of the Hualien City. We infer that this seismicity cluster represents a structure that crops out within the eastern flank of the Central Range. This structure would be different from the Milun fault, which is a known structure in the Hualien area and ruptured during an M7.3 earthquake in October 1951. Another major feature in this area is a listric cluster of seismicity that appears to extend to the surface near the Liwu River mouth, north of the Hualien City. This cluster likely represents an E-W striking structure that dips to the south. Based on the focal mechanisms of several recent moderate earthquakes that occurred within these seismic clusters, we suggest that these two structures are reverse faults. We are currently collecting more data, such as the crustal deformation patterns from GPS networks, 3-D velocity structure, and the bedrock structural features from field investigations, to further understand these two unknown structures and the general seismotectonic characteristics of this area.

  1. Seismotectonic characteristics of the northernmost part of the Longitudinal Valley suture, eastern Taiwan

    NASA Astrophysics Data System (ADS)

    Shyu, J. H.; Chen, C.; Wu, Y.

    2012-12-01

    The island of Taiwan is located at the collisional boundary between the Philippine Sea and the Eurasian plates. In eastern Taiwan, the Longitudinal Valley between the Central Range and the Coastal Range is generally considered as the suture zone. The Ryukyu subduction system, on the other hand, extends southwestward from offshore eastern Taiwan, and intersects with the northernmost Longitudinal Valley suture. As a result, this area is characterized by frequent earthquakes and complex geological structures. Although there have been several tectonic investigations in this area, detailed knowledge of seismotectonic characteristics of this complicated region is still very limited. Recently, we have obtained high resolution earthquake data by combining records from seismic stations of the Japan Meteorological Agency (JMA) and data from Taiwan Central Weather Bureau Seismic Network (CWBSN) and Taiwan Strong Motion Instrumentation Program (TSMIP). Therefore, we attempted to analyze this area in detail using these high resolution seismic data, together with tectonic geomorphic investigations. The distribution of background seismicity shows that many earthquakes occurred at about 10 km deep in this area, and a linear seismicity band extends to the surface west of the Hualien City. We infer that this band of seismicity represents a structure that crops out within the eastern flank of the Central Range. This structure would be different from the Milun fault, which is a known structure in the Hualien area and ruptured during an M7.3 earthquake in October 1951. Another major feature in this area is a listric band of seismicity that appears to extend to the surface near the Liwu River mouth, north of the Hualien City. This seismicity band likely represents an E-W striking structure that dips to the south. Based on the focal mechanisms of several recent moderate earthquakes that occurred within these seismic bands, we suggest that these two structures are reverse faults. These two structures may connect with each other to form a major boundary structure system in this area. In the northernmost part of the Longitudinal Valley suture, we propose that as the Coastal Range subducts northward beneath the Eurasian plate with the Philippine Sea plate, the shallow sediments of the Longitudinal Valley, being a buoyant block, do not subduct, but overthrust northward and westward instead.

  2. Deformation and seismicity of Taiwan

    PubMed Central

    Vita-Finzi, Claudio

    2000-01-01

    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 ≈ 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

  3. Deformation and seismicity of Taiwan.

    PubMed

    Vita-Finzi, C

    2000-10-10

    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

  4. Induced abortion in Taiwan.

    PubMed

    Wang, P D; Lin, R S

    1995-04-01

    Induced abortion is widely practised in Taiwan; however, it had been illegal until 1985. It was of interest to investigate induced abortion practices in Taiwan after its legalization in 1985 in order to calculate the prevalence rate and ratio of induced abortion to live births and to pregnancies in Taiwan. A study using questionnaires through personal interviews was conducted on more than seventeen thousand women who attended a family planning service in Taipei metropolitan areas between 1991 and 1992. The reproductive history and sexual behaviour of the subjects were especially focused on during the interviews. Preliminary findings showed that 46% of the women had a history of having had an induced abortion. Among them, 54.8% had had one abortion, 29.7% had had two, and 15.5% had had three or more. The abortion ratio was 379 induced abortions per 1,000 live births and 255 per 1,000 pregnancies. The abortion ratio was highest for women younger than 20 years of age, for aboriginal women and for nulliparous women. When logistic regression was used to control for confounding variables, we found that the number of previous live births is the strongest predictor relating to women seeking induced abortion. In addition, a significant positive association exists between increasing number of induced abortions and cervical dysplasia. PMID:7738988

  5. Maternity Leave in Taiwan

    PubMed Central

    Feng, Joyce Yen; Han, Wen-Jui

    2011-01-01

    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 versus formula. We found that the time when mothers returned to work coincided with the duration of guaranteed leave. In particular, mothers with a labor pension plan resumed work significantly earlier than mothers with no pension plan, and mothers with no pension plan returned to work significantly later than those with pension plans. The short leave of absence guaranteed under existing policies translated into mothers spending less time with their children and being more likely to exclusively use formula by 6 months after birth. In contrast, mothers who resumed work later than 6 months after birth were more likely to have not worked before birth or to have quit their jobs during pregnancy. Implications and recommendations for parental leave policy in Taiwan are discussed. PMID:21603074

  6. Taiwan Space Programs

    NASA Astrophysics Data System (ADS)

    Liu, Jann-Yenq

    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 of FORMOSAT-1 includes three scientific experiments for measuring the effects of ionospheric plasma and electrodynamics, taking the ocean color image and conducting Ka-band communication experiment. The FORMOSAT- 1 mission was ended by June 15, 2004. FORMOSAT-2, launched on May 21, 2004 onto the Sun-synchronous orbit located at 891 km above ground. The main mission of FORMOSAT-2 is to conduct remote sensing imaging over Taiwan and on terrestrial and oceanic regions of the entire earth. The images captured by FORMOSAT-2 during daytime can be used for land distribution, natural resources research, environmental protection, disaster prevention and rescue work etc. When the satellite travels to the eclipsed zone, it observes natural phenomena of lighting in the upper atmosphere. FORMOSAT-3 is an international collaboration project between Taiwan and the US to develop advanced technology for the real-time monitoring of the global climate. This project is also named Constellation Observing System for Meteorology, Ionosphere and Climate, or FORMOSAT-3/COSMIC for short. Six micro-satellites were launched on 15 April 2007 and eventually placed into six different orbits at 700 800 kilometer above the earth ground. These satellites orbit around the earth to form a LEO constellation that receives signals transmitted by the 24 US GPS satellites. The satellite observation covers the entire global atmosphere and ionosphere, providing over 2,500 global sounding data per day. These data distribute uniformly over the earth's atmosphere. The global climate information collection and analysis can be completed in three hours while the sounding data is updated every 90 minutes for updating weather forecast. In addition, this system can also be used as the long-term climate change research, interactive ionosphere monitoring, global space weather forecast, and earth gravity research. From 1997 to 2003, there are three launches of sounding rockets. To compliment the second phase of Taiwan's national space technology long-term development plan, the sounding rocket space exploration project was established. The timeframe of the second phase sounding rocket project is 15 years, from January 2004 to December 2018, and 10 15 sounding rockets will be launched during this time period. In this paper, the current status and results of the programs are presented in detail.

  7. Practical Applications of Low Cost Seismic Network for Producing Quick Shaking Map in Taiwan

    NASA Astrophysics Data System (ADS)

    Wu, Yih-Min

    2014-05-01

    Two major earthquakes of ML greater than 6.0 occurred in Taiwan in the first half of 2013. The vibrantly shakings brought landslides, falling rocks and casualties. This paper presents a seismic network developed by National Taiwan University (NTU) with 401 Micro-ElectroMechanical Systems (MEMS) accelerators. The network recorded high quality strong motion signals of the two events and produced delicate shaking maps within one minute after the earthquake occurrence. The high shaking regions of the intensity map produced by the NTU system precisely indicate the locations of damages and casualties. Equipping with the dense array of MEMS accelerometers, the NTU system is able to accommodate 10% signals loss from part of the seismic stations and maintains its normal functions for producing shaking maps. The system also has the potential to identify the direction of rupture which is one of the key indices to estimate possible damages. The low cost MEMS accelerator array shows its potential in real-time earthquake shaking map generation and damage avoidance.

  8. Seismic Safety Margins Research Program, Phase I. Project II: seismic input. Compilation, assessment and expansion of the strong earthquake ground motion data base

    SciTech Connect

    Crouse, C B; Hileman, J A; Turner, B E; Martin, G R

    1980-04-01

    A catalog has been prepared which contains information for: (1) world-wide, ground-motion accelerograms, (2) the accelerograph sites where these records were obtained, and (3) the seismological parameters of the causative earthquakes. The catalog is limited to data for those accelerograms which have been digitized and published. In addition, the quality and completeness of these data are assessed. This catalog is unique because it is the only publication which contains comprehensive information on the recording conditions of all known digitized accelerograms. However, information for many accelerograms is missing. Although some literature may have been overlooked, most of the missing data has not been published. Nevertheless, the catalog provides a convenient reference and useful tool for earthquake engineering research and applications.

  9. Space programs in Taiwan

    NASA Astrophysics Data System (ADS)

    Lee, Lou-Chuang; Chang, Guey-Shin; Ting, Nan-Hong

    2013-10-01

    Taiwan's current and future space programs are briefly introduced in this paper. The National Space Organization (NSPO) in Taiwan has successfully carried out three satellite programs (FORMOSAT-1, 2, &3) since its establishment in 1991. FORMOSAT-1 is a scientific satellite performing three scientific experiments for measuring the density, velocity and temperature of ionospheric plasmas, taking the ocean color image, and conducting Ka-band communication experiments. Equipped with a 2m ground resolution remote sensing instrument, FORMOSAT-2 operates in a sun-synchronous orbit with revisit time equal to one day. This unique feature of the daily revisit capability is significantly useful for post disaster assessment and environmental monitoring. FORMOSAT-2 also carries a scientific payload "Imager of Sprites and Upper Atmospheric Lightning (ISUAL)". ISUAL provides the world's first long-term satellite observations on the lighting phenomenon in the earth's upper atmosphere. FORMOSAT-3 is a constellation of six micro-satellites to collect atmospheric and ionospheric data for weather prediction and for climate, ionosphere, and geodesy research. FORMOSAT-3 has demonstrated the ability to significantly increase the accuracy of weather forecasting by utilizing the GPS Radio Occultation (GPS-RO) technique. Currently, NSPO is pursuing the follow-on space missions of FORMOSAT-5 and FORMOSAT-7. FORMOSAT-5 will be the first to utilize a CMOS detector on a high-resolution earth-observation camera. FORMOSAT-7 is a joint mission of Taiwan/US to deploy a 12-satellite constellation operational system to provide dense and timely GNSS RO data to the global communities for real-time weather forecast as well as space science research.

  10. Taiwan orogeny: thin-skinned or lithospheric collision?

    NASA Astrophysics Data System (ADS)

    Wu, Francis T.; Rau, Ruey-Juin; Salzberg, David

    1997-06-01

    The Taiwan orogeny is young and presently very active. It provides an excellent environment for studying ongoing orogenic processes, especially since the region is monitored intensively with dense seismological and geodetic networks, and new studies aiming at deciphering shallow and deep structures in and around Taiwan have been recently conducted or are being planned. The available data can be used continually to test critically hypotheses of the Taiwan orogeny. Hypotheses dealing with the mechanics of mountain building are basic to the understanding of Taiwan orogeny and are particularly amenable to testing. The widely cited 'thin-skinned tectonics' hypothesis was formulated to explain mainly the geologic and relatively shallow (<10 km) seismic data. In various forms of this hypothesis, the mountain building involves the deformation of ready-to-fail (Tertiary) sediments in a thin (<20 km at the deepest point) wedge deformed by the advancing Philippine Sea plate; the Eurasian plate is assumed to subduct the Philippine Sea plate with the Taiwan orogenic belt on top as an accretionary wedge. We tested this hypothesis against newly acquired seismological and geophysical data and found it to be largely inadequate as a model for Taiwan orogeny, because the evidence for the participation of the lower crust and even the upper mantle in the orogeny is very strong. Rather than the result of deforming a thin wedge, the formation of the Central Range is shown to include the thickening of crust as well as the extrusion of mid- to lower crustal high-velocity materials to shallow depth. Seismicity and focal mechanisms demonstrate that significant deformation is taking place at depths far below what the think-skinned tectonics hypothesis predicts. As an alternative, the lithospheric collision hypothesis is proposed. In this model the Eurasian and the Philippine Sea plates are colliding at least down to a depth of 60 km. This hypothesis involves not only greater depth but also greater lateral extent. It accounts for the formation of the deep-rooted Central Range on the Eurasian side, as well as the shortening and thickening of the margin of the Philippine Sea plate near Taiwan. It also asserts that the Central Range was built mainly under ductile conditions, while in the Western Foothills area, the deformation involves the whole brittle-ductile-brittle-ductile sandwiched crust and upper mantle. Furthermore, it is asserted that the collision effect is transmitted to the Taiwan Strait resulting in normal faulting striking perpendicular to the trend of Taiwan. Among the implications of this hypothesis some can be readily subjected to falsification. By critically evaluating the components and accepting or rejecting them, our understanding of the Taiwan orogeny in particular and mountain building in general can be improved.

  11. Geotechnical and Surface Wave Investigation of Liquefaction and Strong Motion Instrumentation sites of the Denali Fault, Mw 7.9, Earthquake

    NASA Astrophysics Data System (ADS)

    Kayen, R.; Thompson, E.; Minasian, D.; Collins, B.; Moss, R.; Sitar, N.; Carver, G.

    2003-12-01

    Following the Mw 7.9 earthquake on the Denali and Totschunda faults on 3 November 2002, we conducted two investigations to map the regional extent and severity of liquefaction ground failures and assess the geotechnical properties of these sites, as well as profile the soil properties beneath three seismometers located at Alyeska Pump Stations 9, 10, and 11. The most noteworthy observations are that liquefaction damage was focused towards the eastern end of the rupture area. For example, liquefaction features in the river bars of the Tanana River, north of the fault-break, are sparsely located from Fairbanks to Delta, but are pervasive throughout the eastern area of the break to Northway Junction, the eastern limit of our survey. Likewise, for the four glacier-proximal rivers draining toward the north, little or no liquefaction was observed on the western Delta and Johnson Rivers, whereas the eastern Robertson River and non-glacial Tok River, and especially the Nabesna River, had observable-to-abundant fissures and sand vents. Several rivers systems were studied in detail. The Nabesna River emerges from its glacier, and drains and fines northward as it crosses the fault zone resulting in an asymmetrical liquefaction pattern. South of the fault, falling liquefaction resistance of soil (fining from sandy gravel to gravely sand) and rising loads from ground motions (approaching the fault) abruptly intersect such that there is a well defined, narrow, soil transition from undisturbed-to-fully liquefied approximately 5 kilometers from the fault. North of the fault, both liquefaction resistance (continued fining) and ground motions fall in tandem, leaving a much broader zone of liquefaction. The Delta River liquefaction occurrence is more complex, where side-entering glacial rivers form non-liquefiable gravel fans and alter the composition and compactness of the main-stem deposits. Immediately upstream of the gravelly Canwell glacier tributary, and immediately at the fault crossing, liquefaction features are abundant. To characterize soil properties, we used a portable continuous sine wave-spectral analysis of surface waves (CSS-SASW) apparatus to profile the shear wave velocity of the ground, and an auger to profile the corresponding texture of the river deposits. We occupied 25 liquefaction evaluation test sites along with the three Alyeska seismometer sites. On the Nabesna, Delta and other rivers, we only find liquefaction features in soil deposits where normalized shear wave velocities fall below 225 m/s. Severity of fissures and lateral spreads dramatically increase in soils as the velocities fall, especially below 170 m/s. In some cases, the most pronounced ground failures are far from the fault zone (60-100 km) in extremely loose, low velocity fine sands. Geotechnical testing performed on field samples revealed that liquefied soils ranged from well graded sandy gravels in close proximity to the fault (< 5km) to silty sands and low plasticity silts at greater distances. At the Alyeska pump station seismometer sites, we are able to invert profiles of shear wave velocity to depths of 140-200 meters. The averaged NEHRP (30 meter) velocities for pump stations 9, 10, and 11 are 376 m/s, 316 m/s, and 362 m/s, respectively.

  12. Comparison of the low-cost MEMS accelerometers used by the Quake-Catcher Network and traditional strong motion seismic sensors

    NASA Astrophysics Data System (ADS)

    Cochran, E. S.; Lawrence, J.; Kaiser, A. E.; Fry, B.; Chung, A. I.; Evans, J. R.

    2011-12-01

    Accelerometers based on low-cost micro-electro-mechanical systems (MEMS) have improved swiftly, making the rapid deployment of dense seismic arrays possible. For example, the Quake-Catcher Network (QCN) makes use of MEMS-based tri-axial sensors installed in homes and businesses to record earthquakes, with almost 2000 participants worldwide. QCN utilizes an open-source distributed-computing system, called the Berkeley Open Infrastructure for Network Computing (BOINC), to retrieve waveforms from continuous or triggered recordings back to the QCN server. Furthermore, the QCN approach can also be used to augment existing seismic networks for rapid-earthquake detection purposes, as well as studies on seismic source- and site-related phenomena. Following the 3 September 2010 Mw7.1 Darfield earthquake, 192 QCN stations were installed in a dense array to record the on-going aftershock sequence in and around the city of Christchurch. We examine the peak ground motions recorded during a M5.1 aftershock and find that peak ground acceleration (PGA) is spatially variable, but with a clear decay in amplitude with distance. In general, closely located GeoNet and QCN stations report similar PGA. Several QCN stations were located within 1 km of existing GeoNet stations, providing an opportunity to compare time series and amplitude spectra. For these closely spaced pairs of stations, the amplitude spectra observed from the horizontal components are highly correlated with average cross-correlation coefficients of 0.9 or higher. In addition, we find the correlation coefficient decreases with increasing distance between station pairs. In future work we will compare the instrumental sensitivity between traditional and MEMS-based sensors by conducting shake table tests of five different types of MEMS sensors at the Albuquerque Seismic Lab.

  13. Therapeutic apheresis in Taiwan.

    PubMed

    Yeh, J H; Chiu, H C

    2001-12-01

    From July 1, 1999, to June 30, 2000, the Formosan Blood Purification Society conducted a survey on the current status of therapeutic apheresis (TA) treatments in Taiwan. There were 13 centers with a total of 437 patients, 498 courses, and 2,086 procedures. The most common indication was for neurological disorders (58.4%), which included mainly myasthenia gravis (34.9%) and Guillain-Barr syndrome (18.2%). The other indications were hematological disorders (19.3%), hepatic-pancreatic disorders (12.3%), and rheumatic disorders (7.1%). Seventy-one percent of TA treatments were reported to be effective. Plasma exchange (PE) performed by either centrifugation or the filtration method constituted 55.4% of TA treatments, the double-filtration (DF) method constituted 39.3% of treatments, and cytapheresis constituted 5.3% of treatments. The most common machines used for TA were the Plasauto iQ, the KM 8800, the Hemonetics series, and the Fenwal CS-3000. The overall frequency of complications was 42.2% per course and 12.9% per procedure. Among them, fever, urticaria, and hypotension were the major complications. As compared with the trends of TA treatment in the world, PE still represents the major TA treatment in Taiwan, which should be replaced by DF or more selective adsorptive methods to reduce the PE-related adverse effects. PMID:11800091

  14. Holographic Screening Length on Parallel Motion of Quark-Antiquark Pair in Four Dimensional Strongly Coupled = 4 super-Yang-Mills plasma

    NASA Astrophysics Data System (ADS)

    Nata Atmaja, Ardian

    2014-10-01

    We study the screening length of a quark-antiquark pair moving in a strongly coupled hot plasma of = 4 super-Yang-Mills using AdS/CFT correspondence where the background metric is five dimensional AdS black hole. We take the string solution as such the separation length L of quark-antiquark pair is parallel to the string velocity v. The screening length and the bound energy are computed numerically using Mathematica. We find that the plots are bounded from below by some functions that are related to the momentum flow of the drag force configuration Pc. We compare the result by computing the screening length in the quark-antiquark reference frame by boosting the AdS black hole.

  15. Is the Lishan fault of Taiwan active?

    NASA Astrophysics Data System (ADS)

    Kuo-Chen, Hao; Wu, Francis; Chang, Wu-Lung; Chang, Chih-Yu; Cheng, Ching-Yu; Hirata, Naoshi

    2015-10-01

    The Lishan fault has been characterized alternately as a major discontinuity in stratigraphy, structures and metamorphism, a ductile shear zone, a tectonic suture or non-existent. In addition to being a geological boundary, it also marks transitions in subsurface structures. Thus, the seismicity to the west of the fault permeates through the upper and mid-crust while beneath the Central Range it is noticeably less and largely concentrated in the upper 12 km. A prominent west-dipping conductive zone extends upward to meet the Lishan fault. Also, the eastward increase of crust thickness from ~ 30 km in the Taiwan Strait quickens under the Lishan fault to form a root of over 50 km under the Central Range. In the past, the small magnitude seismicity along the Lishan fault has been noticed but is too diffuse for definitive association with the fault. Recent processing of aftershock records of the 1999 Mw 7.6 Chi-Chi earthquake using Central Weather Bureau data and, especially, data from three post-Chi-Chi deployments of seismic stations across central Taiwan yielded hypocenters that appear to link directly to the Lishan structure. The presence of a near 4-km-long vertical seismic zone directly under the surface trace of the Lishan fault indicates that it is an active structure from the surface down to about 35 km, and the variety of focal mechanisms indicates that the fault motion can be complex and depth-dependent.

  16. Feasibility study of a nation-wide Early Warning System: the application of the EEW software PRESTo on the Italian Strong Motion Network (RAN)

    NASA Astrophysics Data System (ADS)

    Zollo, Aldo; Picozzi, Matteo; Elia, Luca; Martino, Claudio; Brondi, Piero; Colombelli, Simona; Emolo, Antonio; Festa, Gaetano; Marcucci, Sandro

    2014-05-01

    The past two decades have witnessed a huge progress in the development, implementation and testing of Earthquakes Early Warning Systems (EEWS) worldwide, as the result of a joint effort of the seismological and earthquake engineering communities to set up robust and efficient methodologies for the real-time seismic risk mitigation. The leading experience of the operational early warning system implemented by the Japan Meteorological Agency showed the effectiveness of a combined onsite and network-based approach to rapidly broadcast the rapid warning after a potential damaging earthquake. At the nation-wide scale, the Japanese system makes use of real-time data streamed by the extremely dense accelerograph array (about 1000 seismic instruments) deployed across Japan. With more than 750 accelerometric stations installed over all the active seismic zones, target cities and strategic infrastructures, Italy has the potential for a nation-wide early warning system, although the communication network and data sharing must be expanded and improved. A significant number of these stations are nodes of the RAN (Italian Accelerometric Network) managed by the Italian national emergency management department (Dipartimento della Protezione Civile, DPC), whose data are used for emergency response services. In the framework of the REAKT-Strategies and tools for Real Time Earthquake RisK ReducTion FP7 European project, the AMRA-RISSCLab group is engaged in a feasibility study on the implementation of the EEW software PRESTo earthquake early warning platforms on the Italian accelerometric network (RAN) PRESTo (PRobabilistic and Evolutionary early warning SysTem) is a highly configurable and easily portable platform for Earthquake Early Warning. The system processes the live accelerometric streams from the stations of a seismic network to promptly provide probabilistic and evolutionary estimates of location and magnitude of detected earthquakes while they are occurring, as well as shaking prediction at the regional scale. Alarm messages containing those parameters can reach target sites before the destructive waves, enabling automatic safety procedures. The earthquake location is obtained by an evolutionary, probabilistic approach that uses information from both triggered and not-yet-triggered stations at each time step. Magnitude estimation is based on a Bayesian approach that uses the peak displacement measured on short 2-4 second windows of P- and S-waves signal. Peak ground motion is estimated at target sites by GMPEs using location and magnitude. The performance of the potential EW system at the national scale has been investigated through simulated earthquake scenarios using real-data from several M 5-6 earthquakes recorded by the network RAN. Furthermore, a statistical approach has been implemented considering a nation-wide grid of synthetic sources, the same grid which is used to derive the seismic hazard map in Italy. By considering a virtual testing period of 50 years, each grid's node is considered as a seismic source capable of generating a sequence of earthquakes with magnitude varying according the seismogenic zones properties to which it belongs. Then, the EW algorithm, PRESTo, is run on the sequences of synthetic data created for each of the grid's points considering the present-day RAN configuration, and network performance in terms of lead-time, errors in event location and magnitude determination is computed for the tested sources.

  17. Tide-modulated gas emissions and tremors off SW Taiwan

    NASA Astrophysics Data System (ADS)

    Hsu, Shu-Kun; Wang, Shiou-Ya; Liao, Yen-Che; Yang, Tsanyao F.; Jan, Sen; Lin, Jing-Yi; Chen, Song-Chuen

    2013-05-01

    The continental margin off SW Taiwan is in an incipient stage of orogeny and contains numerous active mud diapirs and mud volcanoes. Gas emissions out of the seabed off SW Taiwan are revealed by acoustic images from 38 kHz echo sounders or sub-bottom profilers. However, the mechanism for gas emissions is still poorly understood. In this study, we show that the gas emissions out of the seabed and the associated tremors off SW Taiwan are strongly correlated with the ocean tides, especially with the diurnal and semidiurnal constituents. Particularly, for each tidal day the strong gas emissions (expulsions) and long-duration tremors occur mainly during both the rising periods to the higher high tides and the falling periods to the lower low tides. Both the gas emissions and tremor activities are generally quiescent near the tidal datum. On average, the daily intensity of gas emissions and the magnitude of tremors are positively proportional to the daily tidal range; a larger slope site implies a greater concentration of gas in the shallow sediments. Most of the individual tremors and long-duration tremors observed off SW Taiwan occur as results of the strong gas expulsions out of the gas-bearing seabed. The high-frequency components of the induced tremors quickly decay and are followed by horizontal low-frequency (~7 Hz) harmonic oscillations of the seabed. Long-duration tremors may enhance seafloor instability and increase the potential for submarine landslides.

  18. Scrap car recycling in Taiwan

    SciTech Connect

    Lee, C.H.; Tai, H.S.; Fan, R.K.S.

    1997-12-31

    The official figure of registered automobiles released by the Ministry of Transportation of Taiwan, R.O.C. as of the end of April 1996, is approximately 4.8 millions. Among them, 18% of the cars are between seven and ten years old and 15% of the cars are old than ten years. The result of this large number of old cars is the problem of abandoned cars on the street of Taiwan. This phenomena not only hinders traffic flow but also undermines the living quality in the cities. To minimize these negative effects, EPA has promulgated a Scrap Motor Vehicles Management Regulation to enforce the scrap car recycling in Taiwan. Under this regulation, a buyer of a new vehicle has to pay the Scrap Motor Vehicle Disposal fee (NT$ 3000, or US$ 110 for a car; and NT$ 700, or US$ 25 for a motorcycle). This paper presents the current status of scrap car recycling in Taiwan.

  19. Numerical studies on Heavy Rainfall Events over Northern Taiwan in Mei-Yu Season

    NASA Astrophysics Data System (ADS)

    Lin, Pay-Liam

    2014-05-01

    Two unusual heavy rainfall events occurred in northern Taiwan from late evening of 11 June to the early morning of 12 June 2012 and late evening of 2 June to the early morning of 3 June 1984. In a few hours, more than 400 mm rainfall were recorded over northwestern Taiwan in these two events. The mechanisms for the commencement and maintenance of this localized heavy rainfall events over northern Taiwan are investigated using the NCEP global grid data, satellite imageries, radar reflectivities, and simulations from the Weather Research and Forecast (WRF) model. These events occurred under favorable large-scale environment that included: upper-level divergence; low-level high equivalent potential temperature; low level of free convection (LFC); and subsynoptic-scale ascending motion over the northern Taiwan Strait and northern Taiwan. In the late night of 2 June, the main heavy rainfall area is simulated to the southeast of the low-level windshift line associated with a trough axis, which is located in the southeastern China coast. The simulated heavy rainfall area moves eastward toward northeastern Taiwan Strait and the northwestern coast of Taiwan as the windshift line continues to propagate eastward. The heavy convective rainfall is enhanced in the eastern Taiwan Strait by orographic blocking where the prevailing southwesterly wind within the Taiwan Strait converges with the orographically deflected flow with a southerly wind component off the western/northwestern Taiwan coast. As the simulated convective area continues to move toward northern Taiwan, it intensifies in a localized low-level convergence area over the northeastern Taiwan Strait and northwestern coast of Taiwan where a barrier jet along the coast converges with the northwesterly winds behind the surface front. Furthermore, in the early morning of 3 June, the simulated rainfall is heavier where the barrier jet encounters the leading edge of the cold pool caused by rain evaporative cooling. As the convective systems drift inland, the orographic lifting of the pre-frontal southwesterly flow helps to produce higher simulated rainfall intensity in the southern slopes of the Taipei Basin. The simulated daily accumulated rainfall over the Taipei Basin and northwestern coast of Taiwan is about 200 and 400 mm, respectively, about 50 mm less than observed. In an experiment without Taiwan's topography (the NT run), the simulated rainfall intensity over the northern Taiwan Strait and the northwestern coast of Taiwan is much less. In contrast to the control run, despite the presence of favorable large-scale settings, no convective systems move to the northern part of Taiwan from the northern Taiwan Strait in the NT run without heavy rainfall simulated over northern Taiwan. Two events will be comparatively investigated by WRF on the formation and maintainence of heavy rainfall in Mai-Yu season.

  20. Numerical studies on Heavy Rainfall Events over Northern Taiwan in Mei-Yu Season

    NASA Astrophysics Data System (ADS)

    Lin, P.; Chen, C.

    2013-12-01

    Two unusual heavy rainfall events occurred in northern Taiwan from late evening of 11 June to the early morning of 12 June 2012 and late evening of 2 June to the early morning of 3 June 1984. In a few hours, more than 400 mm rainfall were recorded over northwestern Taiwan in these two events. The mechanisms for the commencement and maintenance of this localized heavy rainfall events over northern Taiwan are investigated using the NCEP global grid data, satellite imageries, radar reflectivities, and simulations from the Weather Research and Forecast (WRF) model. These events occurred under favorable large-scale environment that included: upper-level divergence; low-level high equivalent potential temperature; low level of free convection (LFC); and subsynoptic-scale ascending motion over the northern Taiwan Strait and northern Taiwan. In the late night of 2 June, the main heavy rainfall area is simulated to the southeast of the low-level windshift line associated with a trough axis, which is located in the southeastern China coast. The simulated heavy rainfall area moves eastward toward northeastern Taiwan Strait and the northwestern coast of Taiwan as the windshift line continues to propagate eastward. The heavy convective rainfall is enhanced in the eastern Taiwan Strait by orographic blocking where the prevailing southwesterly wind within the Taiwan Strait converges with the orographically deflected flow with a southerly wind component off the western/northwestern Taiwan coast. As the simulated convective area continues to move toward northern Taiwan, it intensifies in a localized low-level convergence area over the northeastern Taiwan Strait and northwestern coast of Taiwan where a barrier jet along the coast converges with the northwesterly winds behind the surface front. Furthermore, in the early morning of 3 June, the simulated rainfall is heavier where the barrier jet encounters the leading edge of the cold pool caused by rain evaporative cooling. As the convective systems drift inland, the orographic lifting of the pre-frontal southwesterly flow helps to produce higher simulated rainfall intensity in the southern slopes of the Taipei Basin. The simulated daily accumulated rainfall over the Taipei Basin and northwestern coast of Taiwan is about 200 and 400 mm, respectively, about 50 mm less than observed. In an experiment without Taiwan's topography (the NT run), the simulated rainfall intensity over the northern Taiwan Strait and the northwestern coast of Taiwan is much less. In contrast to the control run, despite the presence of favorable large-scale settings, no convective systems move to the northern part of Taiwan from the northern Taiwan Strait in the NT run without heavy rainfall simulated over northern Taiwan. Two events will be comparatively investigated by WRF on the formation and maintainence of heavy rainfall in Mai-Yu season.

  1. Listeriosis, Taiwan, 1996-2008.

    PubMed

    Huang, Yu-Tsung; Liao, Chun-Hsing; Yang, Chia-Jui; Teng, Lee-Jene; Wang, Jin-Town; Hsueh, Po-Ren

    2011-09-01

    During 1996-2008, a total of 48 patients with listeriosis were identified at a Taiwan hospital. Average annual incidence increased from 0.029 to 0.118 cases per 1,000 admissions before and after January 2005. Serotype 1/2b predominated; serotype 4b emerged since 2004. Food monitoring and disease surveillance systems could help control listeriosis in Taiwan. PMID:21888806

  2. Subsurface imaging, TAIGER experiments and tectonic models of Taiwan

    NASA Astrophysics Data System (ADS)

    Wu, Francis T.; Kuo-Chen, H.; McIntosh, K. D.

    2014-08-01

    The seismicity, deformation rates and associated erosion in the Taiwan region clearly demonstrate that plate tectonic and orogenic activities are at a high level. Major geologic units can be neatly placed in the plate tectonic context, albeit critical mapping in specific areas is still needed, but the key processes involved in the building of the island remain under discussion. Of the two plates in the vicinity of Taiwan, the Philippine Sea Plate (PSP) is oceanic in its origin while the Eurasian Plate (EUP) is comprised partly of the Asian continental lithosphere and partly of the transitional lithosphere of the South China Sea basin. It is unanimously agreed that the collision of PSP and EU is the cause of the Taiwan orogeny, but several models of the underlying geological processes have been proposed, each with its own evolutionary history and implied subsurface tectonics. TAIGER (TAiwan Integrated GEodynamics Research) crustal- and mantle-imaging experiments recently made possible a new round of testing and elucidation. The new seismic tomography resolved structures under and offshore of Taiwan to a depth of about 200 km. In the upper mantle, the steeply east-dipping high velocity anomalies from southern to central Taiwan are clear, but only the extreme southern part is associated with seismicity; toward the north the seismicity disappears. The crustal root under the Central Range is strongly asymmetrical; using 7.5 km/s as a guide, the steep west-dipping face on the east stands in sharp contrast to a gradual east-dipping face on the west. A smaller root exists under the Coastal Range or slightly to the east of it. Between these two roots lies a well delineated high velocity rise spanning the length from Hualien to Taitung. The 3-D variations in crustal and mantle structures parallel to the trend of the island are closely correlated with the plate tectonic framework of Taiwan. The crust is thickest in the central Taiwan collision zone, and although it thins toward the south, the crust is over 30 km thick over the subduction in the south; in northern Taiwan, the northward subducting PSP collides with Taiwan and the crust thins under northern Taiwan where the subducting indenter reaches 50 km in depth. The low Vp/Vs ratio of around 1.6 at a mid-crustal depth of 25 km in the Central Range indicates that current temperatures could exceed 700 C. The remarkable thickening of the crust under the Central Range, its rapid uplift without significant seismicity, its deep exhumation and its thermal state contribute to make it the core of orogenic activities on Taiwan Island. The expanded network during the TAIGER deployment captured broadband seismic data yielding enhanced S-splitting results with mainly SKS/SKKS data. The polarization directions of the fast S-waves follow very closely the structural trends of the island, supporting the concept of a vertically coherent Taiwan orogeny in the outer few hundred kilometers of the Earth.

  3. Progress and Prospect of Physics Research and Education in Taiwan

    NASA Astrophysics Data System (ADS)

    Raynien Kwo, J.

    2010-03-01

    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.

  4. 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)

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

    2013-09-01

    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.

  5. Triggered slip on a back reverse fault in the Mw6.8 2013 Lushan, China earthquake revealed by joint inversion of local strong motion accelerograms and geodetic measurements

    NASA Astrophysics Data System (ADS)

    Zhang, Guohong; Hetland, Eric A.; Shan, Xinjian; Vallée, Martin; Liu, Yunhua; Zhang, Yingfeng; Qu, Chunyan

    2016-03-01

    The 2013 Mw6.8 Lushan, China earthquake occurred in the southwestern end of the Longmenshan fault zone. We jointly invert local strong motion data and geodetic measurements of coseismic surface deformation, including GPS and InSAR, to obtain a robust model of the rupture process of the 2013 Lushan earthquake. Our joint inversion best model involves the rupture of two opposing faults during the Lushan earthquake, a main fault and a secondary fault. It is only when the secondary fault is included that both the GPS and InSAR measurements are fit along with the near-field strong motion. Over 75% of the computed moment was released in slip on the main fault segment, a northwest dipping, listric thrust fault, with buried thrust and dextral strike-slip at hypocenter depths, and with only minor slip closer to the surface. The secondary fault mainly involved oblique thrust slip or pure dextral strike-slip at shallower depths, and accounts for just under 24% of the moment released in the Lushan earthquake. Coulomb stress changes of about 0.5 MPa on the secondary fault segment at the time coseismic slip initiated on that fault indicate that slip was likely triggered by the coseismic slip on the main blind thrust fault. Our coseismic slip model is consistent with a sub-horizontal and east-west to southeast-northwest trending most compressive stress. Our inferred coseismic slip model is also consistent with previous GPS derived models of strain accumulation on the Longmenshan fault system.

  6. Anatomy of strong ground motion: near-source records and three-dimensional physics-based numerical simulations of the Mw 6.0 2012 May 29 Po Plain earthquake, Italy

    NASA Astrophysics Data System (ADS)

    Paolucci, R.; Mazzieri, I.; Smerzini, C.

    2015-12-01

    Stimulated by the recent advances in computational tools for the simulation of seismic wave propagation problems in realistic geological configurations, this paper presents a 3D physics-based numerical analysis of near-source ground motion during the MW 6.0 2012 May 29 earthquake in the Po Plain, Northern Italy. To reproduce with sufficient accuracy some of the most peculiar features of the near-source strong-motion records and of the spatial variability of damage distribution, this study required a sequence of investigations, starting from the analysis of a wide set of near-source records, to the calibration of an improved kinematic seismic source model, up to the development of a 3D numerical model of the portion of the Po Plain interested by the earthquake. The latter includes the basin geometry, characterized by sediment thickness sharply varying from few tens of metres to some kilometres. The spatial resolution of the numerical model is suitable to propagate frequencies up to about 1.5 Hz. Numerical simulations were performed using the open-source high-performance code SPEED, based on the Discontinuous Galerkin Spectral Elements method. The 3D numerical model, coupled with the updated slip distribution along the rupturing fault, proved successful to reproduce with good agreement, measured through quantitative goodness-of-fit criteria, the most relevant features of the observed ground motion. These include: (i) the large fault normal velocity peaks at the near-source stations driven by updip directivity effects; (ii) the small-scale variability at short distance from the source, resulting in the out-of-phase motion at stations separated by only 3 km distance; (iii) the propagation of prominent trains of surface waves, especially in the Northern direction; (iv) the map of earthquake-induced ground uplift with maximum values of about 10 cm, in substantial agreement with geodetic measurements and (v) the two-lobed pattern of the peak ground velocity map, well correlated with the distribution of macroseismic intensity.

  7. Uplift of Tainan Tableland (SW Taiwan) revealed by SAR Interferometry

    NASA Astrophysics Data System (ADS)

    Fruneau, B.; Pathier, E.; Raymond, D.; Deffontaines, B.; Lee, C. T.; Wang, H. T.; Angelier, J.; Rudant, J. P.; Chang, C. P.

    Interferometric processing of five SAR-ERS images reveals uplift of the Tainan Tableland (SW of Taiwan) during the period 1996-1998. The maximum measured ground motion for these two years is 2.8 cm along the radar line of sight towards the satellite, indicating for the displacement vector a vertical component of 3.2 cm, and a horizontal component of 1.6 cm towards the WSW considering additional information from GPS data. The reconstructed displacement field is consistent with the geological interpretation of the Tainan Tableland as an actively growing anticline connected to the Taiwan fold-and-thrust belt. This implies that the deformation front is located farther west than usually assumed in the Tainan area. The large Tainan city is thus located in an active deformation zone. Seismic hazard assessment is however difficult because the mechanisms and kinematics are not known in detail.

  8. Strong Ground Motions Scenarios for Mexico City

    NASA Astrophysics Data System (ADS)

    Cabrera, E.; Chavez, M.; Madariaga, R.; Mai, P. M.; Frisenda, M.; Perea, N.

    2005-12-01

    The recordings available in Mexico City (MC) for extreme magnitude Subduction Superficial (SS), Subduction Deep (SD), and Crustal Superficial (CS) events are about 30 accelerograms (obtained at 10 sites) for the SS 19 09 1985 earthquake (Ms 8.1, Mw 8.01). In this work we generated broadband synthetic accelerograms expected in MC stiff (S) and compressive soils (C),for SS (Mw 8.5, 8.7), SD (Mw 7.6) and CS (Mw 7.5) earthquakes.The frequencies lower than 0.5 Hz were simulated by using a 4th order FD method, including a (fractal) finite-fault description of the sources. The frequencies larger than 0.5 Hz were modeled by the empirical Green function technique. We propose upper bounds of 0.4g and 2g (g=9.8m/s2)for the maximum response spectra acceleration(5 percent damping) expected in the S and C soils of MC, respectively.

  9. Quantifying the seismicity on Taiwan

    NASA Astrophysics Data System (ADS)

    Wu, Yi-Hsuan; Chen, Chien-Chih; Turcotte, Donald L.; Rundle, John B.

    2013-07-01

    We quantify the seismicity on the island of Taiwan using the frequency-magnitude statistics of earthquakes since 1900. A break in Gutenberg-Richter scaling for large earthquakes in global seismicity has been observed, this break is also observed in our Taiwan study. The seismic data from the Central Weather Bureau Seismic Network are in good agreement with the Gutenberg-Richter relation taking b ? 1 when M < 7. For large earthquakes, M ? 7, the seismic data fit Gutenberg-Richter scaling with b ? 1.5. If the Gutenberg-Richter scaling for M < 7 earthquakes is extrapolated to larger earthquakes, we would expect a M > 8 earthquake in the study region about every 25 yr. However, our analysis shows a lower frequency of occurrence of large earthquakes so that the expected frequency of M > 8 earthquakes is about 200 yr. The level of seismicity for smaller earthquakes on Taiwan is about 12 times greater than in Southern California and the possibility of a M ? 9 earthquake north or south of Taiwan cannot be ruled out. In light of the Fukushima, Japan nuclear disaster, we also discuss the implications of our study for the three operating nuclear power plants on the coast of Taiwan.

  10. Professional Counseling in Taiwan: Past to Future

    ERIC Educational Resources Information Center

    Guo, Yuh-Jen; Wang, Shu-Ching; Combs, Don C.; Lin, Yi-Chun; Johnson, Veronica

    2013-01-01

    Because of the recent introduction of a licensure law, professional counseling has grown rapidly in Taiwan after decades of slow development. The authors provide a historical review of the development of professional counseling in Taiwan and discuss the current status and future trajectory of professional counseling in Taiwan.

  11. 76 FR 13660 - Polyvinyl Alcohol From Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-14

    ... COMMISSION Polyvinyl Alcohol From Taiwan Determination On the basis of the record \\1\\ developed in the... United States is materially injured by reason of imports from Taiwan of polyvinyl alcohol, provided for... of a preliminary determination by Commerce that imports of polyvinyl alcohol from Taiwan were...

  12. Surface waves in the western Taiwan coastal plain from an aftershock of the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Wang, G.-Q.; Tang, G.-Q.; Boore, D.M.; Van Ness, Burbach, G.; Jackson, C.R.; Zhou, X.-Y.; Lin, Q.-L.

    2006-01-01

    Significant surface waves were recorded in the western coastal plain (WCP) of Taiwan during the 1999 Chi-Chi, Taiwan, earthquake and its series of aftershocks. We study in detail the surface waves produced by one aftershock (20 September 1999, 18hr 03m 41.16sec, M 6.2) in this paper. We take the Chelungpu-Chukou fault to be the eastern edge of the WCP because it marks a distinct lateral contrast in seismic wave velocities in the upper few kilometers of the surface. For many records from stations within the WCP, body waves and surface waves separate well in both the time domain and the period domain. Long-period (e.g., >2 sec) ground motions in the plain are dominated by surface waves. Significant prograde Rayleigh wave particle motions were observed in the WCP. The observed peak ground velocities are about 3-5 times larger than standard predictions in the central and western part of the plain. Observed response spectra at 3 sec, 4 sec, and 5 sec at the center of the plain can be 15 times larger than standard predictions and 10 times larger than the predictions of Joyner (2000) based on surface wave data from the Los Angeles basin. The strong surface waves were probably generated at the boundary of the WCP and then propagated toward the west, largely along radial directions relative to the epicenter. The geometry of the boundary may have had a slight effect on propagation directions of surface waves. Group velocities of fundamental mode Rayleigh and Love waves are estimated using the multiple filter analysis (MFA) technique and are refined with phase matched filtering (PMF). Group velocities of fundamental mode surface waves range from about 0.7 km/sec to 1.5 km/sec for the phases at periods from 3 sec to 10 sec. One important observation from this study is that the strongest surface waves were recorded in the center of the plain. The specific location of the strongest motions depends largely on the period of surface waves rather than on specific site conditions or plain structures. Accordingly, we conjecture that surface waves could be generated in a wide area close to boundaries of low-velocity sedimentary wave guides. In the case studied in this article the area can be as wide as 30 km (from the Chelungpu fault to the center of the plain). Surface waves converted by P and S waves at different locations would overlap each other and add constructively along their propagation paths. As a result, the surface waves would get stronger and stronger. Beyond a certain distance to the boundary, no more surface waves would be generated. Consequently, no more local surface waves would be superimposed into the invasive surface waves, and the surface waves would tend to decay in amplitude with distance.

  13. Black monazite from Taiwan

    USGS Publications Warehouse

    Matzko, J.J.; Overstreet, W.C.

    1977-01-01

    Two forms of detrital monazite are known in offshore bars in southwestern Taiwan: a yellow-green to colorless form and an unusual but abundant pelletlike form, generally black but also colored gray or brown. These black pellets, which are about 160 by 200 microns in size, are composed of fine-grained monazite crystals from 2 to 20 microns in size. The pellets are associated with highly variable amounts of discrete grains of detrital quartz, rutile, amphibole, tourmaline, and other minerals. Intergrown with the monazite are quartz, a cerium oxide mineral, chlorite, sulfides, and other minerals. Opaqueness of the pelletlike monazite is due principally to the cryptocrystalline nature of part of the monazite; only a small part of the opaqueness can be attributed to opaque inclusions. The black pelletlike monazite lacks thorium and has a high content of europium. In this respect, as in color, shape, size, and inclusions, the pelletlike monazite differs from the yellow-green detrital monazite. Despite the fact that they occur together in the littoral placers, they appear to have had different origins. The yellow-green monazite originated as an accessory mineral in plutonic rocks and has accumulated at the coast through erosion and transport. The origin of the pelletlike monazite is as yet unknown, but it is here inferred that it originated in unconsolidated coastal plain sediments through migration of cerium from the detrital monazite during weathering, and of the intermediate weight mobile rare earths from clay minerals during diagenesis. Possibly these pelletlike grains are detrital particles formed through erosion and transport from originally larger aggregates cemented by diagenetic monazite.

  14. Taiwan`s experience with municipal waste recycling

    SciTech Connect

    Lee, C.H.

    1998-12-31

    Currently, each person on the average produces 1.15 kg of the municipal waste per day and a total of 9 million metric tons were generated annually in Taiwan. The disposal of such a huge amount of waste presents tremendous challenge for the island due to the scarcity of landfills and incineration facilities available locally. EPA of Taiwan, R.O.C. thus takes an active role in promoting waste recycling to reduce the garbage produced in municipalities. In order to efficiently utilize the government`s human and financial resources used in recycling, started from January 31, 1989, EPA has mandated the producer responsibility recycling program for several designated post-consumer products such as PET, PVC bottles, scrap tires, scrap motor vehicles, etc. Producer responsibility recycling program specifies that the manufacturers, importers and sellers of these designated products have the responsibility to retrieve their products and recycle them properly. Several negative effects have been encountered while the implementation of this producer responsibility recycling program in Taiwan which resulted in a modification of this recycling program recently. This paper presents the encountered experiences on the implementation of municipal waste recycling program in Taiwan.

  15. Ophthalmic plastic and orbital surgery in Taiwan.

    PubMed

    Hsu, Chi-Hsin; Lin, I-Chan; Shen, Yun-Dun; Hsu, Wen-Ming

    2014-06-01

    We describe in this paper the current status of ophthalmic plastic and orbital surgery in Taiwan. Data were collected from the Bureau of National Health Insurance of Taiwan, the Bulletin of the Taiwan Ophthalmic Plastic and Reconstructive Society, and the Statistics Yearbook of Practicing Physicians and Health Care Organizations in Taiwan by the Taiwan Medical Association. We ascertained that 94 ophthalmologists were oculoplastic surgeons and accounted for 5.8% of 1621 ophthalmologists in Taiwan. They had their fellowship training abroad (most ophthalmologists trained in the United States of America) or in Taiwan. All ophthalmologists were well trained and capable of performing major oculoplastic surgeries. The payment rates by our National Health Insurance for oculoplastic and orbital surgeries are relatively low, compared to Medicare payments in the United States. Ophthalmologists should promote the concept that oculoplastic surgeons specialize in periorbital plastic and aesthetic surgeries. However, general ophthalmologists should receive more educational courses on oculoplastic and cosmetic surgery. PMID:24898627

  16. Motion Sickness

    MedlinePLUS

    ... people traveling by car, train, airplanes and especially boats. Motion sickness can start suddenly, with a queasy ... motion sickness. For example, down below on a boat, your inner ear senses motion, but your eyes ...

  17. Classifying Motion.

    ERIC Educational Resources Information Center

    Duzen, Carl; And Others

    1992-01-01

    Presents a series of activities that utilizes a leveling device to classify constant and accelerated motion. Applies this classification system to uniform circular motion and motion produced by gravitational force. (MDH)

  18. Strategic planning of developing automatic optical inspection (AOI) technologies in Taiwan

    NASA Astrophysics Data System (ADS)

    Fan, K. C.; Hsu, C.

    2005-01-01

    In most domestic hi-tech industries in Taiwan, the automatic optical inspection (AOI) equipment is mostly imported. In view of the required specifications, AOI consists of the integration of mechanical-electrical-optical-information technologies. In the past two decades, traditional industries have lost their competitiveness due to the low profit rate. It is possible to promote a new AOI industry in Taiwan through the integration of its strong background in mechatronic technology in positioning stages with the optical image processing techniques. The market requirements are huge not only in domestic need but also in global need. This is the main reason to promote the AOI research for the coming years in Taiwan. Focused industrial applications will be in IC, PCB, LCD, communication, and MEMS parts. This paper will analyze the domestic and global AOI equipment market, summarize the necessary fish bone technology diagrams, survey the actual industrial needs, and propose the strategic plan to be promoted in Taiwan.

  19. Herbal Medicine Research in Taiwan*

    PubMed Central

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

    2006-01-01

    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. PMID:16550238

  20. Faculty Autonomy: Perspectives from Taiwan.

    ERIC Educational Resources Information Center

    Dee, Jay R.; Henkin, Alan B.; Chen, Jessica Hsin-Hwa

    2000-01-01

    Investigated whether institutional autonomy related to faculty autonomy in Taiwan's higher education system, which has recently implemented policies to enhance institutional autonomy. Faculty surveys conditionally supported the claim that faculty members work within the constraints of regulated autonomy, where individual behaviors are delimited by

  1. Reconstructing Transition Knowledge in Taiwan

    ERIC Educational Resources Information Center

    Cheng, Chen-chen

    2012-01-01

    Taking a post-colonial stand and using school to work transition as an example, the author re-examines the special education discourses in Taiwan and attempts to construct alternate understandings of transition from sociological and cultural perspectives. A review of past transition literature and a survey of the educational background of the

  2. Principal Leadership in Taiwan Schools

    ERIC Educational Resources Information Center

    Shouse, Roger C.; Lin, Kuan-Pei

    2010-01-01

    During the past two decades, Taiwan's Ministry of Education has responded to globalization by restructuring school curricular, instructional, and decision making practices along western lines in an attempt to attain legitimacy on the world stage. As a result, Taiwanese principals, once kings within their schools, now must share power with other

  3. Technology Education Reform in Taiwan.

    ERIC Educational Resources Information Center

    Lee, Lung-Sheng Steven

    Technology education in Taiwan, presently called living technology (LT), is a new area that has evolved from handicraft, industrial arts, and other areas. LT is offered mainly at the secondary school level, although it is required for all students in grades 1-11. In response to calls for curriculum reform, the present elementary and junior high

  4. Kindergartener's Technology Education in Taiwan.

    ERIC Educational Resources Information Center

    Lai, Chun-Chin

    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

  5. Calibration of PS09, PS10, and PS11 trans-Alaska pipeline system strong-motion instruments, with acceleration, velocity, and displacement records of the Denali fault earthquake, 03 November 2002

    USGS Publications Warehouse

    Evans, John R.; Jensen, E. Gray; Sell, Russell; Stephens, Christopher D.; Nyman, Douglas J.; Hamilton, Robert C.; Hager, William C.

    2006-01-01

    In September, 2003, the Alyeska Pipeline Service Company (APSC) and the U.S. Geological Survey (USGS) embarked on a joint effort to extract, test, and calibrate the accelerometers, amplifiers, and bandpass filters from the earthquake monitoring systems (EMS) at Pump Stations 09, 10, and 11 of the Trans-Alaska Pipeline System (TAPS). These were the three closest strong-motion seismographs to the Denali fault when it ruptured in the MW 7.9 earthquake of 03 November 2002 (22:12:41 UTC). The surface rupture is only 3.0 km from PS10 and 55.5 km from PS09 but PS11 is 124.2 km away from a small rupture splay and 126.9 km from the main trace. Here we briefly describe precision calibration results for all three instruments. Included with this report is a link to the seismograms reprocessed using these new calibrations: http://nsmp.wr.usgs.gov/data_sets/20021103_2212_taps.html Calibration information in this paper applies at the time of the Denali fault earthquake (03 November 2002), but not necessarily at other times because equipment at these stations is changed by APSC personnel at irregular intervals. In particular, the equipment at PS09, PS10, and PS11 was changed by our joint crew in September, 2003, so that we could perform these calibrations. The equipment stayed the same from at least the time of the earthquake until that retrieval, and these calibrations apply for that interval.

  6. Gravity anomalies of the active mud diapirs off southwest Taiwan

    NASA Astrophysics Data System (ADS)

    Doo, Wen-Bin; Hsu, Shu-Kun; Lo, Chung-Liang; Chen, Song-Chuen; Tsai, Ching-Hui; Lin, Jing-Yi; Huang, Yuan-Ping; Huang, Yin-Sheng; Chiu, Shye-Donq; Ma, Yu-Fang

    2015-12-01

    Overpressure and buoyant effect of underlying sediments are generally used to account for the upward motion or formation of submarine mud volcanoes and mud diapirs. In this study, we process and interpret the gravity anomalies associated with the active mud diapirs off SW Taiwan. Geologically, the mud diapirs are just formed and are still very active, thus we can better understand the initial process of the mud diapirs formation through the gravity analysis. Our results show that the density contrasts of the submarine mud diapirs with respect to the surroundings are generally positive. Because the study area is in a tectonically compressive regime and the gas plume venting from the submarine mud volcanoes is very active, we thus infer that mechanically the mud diapirs off SW Taiwan have been formed mainly due to the tectonic compression on the underlying sediments of high pore-fluid pressure, instead of the buoyancy of the buried sediments. The overpressured sediments and fluid are compressed and pushed upwards to pierce the overlying sediments and form the more compacted mud diapirs. The relatively denser material of the mud diapirs probably constrains the flowing courses of the submarine canyons off SW Taiwan, especially for the upper reaches of the Kaoping and Fangliao submarine canyons.

  7. Stochastic ground motion simulation

    USGS Publications Warehouse

    Rezaeian, Sanaz; Xiaodan, Sun

    2014-01-01

    Strong earthquake ground motion records are fundamental in engineering applications. Ground motion time series are used in response-history dynamic analysis of structural or geotechnical systems. In such analysis, the validity of predicted responses depends on the validity of the input excitations. Ground motion records are also used to develop ground motion prediction equations(GMPEs) for intensity measures such as spectral accelerations that are used in response-spectrum dynamic analysis. Despite the thousands of available strong ground motion records, there remains a shortage of records for large-magnitude earthquakes at short distances or in specific regions, as well as records that sample specific combinations of source, path, and site characteristics.

  8. A Comprehensive View Of Taiwan Orogeny From TAIGER Perspective

    NASA Astrophysics Data System (ADS)

    Wu, F. T.; Kuochen, H.; McIntosh, K. D.; Okaya, D. A.; Lavier, L. L.

    2012-12-01

    Arc-continent collision is one of the basic mechanisms for building continental masses. Taiwan is young and very active. Based on known geology a multi-disciplinary geophysical experiment was designed to image the orogeny in action. Logistics for R/V Langseth, OBS and PASSCAL instruments was complex; nevertheless the field works were completed within the project period. The resulting dataset allows us to map the structures of the shallow crust and the upper mantle. The amount of data gathered is large; some key observations and current interpretations are: (I) Observation: Crustal roots on both Eurasian and Philippine Sea plates, with a high velocity rise in between. Interpretation: Deformation throughout lithosphere on both sides of the initial suture; shortening of lithosphere near plate boundary produce high velocity rise. (II) Observation: Upper mantle high velocity anomaly coincides with a steep east-dippping Wadati-Benioff seismicity in southern Taiwan; the anomaly continues part of the way to central Taiwan but it is aseismic; under northern Taiwan the anomaly is very weak and disorganized. Interpretation: Active subduction in the south (up to 22.8N) and may be eclogitization in the lower crust and delamination in central Taiwan. (III) Observation: Low Vp/Vs, low resistivity in the core of Central Range. Interp: dry, felsic rocks at relatively high temper (up to 750OC). (IV) Obs: Strong SKS splitting (~2 sec) with trend-parallel fast axis. Interp: Shearing throughout uppermost mantle. Preliminary 2-D geodynamic modeling produces the primary observed features from simple initial model of an arc impinging on continental margin.

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

    ERIC Educational Resources Information Center

    Mok, Ka Ho; Chan, Ying

    2008-01-01

    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 attempted

  10. Optical stimulated Luminescence Signal on Modern Fluvial Deposit in Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Y. G.; Wu, T. S.; Chen, Y. W.; Kuo, Y. T.

    2014-12-01

    The river terraces overlain by fluvial and debris-flow deposit are widely distributed in Taiwan due to its active tectonic situation. They are not only critical in reconstructing the river evolution, but also of importance in understanding neotectonics. However, the age estimation for the terraces has their own problems by C-14 as well as OSL (Optical Stimulated Luminescence) dating method. For C-14 method, the major problem is the difficulty in discovering the suitable samples, but for OSL method the zeroing effect of the sediments becomes the major barrier if quartz SAR (Single Aliquot Regenerative) procedure is applied. In order to test the residual dose from different drainage areas in Taiwan, modern deposits were collected from 13 main rivers and 3 samples for each from upper-stream to downstream. The apparent dose of modern fluvial deposit was defined as residual dose and believed to be able to give a hint for estimating the zeroing effect for river terraces. Quartz SAR OSL procedure on small aliquot was adopted for all samples in this study. Our results show the residual dose in western Taiwan strongly relies on the source from. If we further apply the mean value of smallest 5% on samples from modern debris flow deposits in upper-stream, the residual dose rise up as high as ~40Gy but lower down to ~15Gy for samples collected from river mouth estuary. It implies that there will be a large error when evaluating the age of debris deposit terrace by quartz SAR OSL procedure. However, if the modern river does not suffer from debris flow in upper-stream, the residual dose is ~5Gy in upper stream and only -0.7~2Gy to the lower steam estuary, which provide better chance to derive relatively reliable ages. We also find that the luminescence characteristics is different between the samples in western and eastern Taiwan respectively. The quartz grains from eastern Taiwan are much dimer than those of the western Taiwan. We may therefore face severe challenge to approach a reliable age for a river terrace located in eastern Taiwan.

  11. Active Extensional Structures Discovered by the Airborne LiDAR Mapping in the Tatun Volcanic Region, Taiwan

    NASA Astrophysics Data System (ADS)

    Chan, Y.; Chang, K.; Chen, R.; Lee, J.; Hsieh, Y.

    2006-12-01

    Complex tectonic deformation is present in northern Taiwan where the Philippine Sea plate is subducting under the Eurasian plate and the Okinawa trough is opening to the east. The Tatun volcanic region and the Taipei metropolitan basin are considered the products resulted from such complex tectonic environment. Furthermore, contractional deformation was prevailed in the earlier stage, as evidenced by several major thrust faults truncating the Tertiary strata. However, the expected nowadays extensional deformation is not fully characterized, for example, the Shanchiao fault bounding the western Taipei basin and its northern extension into the Tatun volcanic region. Based on industrial seismic profiles, it appeared that several well developed normal faults reactivated pre-existing thrust faults offshore northern Taiwan. These normal faults likely extend into the land where the Tatun volcanics erupted through and covered on the Tertiary strata. It is our intentions to better inspect the deformational pattern existing within the Tatun volcanic region where forests dominate on the surface making field investigation difficult. In this study we apply high-resolution airborne LiDAR-derived digital terrain model to characterize possible joints, fractures, and faults in the Tatun volcanic region. The LiDAR-derived DTM was processed so that bare ground is revealed using virtual removal of forests. The derived 2-m DTM was then examined to map out topographic features possibly resulted from the linear geologic structures. We discovered clear distribution and pattern of the joints and fractures in the Tatun volcanic region for the first time. The mapped structural patterns reveal strong evidence for regional extensional deformation in northern Taiwan, especially within the Tatun volcanic region. We also uncovered branches of normal faults extending possibly from the Shanchiao fault into the Tatun volcanic region. The discovered normal fault, perhaps active, cut across flat regions with averaging 3.3 meters in displacement. A field outcrop was found which contains fault gouge and striations indicating normal and strike-slip in motion. This further supports that the extensional deformation is young and an ongoing process in northern Taiwan, and that the region may produce significant earthquakes through such mechanism.

  12. Queering Taiwan: in search of nationalism's other.

    PubMed

    Chen, Li-fen

    2011-01-01

    This article deals with the formation of Taiwans homosexual cultural politics in the 1990s, the impact and implications of which are yet to be examined within the larger context of Taiwans 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 Taiwans 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

  13. Severe Dengue Fever Outbreak in Taiwan.

    PubMed

    Wang, Sheng-Fan; Wang, Wen-Hung; Chang, Ko; Chen, Yen-Hsu; Tseng, Sung-Pin; Yen, Chia-Hung; Wu, Deng-Chyang; Chen, Yi-Ming Arthur

    2016-01-01

    Dengue fever (DF) is a vector-borne disease caused by dengue viruses (DENVs). Epidemic dengue occurs intermittently in Taiwan. In 2014, Taiwan experienced its largest DF outbreak. There were 15,732 DF cases reported. There were a total of 136 dengue hemorrhagic fever (DHF) cases, of which 20 resulted in death. Most DF cases were reported in southern Taiwan. A total of 15,043 (96%) cases were from Kaohsiung, a modern city in southern Taiwan. This report reviews DF epidemics in Taiwan during 2005-2014. The correlation between DF and DHF along with temperature and precipitation were conjointly examined. We conclude that most dengue epidemics in Taiwan resulted from imported DF cases. Results indicate three main factors that may have been associated with this DF outbreak in Kaohsiung: an underground pipeline explosion combined with subsequent rainfall and higher temperature. These factors may have enhanced mosquito breeding activity, facilitating DENV transmission. PMID:26572871

  14. Strong Interaction

    SciTech Connect

    Karsch, F.; Vogelsang, V.

    2009-09-29

    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.

  15. Taiwan's industrial heavy metal pollution threatens terrestrial biota.

    PubMed

    Hsu, M J; Selvaraj, K; Agoramoorthy, G

    2006-09-01

    The bioconcentration levels of essential (Cu, Fe, Mg, Mn, and Zn) and non-essential (As, Cd, Hg, Pb, and Sn) elements have been investigated in different terrestrial biota such as fungi, plant, earthworm, snail, crab, insect, amphibian, lizard, snake, and bat including the associated soil, to investigate the ecosystem health status in Kenting National Park, Taiwan. High bioconcentrations of Cd, Hg, and Sn in snail, earthworm, crab, lizard, snake, and bat indicated a contaminated terrestrial ecosystem. High concentrations of Cd, Hg, and Sn in plant species, effective bioaccumulation of Cd by earthworm, snail, crab and bat, as well as very high levels of Hg found in invertebrates, amphibians, and reptiles revealed a strong influence from industrial pollution on the biotic community. This study for the first time presents data on the impact of heavy metal pollution on various terrestrial organisms in Taiwan. PMID:16414161

  16. Tornillos and Other Volcanic Tremors in Tatun Volcanoes, Northern Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, C.; Konstantinou, K.; Pu, S.; Huang, Y.; Lin, Y.; You, S.

    2004-12-01

    This is the first time to report several types of volcanic signals such as Tornillos (screws), harmonic signals (drops) and continuously short-period volcanic tremors at the Tatun volcanic group (Taiwan), which was usually considered as extinct because there was no any historical eruption. These volcanic signals are often reported in the active volcanoes in the earth. In particular, the tornillos have been considered as the potential precursor for volcanic eruption at Galeras volcano, Colombia. Combining all of these volcanic signals with the presviously geochemical analyses from the Helium isotop ratio, we strongly suggest that volcanic activities in the Tatun volcanic area might not be totally extinct yet and further investigations have to been done for evaluation of potential volcanic activities because the Tatun volcano group is not only just nearby two nuclear power plants but also about 15 km north to Taipei, the capital of Taiwan, in which more than seven million people live on.

  17. Stress tensor analysis in the Taiwan area from focal mechanisms of earthquakes

    NASA Astrophysics Data System (ADS)

    Yih-Hsiung, Yeh; Eric, Barrier; Cheng-Horng Lin; Jacques, Angelier

    1991-12-01

    We produce a map of the stress pattern in and around Taiwan based on 200 earthquake focal mechanism solutions. These solutions were determined by using data from Taiwan Telemetered Seismographic Network, microearthquake surveys and WWSSN. The stresses are derived through a minimization of angles between the slip vector and the shear stress on each nodal plane considered as a fault, employing appropriate weighting factors. The whole set of focal mechanisms is divided into several groups, mainly according to apparent clustering of the event locations. The results show that the direction of maximum principal stress in Taiwan area is nearly horizontal and SE-NW on average. This is in good agreement with the direction of relative motion between the Philippine Sea plate and the Eurasian plate. In western Taiwan, the fan-shaped distribution of the maximum principal stress is consistent with the direction of Philippine Sea-Eurasian plate convergence through a simple model of viscous material indented by a rigid wedge. In the northeastern part of Taiwan, a nearly horizontal minimum principal stress oriented N-S is found for shallow depths; it occurs in a region of low seismic velocities, probably related to the back-arc activity of the Okinawa Trough. Down-dip compressional and down-dip extensional stresses have been identified in different depth ranges within the subducting slab of the Philippine Sea plate in the northern Taiwan; this may reflect the slab characteristics in this area. A complex stress pattern prevails in the Hualien area, at the junction between the Ryukyu subduction system and the Taiwan collision zone.

  18. Occupational Neurotoxic Diseases in Taiwan

    PubMed Central

    Liu, Chi-Hung; Huang, Chu-Yun

    2012-01-01

    Occupational neurotoxic diseases have become increasingly common in Taiwan due to industrialization. Over the past 40 years, Taiwan has transformed from an agricultural society to an industrial society. The most common neurotoxic diseases also changed from organophosphate poisoning to heavy metal intoxication, and then to organic solvent and semiconductor agent poisoning. The nervous system is particularly vulnerable to toxic agents because of its high metabolic rate. Neurological manifestations may be transient or permanent, and may range from cognitive dysfunction, cerebellar ataxia, Parkinsonism, sensorimotor neuropathy and autonomic dysfunction to neuromuscular junction disorders. This study attempts to provide a review of the major outbreaks of occupational neurotoxins from 1968 to 2012. A total of 16 occupational neurotoxins, including organophosphates, toxic gases, heavy metals, organic solvents, and other toxic chemicals, were reviewed. Peer-reviewed articles related to the electrophysiology, neuroimaging, treatment and long-term follow up of these neurotoxic diseases were also obtained. The heavy metals involved consisted of lead, manganese, organic tin, mercury, arsenic, and thallium. The organic solvents included n-hexane, toluene, mixed solvents and carbon disulfide. Toxic gases such as carbon monoxide, and hydrogen sulfide were also included, along with toxic chemicals including polychlorinated biphenyls, tetramethylammonium hydroxide, organophosphates, and dimethylamine borane. In addition we attempted to correlate these events to the timeline of industrial development in Taiwan. By researching this topic, the hope is that it may help other developing countries to improve industrial hygiene and promote occupational safety and health care during the process of industrialization. PMID:23251841

  19. Scrap computer recycling in Taiwan

    SciTech Connect

    Lee, C.H.; Chang, S.L.; Wang, K.M.; Wen, L.C.

    1999-07-01

    It is estimated that approximately 700,000 scrap personal computers will be generated each year in Taiwan. The disposal of such a huge amount 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 in the scrap computers may cause serious pollution to the environment, if they are not properly disposed. Thus, EPA of Taiwan has declared scrap personal computers as a producer responsibility recycling product on July 1997 to mandate that the manufacturers, importers and sellers of personal computers have to recover and recycle their scrap computers properly. Beginning on June 1, 1998, a scrap computer recycling plan is officially implemented on the island. Under this plan, consumers can deliver their unwanted personal computers to the designated collection points to receive reward money. Currently, only six items are mandated to be recycled in this recycling plan. They are notebooks, monitor and the hard disk, power supply, printed circuit board and shell of the main frame of the personal computer. This paper presents the current scrap computer recycling system in Taiwan.

  20. Decadal Erosion Rates Derived From An Earthquake-Induced Landslide Region, Central Taiwan

    NASA Astrophysics Data System (ADS)

    Chan, Y.; Lu, C.; Chang, K.; Chen, R.

    2010-12-01

    The island of Taiwan is resulted from the collision between the Philippine sea plate and the Eurasian plate. The subtropical climate and averaging four typhoons annually, combined with frequent earthquakes, influence much of the Taiwan region. Due to the factors above, not only the active orogeny of Taiwan causes the high uplift rate at about 4 mm/yr, but also drive amazing erosion rate of about 3-6 mm/yr. Previous study indicated approximately 1.9% of global suspended sediment is derived from the small island of Taiwan, which is only about 0.024% of Earths subaerial surface. Furthermore, modern erosion rates are strongly influenced by large earthquakes and typhoons, and the sediment fluxes after the Mw 7.6 Chi-Chi earthquake of Taiwan are much higher than those before the earthquake. Here we study the Chiufenerhshan landslide, which is one of the large landslides triggered by the Chi-Chi earthquake in the central Taiwan. The avalanche transported a mass of sedimentary rock about 60 m thick and 1.5 km long. Based on the high-resolution topographic data sets from LiDAR or photogrammetry at various years and rain fall data, we have reached the following conclusions: In the period of 8.5 years after the Chi-Chi earthquake, almost 4.2% of the landslide deposits were transported out of the landslide system. Comparing with the mean annual erosion rate of 3-6 mm/yr in Taiwan, the sediment brought out of Chiufenerhshan landslide area is 89.4 mm/yr, a significant amount contributed by the landslide. The mean sediment discharge from this small system is as large as 0.064% of the sediment discharge from the whole Taiwan annually; while the area is only about 0.005% of Taiwans subaerial surface. Thus, the landslide process has contributed much more to the surface erosion of the Taiwan mountain than other erosion processes.

  1. Taiwan Earthquake Damage Index Sin Mei Nga* and Masataka Andob a* Department of Geology, Chinese Culture University, No. 55, Hwa-Kang Road, Yang-Ming-Shan, Taipei 11114, Taiwan b Institute of Earth Sciences, Academia Sinica, 128, Sec2, Academia Road, Nangang, Taipei 11529, Taiwan * Corresponding author. Tel.: +886 (02) 28 61 05 11 ext.26133 fax: +886 (02) 28 61 49 59 E-mail: wsw2@ulive.pccu.edu.tw or sin_mei_josephine_ng@hotmail.com

    NASA Astrophysics Data System (ADS)

    Ng, S.

    2012-12-01

    Taking advantage of a previous study and twelve-year, free-field strong motion data in Taiwan, a preliminary, five-level earthquake damage index is newly proposed: I-No (no damage), II-Very Light, III-Light, IV-Moderate, and V-Heavy. For index I, PGA and PGV are, respectively, <62.5 gal and <11 cm/s. Likewise, for index II, PGA is ≧62.5 and ≦187.5 gal; but, PGV is ≧11 and ≦35 cm/s. Similarly, PGA is ≧187.5 and ≦325 gal; but, PGV is ≧35 and ≦55 cm/s for index III. The corresponding PGA and PGV, for index IV, are ≧325 and ≦450 gal and ≧55 and ≦75 cm/s. Finally, for index V, PGA and PGV are respectively >450 gal and >75 cm/s. Ten damaging seismic events in the past twelve years are redefined using this new earthquake damage index, with the devastating Chi-Chi earthquake and one non-damaging event as reference earthquakes. This newly proposed index depicts seismic hazard of these earthquakes with higher accuracy when compared to the existing intensity scale in Taiwan region. For further analysis, Japan earthquakes are also plotted as references.

  2. Spatial distribution of non volcanic tremors offshore eastern Taiwan

    NASA Astrophysics Data System (ADS)

    Xie, X. S.; Lin, J. Y.; Hsu, S. K.; Lee, C. H.; Liang, C. W.

    2012-04-01

    Non-volcanic tremor (NVT), originally identified in the subduction zone of the southwest Japan, have been well studied in the circum-Pacific subduction zones and the transform plate boundary in California. Most studies related NVT to the release of fluids, while some others associated them with slow-slip events, and can be triggered instantaneously by the surface waves of teleseismic events. Taiwan is located at a complex intersection of the Philippines Sea Plate and the Eurasian Plate. East of Taiwan, the Philippine Sea plate subducts northward beneath the Ryukyu arc. The major part of the island results from the strong convergence between the two plates and the convergent boundary is along the Longitudinal Valley. Moreover, an active strike-slip fault along the Taitung Canyon was reported in the offshore eastern Taiwan. In such complicate tectonic environments, NVT behavior could probably bring us more information about the interaction of all the geological components in the area. In this study, we analyze the seismic signals recorded by the Ocean bottom Seismometer (OBS) deployed offshore eastern Taiwan in September 2009. TAMS (Tremor Active Monitor System) software was used to detect the presence of NVT. 200 tremor-like signals were obtained from the 3 weeks recording period. We use the SSA (Source-Scanning Algorithm) to map the possible distribution of the tremor. In total, 180 tremors were located around the eastern offshore Taiwan. The tremors are mainly distributed in two source areas: one is along the Taitung Canyon, and the other is sub-parallel to the Ryukyu Trench, probably along the plate interface. Many tremors are located at depth shallower than 5 km, which suggests a possible existence of a weak basal detachment along the sea bottom. Other tremors with larger depth may be related to the dehydration of the subducting sea plate as suggested by the former studies. Limited by the short recording period of the OBS experiment, we could not obtain any possible repeating interval and the spatial migration about the tremor occurrence. However, the presence of NVT offshore eastern Taiwan shown in our study still brings us valuable understanding about the undergoing tectonic processes in the marine area.

  3. Effects of the hanging wall and footwall on peak acceleration during the Jiji (Chi-Chi), Taiwan Province, earthquake

    NASA Astrophysics Data System (ADS)

    Yu, Yan-Xiang; Gao, Meng-Tan

    2001-11-01

    The M=7.6 Jiji (Chi-Chi) earthquake, Taiwan Province, on September 21, 1999 (local time) is a thrust fault style earthquake. The empirical attenuation relations of the horizontal and vertical peak ground accelerations (PGA) for the Jiji (Chi-Chi) earthquake are developed by regression method. By examining the residuals from the Jiji (Chi-Chi) earthquake-specific peak acceleration attenuation relations, it is found that there are systematic differences between PGA on the hanging-wall and footwall. The recorded peak accelerations are higher on the hanging-wall and lower on the footwall. The clear asymmetry of PGA distribution to the surface rupture trace can also be seen from the PGA contour map. These evidences indicate that the PGA attenuates faster on the hanging-wall than on the footwall. In the study of near-source strong motion, seismic hazard assessment, scenario earthquake and seismic disaster prediction, the style-of-faulting must be considered in order that the attenuation model can reflect the characteristic of ground motion in various seismic environmental regions.

  4. Ethnic Inequalities and Educational Attainment in Taiwan

    ERIC Educational Resources Information Center

    Jao, Jui-Chang; McKeever, Matthew

    2006-01-01

    In this article, the authors examine educational stratification in Taiwan against the background of an ethnically based political economy. They investigate how educational attainment is related to ethnicity and other background factors, such as parental class and education, and if these relationships changed over time as Taiwan became a more

  5. Educating Students with Learning Disabilities in Taiwan

    ERIC Educational Resources Information Center

    Hsiao, Yun-Ju

    2011-01-01

    In East Asia, Taiwan is one of only a few countries that has a clear definition of learning disabilities (LD) as well as operational criteria for the identification of LD. In Taiwan, special education services for students with LD are mandated in the Special Education Act of 1984. According to the official statistics from the Taiwanese Special

  6. Applying environmental externalities to US Clean Coal Technologies for Taiwan

    SciTech Connect

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

    1992-09-01

    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.

  7. Applying environmental externalities to US Clean Coal Technologies for Taiwan

    SciTech Connect

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

    1992-01-01

    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.

  8. Plate motion

    SciTech Connect

    Gordon, R.G. )

    1991-01-01

    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.

  9. Peak ground motion predictions in India: an appraisal for rock sites

    NASA Astrophysics Data System (ADS)

    Nath, Sankar Kumar; Thingbaijam, Kiran Kumar Singh

    2011-04-01

    Proper selection and ranking of Ground Motion Prediction Equations (GMPEs) is critical for successful logic-tree implementation in probabilistic seismic hazard analysis. The present study explores this issue in predicting peak ground accelerations at the rock sites in India. Macroseismic intensity data complemented with limited strong ground-motion recordings are used for the purpose. The findings corroborate the possible conformity between the GMPEs developed for tectonically active shallow crust across the globe. On the other hand, the relevant GMPEs in the intraplate regions cluster into two different groups with the equations of lower ranks catering to higher ground motions. The earthquakes in the subduction zones have significant regional implications. However, affinity in the ground-motion attenuations between the major interface events ( M W > 7.4) in Andaman-Nicobar, Japan and Cascadia, respectively, is noted. This can be also observed for the intraslab events in the Hindukush and Taiwan respectively. Overall, we do not observe any significant advantage with the equations developed using the regional data. These findings are expected to be useful in probabilistic seismic hazard analysis across the study region.

  10. Analyzing Strain to Create a Regional Deformation Model of Northern Taiwan

    NASA Astrophysics Data System (ADS)

    VanderLeest, R. A.; Byrne, T. B.; Rau, R.

    2012-12-01

    A Global Positioning System (GPS) network is used to calculate the strain and rotations at the intersection of an arc-continent collision and retreating trench in northern Taiwan. The island of Taiwan forms as Eurasia collides obliquely with the Philippine Sea plate (PSP), resulting in substantial along-strike extension throughout the island. In northern Taiwan, the PSP is also subducting towards the northwest beneath Eurasia and the associated Ryukyu trench is rolling back, forming the Okinawa Trough. GPS velocities were collected over a ten-year period (1995-2005) from 125 stations (Rau et al., 2008) and were inverted to calculate the 2D velocity gradient tensors (Allmendinger, Cardozo and Fisher, 2012). In northwest Taiwan, although the GPS velocities relative to the Penghu Island are low, volumetric strains are negative and generally show N-S shortening. Areas of E-W shortening and extension also occur, however. The GPS data suggests a heterogeneous deformation field consistent with the occurrence of thrust (e.g., Hukou fault), strike slip, and oblique slip normal faults (e.g., Nankan and Schanciao) in northwest Taiwan. In northeast Taiwan, GPS velocities show an increase in magnitude from north to south as well as a change from NE trending velocities to SE trending velocities. Volumetric strains are generally positive, indicating extension, which is consistent with spreading in the Okinawa Trough as it propagates into the Ilan Plain. Spreading in the Okinawa Trough and rotation from NE to SE velocities reflect rollback of the Ryukyu Trench. Therefore, northern Taiwan exhibits N-S shortening in the west and rotation and extrusion in the east. This complex deformation pattern is similar to larger continental collision areas such as the extrusion and rotation of China associated with the northward motion of India and the Mediterranean-Middle Eastern extrusion and rotation associated with the northward motion of Arabia. Allmendinger, R.W., Cardozo, N., Fisher, D.M. (2012), Structural Geology Algorithms: Vectors and Tensors, Cambridge University Press, New York, N.Y. Cardozo, N., and Allmendinger, R. W. (2009), SSPX: A program to compute strain from displacement/velocity data, Computers & Geosciences, 35,1343-1357. Rau, R.-J., Ching, K.-E., Hu, J.-C., and Lee, J.-C. (2008), Crustal deformation and block kinematics in transition from collision to subduction: Global positioning system measurements in northern Taiwan, 1995-2005, J. Geophys. Res., 113, B09404, doi: 10.1029/2007JB005414.

  11. Estimation of foreign versus domestic contributions to Taiwan's air pollution

    NASA Astrophysics Data System (ADS)

    Chen, Jen-Ping; Yang, Cheng-En; Tsai, I.-Chun

    2015-07-01

    Based on the analysis of observational data obtained over a period of 17 years, this study developed a novel approach estimating long-term changes in the relative contributions of domestic and foreign sources to air pollution levels over the island of Taiwan. The contribution from foreign sources was calculated using data measured at selected coastal monitoring stations under specific meteorological conditions. The domestic contribution was derived by subtracting the foreign contribution from the overall concentration, which was calculated with island-wide monitoring station data averaged using Thiessen polygon area weighting. The trends of mean CO, NO, NO2 and SO2 concentrations in Taiwan were -2.1%, -3.3%, -1.4% and 0% yr-1; while the background concentrations varied by -1.0%, 5.7%, 3.8% and 6.6% yr-1, respectively. These figures suggest that the efforts of Taiwan in reducing air pollution are largely being negated by foreign contributions. Ozone showed a steady increase of 3.3% yr-1, and a portion of this was associated with a 1.0% yr-1 increase in background values. Local and background PM10 concentrations did not show significant long-term trends, but rather strong inter-annual variations associated with dust storm activity in East Asia. The domestic fractions of NO and NO2 respectively decreased from 90% and 85% in 1994 to less than 60% and 70% in 2010. In contrast, the domestic fraction of SO2 decreased from 82% in 1994 to 27% in 2010. The domestic fraction of CO exhibited no obvious trend due to concurrent decreases in local and background contributions. Background O3 values tended to drop across Taiwan due to the titration effect from domestic NO emissions, and the fraction of domestic O3 titration decreased from 50% in the mid-90s to 25% in 2010.

  12. Motion-based motion deblurring.

    PubMed

    Ben-Ezra, Moshe; Nayar, Shree K

    2004-06-01

    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

  13. Upper-ocean currents around Taiwan

    NASA Astrophysics Data System (ADS)

    Liang, W.-D.; Tang, T. Y.; Yang, Y. J.; Ko, M. T.; Chuang, W.-S.

    2003-03-01

    Current velocity, measured by Shipboard Acoustic Doppler Current Profiler (Sb-ADCP) during 1991-2000, was used to study the upper-ocean (<300 m) currents around Taiwan. The collected data were debugged, calibrated, grid, and averaged to compose a three-dimensional current-velocity distribution. The validity of the composite current velocity was supported by 12 sets of moored current-velocity time series. Qualitative agreement was obtained. The moored time series also indicated that the seasonal variation of current around Taiwan was generally weak except for the shallow-water regimes. The composite and moored currents revealed a branch of the Kuroshio that intruded steadily and persistently into the South China Sea. Part of the intruded Kuroshio flowed out of the South China Sea through the northern Luzon Strait and re-united with the main stream Kuroshio. The Kuroshio had two velocity maximum cores southeast of Taiwan, but gradually combined into one as the Kuroshio flowed north. The Kuroshio was deflected by the I-Lan Ridge east of Taiwan and the zonal-running shelf break northeast of Taiwan. At the shelf break, the Kuroshio split, with one branch intruding onto the shelf. West of the Luzon Strait, the Kuroshio intruded into the South China Sea. Some water flowed northward into the Taiwan Strait and re-joined the Kuroshio. Currents in the Taiwan Strait flowed primarily in a northward direction, except for the southward current near the coast of Mainland China. North of the Taiwan Strait, a branch of the northward flow followed the northern coast of Taiwan to join the Kuroshio. The composite current varied consistently from season to season. There was generally poor correlation between currents and local winds, especially in the deep-water regime. Remote forces were important in the currents around Taiwan.

  14. Magnetotelluric Imaging of an Arc-Continent Collision Beneath Central Taiwan

    NASA Astrophysics Data System (ADS)

    Bertrand, E. A.; Unsworth, M. J.; Chiang, C.; Chen, C.; Turkoglu, E.; Hsu, H.; Hill, G. J.

    2007-12-01

    Arc-continent collisions are a fundamental part of the plate tectonic cycle and play an important role in mountain building and the growth of continents. Studying this process in ancient orogens is often hindered by tectonic overprinting and poorly resolved synorogenic plate kinematics and tectonic settings. The Taiwan arc-continent collision between the Luzon arc and the Eurasian continental margin is one of the most active arc-continent collisions in the world. The current plate motions and surface geology are well understood, making Taiwan an ideal location for geophysical investigations of this important tectonic process. The Taiwan Integrated Geodynamical Research (TAIGER) project was initiated in 2004 to image the lithospheric structure beneath Taiwan. The project includes the acquisition of both active and passive seismic data plus detailed magnetotellurics (MT) surveys. MT is a passive geophysical technique which records time variations of natural electromagnetic fields at the surface of the Earth and can determine the subsurface resistivity. This parameter can be used to constrain lithospheric composition and strength. Over the fall of 2006 and spring of 2007, 82 long-period MT soundings were acquired in Taiwan. The fieldwork was accomplished by collaboration between the University of Alberta and National Central University of Taiwan. In fall 2007, collection of additional broadband MT will complement these data. The long-period data were processed using robust techniques and remotely referenced with a station on the PengHu islands (~100km from the nearest site) to reduce the influence of cultural noise. The conductive Taiwan strait separating PengHu from the mainland acts as an effective attenuator of cultural EM fields. Two closely spaced parallel transects across central Taiwan are formed by 46 of these stations with a nominal spacing of 5km. Dimensionality analysis of these transects using the McNeice-Jones tensor decomposition algorithm reveal local 3-D effects in some data. However, an overall regional 2-D strike direction is defined that is parallel to the coastline of Taiwan. Regularized 2-D inversions of these transects image conductive sedimentary rocks in the western foreland basin and an east dipping mid-crustal conductor beneath the fold-and-thrust belt. A sharp boundary is observed between the western sedimentary rocks and the more resistive slates and metamorphic rocks to the east in the Central Range. This boundary coincides with a conductor rising from the mid-crust that may be related to interconnected fluids.

  15. Slip history and dynamic implications of the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Ji, C.; Helmberger, D.V.; Wald, D.J.; Ma, K.-F.

    2003-01-01

    We investigate the rupture process of the 1999 Chi-Chi, Taiwan, earthquake using extensive near-source observations, including three-component velocity waveforms at 36 strong motion stations and 119 GPS measurements. A three-plane fault geometry derived from our previous inversion using only static data [Ji et al., 2001] is applied. The slip amplitude, rake angle, rupture initiation time, and risetime function are inverted simultaneously with a recently developed finite fault inverse method that combines a wavelet transform approach with a simulated annealing algorithm [Ji et al., 2002b]. The inversion results are validated by the forward prediction of an independent data set, the teleseismic P and SH ground velocities, with notable agreement. The results show that the total seismic moment release of this earthquake is 2.7 ?? 1020 N m and that most of the slip occured in a triangular-shaped asperity involving two fault segments, which is consistent with our previous static inversion. The rupture front propagates with an average rupture velocity of ???2.0 km s-1, and the average slip duration (risetime) is 7.2 s. Several interesting observations related to the temporal evolution of the Chi-Chi earthquake are also investigated, including (1) the strong effect of the sinuous fault plane of the Chelungpu fault on spatial and temporal variations in slip history, (2) the intersection of fault 1 and fault 2 not being a strong impediment to the rupture propagation, and (3 the observation that the peak slip velocity near the surface is, in general, higher than on the deeper portion of the fault plane, as predicted by dynamic modeling.

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

    ERIC Educational Resources Information Center

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

    2013-01-01

    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

  17. Taiwan's Responses to Globalisation: Internationalisation and Questing for World Class Universities

    ERIC Educational Resources Information Center

    Song, Mei-Mei; Tai, Hsiou-Hsia

    2007-01-01

    In recent years, Taiwan has demonstrated strong policy change to counteract the potential threats brought upon by globalisation such as the opening of the higher education market to a foreign trade partner and increasing competition from neighbouring countries. In light of these challenges, the Taiwanese government launched a series of…

  18. A model for the termination of the Ryukyu subduction zone against Taiwan: A junction of collision, subduction/separation, and subduction boundaries

    USGS Publications Warehouse

    Wu, F.T.; Liang, W.-T.; Lee, J.-C.; Benz, H.; Villasenor, A.

    2009-01-01

    The NW moving Philippine Sea plate (PSP) collides with the Eurasian plate (EUP) in the vicinity of Taiwan, and at the same time, it subducts toward the north along SW Ryukyu. The Ryukyu subduction zone terminates against eastern Taiwan. While the Ryukyu Trench is a linear bathym??trie low about 100 km east of Taiwan, closer to Taiwan, it cannot be clearly identified bathymetrically owing to the deformation related to the collision, making the location of the intersection of the Ryukyu with Taiwan difficult to decipher. We propose a model for this complex of boundaries on the basis of seismicity and 3-D velocity structures. In this model the intersection is placed at the latitude of about 23.7??N, placing the northern part of the Coastal Range on EUP. As PSP gets deeper along the subduction zone it collides with EUP on the Taiwan side only where they are in direct contact. Thus, the Eurasian plate on the Taiwan side is being pushed and compressed by the NW moving Philippine Sea plate, at increasing depth toward the north. Offshore of northeastern Taiwan the wedge-shaped EUP on top of the Ryukyu subducting plate is connected to the EUP on the Ryukyu side and coupled to the NW moving PSP by friction at the plate interface. The two sides of the EUP above the western end of the subduction zone are not subjected to the same forces, and a difference in motions can be expected. The deformation of Taiwan as revealed by continuous GPS measurements, geodetic movement along the east coast of Taiwan, and the formation of the Hoping Basin can be understood in terms of the proposed model. Copyright 2009 by the American Geophysical Union.

  19. Health risk assessment for residents exposed to atmospheric diesel exhaust particles in southern region of Taiwan

    NASA Astrophysics Data System (ADS)

    Chio, Chia-Pin; Liao, Chung-Min; Tsai, Ying-I.; Cheng, Man-Ting; Chou, Wei-Chun

    2014-03-01

    Evidence shows a strong association among air pollution, oxidative stress (OS), deoxyribonucleic acid (DNA) damage, and diseases. Recent studies indicated that the aging, human neurodegenerative diseases and cancers resulted from mitochondrial dysfunction and OS. The purpose of this study is to provide a probabilistic risk assessment model to quantify the atmospheric diesel exhaust particles (DEP)-induced pre-cancer biomarker response and cancer incidence risk for residents in south Taiwan. We conducted entirely monthly particulate matter sampling data at five sites in Kaohsiung of south Taiwan in the period 2002-2003. Three findings were found: (i) the DEP dose estimates and cancer risk quantification had heterogeneously spatiotemporal difference in south Taiwan, (ii) the pre-cancer DNA damage biomarker and cancer incidence estimates had a positive yet insignificant association, and (iii) all the estimates of cancer incidence in south Taiwan populations fell within and slight lower than the values from previous cancer epidemiological investigations. In this study, we successfully assessed the tumor incidence for residents posed by DEP exposure in south Taiwan compared with the epidemiological approach. Our approach provides a unique way for assessing human health risk for residences exposed to atmospheric DEP depending on specific combinations of local and regional conditions. Our work implicates the importance of incorporating both environmental and health risk impacts into models of air pollution exposure to guide adaptive mitigation strategies.

  20. Deposition of beryllium-7 in Hsinchu, Taiwan.

    PubMed

    Chao, J H; Chiu, Y J; Lee, H P; Lee, M C

    2012-02-01

    In the present study, factors that influence the distribution and variation of (7)Be in Hsinchu, Taiwan were elucidated. The (7)Be activity including the deposition flux and air concentration was continuously monitored and recorded throughout a 15-year period (1996-2010). To explain the observed variability in the (7)Be activity over time, air concentration and deposition flux of (7)Be were correlated to rainfall and solar activity. The monthly average deposition flux and air concentration of (7)Be were inversely related to solar activity with the 11-year cycle and were not strongly correlated to rainfall. The highest seasonal deposition flux of (7)Be occurred in March, which is commonly referred to as the spring maximum, due to air-mass mixing processes in the troposphere. The air concentration of (7)Be was seasonally variable and was significantly affected by monsoons. The lowest deposition flux and air concentration of (7)Be were observed in July and August due to the occurrence of southwest monsoons from low latitudes, which carry air masses with low concentrations of (7)Be. The deposition flux was enhanced by precipitation, which increased the deposition velocity, transferring more (7)Be from the troposphere to the ground. The fraction of dry to total deposition varied seasonally and was equal to 9.86%, on average. PMID:22056921

  1. The Evolution of Education and Training Strategies in Singapore, Taiwan and S. Korea: A Development Model of Skill Formation.

    ERIC Educational Resources Information Center

    Ashton, D.; Green, F.; Sung, J.; James, D.

    2002-01-01

    Examination of the government role in labor force development in Singapore, Taiwan, and South Korean identified strategies and structures enabling the "East Asian Miracle" of economic development, including strong states with high autonomy regarding capital and labor, super-ministries linking institutions, and strong central control of education

  2. Motion Aftereffects Transfer between Touch and Vision

    PubMed Central

    Konkle, Talia; Wang, Qi; Hayward, Vincent; Moore, Christopher I.

    2012-01-01

    Summary Current views on multisensory motion integration assume separate substrates where visual motion perceptually dominates tactile motion [1, 2]. However, recent neuroimaging findings demonstrate strong activation of visual motion processing areas by tactile stimuli [3–6], implying a potentially bidirectional relationship. To test the relationship between visual and tactile motion processing, we examined the transfer of motion aftereffects. In the well-known visual motion aftereffect, adapting to visual motion in one direction causes a subsequently presented stationary stimulus to be perceived as moving in the opposite direction [7, 8]. The existence of motion aftereffects in the tactile domain was debated [9–11], though robust tactile motion aftereffects have recently been demonstrated [12, 13]. By using a motion adaptation paradigm, we found that repeated exposure to visual motion in a given direction produced a tactile motion aftereffect, the illusion of motion in the opponent direction across the finger pad. We also observed that repeated exposure to tactile motion induces a visual motion aftereffect, biasing the perceived direction of counterphase gratings. These crossmodal aftereffects, operating both from vision to touch and from touch to vision, present strong behavioral evidence that the processing of visual and tactile motion rely on shared representations that dynamically impact modality-specific perception. PMID:19361996

  3. Taiwan: Facing the future with nuclear power

    SciTech Connect

    1994-07-01

    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.

  4. Opportunity, Choice, and Burglary Victimization in Taiwan.

    PubMed

    Kuo, Shih-Ya

    2015-07-01

    This study examined burglary victimization in Taiwan with an application of the structure-choice model that included four theoretical dimensions: proximity to crime, exposure to crime, target attractiveness, and guardianship. Drawing on the 2000 Taiwan Areas Criminal Victimization Survey, the results of the current study showed a moderate effect of the opportunity model on Taiwan's burglary victimization. Also, this study found both consistent and conflicting findings in the current data. The null effect of motorcycles (including scooters) that represented the concept of target attractiveness in relation to burglary risk reflected a difference in population density and transportation needs between Taiwan and the West. Clearly, the role of social context needs to be understood when studies apply a Western model to a non-Western context. PMID:24459209

  5. Instrumental intensity distribution for the Hector Mine, California, and the Chi-Chi, Taiwan, earthquakes: Comparison of two methods

    USGS Publications Warehouse

    Sokolov, V.; Wald, D.J.

    2002-01-01

    We compare two methods of seismic-intensity estimation from ground-motion records for the two recent strong earthquakes: the 1999 (M 7.1) Hector Mine, California, and the 1999 (M 7.6) Chi-Chi, Taiwan. The first technique utilizes the peak ground acceleration (PGA) and velocity (PGV), and it is used for rapid generation of the instrumental intensity map in California. The other method is based on the revised relationships between intensity and Fourier amplitude spectrum (FAS). The results of using the methods are compared with independently observed data and between the estimations from the records. For the case of the Hector Mine earthquake, the calculated intensities in general agree with the observed values. For the case of the Chi-Chi earthquake, the areas of maximum calculated intensity correspond to the areas of the greatest damage and highest number of fatalities. However, the FAS method producees higher-intensity values than those of the peak amplitude method. The specific features of ground-motion excitation during the large, shallow, thrust earthquake may be considered a reason for the discrepancy. The use of PGA and PGV is simple; however, the use of FAS provides a natural consideration of site amplification by means of generalized or site-specific spectral ratios. Because the calculation of seismic-intensity maps requires rapid processing of data from a large network, it is very practical to generate a "first-order" map from the recorded peak motions. Then, a "second-order" map may be compiled using an amplitude-spectra method on the basis of available records and numerical modeling of the site-dependent spectra for the regions of sparse station spacing.

  6. Onychomycosis Associated with Exophiala oligosperma in Taiwan.

    PubMed

    Wen, Yu-Min; Rajendran, Ranjith Kumar; Lin, Ying-Fang; Kirschner, Roland; Hu, Sindy

    2016-02-01

    A fungus was isolated from a nail of a 54-year-old female patient with onychomycosis in Taiwan. Based on ITS rDNA as well as beta tubulin gene sequences and microscopic analyses, this fungus was identified as Exophiala oligosperma. This is the first record of E. oligosperma in Taiwan. Negative keratin azure test indicates that keratin degradation is not involved in cases of E. oligosperma associated with skin and nail diseases. PMID:26378025

  7. H/V spectral ratios of the continental margin sediments offshore southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, Jing-Yi; Cheng, Win-Bin; Chin, Shao-Jinn; Hsu, Shu-Kun

    2015-04-01

    For decades, it has been mentioned that submarine slope failures are spatially linked to the presence of gas hydrates/gas-charged sediments. When triggered by earthquakes, over steepen and instable sediments may prompt breakouts of the slopes containing gas hydrates and cause submarine landslides and tsunamis. Widely distributed BSRs have been observed in the area offshore of southwestern Taiwan where the active accretionary complex meets with the passive China continental margin. In the region, large or small scale landslides were also reported based on seismic interpretations. In order to clarify the link between earthquake, landslide and the presence of gas hydrate, we evaluate the response of seafloor sediments in regard to passive dynamic loads. Horizontal-to-vertical (H/V) spectral ratios are used to characterize the local sediment response. Ambient noise as well as distant earthquake is used as generators of the passive dynamic loads. Based on this study, we aim to characterize the site in terms of its physical properties and the local site effect produced by shallow marine sediments. Estimating H/V spectral ratios of data recorded by the short period OBSs (Ocean Bottom Seismometer) deployed in the active and paqssive margin offshore southwestern Taiwan show similar spectral characteristics and provide a general understanding of the preferential vibration modes of sediment systems. The results show that the maximal H/V ratios appeared in the range of 5-10 Hz, where the horizontal amplitudes increased by an order of magnitude relative to the vertical amplitude. The stations located in the northwestern part of study area were characterized by another relatively small peak at proximately 2 Hz, which may indicates the presence of a discontinuity of sediments. For most stations, the H/V ratios estimated based on the earthquakes (i.e. strong input signal) and noise (background, micro-seismic noise) records were characterized by different pattern. No distinct peak is observed for the H/V pattern calculated during earthquakes. This phenomenon may suggest that no clear sedimentary boundary exist when a stronger motion applies. We found that the resonance frequency for the relative rigid material, such as mud diapir, is relatively higher, about 9 Hz. Moreover, their main resonance frequency is not affected by occurrence of earthquakes. On the general sedimentary layer and marine landslide, the resonance frequency shows relatively low value, about 7~8 Hz. When the site is affected by earthquakes, the main frequency becomes unclear. Finally, when a site is characterized by very thick sedimentary layer, the frequency of about 5 Hz is the lowest observed in the experiment.

  8. Early Austronesians: into and out of Taiwan.

    PubMed

    Ko, Albert Min-Shan; Chen, Chung-Yu; Fu, Qiaomei; Delfin, Frederick; Li, Mingkun; Chiu, Hung-Lin; Stoneking, Mark; Ko, Ying-Chin

    2014-03-01

    A Taiwan origin for the expansion of the Austronesian languages and their speakers is well supported by linguistic and archaeological evidence. However, human genetic evidence is more controversial. Until now, there had been no ancient skeletal evidence of a potential Austronesian-speaking ancestor prior to the Taiwan Neolithic ~6,000 years ago, and genetic studies have largely ignored the role of genetic diversity within Taiwan as well as the origins of Formosans. We address these issues via analysis of a complete mitochondrial DNA genome sequence of an ~8,000-year-old skeleton from Liang Island (located between China and Taiwan) and 550 mtDNA genome sequences from 8 aboriginal (highland) Formosan and 4 other Taiwanese groups. We show that the Liangdao Man mtDNA sequence is closest to Formosans, provides a link to southern China, and has the most ancestral haplogroup E sequence found among extant Austronesian speakers. Bayesian phylogenetic analysis allows us to reconstruct a history of early Austronesians arriving in Taiwan in the north ~6,000 years ago, spreading rapidly to the south, and leaving Taiwan ~4,000 years ago to spread throughout Island Southeast Asia, Madagascar, and Oceania. PMID:24607387

  9. Circular motion

    NASA Astrophysics Data System (ADS)

    Newton, Isaac; Henry, Richard Conn

    2000-07-01

    An extraordinarily simple and transparent derivation of the formula for the acceleration that occurs in uniform circular motion is presented, and is advocated for use in high school and college freshman physics textbooks.

  10. Circular Motion.

    ERIC Educational Resources Information Center

    Lee, Paul D.

    1995-01-01

    Provides a period-long activity using battery powered cars rolling in a circular motion on a tile floor. Students measure the time and distance as the car moves to derive the equation for centripetal acceleration. (MVL)

  11. 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)

    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

    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.

  12. On strong anomalous diffusion

    NASA Astrophysics Data System (ADS)

    Castiglione, P.; Mazzino, A.; Muratore-Ginanneschi, P.; Vulpiani, A.

    1999-10-01

    Superdiffusive behavior, i.e., < x2( t)>? t2 ?, with ?>1/2, is in general not completely characterized by a unique exponent. We study some systems exhibiting strong anomalous diffusion, i.e., ? tq?( q) where ?(2)>1/2 and q?( q) is not a linear function of q. This feature is different from the weak superdiffusive regime, i.e., ?( q)=const>1/2, occurring in random shear flows. Strong anomalous diffusion can be generated by nontrivial chaotic dynamics, e.g., Lagrangian motion in 2D time-dependent incompressible velocity fields, 2D symplectic maps and 1D intermittent maps. Typically the function q?( q) is piecewise linear. This is due to two mechanisms: a weak anomalous diffusion for the typical events and a ballistic transport for the rare excursions. In order to have strong anomalous diffusion one needs a violation of the hypothesis of the central limit theorem, this happens only in a very narrow region of the control parameters space. In the presence of strong anomalous diffusion one does not have a unique exponent and therefore one has the failure of the usual scaling P( x, t)= t- ?F( x/ t?) of the probability density. This implies that the effective equation at large scale and long time for P( x, t), obeys neither the usual Fick equation nor other linear equations involving temporal and/or spatial fractional derivatives.

  13. SAR motion compensation using autofocus

    NASA Astrophysics Data System (ADS)

    Blacknell, D.; Quegan, S.

    1991-02-01

    Conventional motion compensation schemes correct for unwanted synthetic aperture radar (SAR) platform motions using information from an inertial measurement unit (IMU). Autofocus techniques, which focus SAR images, produce an 'autofocus parameter' which is related to the platform motion. In this paper, strong evidence is presented to support the assumption that the contrast optimization autofocus algorithm behaves as a least-squares quadratic fitting to the SAR platform trajectory. Using this assumption, the relationship between the autofocus parameter and across-track accelerations of the SAR platform is derived. This allows the SAR platform motion to be estimated from the autofocus parameter measurements and incorporated in a motion compensation instead of IMU measurements. Three implementations of motion compensation using autofocus are compared and the achievable image quality is quantified.

  14. Local Ablation for Hepatocellular Carcinoma in Taiwan

    PubMed Central

    Lin, Shi-Ming

    2013-01-01

    Hepatocellular carcinoma (HCC) is the second commonest cancer in Taiwan. The national surveillance program can detect HCC in its early stages, and various curative modalities (including surgical resection, orthotopic liver transplantation, and local ablation) are employed for the treatment of small HCC. Local ablation therapies are currently advocated for early-stage HCC that is unresectable because of co-morbidities, the need to preserve liver function, or refusal of resection. Among the various local ablation therapies, the most commonly used modalities include percutaneous ethanol injection and radiofrequency ablation (RFA); percutaneous acetic acid injection and microwave ablation are used less often. RFA is more commonly employed than other local ablative modalities in Taiwan because the technique is highly effective, minimally invasive, and requires fewer sessions. RFA is therefore advocated in Taiwan as the first-line curative therapy for unresectable HCC or even for resectable HCC. However, current RFA procedures are less effective against tumors that are in high-risk or difficult-to-ablate locations, are poorly visualized on ultrasonography (US), or are large. Recent advancements in RFA in Taiwan can resolve these issues by the creation of artificial ascites or pleural effusion, application of real-time virtual US assistance, use of combination therapy before RFA, or use of switching RF controllers with multiple electrodes. This review article provides updates on the clinical outcomes and advances in local ablative modalities (mostly RFA) for HCC in Taiwan. PMID:24159599

  15. What University Governance Can Taiwan Learn from the United States?

    ERIC Educational Resources Information Center

    Lee, Lung-Sheng; Land, Ming H.

    2010-01-01

    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…

  16. Super Typhoon Halong off Taiwan

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On July 14, 2002, Super Typhoon Halong was east of Taiwan (left edge) in the western Pacific Ocean. At the time this image was taken the storm was a Category 4 hurricane, with maximum sustained winds of 115 knots (132 miles per hour), but as recently as July 12, winds were at 135 knots (155 miles per hour). Halong has moved northwards and pounded Okinawa, Japan, with heavy rain and high winds, just days after tropical Storm Chataan hit the country, creating flooding and killing several people. The storm is expected to be a continuing threat on Monday and Tuesday. This image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on July 14, 2002. Please note that the high-resolution scene provided here is 500 meters per pixel. For a copy of the scene at the sensor's fullest resolution, visit the MODIS Rapid Response Image Gallery. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  17. GEOPHYSICS. Layered deformation in the Taiwan orogen.

    PubMed

    Huang, T-Y; Gung, Y; Kuo, B-Y; Chiao, L-Y; Chen, Y-N

    2015-08-14

    The underthrusting of continental crust during mountain building is an issue of debate for orogens at convergent continental margins. We report three-dimensional seismic anisotropic tomography of Taiwan that shows a nearly 90 rotation of anisotropic fabrics across a 10- to 20-kilometer depth, consistent with the presence of two layers of deformation. The upper crust is dominated by collision-related compressional deformation, whereas the lower crust of Taiwan, mostly the crust of the subducted Eurasian plate, is dominated by convergence-parallel shear deformation. We interpret this lower crustal shearing as driven by the continuous sinking of the Eurasian mantle lithosphere when the surface of the subducted plate is coupled with the orogen. The two-layer deformation clearly defines the role of subduction in the formation of the Taiwan mountain belt. PMID:26273051

  18. Brownian Motion.

    ERIC Educational Resources Information Center

    Lavenda, Bernard H.

    1985-01-01

    Explains the phenomenon of Brownian motion, which serves as a mathematical model for random processes. Topics addressed include kinetic theory, Einstein's theory, particle displacement, and others. Points out that observations of the random course of a particle suspended in fluid led to the first accurate measurement of atomic mass. (DH)

  19. [The Taiwan Nurses Association and professional diplomacy].

    PubMed

    Lee, Sheuan

    2014-08-01

    The Taiwan Nurses Association (TWNA) is publishing a special centenary issue to commemorate the 100th anniversary of the association in 2014. For this issue, TWNA invited the author to write a review article that addresses the involvement of the TWNA in professional diplomacy and international exchange over the past century. The author reviews the history of both TWNA and the International Council of Nurses and introduces the contributions of the association in the field of professional diplomacy and the positive contributions of many Taiwan nursing leaders to global healthcare and society. The purpose of the paper is to convey the traditions and experiences of TWNA forward to the next generation. PMID:25125155

  20. Gas Composition of Cored Sediments from Gas Hydrate Potential Area Offshore SW Taiwan

    NASA Astrophysics Data System (ADS)

    Yang, T. F.; Chuang, P.; Chen, H.; Chen, N.; Lin, S.; Wang, Y.; Chung, S.

    2010-12-01

    The widely distributed BSRs imply the existence of potential gas hydrates in offshore southwestern Taiwan. To better constrain the gas sources in this area, in total 22 cores have been collected from different tectonic environments in offshore SW Taiwan during the r/v Marion Dufresne 178 cruise, including 17 giant piston cores, 4 CASQ box cores, and 1 gravity core. The results show that the major gas is methane with very few ethane and carbon dioxide. It indicates they are mostly biogenic source in origin. However, some gas samples from active margin do also exhibit heavier carbon 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 thermogenic gas source in this region. Sulfate-methane interface (SMI) can be identified from the methane vs. sulfate profiles and the depth of SMI, which usually is considered to be related to the methane flux in one area. Although 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.

  1. Temporal variations of volume transport through the Taiwan Strait, as identified by three-year measurements

    NASA Astrophysics Data System (ADS)

    Chen, Hsien-Wen; Liu, Cho-Teng; Matsuno, Takeshi; Ichikawa, Kaoru; Fukudome, Ken-ichi; Yang, Yih; Doong, Dong-Jiing; Tsai, Wei-Ling

    2016-02-01

    The water characteristics of the East China Sea depend on influxes from river run-off, the Kuroshio, and the Taiwan Strait. A three-year observation using an acoustic Doppler current profiler (ADCP) operated on a ferry provides the first nearly continuous data set concerning the seasonal flow pattern and the volume transport from the Taiwan Strait to the East China Sea. The observed volume transport shows strong seasonality and linkage to the along-strait wind stress. An empirical regression formula between the volume transport and wind was derived to fill the gaps of observation so as to obtain a continuous data set. Based on this unique data set, the three-year mean of monthly volume transport is northeastward throughout the year, large (nearly 3 Sv) in summer and low (nearly zero) in winter. The China Coastal Current flows southward in winter, while the northward-flowing Taiwan Strait Current may reverse direction during severe northeasterly winds in the winter or under typhoons. The sea level difference across Taiwan Strait is closely correlated to the transport through the strait, and their relation is found seasonally nearly stable.

  2. Phylogenetic and molecular dating analysis of Taiwan Blue Pheasant (Lophura swinhoii).

    PubMed

    Jiang, Lichun; Wang, Gaochao; Peng, Rui; Peng, Quekun; Zou, Fangdong

    2014-04-10

    The Swinhoe's Pheasant (Lophura swinhoii) is an endemic and most endangered species to Taiwan, China. It belongs to the genus Lophura, family Phasianidae. To further investigate the evolutionary history of L. swinhoii, we determined its complete mitochondrial genome and reconstructed a single, robust phylogenetic tree. Our results showed that L. swinhoii is clustered with Lophura nycthemera and forms a sister group of Lophura ignita. The genus Lophura is strongly supported as the sister taxon of the genus Crossoptilon. The molecular clock analysis showed that the genetic divergence of L. swinhoii occurred in 2.71 (1.31-4.22) Mya. The most common ancestor of L. swinhoii might have migrated from mainland of South East Asia to Taiwan Island by the land bridge at 2.71 Mya ago. Taiwan Island is separated from the mainland by the sea (Taiwan Strait) and formed a separate island at around 2.5 Mya because of the transgression and regression. Therefore, geographical isolation and climate change may accelerate the evolution of L. swinhoii. In this study, we propose a biogeographic hypothesis for speciation of the L. swinhoii based on known events of the geographic and geological history of South East Asia and southeast China, which would benefit the understanding of evolutionary history of L. swinhoii as well as other galliform birds. PMID:24508942

  3. Enhancing the Interactive Relationship between Lifelong Learning and Social Changes to Carry Out a Learning Society in Taiwan

    ERIC Educational Resources Information Center

    Wang, Cheng-Yen

    2008-01-01

    A national white paper was published in 1998 with 14 action plans to be the blueprints for developing lifelong learning. These were based on continuously strong recommendations of academics and lobbying groups in Taiwan. Many national policies were formulated and implemented based on the white paper and its action plans, and this has paved a way…

  4. A seismicity burst following the 2010 M6.4 Jiashian earthquake - implications for short-term seismic hazards in southern Taiwan

    NASA Astrophysics Data System (ADS)

    Chan, C.; Wu, Y.

    2012-12-01

    Following the 4 March 2010 Mw 6.4 Jiashian earthquake the seismicity rate in southern Taiwan was determined to be significantly higher than before the quake and aroused seismic hazard awareness. In this work, seismic hazards were investigated in terms of earthquake activity, the Coulomb stress change, the rate-and-state friction model, and short-term seismic hazard assessments. The significantly higher seismicity rate that followed the 2010 Jiashian earthquake was found to mainly be attributed to aftershock decay, in terms of the modified Omori formula. The results suggest that aftershock duration may continue until the end of 2012. The spatial migration of seismicity was modeled using the Coulomb stress changes of large earthquakes. Most of the consequent events were distributed in the vicinity of large earthquakes. The observations corresponded to a remarkable stress increase within the same area. Additionally, large events were located within regions with stress increases promoted by previous earthquakes. The results confirm interactive relationships between large events. By considering time-dependency, the seismicity rate evolution was estimated using the rate-and-state friction model. The results indicated that a high seismic rate will persist at least until the end of 2012. Short-term probabilistic seismic hazard assessments were also applied in terms of the probability of strong ground motion. Using this application, a sudden jump in seismic hazards in southern Taiwan was accompanied by each large earthquake. At the end of 2012 it is expected that hazards will return to a background level. Our results may be valuable in the future to decision-makers and public officials engaged in seismic hazard mitigation.

  5. Taiwan's underwater cultural heritage documentation management

    NASA Astrophysics Data System (ADS)

    Tung, Y.-Y.

    2015-09-01

    Taiwan is an important trading and maritime channels for many countries since ancient time. Numerous relics lie underwater due to weather, wars, and other factors. In the year of 2006, Bureau of Cultural Heritage (BOCH) entrusted the Underwater Archaeological Team of Academia Sinica to execute the underwater archaeological investigation projects. Currently, we verified 78 underwater targets, with 78 site of those had been recognized as shipwrecks sites. Up to date, there is a collection of 638 underwater objects from different underwater archaeological sites. Those artefacts are distributed to different institutions and museums. As very diverse management methods/systems are applied for every individual institution, underwater cultural heritage data such as survey, excavation report, research, etc. are poorly organized and disseminated for use. For better communication regarding to Taiwan's underwater cultural heritage in every level, a universal format of documentation should be established. By comparing the existing checklist used in Taiwan with guidelines that are followed in other countries, a more intact and appropriate underwater cultural heritage condition documentation system can be established and adapted in Taiwan.

  6. The Quality of Life in Taiwan

    ERIC Educational Resources Information Center

    Yao, Grace; Cheng, Yen-Pi; Cheng, Chiao-Pi

    2009-01-01

    The AsiaBarometer survey of 1,006 respondents shows that in Taiwan, people have access to modern utilities and digital media, signs of materialistic achievement, and yet are more concerned with physical security and financial safety than with personal growth. Regardless of their demographic backgrounds and value priorities, the Taiwanese, like

  7. Gestalt Group Dreamwork Demonstrations in Taiwan

    ERIC Educational Resources Information Center

    Coven, Arnold B.

    2004-01-01

    The application of Gestalt dreamwork was explored with counselor education students and professors at two Taiwan universities. The literature indicates Asians are reluctant to disclose personal matters or to display emotions. Contrary to expectations, the Taiwanese participants readily enacted roles, were personally open, and expressed intense

  8. No Aboriginal Students left Behind in Taiwan

    ERIC Educational Resources Information Center

    Wu, Sue-Jen; Hartzler-Miller, Cynthia

    2005-01-01

    The project is motivated by Taiwan's huge gap of educational levels between the aborigines and the Hans. The low achievement of aboriginal students lies in factors related to problems in finance, health, and cultural difference, which contribute to their sense of self-deprecation. The purpose of the project is to provide early intervention and

  9. Sustainability of Higher Education Institutions in Taiwan

    ERIC Educational Resources Information Center

    Su, H. Jenny; Chang, Tzu-chau

    2010-01-01

    Purpose: The purpose of this paper is to provide the rationale and context for recent national policy and funded initiatives to support sustainability developments within higher education in Taiwan, including practical and educational aspects. Concrete examples and specific outcomes are reviewed, to produce a profile across the higher education

  10. Faculty Development Practices in Taiwan Higher Education.

    ERIC Educational Resources Information Center

    Flack, Bruce C.

    The universities in Taiwan, in carrying out their missions of research, teaching, and public service, have made significant advances in improving the quality of their faculties. Both public and private universities have undertaken a variety of faculty development activities to help their faculties grow professionally and to remain vital. The major…

  11. Ethos Derived from Karaoke Performance in Taiwan.

    ERIC Educational Resources Information Center

    Ma, Ringo

    Karaoke (singing along to music videos) has swept Taiwan with such force that many people go to singing schools to improve their singing. Three cases in this paper demonstrate how the ethos, or credibility, of the singer is a combination of initial and derived ethos. Who the singer is tends to determine how much attention he or she receives…

  12. An Inquiry into Teacher Concerns in Taiwan.

    ERIC Educational Resources Information Center

    Chen, Yih-fen; Reeves, Carolyn

    This study identified concerns of teachers in Taiwan and contrasted concerns of these teachers with the 56 concerns which comprise the Teacher Concerns Checklist (TCC), Form B, developed in the United States. A total of 294 teachers (155 preservice teachers and 139 inservice teachers) completed a Chinese version of the Survey of Teacher Concerns.

  13. Women's Aspirations for Graduate Education in Taiwan

    ERIC Educational Resources Information Center

    Lin, Meng-Jie

    2011-01-01

    This study investigates female undergraduates' aspirations for master's and doctoral degree programs in Taiwan's universalized and stratified higher education system. It considers the potential effects of economic prospects, parental attitudes, and gender values. First, graduate education is perceived as a means to enhance one's comparative

  14. Improving the Textbook Adoption Process in Taiwan

    ERIC Educational Resources Information Center

    Ho, Hsuan-fu; Hsu, Ying-tsun

    2011-01-01

    Textbooks were centrally selected in Taiwan until 1996 when the government commissioned its Textbook Liberalization Reform. Although this policy received complements from scholars and the general public, it encounters many unexpected problems in its implementation. The aims of this research are thus to identify the major criteria used by…

  15. Internet Addiction among High Schoolers in Taiwan.

    ERIC Educational Resources Information Center

    Lin, Sunny S. J.; Tsai, Chin-Chung

    The purpose of this study was to develop a reliable and valid measurement for the identification of Internet addictive high school students. There were 615 subjects selected by a stratified sampling from the population of Taiwanese 10th to 12th graders. The final version of the Internet Addiction Scale for Taiwan High Schoolers (IAST) contained 20

  16. The Workforce Education and Development in Taiwan

    ERIC Educational Resources Information Center

    Lee, Lung-Sheng

    2012-01-01

    Workforce education and development (WED) can be broadly defined as those formal, informal and nonformal activities that prepare people for work. In Taiwan, it includes technological and vocational education (TVE), human resource development (HRD), public vocational training and adult education. In order to promote information exchanges and…

  17. Collective Beam Instabilities in the Taiwan Light Source

    SciTech Connect

    Chao, Alex W.

    2002-08-12

    The storage ring at Taiwan Light Source has experienced a strong collective instability since 1994. Various cures have been attempted to suppress this instability, including the use of damping antenna, tunable rf plungers, different filling patterns, and rf gap voltage modulation. So far these cures have improved the beam intensity, but the operation remains to be limited by the instability. The dominant phenomenon is the longitudinal coupled bunch instability. The major source of longitudinal impedance is from rf cavities of Doris type. The high-order modes of the cavity were numerically analyzed using a 3-D code GdfidL. The correlation of the observed phenomenon in user operation with high-order modes of rf cavities will be presented. Results of various attempts to suppress beam instabilities will be summarized. Proposed cures for beam instabilities will be discussed.

  18. Aging scaled Brownian motion.

    PubMed

    Safdari, Hadiseh; Chechkin, Aleksei V; Jafari, Gholamreza R; Metzler, Ralf

    2015-04-01

    Scaled Brownian motion (SBM) is widely used to model anomalous diffusion of passive tracers in complex and biological systems. It is a highly nonstationary process governed by the Langevin equation for Brownian motion, however, with a power-law time dependence of the noise strength. Here we study the aging properties of SBM for both unconfined and confined motion. Specifically, we derive the ensemble and time averaged mean squared displacements and analyze their behavior in the regimes of weak, intermediate, and strong aging. A very rich behavior is revealed for confined aging SBM depending on different aging times and whether the process is sub- or superdiffusive. We demonstrate that the information on the aging factorizes with respect to the lag time and exhibits a functional form that is identical to the aging behavior of scale-free continuous time random walk processes. While SBM exhibits a disparity between ensemble and time averaged observables and is thus weakly nonergodic, strong aging is shown to effect a convergence of the ensemble and time averaged mean squared displacement. Finally, we derive the density of first passage times in the semi-infinite domain that features a crossover defined by the aging time. PMID:25974439

  19. Seismogenic strain across the transition from fore-arc slivering to collision in southern Taiwan

    NASA Astrophysics Data System (ADS)

    Lewis, Jonathan C.; O'Hara, Daniel J.; Rau, Ruey-Juin

    2015-06-01

    Tectonic slivers have profound implications on the mechanical behavior of fore arcs and subduction zones. Southern Taiwan is characterized by precollision fore-arc slivering that likely exerts important controls on the evolution of collision. Inversion of focal mechanism solutions for seismogenic strain reveals spatially partitioned plate motion south of Taiwan, with dip-slip faulting nearer the Manila trench and strike-slip faulting nearer the Luzon arc. To the north these kinematics are less clearly segregated, and both types of faults appear to occur in the same volume of crust. Further north deformation is dominated by oblique slip on potentially reactivated steep reverse faults in the collision zone. Existing work on the active fault zones in Taiwan suggests that the subduction-to-collision transition is marked by a releasing step between the strike-slip fault that bounds the fore-arc sliver and the oblique thrusts of the collision zone. This configuration may help to explain the lack of fore-arc basement and cover exposed in the suture zone marked by the Longitudinal Valley.

  20. Precision of surface wave displacement seismograms from the 2011 MW 9.0 Tohoku, Japan earthquake recorded by a dense high-rate GPS network in Taiwan

    NASA Astrophysics Data System (ADS)

    Hung, H.; Rau, R.

    2011-12-01

    High-rate GPS positioning has been demonstrated by its capability in measuring seismic waves of large amplitudes over a wide range of temporal and spatial scales. In Taiwan, over 200 continuous GPS (CGPS) stations with high-rate (1-Hz) records are operated normally in real-time, yet infrequent exploit for scientific research. Surface waves of the 2011 MW 9.0 Tohoku, Japan Earthquake were well recorded by high-rate GPS stations and broadband seismometers in Taiwan out to epicentral distances of 2400 - 2800 km. We investigate the potentiality of high-rate GPS displacements for seismology by the GPS position precision analysis and the comparisons of the motions of co-located broadband seismometers data sets after velocity integral process. 1-Hz observations of 183 CGPS stations in Taiwan and neighboring islands were processed by precise point positioning (PPP) to estimate epoch-by-epoch positions for Tohoku earthquake. Modified Sidereal Filtering (MSF) has been used to mitigate the near-daily periodical variations of high-rate position time series influenced by multipath effect, and the band-pass filter was used to remove noises in inconsequentially marginal frequency. The results show the precision are improved after MSF from 8.7 mm to 5.9 mm in the horizontal and from 28.6 mm to 21.4 mm in the vertical displacements. High consistency between the high-rate GPS and seismometer results of surface waves from Tohoku earthquake are achieved, and the cross correlation coefficient are enhanced by the band-pass filter (0.008 - 0.1 Hz) from 0.85 to 0.95 in the horizontal and from 0.58 to 0.85 in the vertical displacements. Only ~2/3 (115/183) CGPS displacements are estimated efficiently for healthy derived surface waves, and the poor records are strongly related to the poor sky view environments (mountainous and urban areas) and some abnormal offsets in displacements are attributed to the cycle slip effect. In the following study, we will explore the characteristics of waveform and wave-propagation from these high-rate GPS surface waves.

  1. Gravity anomaly caused by the mud diapirs off southwest Taiwan and its implication to the development of the submarine canyons

    NASA Astrophysics Data System (ADS)

    Doo, Wen-Bin; Hsu, Shu-Kun; Huang, Yuan-Ping; Chen, Song-Chuen

    2015-04-01

    Both the overpressure and buoyancy effects are generally used to account for the formation of submarine mud volcanoes (MVs) and mud diapirs (MDs). According to the distribution of the MDs and structural features, the compressive tectonic stress should play an important role on the formation of the MDs in the offshore area of southwest Taiwan. Onland Taiwan, the Tainan and Chungchou anticlinal structures (associated with MD) reveal positive gravity anomalies. The MDs in offshore southwest Taiwan are considered to be more active than onshore diapirs. However, the gravity nature of the submarine MDs is not clear. In 2012 and 2013, we have collected shipboard gravity data using R/V Ocean Researcher I in the offshore area of southwest Taiwan. By removing the gravimetric effect from the water-sediment interface and the regional gravity effect along the profiles, we find that the gravity contrasts of the MDs with respect to the surrounding strata are generally positive. The results seem conflict with the buoyant force that triggers the upward motion of the MDs. The positive density contrasts of the MDs can further indicate the relatively rigid rocks which influence the development of the Kaoping and the Fangliao Canyon.

  2. Cancer incidence in the vicinity of nuclear power plants in Taiwan: a population-based study.

    PubMed

    Wang, Shiow-Ing; Yaung, Chih-Liang; Lee, Long-Teng; Chiou, Shang-Jyh

    2016-01-01

    Numerous antinuclear demonstrations reveal that the public is anxious about the potential health effects caused by nuclear power plants. The purpose of this study is to address the question "Is there a higher cancer incidence rate in the vicinity of nuclear power plants in Taiwan?" The Taiwan Cancer Registry database from 1979 to 2003 was used to compare the standardized incidence rate of the top four cancers with strong evidence for radiation risks between the "plant-vicinity" with those "non-plant-vicinity" groups. All cancer sites, five-leading cancers in Taiwan, and gender-specific cancers were also studied. We also adopted different observation time to compare the incidence rate of cancers between two groups to explore the impact of the observation period. The incidences of leukemia, thyroid, lung, and breast cancer were not significantly different between two groups, but cervix uteri cancer showed higher incidence rates in the plant-vicinity group. The incidence of cervical cancer was not consistently associated with the duration of plant operation, according to a multiyear period comparison. Although there was higher incidence in cervix cancer in the plant-vicinity group, our findings did not provide the crucial evidence that nuclear power plants were the causal factor for some cancers with strong evidence for radiation risks. PMID:26330316

  3. Motion Simulator

    NASA Technical Reports Server (NTRS)

    1993-01-01

    MOOG, Inc. supplies hydraulic actuators for the Space Shuttle. When MOOG learned NASA was interested in electric actuators for possible future use, the company designed them with assistance from Marshall Space Flight Center. They also decided to pursue the system's commercial potential. This led to partnership with InterActive Simulation, Inc. for production of cabin flight simulators for museums, expositions, etc. The resulting products, the Magic Motion Simulator 30 Series, are the first electric powered simulators. Movements are computer-guided, including free fall to heighten the sense of moving through space. A projection system provides visual effects, and the 11 speakers of a digital laser based sound system add to the realism. The electric actuators are easier to install, have lower operating costs, noise, heat and staff requirements. The U.S. Space & Rocket Center and several other organizations have purchased the simulators.

  4. Transmission capability of asymmetric digital subscriber lines in Taiwan

    NASA Astrophysics Data System (ADS)

    Wei, Shyue-Win; Leu, Shyue-Tzong; Wei, Che-Ho

    1995-04-01

    The transmission capacity of discrete multitone (DMT) modulation system for Taiwan's subscriber loops is evaluated in this study. Based on the characteristics of Taiwan's local loops, the transmission capacity is estimated to be 1.544 Mb/s and 6 Mb/s in Taiwan. Simulation results also show how many percents of users in Taiwan may have 1.544 Mb/s or 6 Mb/s of asymmetric digital subscriber lines (ADSL) services. Self far-end crosstalk (FEXT) and additive white Gaussian noise (AWGN) are considered to be the dominant noise sources in the work.

  5. Molluscan fauna of Gueishan Island, Taiwan.

    PubMed

    Huang, Chih-Wei; Hsiung, Ta-Wei; Lin, Si-Min; Wu, Wen-Lung

    2013-01-01

    This dataset records the occurrence and inventory of molluscan fauna on Gueishan Island, the only active volcanic island in Taiwan, based on the literature survey and field investigation conducted between 2011 and 2012. The literature review involved seven studies published from 1934 to 2003, which collectively reported 112 species from 61 genera and 37 families of Mollusca on Gueishan Island. Through our field investigation, we identified 34 species from 28 genera and 23 families. Fourteen of these species were new records on Gueishan Island: Liolophura japonica, Lottia luchuana, Nerita costata, Nerita rumphii, Diplommatina suganikeiensis, Littoraria undulata, Solenomphala taiwanensis, Assiminea sp., Siphonaria laciniosa, Laevapex nipponica, Carychium hachijoensis, Succinea erythrophana, Zaptyx crassilamellata, and Allopeas pyrgula. In Total, there are 126 species from 71 genera and 45 families of Mollusca on Gueishan Island. These data have been published through GBIF [http://taibif.org.tw/ipt/resource.do?r=gueishan_island] and integrated into the Taiwan Malacofauna Database (http://shell.sinica.edu.tw/). PMID:23717182

  6. Development of genetic counseling services in Taiwan.

    PubMed

    Chien, Shu; Su, Pen-Hua; Chen, Suh-Jen

    2013-12-01

    Taiwan is an emerging industrial country in subtropical Asia with a population of 23 million. There were around 200,000 newborns in 2011. Delayed first marriage, low birth rate, and rapid aging are major demographic issues. Genetic counseling services were established following the rapid introduction of genetic technology and enactment of relevant laws and regulations. Ultrasound was first used in 1968 to examine pregnant women. The first amniotic fluid laboratory was founded in 1981 to identify chromosomal abnormalities. In 1984, the Genetic Health Act was legislated for prevention and control of genetic disorders, and the metabolic disorder screen project was launched. National Health Insurance with overall coverage of prenatal examinations was established in 1995. A master-level genetic counseling program was launched in 2003 and by 2011 has graduated eighty students. Two professional societies have been formed to certify genetic counselors, and 66 professionals have been certified. In summary, genetic counseling services in Taiwan are continuously improving. PMID:23595168

  7. SARS in Healthcare Facilities, Toronto and Taiwan

    PubMed Central

    Simor, Andrew E.; Su, Ih-Jen; Maloney, Susan; Ofner, Marianna; Chen, Kow-Tong; Lando, James F.; McGeer, Allison; Lee, Min-Ling; Jernigan, Daniel B.

    2004-01-01

    The healthcare setting was important in the early spread of severe acute respiratory syndrome (SARS) in both Toronto and Taiwan. Healthcare workers, patients, and visitors were at increased risk for infection. Nonetheless, the ability of individual SARS patients to transmit disease was quite variable. Unrecognized SARS case-patients were a primary source of transmission and early detection and intervention were important to limit spread. Strict adherence to infection control precautions was essential in containing outbreaks. In addition, grouping patients into cohorts and limiting access to SARS patients minimized exposure opportunities. Given the difficulty in implementing several of these measures, controls were frequently adapted to the acuity of SARS care and level of transmission within facilities. Although these conclusions are based only on a retrospective analysis of events, applying the experiences of Toronto and Taiwan to SARS preparedness planning efforts will likely minimize future transmission within healthcare facilities. PMID:15200808

  8. Reasons for permanent tooth extractions in Taiwan.

    PubMed

    Lee, Chen-Yi; Chang, Yong-Yuan; Shieh, Tien-Yu; Chang, Chin-Shun

    2015-03-01

    There has been no study in Taiwan on reasons for extraction of permanent teeth. This study aimed to determine the reasons for permanent teeth extraction in Taiwan. This study performed a secondary data analysis based on the National Health Insurance Research Database. The 2009 database was adopted and there are 131 104 records of dental visits in the database; among them, 4958 visits (from 4811 patients) have a coding of extraction. The results showed that dental caries (55.3%) was the main reason for tooth extraction, followed by periodontal disease (22.1%). Extraction because of dental caries was commonly observed in all age-groups, and extractions because of periodontal disease increased in those older than 35 years. Maxillary and mandibular third molar were the most frequently removed tooth types, and most were extracted because of dental caries and impaction respectively. PMID:22743854

  9. Chemical weathering rates applying riverine total dissolved solid export to estimate in subtropical orogenic arc, Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Pei-Hao; Huang, -Chuan, Jr.; Teng, Tse-Yang; Lee, Tsung-Yu; Lee, Li-Chin; Liu, Ying-San

    2015-04-01

    Chemical weathering rate (CWR) plays an important role in the global geochemical cycle. It is one of the major processes to uptake and transfer CO2 to dissolved bicarbonate in terrestrial waters. However, the CWR in high-standing island marked by quick uplift is rarely documented. The high-lifting orogenic island, such as Taiwan, attracts much attention on extreme sediment discharge and physical denudation rate (PDR) whereas the accompanying chemical weathering is less discussed. In this study, we collected 30 catchments around the island to investigate the comprehensive CWR with regards to the controls of lithology, streamflow and PDR. Results show that the average silicate and carbonate weathering rate of Taiwan are 74.13 and 287.09 ton/km2/yr, which correspond to 22.59 and 73.36 105mol/km2/yr of CO2 consumption. While the world average weathering rate are 5.87 and 12.32 ton/km2/yr in silicate and carbonate, respectively, which uptake 0.86 and 11.61 105mol/km2/yr of CO2. In general, the CWR is mainly contributed by carbonate weathering and moderately controlled by lithology and uplift rate. The carbonate and silicate weathering dominate the eastern and northern Taiwan, respectively. Specifically, stream flow predominately controlls the carbonate weathering except in northern Taiwan, while it plays a secondary role in silicate weathering. The CWR increases with PDR, but the strongly positive correlation gradually diminishes when the PDR exceeds 104 ton/km2/yr. Further study is suggested to explore the variation of the strongly positive correlation between PDR and CWR which may affect the estimation of CO2 consumption.

  10. Carbon dioxide sorption/ desorption characteristics of coals in Taiwan

    NASA Astrophysics Data System (ADS)

    Chien-Hung, Hsiao; Loung-Yie, Tsai

    2013-04-01

    Geological sequestration of CO2 into depleted oil reservoir, saline aquifer or unmineable coal seam is now being actively investigated for the purpose of reducing greenhouse gas in the atmosphere. Understanding the physical, chemical, and thermodynamic phenomena occurred with CO2 injection is very important in marking a reliable prediction of sequestration. This study examined the feasibility of carbon dioxide sequestration into unmineable coal seams in Taiwan. A total of 20 Miocene-aged coal samples from Western Foothill Belt, NW Taiwan, were collected. The stratigraphy include Mushan, Shihti, and Nanchuang Formation from bottom up. Proximate and petrographic analyses include maceral composition, Vitrinite reflectance were also measured. Carbon dioxide adsorption isotherms were analyzed at 35 degrees Celsius and up to 800 psi, by using a gravimetric ad/desorption apparatus. Isotherms were then fitted with a modified Langmuir Isotherm model by using Langmuir Pressure and Langmuir Volume so the model can be applied to supercritical conditions. According to the result of adsorption experiment, the pressure and temperature were quite significant. The gas storage capacity of CO2 was about 400 600 scf/ton at pressure up to 800 psi. Comparing the results of adsorption capacity with Proximate analysis and vitrinite reflectance, the Langmuir Volume shows a strong positive correlation with fixed carbon and vitrinite content. Furthermore, Adsorption capacity is closely related to micropores which were also rank and maceral dependent. It is noticed that the observed coal pore structures were affected by rank, and then exhibit have different diffusion rate of CO2.Finally, images under SEM were evaluated to understand the pathways of gas sorption.

  11. Methicillin-Resistant Staphylococcus aureus Ocular Infection in Taiwan

    PubMed Central

    Kang, Yu-Chuan; Hsiao, Ching-Hsi; Yeh, Lung-Kun; Ma, David H.K.; Chen, Phil Y.F.; Lin, Hsin-Chiung; Tan, Hsin-Yuan; Chen, Hung-Chi; Chen, Shin-Yi; Huang, Yhu-Chering

    2015-01-01

    Abstract Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. This observational study aimed to characterize clinical features, antibiotic susceptibility, and genotypes of ocular infections caused by MRSA based on the clinical and molecular definitions of community-associated (CA) and healthcare-associated (HA) strains. Fifty-nine patients with culture-proven S aureus ocular infection were enrolled from January 1, 2010 to December 31, 2011 at Chang Gung Memorial Hospital, Taiwan. Antibiotic susceptibility was verified using disk diffusion/E test. For characterization, staphylococcal cassette chromosome mec (SCCmec), pulsed-field gel electrophoresis (PFGE), multilocus sequence type (MLST), and Panton–Valentine leukocidin (PVL) gene, were performed. MRSA isolates from the patients with HA factors were classified as clinically defined HA-MRSA, and those carrying SCCmec type I to III as molecularly defined HA-MRSA. Thirty-four patients with MRSA ocular infection were identified. The most common clone of CA-MRSA and HA-MRSA isolates was ST59/PFGE type D/SCCmec IV,VT/PVL (+) (n = 12) and CC 239/PFGE type A/SCCmec III, IIIA/PVL(−) (n = 10), respectively. All the 11 patients with molecularly defined HA-MRSA infections and 50% of the 22 patients with molecularly defined CA-MRSA infections were found to have HA factors (P = .005). CA-MRSA tended to cause lid infections, whereas HA-MRSA tended to cause corneal infections. Contrary to HA-MRSA isolates, nearly all the CA-MRSA isolates were susceptible to trimethoprim/sulfamethoxazole and fluoroquinolones under either clinical or molecular classifications. In Taiwan, CA-MRSA isolates exhibited considerably higher susceptibility to fluoroquinolones when compared with HA-MRSA isolates. A strong correlation was observed between the HA factors and molecularly defined HA-MRSA isolates. PMID:26496268

  12. Spiral motion formation in astrophysics

    NASA Astrophysics Data System (ADS)

    Kov?, Ji?

    2013-11-01

    Motion of charged matter in gravitational and large-scale magnetic fields represents one of the most discussed topics in astrophysics. Here, one of the particular problems is addressed: the spiral motion of charged test particles as a possible mechanism for generation of weak toroidal magnetic field (magnetic loop) complementary to the prescribed large-scale one. To this aim, by contrast with the usually assumed scenario with particles circling in spirals along with the magnetic lines of a magnetic field dominating over gravity, the perturbed stable circular equatorial motion is discussed when the gravity of the central object plays at least a comparable role to electromagnetism. It is shown that the proper relation between the epicyclic and orbital frequencies necessary for the spiral motion cannot be easily achieved in the basic fields configuration within the Newtonian theory. The inclusion of the strong-field general relativistic effect, however, yields the desired conditions for particles to orbit in spirals.

  13. Education of biomedical engineering in Taiwan.

    PubMed

    Lin, Kang-Ping; Kao, Tsair; Wang, Jia-Jung; Chen, Mei-Jung; Su, Fong-Chin

    2014-01-01

    Biomedical Engineers (BME) play an important role in medical and healthcare society. Well educational programs are important to support the healthcare systems including hospitals, long term care organizations, manufacture industries of medical devices/instrumentations/systems, and sales/services companies of medical devices/instrumentations/system. In past 30 more years, biomedical engineering society has accumulated thousands people hold a biomedical engineering degree, and work as a biomedical engineer in Taiwan. Most of BME students can be trained in biomedical engineering departments with at least one of specialties in bioelectronics, bio-information, biomaterials or biomechanics. Students are required to have internship trainings in related institutions out of campus for 320 hours before graduating. Almost all the biomedical engineering departments are certified by IEET (Institute of Engineering Education Taiwan), and met the IEET requirement in which required mathematics and fundamental engineering courses. For BMEs after graduation, Taiwanese Society of Biomedical Engineering (TSBME) provides many continue-learning programs and certificates for all members who expect to hold the certification as a professional credit in his working place. In current status, many engineering departments in university are continuously asked to provide joint programs with BME department to train much better quality students. BME is one of growing fields in Taiwan. PMID:25571153

  14. Predictors of Burnout Among Nurses in Taiwan.

    PubMed

    Lee, Huan-Fang; Yen, Miaofen; Fetzer, Susan; Chien, Tsair Wei

    2015-08-01

    Nurse burnout is a crucial issue for health care professionals and impacts nurse turnover and nursing shortages. Individual and situational factors are related to nurse burnout with predictors of burnout differing among cultures and health care systems. The predictors of nurse burnout in Asia, particularly Taiwan, are unknown. The purpose of this study was to investigate the predictors of burnout among a national sample of nurses in Taiwan. A secondary data analysis of a nationwide database investigated the predictors of burnout among 1,846 nurses in Taiwan. Hierarchical regression analysis determined the relationship between predictors and burnout. Predictors of Taiwanese nurse burnout were age, physical/psychological symptoms, job satisfaction, work engagement, and work environment. The most significant predictors were physical/psychological symptoms and work engagement. The variables explained 35, 39, and 18 % of the emotional exhaustion, personal accomplishment, and depersonalization variance for 54 % of the total variance of burnout. Individual characteristics and nurse self-awareness, especially work, engagement can impact Taiwanese nurses' burnout. Nurse burnout predictors provide administrators with information to develop strategies including education programs and support services to reduce nurse burnout. PMID:25536942

  15. The Status of the Taiwan Photon Source

    NASA Astrophysics Data System (ADS)

    Kuo, C. C.; Wang, J. P.; Chen, J. R.; Hsu, K. T.; Wang, C.; Yang, Y. W.; Luo, G. H.; Chen, C. T.; Liang, K. S.

    2010-06-01

    NSRRC has been operating a 1.5 GeV synchrotron light source, the Taiwan Light Source (TLS), for over 15 years and has established a large user community. For the future development of synchrotron radiation research in Taiwan, a feasibility study report to construct a 3.0 GeV low-emittance storage ring, the Taiwan Photon Source (TPS), was issued in July 2005. The government approval of the TPS project was obtained in December 2007 and the machine will be built at current site of NSRRC. The project has progressed steadily since and reached several major milestones now: the architect firm has finished the site plan and civil design, the accelerator design has been fixed, and purchase of long-lead items begins its course. The TPS storage ring has a circumference of 518.4 meters with a concentric booster of 496.8 meters. The storage ring adopted a 24-cell double-bend structure with a 1.6 nm-rad natural emittance. There are six 12-m and eighteen 7-m ID straights. For user research, five new beamlines have been selected for the Phase I operations: the micro protein crystallography, the materials sub-micron diffraction, the inelastic soft x-ray scattering, the coherent x-ray scattering, and the nano probe beamlines. The civil construction is getting ready to start. The commissioning of the TPS storage ring is targeted for 2013.

  16. Lineage-specific late pleistocene expansion of an endemic subtropical gossamer-wing damselfly, Euphaea formosa, in Taiwan

    PubMed Central

    2011-01-01

    Background Pleistocene glacial oscillations have significantly affected the historical population dynamics of temperate taxa. However, the general effects of recent climatic changes on the evolutionary history and genetic structure of extant subtropical species remain poorly understood. In the present study, phylogeographic and historical demographic analyses based on mitochondrial and nuclear DNA sequences were used. The aim was to investigate whether Pleistocene climatic cycles, paleo-drainages or mountain vicariance of Taiwan shaped the evolutionary diversification of a subtropical gossamer-wing damselfly, Euphaea formosa. Results E. formosa populations originated in the middle Pleistocene period (0.3 Mya) and consisted of two evolutionarily independent lineages. It is likely that they derived from the Pleistocene paleo-drainages of northern and southern Minjiang, or alternatively by divergence within Taiwan. The ancestral North-central lineage colonized northwestern Taiwan first and maintained a slowly growing population throughout much of the early to middle Pleistocene period. The ancestral widespread lineage reached central-southern Taiwan and experienced a spatial and demographic expansion into eastern Taiwan. This expansion began approximately 30,000 years ago in the Holocene interglacial period. The ancestral southern expansion into eastern Taiwan indicates that the central mountain range (CMR) formed a barrier to east-west expansion. However, E. formosa populations in the three major biogeographic regions (East, South, and North-Central) exhibit no significant genetic partitions, suggesting that river drainages and mountains did not form strong geographical barriers against gene flow among extant populations. Conclusions The present study implies that the antiquity of E. formosa's colonization is associated with its high dispersal ability and larval tolerance to the late Pleistocene dry grasslands. The effect of late Pleistocene climatic changes on the subtropical damselfly's historical demography is lineage-specific, depending predominantly on its colonization history and geography. It is proposed that the Riss and Wrm glaciations in the late Pleistocene period had a greater impact on the evolutionary diversification of subtropical insular species than the last glacial maximum (LGM). PMID:21486452

  17. A Seismic Structure Study in the Kaoping Area, Southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, K. P.; Wang, C. Y.; Tsai, Y. B.; Chang, W. Y.

    2014-12-01

    The difference between S wave and S-to-P wave conversion (Sp phase) arrival times is enhanced with Rectilinear Motion Detector filtering to describe alluvial-sediment thickness in the Kaohsiung-Pingtung (Kaoping) plains area. A more complete understanding of the underground structures of the Kaoping area is provided and explains why the surrounding regions in Taiwan experience more earthquakes. Data are based on seismic activity recorded by PANDA for the period 1995 to 1997. The difference between S wave and Sp phase arrival times show that the sedimentary layer is thicker along the west and southwest coast. P wave travel time residuals, high frequency attenuation parameters kappa, and quality factor QP, QSand coda waves confirm this result. We also determined the orientation of the Chaochou fault using the first motion of P-waves arrivals. To the east of the Chaochou fault, stress trends southeast-northwest, while to the west, it trends northeast-southwest. The change of stress trends East and West of Chaochou fault suggest the presence of a highly fluid accretionary wedge in the Kaoping area. The Chaochou fault forms a seismically active tectonic boundary with uplift of the hanging wall leading to westward tilting of the basement of the Kaoping plains. We demonstrate these features are why there are relatively few earthquakes in the Kaoping area. The presence of a highly fluid accretionary wedge is indicated by a thick alluvial layer in the west and southwest Kaoping coast; the Peikung High acts as the indenter that may allow seismic energy to escape and reduce the number of earthquakes in the region.

  18. Ground motion input in seismic evaluation studies

    SciTech Connect

    Sewell, R.T.; Wu, S.C.

    1996-07-01

    This report documents research pertaining to conservatism and variability in seismic risk estimates. Specifically, it examines whether or not artificial motions produce unrealistic evaluation demands, i.e., demands significantly inconsistent with those expected from real earthquake motions. To study these issues, two types of artificial motions are considered: (a) motions with smooth response spectra, and (b) motions with realistic variations in spectral amplitude across vibration frequency. For both types of artificial motion, time histories are generated to match target spectral shapes. For comparison, empirical motions representative of those that might result from strong earthquakes in the Eastern U.S. are also considered. The study findings suggest that artificial motions resulting from typical simulation approaches (aimed at matching a given target spectrum) are generally adequate and appropriate in representing the peak-response demands that may be induced in linear structures and equipment responding to real earthquake motions. Also, given similar input Fourier energies at high-frequencies, levels of input Fourier energy at low frequencies observed for artificial motions are substantially similar to those levels noted in real earthquake motions. In addition, the study reveals specific problems resulting from the application of Western U.S. type motions for seismic evaluation of Eastern U.S. nuclear power plants.

  19. Quantifying biomechanical motion using Procrustes motion analysis.

    PubMed

    Adams, Dean C; Cerney, Melinda M

    2007-01-01

    The ability to quantify and compare the movements of organisms is a central focus of many studies in biology, anthropology, biomechanics, and ergonomics. However, while the importance of functional motion analysis has long been acknowledged, quantitative methods for identifying differences in motion have not been widely developed. In this article, we present an approach to the functional analysis of motion and quantification of motion types. Our approach, Procrustes Motion Analysis (PMA) can be used to distinguish differences in cyclical, repeated, or goal-directed motions. PMA exploits the fact that any motion can be represented by an ordered sequence of postures exhibited throughout the course of a motion. Changes in posture from time step to time step form a trajectory through a multivariate data space, representing a specific motion. By evaluating the size, shape, and orientation of these motion trajectories, it is possible to examine variation in motion type within and among groups or even with respect to continuous variables. This represents a significant analytical advance over current approaches. Using simulated and digitized data representing cyclical, repeated and goal-directed motions, we show that PMA correctly identifies distinct motion tasks in these data sets. PMID:16448654

  20. A Scheme for "The Window of Taiwan National Park"

    NASA Astrophysics Data System (ADS)

    Tang, E. Y.-F.

    2015-08-01

    There are nine distinguished national parks in Taiwan. Each one has its own wild variety of natural inhabitants and cultural resources. However, due to the geographical inaccessibility, partially closed by natural disaster, or under the restrict protection by the authority, most of the places are difficult to reach for the public, not to mention for the disabled people. Therefore, a scheme, with the cutting edge technology, comprising the essences of all nine national parks in a space located in one of the national parks which is more convenient with public transportation system is presented. The idea is to open a window in the hope to offer a platform for better and easy understanding the features of all national parks, to increase the accessibility for disabled people, and to provide advanced services for the public. Recently, the progressing of digital image technology becomes more and more promising. Using mutual interactive ways and game-liked formation to promote the participation of visitors to gain learning experiences is now becoming a mainstream for exhibition in visitor centers and museums around the world. The method of the motion-sensing interactive exhibition has personalized feature which is programmed to store visitor's behaviors and become smarter in response with visitor in order to make each person feel that they are playing in a game. It involves scenarios, concepts and visitors' participation in the exhibition design to form an interactive flow among human, exhibits, and space. It is highly attractive and low barrier for young, senior and disabled people, and for the case of no physical objects to exhibit, visual technology is a way of solution. This paper presents the features and difficulties of national parks in Taiwan. Visitors' behavior and several cases have been investigated and analysed to find a suitable way for combining all the features of national parks in an exhibition. However, it should be noticed that this is not an alternative way trying to create a place for the public to explore visual national parks instead of visiting real ones. The main purpose is not only to provide more information and attract more people to realize the beauty of national parks, but also to inspire visitors' wishes to come and experience in person in the future.

  1. Unstable Electromagnetic Modes in Strongly Magnetized Plasmas

    NASA Astrophysics Data System (ADS)

    Son, S.; Moon, Sung Joon

    2013-09-01

    A theory for instability in the long-time limit, arising from the electron gyro-motion in strongly magnetized plasmas, is presented. The analysis of the electron motion in the presence of a strong magnetic field leads to a theoretical framework similar to that of the Landau damping. Various electromagnetic modes are predicted to be possibly unstable, and the regime where the radiation from this instability would stand out, compared to the incoherent electron-cyclotron radiation, is identified. This instability would be relevant to the inertial confinement fusion and the gamma ray burst.

  2. Current Trends in Aerospace Engineering Education on Taiwan.

    ERIC Educational Resources Information Center

    Hsieh, Sheng-Jii

    A proposal for current trends in Aerospace Engineering Education on Taiwan has been drawn from the suggestions made after a national conference of "Workshop on Aerospace Engineering Education Reform." This workshop was held in January 18-20, 1998, at the Institute of Aeronautics and Astronautics, National Cheng Kung University, Tainan, Taiwan,…

  3. The Construction of Taiwan's Educational Indicator Systems: Experiences and Implications

    ERIC Educational Resources Information Center

    Chien, Maw-Fa; Lee, Chi-Ming; Cheng, Yu-Ping

    2007-01-01

    This study was designed to illuminate the state of education in Taiwan by constructing Educational Indicator Systems. The study, sponsored by the National Science Council between 1998 and 2000, was the first comprehensive indicator project to cover all educational levels in Taiwan. Various research methods were used, including panel discussion,…

  4. Teaching Benchmark Strategy for Fifth-Graders in Taiwan

    ERIC Educational Resources Information Center

    Yang, Der-Ching; Lai, M. L.

    2013-01-01

    The key purpose of this study was how we taught the use of benchmark strategy when comparing fraction for fifth-graders in Taiwan. 26 fifth graders from a public elementary in south Taiwan were selected to join this study. Results of this case study showed that students had a much progress on the use of benchmark strategy when comparing fraction…

  5. International Collaborative Development: Curriculum and Instructional Change in Taiwan.

    ERIC Educational Resources Information Center

    Lee, Phoebe Po

    This study examined an international educational partnership between Florida International University and Taiwan's Fu-Hsing school that emphasized curriculum and instructional change to improve educational quality in Taiwan. Collaborators from the institutions developed criteria for teaching effectiveness and established an evaluation system for

  6. Research on English Teaching and Learning: Taiwan (2004-2009)

    ERIC Educational Resources Information Center

    Chen, Suchiao; Tsai, Yachin

    2012-01-01

    This article analyzes research in second/foreign language teaching and learning conducted in Taiwan over the period 2004-2009. Representative articles published in local refereed journals and conference proceedings--not readily accessible outside Taiwan--are reviewed to reflect current trends in English teaching and learning. The main themes

  7. Operations: A Comparative Study of the United States and Taiwan

    ERIC Educational Resources Information Center

    Lin, Cheng-Yao; Becker, Jerry; Byun, Mi-Ran; Yang, Der-Ching; Huang, Tsai-Wei

    2013-01-01

    This study examined (a) the differences in preservice teachers procedural knowledge in four areas of fraction operations in Taiwan and the United States, (b) the differences in preservice teachers conceptual knowledge in four areas of fraction operations in Taiwan and the United States, and (c) correlation in preservice teachers conceptual

  8. GIS Adoption among Senior High School Geography Teachers in Taiwan

    ERIC Educational Resources Information Center

    Lay, Jinn-Guey; Chen, Yu-Wen; Chi, Yu-Lin

    2013-01-01

    This article explores the adoption of geographic information system (GIS) knowledge and skills through in-service training for high school geography teachers in Taiwan. Through statistical analysis of primary data collected from a census of Taiwan's high school geography teachers, it explores what motivates these teachers to undertake GIS

  9. Intercultural Training for US Business Expatriates in Taiwan

    ERIC Educational Resources Information Center

    Chien, Tien-Chen; McLean, Gary N.

    2011-01-01

    Purpose: This study aims to explore the intercultural training needs for US business expatriates on assignment in Taiwan. The study assesses Taiwan culture-specific training needs of US expatriates from the perspectives of both US expatriates and their Taiwanese colleagues and compares the perceived importance of these intercultural training needs…

  10. A Study of Neutral-Tone Syllables in Taiwan Mandarin

    ERIC Educational Resources Information Center

    Huang, Karen

    2012-01-01

    This dissertation studies the realization of the rhythm of Taiwan Mandarin and focuses on the quality of its unstressed (neutral-tone) syllables. Taiwan Mandarin (TM) is often described as more syllable-timed than Standard Mandarin (SM). In TM, the unstressed syllables occur less frequently. The quality of the unstressed (neutral-tone) syllables…

  11. Kindergarten Teachers' Experience with Reporting Child Abuse in Taiwan

    ERIC Educational Resources Information Center

    Feng, Jui-Ying; Huang, Tzu-Yi; Wang, Chi-Jen

    2010-01-01

    Objective: The objectives were to examine factors associated with reporting child abuse among kindergarten teachers in Taiwan based on the Theory of Planned Behavior (TPB). Method: A stratified quota sampling technique was used to randomly select kindergarten teachers in Taiwan. The Child Abuse Intention Report Scale, which includes demographics,

  12. Intercultural Training for US Business Expatriates in Taiwan

    ERIC Educational Resources Information Center

    Chien, Tien-Chen; McLean, Gary N.

    2011-01-01

    Purpose: This study aims to explore the intercultural training needs for US business expatriates on assignment in Taiwan. The study assesses Taiwan culture-specific training needs of US expatriates from the perspectives of both US expatriates and their Taiwanese colleagues and compares the perceived importance of these intercultural training needs

  13. Kindergarten Teachers' Experience with Reporting Child Abuse in Taiwan

    ERIC Educational Resources Information Center

    Feng, Jui-Ying; Huang, Tzu-Yi; Wang, Chi-Jen

    2010-01-01

    Objective: The objectives were to examine factors associated with reporting child abuse among kindergarten teachers in Taiwan based on the Theory of Planned Behavior (TPB). Method: A stratified quota sampling technique was used to randomly select kindergarten teachers in Taiwan. The Child Abuse Intention Report Scale, which includes demographics,…

  14. The Construction of Taiwan's Educational Indicator Systems: Experiences and Implications

    ERIC Educational Resources Information Center

    Chien, Maw-Fa; Lee, Chi-Ming; Cheng, Yu-Ping

    2007-01-01

    This study was designed to illuminate the state of education in Taiwan by constructing Educational Indicator Systems. The study, sponsored by the National Science Council between 1998 and 2000, was the first comprehensive indicator project to cover all educational levels in Taiwan. Various research methods were used, including panel discussion,

  15. Higher Education Research Community in Taiwan: An Emerging Field

    ERIC Educational Resources Information Center

    Chan, Sheng-Ju; Chan, Ying

    2015-01-01

    This paper aims to explore the evolution and characteristics of the higher education research community in Taiwan. In echoing the development of the East Asian region, Taiwan has made substantial progress during the past two decades. The massification of higher education itself has played a major role in promoting the academic differentiation or

  16. Taiwan Teacher Preparation Program Evaluation: Some Critical Perspectives

    ERIC Educational Resources Information Center

    Liu, Tze-Chang

    2015-01-01

    This paper focuses on the influences and changes of recent Taiwan teacher preparation program evaluation (TTPPE) as one of the national evaluation projects conducted by the Higher Education Evaluation and Accreditation Council of Taiwan. The main concerns are what kind of ideology is transformed through the policy by means of evaluation, and what

  17. Taiwan Teacher Preparation Program Evaluation: Some Critical Perspectives

    ERIC Educational Resources Information Center

    Liu, Tze-Chang

    2015-01-01

    This paper focuses on the influences and changes of recent Taiwan teacher preparation program evaluation (TTPPE) as one of the national evaluation projects conducted by the Higher Education Evaluation and Accreditation Council of Taiwan. The main concerns are what kind of ideology is transformed through the policy by means of evaluation, and what…

  18. A Study of Neutral-Tone Syllables in Taiwan Mandarin

    ERIC Educational Resources Information Center

    Huang, Karen

    2012-01-01

    This dissertation studies the realization of the rhythm of Taiwan Mandarin and focuses on the quality of its unstressed (neutral-tone) syllables. Taiwan Mandarin (TM) is often described as more syllable-timed than Standard Mandarin (SM). In TM, the unstressed syllables occur less frequently. The quality of the unstressed (neutral-tone) syllables

  19. A Re-Examination of the Suicide Rates in Taiwan

    ERIC Educational Resources Information Center

    Chuang, Hwei-Lin; Huang, Wei-Chiao

    2007-01-01

    This paper examines the suicide rates of 23 cities and counties in Taiwan from 1983 to 2001. We found that a combination of economic and social variables can significantly account for the tremendous variations in suicide rates across Taiwan's cities and counties over the last two decades. The level of income per capita in a region appears as the

  20. Parents' Attitudes toward the English Education Policy in Taiwan

    ERIC Educational Resources Information Center

    Chang, Yuh Fang

    2008-01-01

    Taiwan, like many other countries in Asia, introduced considerable changes in English education policy in response to the need for English communication in the global market. During the process of implementing the new English education policy, the Ministry of Education (MOE) of Taiwan encountered several problems. Although researchers have

  1. Negotiating for Change: Women's Movements and Education Reform in Taiwan

    ERIC Educational Resources Information Center

    Lee, Shu-Ching

    2011-01-01

    The dramatic changes during the past 20 years in Taiwan offer a good example of how gender policy in education is facilitated by a combination of interrelated economic, political and social forces. Taiwan's policy on gender education emerged from the interaction of state, education, academic and non-academic feminist positions in reforms. This

  2. 75 FR 15726 - Polyvinyl Alcohol From Taiwan; Determination

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... COMMISSION Polyvinyl Alcohol From Taiwan; Determination On the basis of the record \\1\\ developed in the... Taiwan of polyvinyl alcohol provided for in subheading 3905.30.00 of the Harmonized Tariff Schedule of... threatened with material injury by reason of allegedly LTFV imports of polyvinyl alcohol from...

  3. A Case Study of Undergraduate Course Syllabi in Taiwan

    ERIC Educational Resources Information Center

    Tung, Yao-Tsu

    2010-01-01

    Higher education in Taiwan has been influenced by U.S. and Western practices, and syllabi represent one means to verify this. However, limited research exists in Taiwan on course syllabi and on similarities of syllabi with practices in other countries. In the U.S. as the paradigm shifted from teaching to learning and to the learning-centered

  4. GIS Adoption among Senior High School Geography Teachers in Taiwan

    ERIC Educational Resources Information Center

    Lay, Jinn-Guey; Chen, Yu-Wen; Chi, Yu-Lin

    2013-01-01

    This article explores the adoption of geographic information system (GIS) knowledge and skills through in-service training for high school geography teachers in Taiwan. Through statistical analysis of primary data collected from a census of Taiwan's high school geography teachers, it explores what motivates these teachers to undertake GIS…

  5. Characterization of CADASIL among the Han Chinese in Taiwan: Distinct Genotypic and Phenotypic Profiles.

    PubMed

    Liao, Yi-Chu; Hsiao, Cheng-Tsung; Fuh, Jong-Ling; Chern, Chang-Ming; Lee, Wei-Ju; Guo, Yuh-Cherng; Wang, Shuu-Jiun; Lee, I-Hui; Liu, Yo-Tsen; Wang, Yen-Feng; Chang, Feng-Chi; Chang, Ming-Hung; Soong, Bing-Wen; Lee, Yi-Chung

    2015-01-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is originally featured with a strong clustering of mutations in NOTCH3 exons 3-6 and leukoencephalopathy with frequent anterior temporal pole involvement. The present study aims at characterizing the genotypic and phenotypic profiles of CADASIL in Taiwan. One hundred and twelve patients with CADASIL from 95 families of Chinese descents in Taiwan were identified by Sanger sequencing of exons 2 to 24 of NOTCH3. Twenty different mutations in NOTCH3 were uncovered, including 3 novel ones, and R544C in exon 11 was the most common mutation, accounting for 70.5% of the pedigrees. Haplotype analyses were conducted in 14 families harboring NOTCH3 R544C mutation and demonstrated a common haplotype linked to NOTCH3 R544C at loci D19S929 and D19S411. Comparing with CADASIL in most Caucasian populations, CADASIL in Taiwan has several distinct features, including less frequent anterior temporal involvement, older age at symptom onset, higher incidence of intracerebral hemorrhage, and rarer occurrence of migraine. Subgroup analyses revealed that the R544C mutation is associated with lower frequency of anterior temporal involvement, later age at onset and higher frequency of cognitive dysfunction. In conclusion, the present study broadens the spectrum of NOTCH3 mutations and provides additional insights for the clinical and molecular characteristics of CADASIL patients of Han-Chinese descents. PMID:26308724

  6. Characterization of CADASIL among the Han Chinese in Taiwan: Distinct Genotypic and Phenotypic Profiles

    PubMed Central

    Fuh, Jong-Ling; Chern, Chang-Ming; Lee, Wei-Ju; Guo, Yuh-Cherng; Wang, Shuu-Jiun; Lee, I-Hui; Liu, Yo-Tsen; Wang, Yen-Feng; Chang, Feng-Chi; Chang, Ming-Hung; Soong, Bing-Wen; Lee, Yi-Chung

    2015-01-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is originally featured with a strong clustering of mutations in NOTCH3 exons 36 and leukoencephalopathy with frequent anterior temporal pole involvement. The present study aims at characterizing the genotypic and phenotypic profiles of CADASIL in Taiwan. One hundred and twelve patients with CADASIL from 95 families of Chinese descents in Taiwan were identified by Sanger sequencing of exons 2 to 24 of NOTCH3. Twenty different mutations in NOTCH3 were uncovered, including 3 novel ones, and R544C in exon 11 was the most common mutation, accounting for 70.5% of the pedigrees. Haplotype analyses were conducted in 14 families harboring NOTCH3 R544C mutation and demonstrated a common haplotype linked to NOTCH3 R544C at loci D19S929 and D19S411. Comparing with CADASIL in most Caucasian populations, CADASIL in Taiwan has several distinct features, including less frequent anterior temporal involvement, older age at symptom onset, higher incidence of intracerebral hemorrhage, and rarer occurrence of migraine. Subgroup analyses revealed that the R544C mutation is associated with lower frequency of anterior temporal involvement, later age at onset and higher frequency of cognitive dysfunction. In conclusion, the present study broadens the spectrum of NOTCH3 mutations and provides additional insights for the clinical and molecular characteristics of CADASIL patients of Han-Chinese descents. PMID:26308724

  7. Gravity flows associated with flood events and carbon burial: Taiwan as instructional source area.

    PubMed

    Liu, James T; Kao, Shuh-Ji; Huh, Chih-An; Hung, Chin-Chang

    2013-01-01

    Taiwan's unique setting allows it to release disproportionately large quantities of fluvial sediment into diverse dispersal systems around the island. Earthquakes, lithology, topography, cyclone-induced rainfall, and human disturbance play major roles in the catchment dynamics. Deep landslides dominate the sediment-removal process on land, giving fluvial sediment distinct geochemical signals. Extreme conditions in river runoff, sediment load, nearshore waves and currents, and the formation of gravity flows during typhoon events can be observed within short distances. Segregation of fresh biomass and clastic sediment occurs during the marine transport process, yet turbidity currents in the Gaoping Submarine Canyon carry woody debris. Strong currents in the slope and back-arc basin of the Okinawa Trough disperse fine-grained sediments rapidly and widely. Temporal deposition and remobilization may occur when the shallow Taiwan Strait acts as a receptacle. Taiwan can therefore serve as a demonstration of the episodic aspect of the source-to-sink pathway to both the coastal and deep-ocean environments. PMID:22809183

  8. Community engagement among men who have sex with men living with HIV/AIDS in Taiwan.

    PubMed

    Chuang, Deng-Min; Lacombe-Duncan, Ashley

    2016-04-01

    Community engagement was developed as a global principle in the provision of HIV/AIDS services, yet evidence-based research of implementation of the principle is lacking in Taiwan. This short report aims to understand factors associated with engagement in two types of activities with varying levels of visibility: HIV-related community events and HIV-related community action, in Taiwanese men who have sex with men (MSM) living with HIV. A cross-sectional survey was distributed to a purposive sample of participants recruited from AIDS service organizations (ASOs). Among participants (n = 178), 63.6% were involved in HIV-related community events, while less than half (47.7%) were involved in HIV-related community action. In multivariable analysis, age, involvement in ASOs, and AIDS knowledge were positively associated with engagement in community events, and living in the north of Taiwan, years of infection, and self-stigma were negatively associated with this type of engagement. Few factors, with the exception of involvement in ASOs, were positively associated with engagement in HIV-related community action. To this end, ASOs appear to play a strong role in improving and organizing both types of community engagement in Taiwan. Future studies should evaluate tailored programs delivered through ASOs for strengthening community connectedness among younger, stigmatized, and longer diagnosed MSM living with HIV. PMID:26586156

  9. Cumulative co-seismic displacement and comparison with GPS observations in Taiwan

    NASA Astrophysics Data System (ADS)

    Xu, C.; Chao, B. F.; Sun, W.

    2013-12-01

    The island of Taiwan owes its existence to the collision of the Eurasian plate and the Philippine Sea plate. The strong seismicity can produce permanent displacement field which can be observed by GPS. Both seismological and GPS networks have been fully established in Taiwan for years. In this paper, we will study the earthquake-induced relative movements, including the amplitude and pattern, and determine how much cumulative co-seismic displacement can contribute to the observed GPS signals as long-term 'trends', by comparing the two sets of data. The co-seismic displacement is calculated by adopting the elastic dislocation theory on a spherical Earth as derived by Sun and Okubo. For the GPS observations, we will remove the seasonal and tidal effects by the least square method and the common-mode errors by the empirical orthogonal function technique. The comparison results show that the earthquake-induced displacements account only for a tiny fraction of the GPS signals, implying that the majority of the displacements in Taiwan during the studied period of 1995-2013 (which includes the largest 1999 Chi-Chi earthquake), both horizontal and vertical, are caused aseismically. The comparison also reveals some interesting details about the pattern and behavior of the displacement fields.

  10. Terrane-controlled crustal shear wave splitting in Taiwan

    NASA Astrophysics Data System (ADS)

    Okaya, David; Christensen, Nikolas I.; Ross, Zachary E.; Wu, Francis T.

    2016-01-01

    Taiwan is the result of arc-continent collision associated with the convergence of the Philippine Sea plate with the eastern Eurasian plate continental margin. The locus of deformation is found in eastern Taiwan in the form of mountain building (Central Range) with underlying thickened lithosphere. Rapid tectonic exhumation in the Central Range has uncovered low-to-high-grade metamorphic rocks marked by steep cleavage. We carried out a crustal seismic anisotropy study across Taiwan, producing a database of over 27,000 local earthquake shear wave splitting measurements. Additionally, we carried out rock physics measurements of metamorphic outcrop samples to quantify shear wave rock anisotropy. We produced a map of station-averaged splitting measurements across Taiwan. Patterns of fast shear wave directions correlate with tectonic terranes produced by plate convergence. Deformation-related mineral-preferred orientation in the metamorphic rocks produces a significant amount of the crustal anisotropy in the Taiwan collision zone.

  11. Self Motion Perception and Motion Sickness

    NASA Technical Reports Server (NTRS)

    Fox, Robert A. (Principal Investigator)

    1991-01-01

    The studies conducted in this research project examined several aspects of motion sickness in animal models. A principle objective of these studies was to investigate the neuroanatomy that is important in motion sickness with the objectives of examining both the utility of putative models and defining neural mechanisms that are important in motion sickness.

  12. Millennial-scale variability in vegetation records from the East Asian Islands: Taiwan, Japan and Sakhalin

    NASA Astrophysics Data System (ADS)

    Takahara, Hikaru; Igarashi, Yaeko; Hayashi, Ryoma; Kumon, Fujio; Liew, Ping-Mei; Yamamoto, Masanobu; Kawai, Sayuri; Oba, Tadamichi; Irino, Tomohisa

    2010-10-01

    High-resolution pollen records from Taiwan, Japan and Sakhalin document regional vegetation changes during Dansgaard-Oeschger (D-O) cycles during the last glacial. During the period from the cold phase (GS 18/19) to warm phase (D-O 19), the biome shift from temperate conifer forest to cold/cool conifer forest in Japan and from subtropical forest to temperate deciduous/conifer forest in Taiwan. The vegetation in D-O 17, cool mixed forest in central Japan, temperate deciduous broadleaf forest in western Japan and subtropical forest in Taiwan, indicates warm condition but not wet in all area. These vegetation changes lead to biome shift from MIS (Marine Isotope Stage) 4 to MIS 3. The abundance of Cryptomeria japonica and Fagus crenata in D-O 12 and D-O 8 indicates wet conditions brought by the strong summer monsoon through the Islands and high snowfall brought by the inflow of the Tsushima Warm Current into the Sea of Japan. The registration of other D-O warming events in MIS 3, although reflected by shifts in the abundance of key species, is not sufficient to produce changes in biomes. Development of cold deciduous forest in HS (Heinrich events) 1 in Sakhalin, Hokkaido and central Japan was conspicuous and was much larger than that in YD. Vegetation response in YD was small scale and within the same biome in the East Asian Islands. In D-O 1 at the termination of the last glacial, the same taxa that developed in the early Holocene, cold evergreen needleleaf trees in northern region, temperate deciduous broadleaf trees in central and western Japan, and warm-temperate evergreen trees in Taiwan, increased.

  13. Criminal judgments to medical malpractice in Taiwan.

    PubMed

    Lin, Pyng Jing

    2009-04-01

    Our society is the only country that punishes physicians with medical malpractice by using criminal law as a routine, while most countries in this planet settle almost all medical disputes with civil action. In Taiwan, criminal suits account 79% of all medical malpractice law suits. The purpose of this trial is to investigate the reasons for the overruled criminal judgment by empirical approach. In this study, 15 overruled judgments out of 615 criminal prosecutions were collected from February 1st, 2002 to January 31st, 2005. The judgments of these cases are analyzed by using "the content analytic method". It is found that in these 15 criminal prosecutions, 16 doctors out of 18 defendants lost their trials, which indicates, statistically, one doctor was sentenced to be guilty per every 3 months. Out of these unlucky ones, two-thirds of the criminals were surgeons, one-fifth internists, and the rests are gynecologists and pediatricians. The average of the terms of imprisonment was 6.6months and, fortunately, all of them obtained probation or replacement with forfeit. In these cases, most of the doctors came from local hospitals or clinics, while only two were from the medical centers. Concerning the disputes, five cases were involved with delayed or missed diagnoses of the illness and the other ten in the surgical complications. In the first 4 years of the 21st century, there was one physician in Taiwan sentenced guilty per every 3 months, which is a unique phenomenon in the world. The criminal rate of physicians in Taiwan is the highest in all professionals in the world. Most of these criminal doctors were the laborious, mind-dependent, life-saving surgeons, internists, pediatricians, and gynecologists. According to the causes of the disputes, the difference between the expectation of the doctors and that of the patients should be treated by informed consent doctrine to avoid the very expensive defensive medicine. PMID:19261531

  14. A revision of the genus Amamiclytus Ohbayashi from Taiwan and the Ryukyu Islands (Coleoptera, Cerambycidae)

    PubMed Central

    Niisato, Tatsuya; Han, Chang-do

    2011-01-01

    Abstract The clytine genus Amamiclytus Ohbayashi, 1964, from Taiwan and the Ryukyu Islands is revised. Seven species and one subspecies are recognized as follows: Amamiclytus nobuoi nobuoi Ohbayashi, 1964, (Amami Islands); Amamiclytus nobuoi akusekianus Niisato, 2005, (Tokara Islands); Amamiclytus subnitidus Holzschuh, 1984, (Taiwan); Amamiclytus setiger sp. n. (Taiwan), Amamiclytus nubilus sp. n. (Taiwan), Amamiclytus juni sp. n. (Taiwan), Amamiclytus yulongi sp. n. (Taiwan) and Amamiclytus hirtipes (Matsushita, 1940), comb. n. (Taiwan). All of them are described or redescribed and a key to species is presented. The generic features of Amamiclytus, including male and female genitalia from these taxa, are presented. The systematic position of Amamiclytus within the tribe Clytini is discussed. PMID:21998509

  15. Self-Motion Perception and Motion Sickness

    NASA Technical Reports Server (NTRS)

    Fox, Robert A.

    1991-01-01

    Motion sickness typically is considered a bothersome artifact of exposure to passive motion in vehicles of conveyance. This condition seldom has significant impact on the health of individuals because it is of brief duration, it usually can be prevented by simply avoiding the eliciting condition and, when the conditions that produce it are unavoidable, sickness dissipates with continued exposure. The studies conducted examined several aspects of motion sickness in animal models. A principle objective of these studies was to investigate the neuroanatomy that is important in motion sickness with the objectives of examining both the utility of putative models and defining neural mechanisms that are important in motion sickness.

  16. Malaria control and eradication in Taiwan

    PubMed Central

    1958-01-01

    An intensive programme of residual spraying with DDT carried out over a period of 5 years in Taiwan has reduced malaria morbidity to a very low level. Since 1955, the goal has been complete eradication. Some foci of transmission and/or infection remain, however, and although no resistance problems have been encountered, the principal vector, A. minimus minimus, is still widely distributed. An elaborate surveillance organization is now in the process of creation, with the object of detecting and eliminating all residual foci of transmission and preventing the importation of fresh cases. It is hoped to complete eradication in another 3-5 years. PMID:13596886

  17. Time-frequency response spectrum of rotational ground motion and its application

    NASA Astrophysics Data System (ADS)

    Che, Wei; Luo, Qifeng

    2010-02-01

    The rotational seismic motions are estimated from one station records of the 1999 Jiji (Chi-Chi), Taiwan, earthquake based on the theory of elastic plane wave propagation. The time-frequency response spectrum (TFRS) of the rotational motions is calculated and its characteristics are analyzed, then the TFRS is applied to analyze the damage mechanism of one twelve-storey frame concrete structure. The results show that one of the ground motion components can not reflect the characteristics of the seismic motions completely; the characteristics of each component, especially rotational motions, need to be studied. The damage line of the structure and TFRS of ground motion are important for seismic design, only the TFRS of input seismic wave is suitable, the structure design is reliable.

  18. Invisible motion contributes to simultaneous motion contrast.

    PubMed

    Kawabe, Takahiro; Yamada, Yuki

    2009-03-01

    The purpose of the present study was two-fold. First we examined whether visible motion appearance was altered by the spatial interaction between invisible and visible motion. We addressed this issue by means of simultaneous motion contrast, in which a horizontal test grating with a counterphase luminance modulation was seen to have the opposite motion direction to a peripheral inducer grating with unidirectional upward or downward motion. Using a mirror stereoscope, observers viewed the inducer and test gratings with one eye, and continuous flashes of colorful squares forming an annulus shape with the other eye. The continuous flashes rendered the inducer subjectively invisible. The observers' task was to report whether the test grating moved upward or downward. Consequently, simultaneous motion contrast was observed even when the inducer was invisible (Experiment 1). Second, we examined whether the observers could correctly respond to the direction of invisible motion: It was impossible (Experiment 2). PMID:19185516

  19. Intrusion of the Pearl River plume into the main channel of the Taiwan Strait in summer

    NASA Astrophysics Data System (ADS)

    Bai, Yan; Huang, Ting-Hsuan; He, Xianqiang; Wang, Shu-Lun; Hsin, Yi-Chia; Wu, Chau-Ron; Zhai, Weidong; Lui, Hon-Kit; Chen, Chen-Tung Arthur

    2015-01-01

    The Penghu Channel is the main channel connecting the East and South China Seas, two of the largest marginal seas in the world. Located in the southeast of Taiwan Strait, the Penghu Channel is usually covered by the high salinity water from the South China Sea and the Kuroshio. However, we observed abnormal low-salinity water in the Penghu Channel during a cruise through the southern Taiwan Strait and northern South China Sea in August 2008. We argue that the normalized alkalinity is a good indicator for the identification of a river plume as it is not affected by rainwater. Using satellite-derived water transparency and chlorophyll images and field-measured alkalinity, the source of this low salinity water was found to be the intrusion of the Pearl River plume. A significant phytoplankton bloom across the entire Taiwan Strait occurred with the intrusion event. The intrusion was not a unique event, as we also found a strong jet-shaped Pearl River plume intruding into the Penghu Channel in the summer of 2009 from cloud-free satellite-derived images. Time series satellite data reveal that the Pearl River plume intrudes into the Penghu Channel in the summer of most years. Multiple data analysis and modeling simulation indicate that a large river discharge and strong southwesterly winds on the shelf may be responsible for the significant intrusion of the Pearl River plume into the Penghu Channel in summer. As the Pearl River plume has a high nutrient and dissolved inorganic carbon content, combined with the strong northward flows through the Penghu Channel, such intrusions may contribute to the nutrient dynamics and carbon budget of the East and northern South China Seas.

  20. Molluscan fauna of Gueishan Island, Taiwan

    PubMed Central

    Huang, Chih-Wei; Hsiung, Ta-Wei; Lin, Si-Min; Wu, Wen-Lung

    2013-01-01

    Abstract This dataset records the occurrence and inventory of molluscan fauna on Gueishan Island, the only active volcanic island in Taiwan, based on the literature survey and field investigation conducted between 2011 and 2012. The literature review involved seven studies published from 1934 to 2003, which collectively reported 112 species from 61 genera and 37 families of Mollusca on Gueishan Island. Through our field investigation, we identified 34 species from 28 genera and 23 families. Fourteen of these species were new records on Gueishan Island: Liolophura japonica, Lottia luchuana, Nerita costata, Nerita rumphii, Diplommatina suganikeiensis, Littoraria undulata, Solenomphala taiwanensis, Assiminea sp., Siphonaria laciniosa, Laevapex nipponica, Carychium hachijoensis, Succinea erythrophana, Zaptyx crassilamellata, and Allopeas pyrgula. In Total, there are 126 species from 71 genera and 45 families of Mollusca on Gueishan Island. These data have been published through GBIF [http://taibif.org.tw/ipt/resource.do?r=gueishan_island] and integrated into the Taiwan Malacofauna Database (http://shell.sinica.edu.tw/). PMID:23717182

  1. Fetal exposure to environmental neurotoxins in Taiwan.

    PubMed

    Jiang, Chuen-Bin; Hsi, Hsing-Cheng; Fan, Chun-Hua; Chien, Ling-Chu

    2014-01-01

    Mercury (Hg), lead (Pb), cadmium (Cd), and arsenic (As) are recognized neurotoxins in children that particularly affect neurodevelopment and intellectual performance. Based on the hypothesis that the fetal basis of adult disease is fetal toxic exposure that results in adverse outcomes in adulthood, we explored the concentrations of key neurotoxins (i.e., Hg, Pb, Cd, and As) in meconium to identify the risk factors associated with these concentrations. From January 2007 to December 2009, 545 mother-infant pairs were recruited. The geometric mean concentrations of Pb and As in the meconium of babies of foreign-born mothers (22.9 and 38.1 µg/kg dry weight, respectively) were significantly greater than those of babies of Taiwan-born mothers (17.5 and 33.0 µg/kg dry weight, respectively). Maternal age (≥30 y), maternal education, use of traditional Chinese herbs during pregnancy, and fish cutlet consumption (≥3 meals/wk) were risk factors associated with concentrations of key prenatal neurotoxins. The Taiwan government should focus more attention on providing intervention programs for immigrant mothers to help protect the health of unborn babies. Further investigation on how multiple neurotoxins influence prenatal neurodevelopment is warranted. PMID:25299345

  2. Fetal Exposure to Environmental Neurotoxins in Taiwan

    PubMed Central

    Jiang, Chuen-Bin; Hsi, Hsing-Cheng; Fan, Chun-Hua; Chien, Ling-Chu

    2014-01-01

    Mercury (Hg), lead (Pb), cadmium (Cd), and arsenic (As) are recognized neurotoxins in children that particularly affect neurodevelopment and intellectual performance. Based on the hypothesis that the fetal basis of adult disease is fetal toxic exposure that results in adverse outcomes in adulthood, we explored the concentrations of key neurotoxins (i.e., Hg, Pb, Cd, and As) in meconium to identify the risk factors associated with these concentrations. From January 2007 to December 2009, 545 mother-infant pairs were recruited. The geometric mean concentrations of Pb and As in the meconium of babies of foreign-born mothers (22.9 and 38.1 µg/kg dry weight, respectively) were significantly greater than those of babies of Taiwan-born mothers (17.5 and 33.0 µg/kg dry weight, respectively). Maternal age (≥30 y), maternal education, use of traditional Chinese herbs during pregnancy, and fish cutlet consumption (≥3 meals/wk) were risk factors associated with concentrations of key prenatal neurotoxins. The Taiwan government should focus more attention on providing intervention programs for immigrant mothers to help protect the health of unborn babies. Further investigation on how multiple neurotoxins influence prenatal neurodevelopment is warranted. PMID:25299345

  3. Community resilience after disaster in Taiwan: a case study of Jialan Village with the strengths perspective.

    PubMed

    Wang, Lih-Rong; Chen, Steven; Chen, Joseph

    2013-01-01

    This article examines community resilience in disaster recovery in Jialan Village, where many families lost their homes when Typhoon Morakot struck Taiwan in 2008. In-depth interviews were conducted with policymakers, social workers, resource coordinators, and leaders of the local aboriginal community. The main findings were (a) the village's recovery was due to the effective use and coordination of community resources; (b) partnership building between the public and private sectors was crucial in the community's recovery; and (c) the recovery was enhanced by values such as a strong sense of mutual help, good physical health, positive attitudes, and autonomy. PMID:23679806

  4. Records of new and rare elasmobranchs from Taiwan.

    PubMed

    Hsu, Hua Hsun; Joung, Shoou Jeng; Ebert, David A; Lin, Chia Yen

    2013-01-01

    Five new records of elasmobranchs collected from eastern Taiwan fish markets, Da-xi and Cheng-gong, are presented. Samples were caught by deepsea longliners and bottom trawlers which operate in northeastern waters off Taiwan between 2004 and 2012. These five new species records include the smalltooth sandtiger, Odontaspis ferox (Risso, 1810) (Lamniformes: Odontaspididae), salamander shark, Parmaturus pilosus Garman, 1906 (Carcharhiniformes: Scyliorhinidae), leadhued skate Notoraja tobitukai (Hiyama, 1940) (Rajiformes: Arhynchobatidae), giant skate Dipturus gigas (Ishiyama, 1958) (Rajiformes: Rajidae), and the pelagic stingray Pteroplatytrygon violacea (Bonaparte, 1832) (Myliobatiformes: Dasyatidae), Diagnostic characteristics for each species are given and a key to the genera Parmaturus and Dipturus from Taiwan is presented. PMID:25229118

  5. Munidopsis lauensis Baba & de Saint Laurent, 1992 (Decapoda, Anomura, Munidopsidae), a newly recorded squat lobster from a cold seep in Taiwan.

    PubMed

    Lin, Chia-Wei; Tsuchida, Shinji; Lin, Saulwood; Berndt, Christian; Chan, Tin-Yam

    2013-01-01

    The squat lobster, Munidopsis lauensis Baba & de Saint Laurent, 1992, is recorded from Taiwan for the first time. This species was previously known only from deep-sea hydrothermal vents in the South-West Pacific but it was now found at a deep-sea cold seep site off southwestern Taiwan. The identity of the Taiwanese material is confirmed by comparison of sequences from the barcoding gene COI. Munidopsis lauensis can be easily separated from other congeners in Taiwanese waters by the eyes bearing a strong mesiodorsal spine and a small mesioventral spine, smooth carapace, fingers of the cheliped distally spooned and fixed finger without a denticulate carina on the distolateral margin. The discovery of this species in Taiwan increases the Munidopsis fauna of the island to 38 species. A color photograph and line drawings illustrating distinctive characters are provided for the Taiwanese material. PMID:25112740

  6. Imaging the subsurface of Taiwan using ambient noise tomography and full waveform inversion

    NASA Astrophysics Data System (ADS)

    Rodzianko, Anastasia

    Arc-continent collision is a process that over millions of years built most of the existing continents. Continental crust is thought to remain on the surface during these plate interactions, and its mass loss is accounted for by shortening. Remnants and clues about the mechanics of this process are available on the surface of Earth, but to understand the mechanics one must probe the subsurface of modern day arc-continent collisions. Taiwan is such an example: it is the result of a complex, actively deforming tectonic boundary between the Eurasian and Philippine Sea plates. This seismically active location provides an excellent venue for seismically imaging processes related to arc-continent collision, which is what the TAIGER (TAiwan Integrated GEodynamics Research) project was created to accomplish. In this thesis, data collected by the TAIGER deployment, supplemented by observations from the permanent BATS (Broadband Array in Taiwan for Seismology) network, is used to create a 3D elastic wave velocity model of the crust and upper mantle beneath Taiwan. This model addresses an outstanding question about arc-continent interactions using the tectonic structure of Taiwan: do arc-continent collisions involve the consumption of continental crust? Ambient noise tomography techniques create a 3D Vs model by using continuous ambient noise, which is whitened and cross-correlated between stations to construct empirical Green's functions of Rayleigh waves. The correlations are graded by the signal to noise ratio prior to recovering group and phase velocities of the fundamental mode for periods between 6 and 30 seconds. The results are combined to generate a 3D Vs model from which a Vp model is calculated using a constant Vp/Vs ratio of 1.7. This model, combined with the arrival time model of Kuo-Chen et al. (2012), is used as a starting model for full waveform inversion of teleseismic body and surface waves using the 2.5D technique of Roecker et al. (2010). The results of this study show strong evidence for continental subduction in the southern part of the island. Throughout the entire island, lower shear wave speeds indicate that the crust thickens below the Coastal Mountain Range, forming a root up to ~50 km depth and extending to 90 km depth in the southern part of the island. The west half of the island is generally characterized by a thinner crust and the slowest shear wave speeds in the model. Continental subduction is not inferred from the resulting model of the northern part of the island, where the crustal root is ~60km deep; however, some low-velocity mantle structures are present.

  7. Anharmonicity in nuclear wobbling motion

    SciTech Connect

    Oi, M.

    2007-09-15

    An unexpected strong anharmonicity was observed in the wobbling spectrum in {sup 163}Lu. In an attempt to understand what causes the deviation from the original wobbling model by Bohr and Mottelson, an analysis is presented using several different approaches, such as exact diagonalization, a semiclassical model to deal with anharmonic wobbling motion, and a microscopic method based on the self-consistent cranking calculation.

  8. High frequency waves guided by the subducted plates underneath Taiwan and their association with seismic intensity anomalies

    NASA Astrophysics Data System (ADS)

    Chen, K. H.; Kennett, B. L.; Furumura, T.

    2011-12-01

    Energy from seismic events traveling up a subduction zone reveal large-amplitude, high-frequency signal with sustained long coda. In Japan, such seismic waves guided by the high wave velocity and high Q plate lead to surprisingly large intensity in the forearc area, even if the events are not felt near the epicenter. Seismic events with guided wave characteristics can explain the anomalous ground shaking, and provide useful information on the plate configuration. Taiwan, situated at the plate boundary zone between the Eurasian plate (EP) and the Philippine Sea plates (PSP), exhibits a unique interaction between the EP and PSP. In northeast Taiwan, the PSP subducts beneath the rifted Eurasian plate margin along the Ryukyu Trench, whereas in southwest Taiwan the Eurasian plate subducts underneath PSP. The anomalous seismic intensity from intermediate-depth earthquakes should happen in Taiwan, if the subducted plates are acting as an efficient waveguide for high-frequency seismic waves. Here we investigate the possible relationship between anomalous PGA patterns and the trapping effect of the high frequency signal in the PSP/EP. M>5 earthquakes along the subducted PSP reveal depth dependent waveguide behavior, confirming an association with a wave guide effect in the subducting slab rather than localized site amplification effects. Comparison of the PGA patterns and the seismic characteristics suggests that the abnormal intensity from intermediate-depth events is likely to be a result of excitation of high-frequency signals while propagating along the PSP. The events in EP show an extension of stronger seismic intensity and faster propagation speed along the Longitudinal Valley. This poses the question whether such an elongation of the intensity contours is associated with a fold of the Eurasian plate crust underneath eastern Taiwan. If so, we expect the guided waves to be observed at stations along the east coast or on the eastern flank of Central Range. The seismic waveform characteristics, however, reveal partial guiding across the southern portion of Taiwan and along the east coast, suggesting some of the high frequency energy may couple into the crust due to either long travel distance or thick plate. By detection and quantification of the subduction zone guided waves, the geometry, thickness, velocity gradient, and heterogeneities of the plates can be further inferred through 2D and 3D finite-difference modeling and comparison with other well-established subduction zones. Additionally, knowledge of waveguide characteristics and modeled parameters that fit the observations are critical inputs to connecting with the seismic intensity anomalies for ground motion and earthquake hazard estimation.

  9. COPD in Taiwan: a National Epidemiology Survey

    PubMed Central

    Cheng, Shih-Lung; Chan, Ming-Cheng; Wang, Chin-Chou; Lin, Ching-Hsiung; Wang, Hao-Chien; Hsu, Jeng-Yuan; Hang, Liang-Wen; Chang, Chee-Jen; Perng, Diahn-Warng; Yu, Chong-Jen

    2015-01-01

    Objectives To determine the prevalence of COPD in Taiwan and to document the disease characteristics and associated risk factors. Methods We conducted a random cross-sectional national survey of adults older than 40 years in Taiwan. Respiratory health screening questions identified subjects with diagnosed COPD or whose reported symptoms also fulfilled an epidemiological case definition; these were eligible to complete the survey, which also included indices of symptom severity and disability and questions on comorbidities, medical treatments, smoking habits, and occupations potentially harmful to respiratory health. Subjects with diagnosed COPD were subdivided by smoking status. Subjects who fulfilled the case definition of COPD and smoked were designated as possible COPD. Participants who did not fit the case definition of COPD were asked only about their personal circumstances and smoking habits. Data from these groups were analyzed and compared. Results Of the 6,600 participants who completed the survey, 404 (6.1%) fulfilled the epidemiological case definition of COPD: 137 with diagnosed COPD and 267 possible COPD. The most common comorbidities of COPD were hypertension or cardiovascular diseases (36.1%). Subjects with definite COPD had significantly higher COPD Assessment Test scores than the possible COPD group (14.68.32 vs 12.66.49, P=0.01) and significantly more comorbid illnesses (P=0.01). The main risk factors contributing to health care utilization in each COPD cohort were higher COPD Assessment Test scores (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.041.26), higher modified Medical Research Council Breathlessness Scale scores (OR 1.97, 95% CI 1.113.51), and having more than one comorbidity (OR 5.19, 95% CI 1.0525.61). Conclusion With estimated prevalence of 6.1% in the general population, COPD in Taiwan has been underdiagnosed. Symptoms and comorbidities were independent risk factors for health care utilization in subjects with definite or possible COPD. There is an urgent need to raise awareness of the importance of early evaluation and prompt treatment for subjects with chronic airway symptoms. PMID:26648708

  10. Paths toward hepatitis B immunization in South Korea and Taiwan

    PubMed Central

    2013-01-01

    South Korea and Taiwan have had similar experiences of economic development in the post-war era. The two societies have also successfully overcome the threat of liver cancer by using mass hepatitis B vaccinations. However, to reach their current states, they followed different directions, and experienced differing effects on their national health governance systems. In South Korea, vaccine production occurred prior to effectively introducing immunization programs. In contrast, Taiwan established an effective immunization program first. However, industrialization of vaccines against hepatitis B has failed. Taiwan has to import vaccines for domestic use. This article provides a contextual overview on the different methods South Korea and Taiwan have used to arrive at their modern status of hepatitis B immunization. PMID:23858397

  11. The Problems of Land Consolidation: A Case Study of Taiwan

    ERIC Educational Resources Information Center

    Williams, Jack F.

    1976-01-01

    Problems of agricultural land consolidation, as illustrated by Taiwan's first 10-year land reform phase, include fragmentation of holdings, cost of consolidation, corruption and maladministration by government officials, and timing of operations. (AV)

  12. Taiwan: AIDS NGOs fight to keep human rights law.

    PubMed

    Chung-Li, Pan

    2005-08-01

    Thirty-seven government deputies, all members of the ruling Democratic Progress Party (DPP), have recently proposed a bill to eliminate Article 6-1 of Taiwan's AIDS Prevention and Control Act (1997). PMID:16365972

  13. The Midwife in Taiwan: An Alternative Model for Maternity Care.

    ERIC Educational Resources Information Center

    Kang-Wang, Janet F.

    1980-01-01

    The author compares and analyzes American and Taiwanese maternity care systems, discussing the history of midwifery in Taiwan; the process by which a midwife establishes her practice; and her role in childbirth, abortion, adoption, and other services. (Author/DS)

  14. NRAO Welcomes Taiwan as a New North American ALMA Partner

    NASA Astrophysics Data System (ADS)

    2008-12-01

    The National Radio Astronomy Observatory (NRAO) has announced a formal agreement enabling Taiwanese astronomers to participate in the North American component of the international ALMA partnership, alongside American and Canadian astronomers. Taiwan's efforts will be led by the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). ALMA, the Atacama Large Millimeter/submillimeter Array, is the most ambitious ground-based astronomical observatory in history. Currently under construction in Chiles Atacama Desert at an altitude of 16,500 feet, it promises to revolutionize our understanding of the formation of planets, stars, and galaxies when it begins full science operations early in the next decade. The agreement, signed by the Taipei Economic and Cultural Representative Office and the American Institute in Taiwan, provides for approximately $20 million in ALMA construction funding through the National Science Council (NSC), Taiwans equivalent to the US National Science Foundation (NSF) and Canada's National Research Council (NRC), which have jointly funded North America's existing contribution to the international ALMA project. Activities under the agreement will include joint research projects, development projects, collaboration on construction, support of observatory operations and other forms of cooperation. Access to ALMA observing time will be shared, as will membership on advisory committees. Taiwan is a world-class center for submillimeter-wavelength astronomical research, and were delighted that the ALMA project and all its future users will benefit from the resources and expertise that Taiwans deepening participation brings to this great, global endeavor, said Dr. Fred Lo, NRAO's director. This new agreement increases and diversifies Taiwans Academia Sinica investment in ALMA beyond the levels achieved through its participation in the East Asian component of the ALMA partnership, which is led by the National Astronomical Observatory of Japan. The agreement mirrors previous ones affording Taiwan astronomers enhanced access to NRAOs US-based research facilities. ALMA will be one of the greatest ground-based observatories of the coming decade, and we look forward eagerly to working alongside our colleagues at the NRAO, and with the other ALMA partners, to make ALMA even more successful, said Dr. Paul Ho, ASIAAs director. The ALMA Project is a partnership between the scientific communities of East Asia, Europe and North America with Chile. ALMA is funded in North America by the U.S. National Science Foundation in cooperation with the National Research Council of Canada and the National Science Council of Taiwan. ALMA construction and operations are led on behalf of North America by the National Radio Astronomy Observatory, which is operated under cooperative agreement by Associated Universities, Inc.

  15. Amoebiasis among institutionalized psychiatric patients in Taiwan.

    PubMed Central

    Cheng, H. S.; Wang, L. C.

    1999-01-01

    Although information on amoebiasis among institutionalized psychiatric patients is available, reports on the relationship between behaviour and this infection are not abundant. From July 1995 to June 1996, stool and blood samples were collected from 565 patients in three psychiatric hospitals of North Taiwan. Stool samples were examined using the direct smear and formalin-ethyl acetate sedimentation techniques as well as ProSpecT Entamoeba histolytica Microplate Assay kit. Blood samples were examined by the Amebiasis Serology Microwell ELISA kit. Among these patients, 14 (2.5%) harboured one or two species of intestinal parasites. There were 6 (1.1%) E. histolytica/E. dispar cyst passers: 5 positive in stool ELISA test and 2 with antibodies against E. histolytica. Among demographic factors, type of psychiatric disorder and disability, only a significant sexual difference in seropositivity of E. histolytica was observed. These findings indicate that the infected patients acquired the infections before they entered the hospitals. PMID:10355798

  16. The first archaic Homo from Taiwan

    PubMed Central

    Chang, Chun-Hsiang; Kaifu, Yousuke; Takai, Masanaru; Kono, Reiko T.; Grün, Rainer; Matsu’ura, Shuji; Kinsley, Les; Lin, Liang-Kong

    2015-01-01

    Recent studies of an increasing number of hominin fossils highlight regional and chronological diversities of archaic Homo in the Pleistocene of eastern Asia. However, such a realization is still based on limited geographical occurrences mainly from Indonesia, China and Russian Altai. Here we describe a newly discovered archaic Homo mandible from Taiwan (Penghu 1), which further increases the diversity of Pleistocene Asian hominins. Penghu 1 revealed an unexpectedly late survival (younger than 450 but most likely 190–10 thousand years ago) of robust, apparently primitive dentognathic morphology in the periphery of the continent, which is unknown among the penecontemporaneous fossil records from other regions of Asia except for the mid-Middle Pleistocene Homo from Hexian, Eastern China. Such patterns of geographic trait distribution cannot be simply explained by clinal geographic variation of Homo erectus between northern China and Java, and suggests survival of multiple evolutionary lineages among archaic hominins before the arrival of modern humans in the region. PMID:25625212

  17. Resolving Topographic Steady State in Taiwan

    NASA Astrophysics Data System (ADS)

    Stolar, D. B.; Willett, S. D.; Montgomery, D. R.

    2002-12-01

    The arc-continent collision in Taiwan has resulted in surface uplift, high relief and high rates of erosion. Furthermore, because the collision is older in the north and propagates southward, Taiwan provides an opportunity to observe the evolution of topography, measure rates of evolution and test whether topographic steady-state (SS) is achieved. We address these points by using landscape properties extracted from a 40 m digital elevation model. We use a variety of geomorphic measures in order to determine which provide the best characterization of the pre-SS and SS topography. Values of several topographic characteristics are calculated on 5 km wide transects perpendicular to the Central Range, with values projected onto a trend parallel to the range, thus examining change in topography with north-south position, or equivalently, time since initiation of collision. Along this trend, we calculate and plot (1) the volume of material above sealevel, (2) the mean elevation, and (3) the maximum elevation. All of these parameters increase monotonically from the southern tip of the island to the southern end of the Longitudinal Valley, 100 km to the north. North of this point, these quantities attain roughly constant values. We thus interpret this as topographic SS. Predicted collision propagation rates vary between 50 and 90 mm/yr, implying that SS is achieved 1.5 - 2.5 Myr after emergence above sealevel. We calculate the hypsometry of individual basins in the eastern Central Range and find different characteristic forms for basins south and north of the SS transition. We find that more area is concentrated at low elevations in southern basins than in northern basins. We also calculate river profile parameters through an inversion method which fits the river profile thereby estimating the concavity and channel steepness index. River concavities vary between 0.32 and 0.61, with no discernible spatial trend. Although the topography of north and central Taiwan appears to be in SS at a large scale, there are significant deviations from the expected value. The mean topography and cross-sectional volume show a long-wavelength oscillation at distances of 100 to 300 km north of the south tip of the island, corresponding to structures in the basement around the Yushan Range and the pop-up structure of the Hsueshan Range in north Taiwan. There is also considerable variability in basin hypsometry and river profile parameters within the region thought to be in SS. Many profiles deviate from the smooth exponential curves predicted from river erosion models, which assume uniform uplift rate and erodability, but whether these deviations represent smaller-scale transient behavior initiated by changes in tectonic or climatic conditions or steady spatial variations in lithology or uplift rate is unresolved.

  18. The first archaic Homo from Taiwan.

    PubMed

    Chang, Chun-Hsiang; Kaifu, Yousuke; Takai, Masanaru; Kono, Reiko T; Grn, Rainer; Matsu'ura, Shuji; Kinsley, Les; Lin, Liang-Kong

    2015-01-01

    Recent studies of an increasing number of hominin fossils highlight regional and chronological diversities of archaic Homo in the Pleistocene of eastern Asia. However, such a realization is still based on limited geographical occurrences mainly from Indonesia, China and Russian Altai. Here we describe a newly discovered archaic Homo mandible from Taiwan (Penghu 1), which further increases the diversity of Pleistocene Asian hominins. Penghu 1 revealed an unexpectedly late survival (younger than 450 but most likely 190-10 thousand years ago) of robust, apparently primitive dentognathic morphology in the periphery of the continent, which is unknown among the penecontemporaneous fossil records from other regions of Asia except for the mid-Middle Pleistocene Homo from Hexian, Eastern China. Such patterns of geographic trait distribution cannot be simply explained by clinal geographic variation of Homo erectus between northern China and Java, and suggests survival of multiple evolutionary lineages among archaic hominins before the arrival of modern humans in the region. PMID:25625212

  19. Application of INCSEA principles to the Taiwan Strait.

    SciTech Connect

    Wen-Chung, Chai

    2003-06-01

    The waters surrounding Taiwan are important international waterways. In addition to merchant ships of every nation, the warships of the United States, Japan, Russia, and China may appear in these waters. No hostility is expected between Taiwan and the United States, Japan, or Russia; however, Taiwan and China have a tense relationship, and both sides face a potential for naval incidents. As Taiwan and China expand their naval capability, the International Maritime Organization Convention for the lnternational Regulations for Preventing Collisions at Sea may not be sufficient to prevent naval incidents, any of which might develop into conflict or war. Therefore, China and Taiwan need to develop maritime confidence building measures (CBMs) that could reduce the chance of naval incidents and strengthen mutual trust and confidence. Among the variety of maritime CBM concepts for military purposes, the most successful and effective measure has been the 1972 U.S.-Soviet Union Agreement on the Prevention of Incidents On and Over the High Seas (INCSEA). The success of the agreement demonstrates that CBMs represent a workable alternative to traditional arms controls. The purpose of this paper is to suggest a concrete approach to the constraint of naval activities between China and Taiwan to reduce accidents and misunderstandings. This paper outlines the categories and characteristics of incidents at sea. Next, the author identifies the successful factors of the U.S.-Soviet INCSEA and applies the INCSEA concept to the Taiwan Strait. Finally, the author develops a framework of options and a step-by-step approach for establishing an INCSEA between Taiwan and China.

  20. Characteristics of foot and mouth disease virus in Taiwan.

    PubMed

    Huang, C C; Jong, M H; Lin, S Y

    2000-07-01

    Since March 1997 two strains of foot and mouth disease (FMD) virus have found their way into Taiwan, causing severe outbreaks in pigs and in Chinese yellow cattle. Outbreaks occurred in March 1997 were caused by a pig-adapted virus strain (O/Taiwan/97) which did not infect other species of cloven-hoofed animals by natural route. The epidemic spread over the whole region of Taiwan within two months and the aftermath was 6,147 pig farms infected an