The crustal fluid evolution and the causes of earthquakes(Ⅲ)

Ｔｈｅｃｒｕｓｔａｌｆｌｕｉｄｅｖｏｌｕｔｉｏｎａｎｄｔｈｅｃａｕｓｅｓｏｆｅａｒｔｈｑｕａｋｅｓ（Ⅲ）ＣＨＡＮＧ－ＦＡＮＧＸＵ（徐常芳）ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｌｏｇｙ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂｅｉｊｉｎｇ１０００...     

Probabilistic predictive model with complex remembrance

（王键）Ｐｒｏｂａｂｉｌｉｓｔｉｃｐｒｅｄｉｃｔｉｖｅｍｏｄｅｌｗｉｔｈｃｏｍｐｌｅｘｒｅｍｅｍｂｒａｎｃｅ￥ＪｉａｎＷＡＮＧ（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂｅｉｊｉｎｇ１０００８１，...     

ApplicationofcertaintyfactorsofearthquakeprecursoryanomalyevidencesCF（E）

ＡｐｐｌｉｃａｔｉｏｎｏｆｃｅｒｔａｉｎｔｙｆａｃｔｏｒｓｏｆｅａｒｔｈｑｕａｋｅｐｒｅｃｕｒｓｏｒｙａｎｏｍａｌｙｅｖｉｄｅｎｃｅｓＣＦ（Ｅ）ＺＨＡＯ－ＢＩＺＨＥＮＧ（郑兆），ＪＵＮＺＨＡＮＧ（张军）ａｎｄＭＥＩＱＩＮＧ（庆梅）Ｓｅｉｓｍｏｌｏ...     

Certainty factors of earthquake precursory anomaly evidences CF(E)

ＣｅｒｔａｉｎｔｙｆａｃｔｏｒｓｏｆｅａｒｔｈｑｕａｋｅｐｒｅｃｕｒｓｏｒｙａｎｏｍａｌｙｅｖｉｄｅｎｃｅｓＣＦ（Ｅ）Ｚｈａｏ－ＢｉＺＨＥＮＧ（郑兆）（ＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕｏｆＡｎｈｕｉＰｒｏｖｉｎｃｅ，Ｈｅｆｅｉ２３００３１，Ｃｈ...     

Global shear stress pattern in main seismic active belts

ＧｌｏｂａｌｓｈｅａｒｓｔｒｅｓｐａｔｅｒｎｉｎｍａｉｎｓｅｉｓｍｉｃａｃｔｉｖｅｂｅｌｔｓＬＥＩＸＩＡＯ（肖磊）ＰＥＩ－ＳＨＡＮＣＨＥＮ（陈培善）ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂｅｉ...     

The research on the space time coherence of Xianshuihe fault zone in the process of seismogeny

Ｔｈｅｒｅｓｅａｒｃｈｏｎｔｈｅｓｐａｃｅ┐ｔｉｍｅｃｏｈｅｒｅｎｃｅｏｆＸｉａｎｓｈｕｉｈｅｆａｕｌｔｚｏｎｅｉｎｔｈｅｐｒｏｃｅｓｏｆｓｅｉｓｍｏｇｅｎｙＳＨＩ－ＢＩＡＯＷＡＮＧ（王时标）ＺＨＥＮ－ＸＩＮＧＹＡＯ（姚振兴）Ｉｎｓｔｉｔｕｔｅｏｆ...     

Relationship between global seismicity and solar activities

ＲｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｅｎｇｌｏｂａｌｓｅｉｓｍｉｃｉｔｙａｎｄｓｏｌａｒａｃｔｉｖｉｔｉｅｓＧＵＩ－ＱＩＮＧＺＨＡＮＧ（张桂清）ＢｅｉｊｉｎｇＡｓｔｒｏｎｏｍｉｃａｌＯｂｓｅｒｖａｔｏｒｙ,ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅ...     

Database system for deep seismicsounding

ＤａｔａｂａｓｅｓｙｓｔｅｍｆｏｒｄｅｅｐｓｅｉｓｍｉｃｓｏｕｎｄｉｎｇＣｈｕｎ－ＹｏｎｇＷＡＮＧ；（王椿镛）ＨａｉＬＯＵ（楼海）ａｎｄＹｉ－ＱｉｎｇＳＯＮＧ（宋亦青）（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌ...     

Theoretical researches on three-dimensional coda wave scattering problem

Ｔｈｅｏｒｅｔｉｃａｌｒｅｓｅａｒｃｈｅｓｏｎｔｈｒｅｅ－ｄｉｍｅｎｓｉｏｎａｌｃｏｄａｗａｖｅｓｃａｔｔｅｒｉｎｇｐｒｏｂｌｅｍＹｏｎｇ－ＡｎＮＩＥ；ＪｉａｎＺＥＮＧａｎｄＤｅ－ＹｉＦＥＮＧ（聂永安，曾健，冯德益）（ＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒ...     

Simulation of the active and quiet periods of seismicity

ＳｉｍｕｌａｔｉｏｎｏｆｔｈｅａｃｔｉｖｅａｎｄｑｕｉｅｔｐｅｒｉｏｄｓｏｆｓｅｉｓｍｉｃｉｔｙＺＨＯＮＧ－ＸＭＮＨＵＡＮＧ（黄忠贤）（ＩｎｓｔｉｔｕｔｅｏｆＣｒｕｓｔａｌＤｙｎａｍｉｃｓ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂｅｉｊｉ...     

Design Earthquakes in the U.K.

Three sites in the UK are taken, representative of low, medium and high hazard levels (by UK standards). For each site, the hazard value at 10⁻⁴ annual probability is computed using a generic seismic source model, and a variety of ground motion parameters: peak ground acceleration (PGA), spectral acceleration at 10 Hz and 1 Hz, and intensity. Disaggregation is used to determine the nature of the earthquakes most likely to generate these hazard values. It is found (as might be expected) that the populations are quite different according to which ground motion parameter is used. When PGA is used, the result is a rather flat magnitude distribution with a tendency to low magnitude events (\le 4.5 ML) which are probably not really hazardous. Hazard-consistent scenario earthquakes computed using intensity are found to be in the range 5.8–5.9 ML, which is more in accord with the type of earthquake that one expects to be a worst-case event in the UK. This revised version was published online in July 2006 with corrections to the Cover Date.     

根据截断的G-R模型计算东北地震区震级上限

震级上限是指一个地区可能发生地震的最大震级,其概率意义为发生超过该震级地震的概率几乎为0.在有些地区,由于对其内部的地震构造研究和认识存有局限性,很难根据构造或者地质学的原则来确定震级上限.因此,根据数学模型,采用统计手段,使用地震活动性资料来计算震级上限的估计值是一种可行的方法.本文根据截断的G-R关系模型,采用最大似然计算方法,使用东北地震区的地震目录,计算了东北地震区震级上限,结果表明东北地震区的震级上限应为M_u=7.5左右.计算中我们考虑了不同震级的转换、震级误差的修正以及计算方法的影响.最终结果表明,不论采用何种方案进行计算,东北地震区的震级上限值均始终保持在7.5左右,这说明我们采用本文中方法计算得到的东北地震区的震级上限值是合理可信的,同时也说明在以往的研究中对东北地震区震级上限的估计大都是偏小的.     

Cumulative frequency b value without upper bound magnitude and its regression determination

ＣｕｍｕｌａｔｉｖｅｆｒｅｑｕｅｎｃｙｂｖａｌｕｅｗｉｔｈｏｕｔｕｐｐｅｒｂｏｕｎｄｍａｇｎｉｔｕｄｅａｎｄｉｔｓｒｅｇｒｅｓｓｉｏｎｄｅｔｅｒｍｉｎａｔｉｏｎＪｉａｎ－ＷｅｎＳＨＥＮ（沈建文）（ＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕｏｆＡｎｈｕｉＰ...     

Discussion on the influence of truncation of ground motion residual distribution on probabilistic seismic hazard assessment

Recent studies on assessment of a very low annual probability of exceeding (APE) ground motions, 10-4 or less, have highlighted the importance of the upper bound of ground motions when very low probability results are acquired. The truncation level adopted in probabilistic seismic hazard analysis (PSHA) should be determined by an aleatory uncertainty model (i.e., distribution model) of ground motions and the possible maximum and minimum ground motion values of a specific earthquake. However, at the present ...     

Correction to the crustal thickness of the northwestern China using the data of seis-mic tomography

Introduction The gravity anomaly is an indicator of the density distribution of the underground material. Therefore the gravity anomalies have been important data used for studying the deep crustal struc-ture for a long time. Many people have made detailed researches on the regional crustal structure inverted by Bouguer anomalies. In particular some empirical formulae and practical algorithms about the crustal thickness were brought forward, and a series of results were obtained (MENG, 1996)…     

Tectonophysics and recent geodynamics

Important problems of tectonophysical analysis of observational results in recent geodynamics are considered. The paradox of low rates of recent horizontal deformations of the Earth’s surface is formulated. This paradox states that, according to GPS measurements, the annual mean rates of relative deformations are 10⁻⁹–10⁻¹⁰ per year, whereas, according to ground-based geodetic and deformographic observations, the rates of recent horizontal deformations of the Earth’s surface are on the order of 10⁻⁵–10⁻⁶ per year. This paradox is shown to appear as a result of the application of the procedure of averaging to the displacements obtained on large measuring bases with a low degree of details of the time of observations. It is established that, according to multiyear (over 40 years) data, the annual mean rate of deformation processes in the Kopet Dagh seismically active region is 4 × 10⁻⁸ per annum along the vertical and 3.2 × 10⁻⁸ per year along the horizontal.     

潜在震源区震级上限不确定性研究

潜在震源区的震级上限（Mu）是指在该潜在震源区内可能发生的最大地震的震级．预期未来发生超过该震级地震的概率趋于0．本文运用误差分析及逻辑树等方法,并结合发震模型的数值模拟得到的大震合成目录等结果,系统分析并最终得到了不同途径给出的不同类型潜在震源区震级上限的不确定性．该结果可直接应用于包括地震区划在内的工程地震以及活动断裂危险性评价等工作中．      

Probability Estimates of Extreme Temperature Events: Stochastic Modelling Approach vs. Extreme Value Distributions

The paper deals with the probability estimates of temperature extremes (annual temperature maxima and heat waves) in the Czech Republic. Two statistical methods of probability estimations are compared; one based on the stochastic modelling of time series of the daily maximum temperature (TMAX) using the first-order autoregressive (AR(1)) model, the other consisting in fitting the extreme value distribution to the sample of annual temperature peaks.The AR(1) model is able to reproduce the main characteristics of heat waves, though the estimated probabilities should be treated as upper limits because of deficiencies in simulating the temperature variability inherent to the AR(1) model. Theoretical extreme value distributions do not yield good results when applied to maximum annual lengths of heat waves and periods of tropical days (TMAX 30°C), but it is the best method for estimating the probability and recurrence time of annual one-day temperature extremes. However, there are some difficulties in the application: the use of the two-parameter Gumbel distribution and the three-parameter generalized extreme value (GEV) distribution may lead to different results, particularly for long return periods. The resulting values also depend on the chosen procedure of parameter estimation. Based on our findings, the shape parameter testing for the GEV distribution and the L moments technique for parameter estimation may be recommended.The application of the appropriate statistical tools indicates that the heat wave and particularly the long period of consecutive tropical days in 1994 were probably a more rare event than the record-breaking temperatures in July 1983 exceeding 40°C. An improvement of the probability estimate of the 1994 heat wave may be expected from a more sophisticated model of the temperature series.     

Non‐ergodicity and PEER's framework formula

A framework formula for performance‐based earthquake engineering, advocated and used by researchers at the Pacific Earthquake Engineering Research (PEER) Center, is closely examined. The formula was originally intended for computing the mean annual rate of a performance measure exceeding a specified threshold. However, it has also been used for computing the probability that a performance measure will exceed a specified threshold during a given period of time. It is shown that the use of the formula to compute such probabilities could lead to errors when non‐ergodic variables (aleatory or epistemic) are present. Assuming a Poisson model for the occurrence of earthquakes in time, an exact expression is derived for the probability distribution of the maximum of a performance measure over a given period of time, properly accounting for non‐ergodic uncertainties. This result is used to assess the approximation involved in the PEER formula for computing probabilities. It is found that the PEER approximation of the probability has a negligible error for probabilities less than about 0.01. For larger probabilities, the error depends on the magnitude of non‐ergodic uncertainties and the duration of time considered and can be as much as 20% for probabilities around 0.05 and 30% for probabilities around 0.10. The error is always on the conservative side. Copyright © 2005 John Wiley & Sons, Ltd.     

Influence of uncertainty in delimitation of seismic statistical zone on results of PSHA

The seismic hazard of research area is evaluated by probabilistic analysis method for three different seismic statistical zone scenarios.The influence of uncertainty in seismic statistical zone delimiting on the evaluation result is discussed too.It can be seen that for those local sites along zone‘s border or within areas with vast change of upper bound magnitude among different scenarios the influence on seismic hazard result should not be neglected.