Attenuation relations of Arias intensity based on the Chi-Chi Taiwan earthquake data   总被引：1，自引：0，他引：1  

H. Hwang  C. K. Lin  Y. T. Yeh  S. N. Cheng  K. C. Chen 《Soil Dynamics and Earthquake Engineering》2004,24(7):509-517

This paper presents a derivation of attenuation relations of Arias intensity for various site conditions based on the strong-motion data recorded in the 1999 Chi-Chi Taiwan earthquake. The data are from the mainshock and three large aftershocks with stations in the footwall area and in the area away from the fault. At each station, Arias intensity is computed from two horizontal acceleration time histories. The Arias intensity data are separated into four groups according to site classes assigned to recording stations. For each site class, the attenuation relation of Arias intensity is derived using a two-step regression analysis method. The attenuation relations established in this study can be used to estimate Arias intensity from a rupture of a thrust fault for sites in the footwall area or in the area away from the fault.  相似文献   

Istanbul Earthquake Rapid Response and the Early Warning System   总被引：13，自引：0，他引：13  

M. Erdik  Y. Fahjan  O. Ozel  H. Alcik  A. Mert  M. Gul 《Bulletin of Earthquake Engineering》2003,1(1):157-163

One hundred strong motion accelerometers have been placed in populated areas of Istanbul, within an area of approximately 50×30 km, to constitute a network that will enable rapid shake map and damage assessment after a damaging earthquake. After triggered by an earthquake, each station will process the streaming strong motion to yield the spectral accelerations at specific periods and will send these parameters in the form of SMS messages to the main data center through available GSM network services. A shake map and damage distribution will be automatically generated. The shake and damage maps will be available on the Internet and will also be pushed to several end users. For earthquake early warning information ten strong motion stations were located as close as possible to the Marmara Fault. The continuous on-line data from these stations will be used to provide near-real time warning for emerging potentially disastrous earthquakes. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

TOPEX/POSEIDON-derived space–time variations of the Kuroshio Current: applications of a gravimetric geoid and wavelet analysis     

Cheinway Hwang  Ricky Kao 《Geophysical Journal International》2002,151(3):835-847

  相似文献   

中国大陆科学钻探工程主孔榴辉岩中金红石微量元素地球化学特征   总被引：10，自引：2，他引：8  

余金杰  徐珏  陈振宇  王登红  陈毓川  王平安  李晓峰 《地质学报》2006,80(12):1835-1841

本文利用电子探针分析了中国大陆科学钻探工程主孔各种类型榴辉岩中金红石的Nb、Cr和Zr含量。Zack等(2002)的金红石Nb-Cr图解表明榴辉岩的原岩均为镁铁质岩,但不同类型榴辉岩具有不同的地球化学特征,即:1金红石榴辉岩、石英榴辉岩、角闪岩和钛铁矿榴辉岩中金红石的Nb和Cr含量大致相同,主孔中上述榴辉岩中金红石的Nb、Cr含量与区域上小焦金红石矿区金红石榴辉岩中金红石的Nb、Cr含量基本相同。总体来讲,区域和主孔榴辉岩中金红石以低Nb为特征,反映它们的原岩为镁铁质岩石。2蓝晶石多硅白云母榴辉岩中金红石具最高的Nb和Cr含量,其Nb和Cr均值分别为720×10-6和712×10-6,多硅白云母榴辉岩中金红石比金红石榴辉岩、石英榴辉岩、角闪岩和钛铁矿榴辉岩中金红石富集Cr。利用Zack等(2004)提出的金红石地质温度计,计算得出金红石榴辉岩的金红石形成温度介于608~746℃,石英榴辉岩的金红石温度介于629~680℃,钛铁矿榴辉岩金红石的形成温度介于629~704℃,蓝晶石多硅白云母榴辉岩的金红石形成温度为600℃,角闪岩的金红石形成温度为629℃。一种可能的解释是,榴辉岩在折返过程中退变质作用明显,流体活动强烈,导致金红石中Zr扩散丢失,金红石中Zr含量不同程度地受到角闪岩相退变质过程中再平衡作用的影响,致使计算的温度偏低。  相似文献   

Re-evaluation of Morphological Diagnostic Characteristics of <Emphasis Type="Italic">Hexapleomera</Emphasis> Dudich, 1931 (Crustacea: Tanaidacea), with Description of a New Species     

Jin?Hee?Wi  Chang-Keun?Kang  In?Tae?Lee  Hyeon?Gyeong?JeongEmail author 《Ocean Science Journal》2018,53(4):641-653

An undescribed species of Tanaidacea was collected from Yokji Harbor in the southern coast of Korea. Hexapleomera yokjidona n. sp. can be distinguished from other species of the genus by the distinguishing features of a uropod with five articles, a pleopod basal article lacking inner seta, a mandible setal row with two setae, maxilliped coxa with two proximal setae, pereonites 1–3 together longer than wide, and pereopods 2–3 propodus with three ventral setae. To prove that H. yokjidona is a new species, detailed morphological characteristics of both genders are described and a comprehensive comparison among the species of the genus is tabulated. Additionally, diagnostic characteristics previously used to identify the species of Hexapleomera are reassessed and upgraded.  相似文献   

A probabilistic model for ghost delay time estimation based on recording geometry          下载免费PDF全文

James Rickett  Inês Cecílio 《Geophysical Prospecting》2018,66(5):964-974

In order to deconvolve the ghost response from marine seismic data, an estimate of the ghost operator is required. Typically, this estimate is made using a model of in‐plane propagation, i.e., the ray path at the receiver falls in the vertical plane defined by the source and receiver locations. Unfortunately, this model breaks down when the source is in a crossline position relative to the receiver spread. In this situation, in‐plane signals can only exist in a small region of the signal cone. In this paper, we use Bayes' theory to model the posterior probability distribution functions for the vertical component of the ray vector given the known source–receiver azimuth and the measured inline component of the ray vector. This provides a model for the ghost delay time based on the acquisition geometry and the dip of the wave in the plane of the streamer. The model is fairly robust with regard to the prior assumptions and controlled by a single parameter that is related to the likelihood of in‐plane propagation. The expected values of the resulting distributions are consistent with the deterministic in‐plane model when in‐plane likelihood is high but valid everywhere in the signal cone. Relaxing the in‐plane likelihood to a reasonable degree radically simplifies the shape of the expected‐value surface, lending itself for use in deghosting algorithms. The model can also be extended to other plane‐wave processing problems such as interpolation.  相似文献   

Field measurements for calibration of simplified models of the stiffening effect of infill masonry walls in high-rise RC framed and shear-wall buildings     

Zhou  Yun  Pei  Yilin  Zhou  Yi  Hwang  Hyeon-Jong  Yi  Weijian 《地震工程与工程振动(英文版)》2020,19(1):87-104

As a type of nonstructural component, infill walls play a significant role in the seismic behavior of high-rise buildings. However, the stiffness of the infill wall is generally either ignored or considered by simplified empirical criteria that lead to a period shortening. The difference can be greatly decreased by using a structural identification methodology. In this study, an ambient vibration test was performed on four on-site reinforced concrete high-rise buildings, and the design results were compared with the PKPM models using corresponding finite element(FE) models. A diagonal strut model was used to simulate the behavior of the infill wall, and the identified modal parameters measured from the on-site test were employed to calibrate the parameters of the diagonal strut in the FE models. The SAP2000 models with calibrated elastic modulus were used to evaluate the seismic response in the elastic state. Based on the load-displacement relationship of the infill wall, nonlinear dynamic analysis models were built in PERFORM-3 D and calibrated using the measured modal periods. The analysis results revealed that the structural performance under small/large earthquake records were both strengthened by infill walls, and the contribution of infill walls should be considered for better accuracy in the design process.  相似文献   

Estimating landslide susceptibility areas considering the uncertainty inherent in modeling methods     

Ho?Gul?Kim  Dong?Kun?LeeEmail author  Chan?Park  Yoonjung?Ahn  Sung-Ho?Kil  Sunyong?Sung  Gregory?S.?Biging 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(11):2987-3019

Landslides are one of the most dangerous types of natural disasters, and damage due to landslides has been increasing in certain regions of the world because of increased precipitation. Policy decision makers require reliable information that can be used to establish spatial adaptation plans to protect people from landslide hazards. Researchers presently identify areas susceptible to landslides using various spatial distribution models. However, such data are associated with a high amount of uncertainty. This study focuses on quantifying the uncertainty of several spatial distribution models and identifying the effectiveness of various ensemble methods that can be used to provide reliable information to support policy decisions. The area of study was Inje-gun, Republic of Korea. Ten models were selected to assess landslide susceptibility. Moreover, five ensemble methods were selected for the aggregated results of the 10 models. The uncertainty was quantified using the coefficient of variation and the uncertainty map we developed revealed areas with strongly differing values among single models. A matrix map was created using an ensemble map and a coefficient of variation map. Using matrix analysis, we identified the areas that are most susceptible to landslides according to the ensemble model with a low uncertainty. Thus, the ensemble model can be a useful tool for supporting decision makers. The framework of this study can also be employed to support the establishment of landslide adaptation plans in other areas of the Republic of Korea and in other countries.  相似文献   

Empirical formula for fundamental vibration periods of reinforced concrete buildings in Taiwan     

Li‐Ling Hong  Woei‐Luen Hwang 《地震工程与结构动力学》2000,29(3):327-337

More than 30 buildings around Taiwan have been selected to monitor the floor responses under seismic excitation. The structural array monitoring system in each building controls at most 27 channels of accelerometers distributed in several floors. Those buildings were triggered by many events during the past five years of operation. In each building, the records at the basement can be considered as the ground excitation, and the others at the upper floors are the structural responses. The frequency transfer functions of those buildings can be identified by ARX models, and then the fundamental vibration periods are estimated. The identified fundamental vibration periods using different events are compared in order to ensure the reliability of system identification. An empirical formula in predicting the fundamental vibration period is presented through the regression analysis to the identified fundamental vibration periods of 21 reinforced concrete (RC) moment‐resisting frame (MRF) buildings. It is found that the height of a building plays an important role in predicting the fundamental vibration period, compared with the length, width, and time after completion of the building. It is also found that the RC MRF buildings in Taiwan tend to be stiffer than those in the U.S. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Dynamics of particle export on the Northwest Atlantic margin     

Jeomshik Hwang  Steven J. Manganini  Daniel B. Montluon  Timothy I. Eglinton 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(10):1792-1803

The Northwest Atlantic margin is characterized by high biological productivity in shelf and slope surface waters. In addition to carbon supply to underlying sediments, the persistent, intermediate depth nepheloid layers emanating from the continental shelves, and bottom nepheloid layers maintained by strong bottom currents associated with the southward flowing Deep Western Boundary Current (DWBC), provide conduits for export of organic carbon over the margin and/or to the interior ocean. As a part of a project to understand dynamics of particulate organic carbon (POC) cycling in this region, we examined the bulk and molecular properties of time-series sediment trap samples obtained at 968 m, 1976 m, and 2938 m depths from a bottom-tethered mooring on the New England slope (water depth, 2988 m). Frequent occurrences of higher fluxes in deep relative to shallower sediment traps and low Δ¹⁴C values of sinking POC together provide strong evidence for significant lateral transport of aged organic matter over the margin. Comparison of biogeochemical properties such as aluminum concentration and flux, and iron concentration between samples intercepted at different depths shows that particles collected by the deepest trap had more complex sources than the shallower ones. These data also suggest that at least two modes of lateral transport exist over the New England margin. Based on radiocarbon mass balance, about 30% (±10%) of sinking POC in all sediment traps is estimated to be derived from lateral transport of resuspended sediment. A strong correlation between Δ¹⁴C values and aluminum concentrations suggests that the aged organic matter is associated with lithogenic particles. Our results suggest that lateral transport of organic matter, particularly that resulting from sediment resuspension, should be considered in addition to vertical supply of organic matter derived from primary production, in order to understand carbon cycling and export over continental margins.  相似文献