Lamé parameters inversion based on elastic impedance and its application

The Connolly (1999) elastic impedance (EI) equation is a function of P-wave velocity, S-wave velocity, density, and incidence angle. Conventional inversion methods based on this equation can only extract P-velocity, S-velocity, and density data directly and the elastic impedance at different incidence angles are not at the same scale, which makes comparison difficult. We propose a new elastic impedance equation based on the Gray et al. (1999) Zoeppritz approximation using Lamé parameters to address the conventional inversion method’s deficiencies. This equation has been normalized to unify the elastic impedance dimensions at different angles and used for inversion. Lamé parameters can be extracted directly from the elastic impedance data obtained from inversion using the linear relation between Lamé parameters and elastic impedance. The application example shows that the elastic parameters extracted using this new method are more stable and correct and can recover the reservoir information very well. The new method is an improvement on the conventional method based on Connolly’s equation. Wang Baoli graduated with a Bachelor’s degree in Prospecting Information and Engineering from the China University of Petroleum (East China) in 2004 and earned her Master’s degree from the department of Geophysical Prospecting and Information Technology in the China University of Petroleum ((East China) in 2006. She now studies for her PhD at the China University of Petroleum (East China). Her research interest is elastic impedance inversion.     

北京地区近断层强地震动模拟

文中利用1679年三河-平谷8级地震的有关资料和北京地区地下三维结构的研究成果,建立了相应的震源模型和传播介质模型。利用Graves的三维有限差分程序,计算了北京地区震后的地面峰值速度。通过对计算结果的分析处理,获得了近断层强地震动的近断层效应、方向性效应、上盘效应和盆地效应等基本特征。同时,这些特征也反映了我们所设定的震源和传播介质参数的合理性,以及模拟方法的正确性。另外,分析处理中所获得的这些结果可为北京地区的城市规划和抗震设防提供客观的参考依据     

SQIP方法在华北地区地震中、短期预测中的应用研究

对SQIP地震学中期预测方法在华北地区的中期预测效果进行了重新评价,回溯性全时空扫描检验报准率R值约为0.67~0.68。做了方法中短期和短期预测指标的提取尝试。结果表明综合参量P值异常区由最大出现收缩后,平均约7个月左右发生未来主震,其中6个月内的震例约占有“收缩”震例的53%~54%,在3个月内的约占33%~35%;部分震例发生在异常区消失后7~8个月内。表明P值异常区“收缩”(或消失)一定程度上可以作为中、强地震的中短期预测标志。     

松辽盆地北部火山岩CO2脱气参数及其对CO2资源量估算的意义

为了定量评价火山岩脱CO2气量的潜力，选择松辽盆地北部火山岩进行了低温脱气实验。将火山岩加热到250℃时，脱出挥发份总量为0.0299～0.0790ml/g；其中CO2脱出量为0.0218～0.0706 ml/g（0.429～1.387wt％）。脱挥发份总量与其中CO2量具有良好的正线性相关；挥发份以CO2气为主，其次是Ｎ2气，还伴有H2、CO、CH4等还原性气体，以及更少量的低碳烷烃；基性火山岩比中、酸性火山岩脱出CO2数量较多。火山岩吸附大量CO2气，成为充足气源，火山岩脱出的吸附气主要是辗转而来的深源气，火山岩成为探索幔源气成藏的主要源岩，尤其是基性火山岩。估算CO2资源量，可将250℃时火山岩挥发份含量作为岩石挥发份及残余CO2量的下限值，而全岩分析的总碳含量可作为CO2脱出量的上限值。     

基于GIS的北京市延庆县地质灾害易发性区域划分

随着灾害科学研究的深入，区域地质灾害已成为其重要的研究领域。文章利用遥感技术及GPS工具获取地质灾害的特征信息，在对地质灾害的成因背景分析基础上，运用GIS空间分析功能和地质灾害危险性评价、评估理论构建了地质灾害发育度模型。以北京市延庆县为实验区，采用ArcEngine＆．NET进行易发性分区程序的编写，计算研究区域内单元网格的发育度值。为了克服调查数据的局限性和人为因素，在计算发育度时引入修正系数，从延庆县DEM数据中提取单元格网内的地形坡度值，根据坡度值区间确定修正系数。将发育度计算结果按照一定规律、原则聚类。进行地质灾害易发性区域划分，取得了与实际情况较为一致的结果。基于“3S”技术及灾害地质条件，采用地质灾害发育度模型，可以较好地用于区域地质灾害易发性区域的划分，并能为防灾、减灾提供重要信息。     

额济纳旗胡杨根区水分运动参数的确定--利用Richard方程和气象资料推算

利用Richard方程和气象资料相结合的办法,确定了中国典型的干旱内陆河流──黑河下游额济纳旗地区主要成林的干旱荒漠天然乔木树种──胡杨林地的水分运动参数,主要有导水系数K、比水容量C和水分扩散率D。     

Displaced-Beam Small Aperture Scintillometer Test. Part Ii: Cases-99 Stable Boundary-Layer Experiment

The performance of the Scintec displaced-beam small aperture scintillometer (DBSAS) in the stable boundary layer (SBL) is investigated using data gathered during the CASES-99 experiment in Kansas, U.S.A. The DBSAS is superior to the eddy-covariance method in determining vertical fluxes of sensible heat and momentumclose to the ground and/or over short (< 1 min) averaging intervals. Both aspects are of importance in the shallow and non-stationary SBL.The friction velocity, u_*, the temperature scale, _*, and from these the sensible heat flux, H, were calculated from the indirectly determined dissipation rate, , and the structure parameter of temperature, C_T ², by the DBSAS, which was operated over a path length of 112 m. All these variables are compared with eddy-covariance data for 10-minute time averages. Previously reported systematic errors in the DBSAS, overestimation of u_* for low u_* values and underestimation of u_* for high u_* values, have in part been dealt with by adjusting the beam displacement distance from 2.7 mm to 2.6 mm in the calculations. The latter adjustment is presented as a working hypothesis, not a general solution.     

Using a Large-Aperture Scintillometer to Measure Absorption and Refractive Index Fluctuations

The contributions of refraction and absorption fluctuations to the measured scintillations are observed for a near-infrared absorption region using a NOAA designed large-aperture scintillometer. The logarithmic amplitude spectra are shown to decay with frequency as f^-8/3 for both the absorption and scattering mechanisms. For the absorption mechanism this is in line with similar observations made at microwave and infrared frequencies. However, for finite transmitting and receiving apertures, theory predicts a stronger decay of the scattering mechanism due to aperture averaging. The spectral shape is characterised by a region of low frequency absorption, higher frequency refraction and separated by a flattish transition zone. The upper observed corner frequency (f_C2) compares well with values calculated using the measured transverse windspeed (v) for a known aperture radius. The lower corner frequency (f_C1) position is shown to be sensitive to the ratio of the real and imaginary part of the refractive index structure parameter, (C _nR ² /C _nI ² )^3/8, and v. The part of the spectrum associated with the absorption scintillations is observed to be much less than that due to refraction through the day until evening, when decreasing C _nR ² causes C _nR ² /C _nI ² to decrease and absorption to become significant. If absorption is ignored, this may have consequences for calculating nocturnal surface fluxes. During unstable, daytime conditions the large aperture scintillometer is most sensitive to refractive scintillations despite having an infrared source transmitting in a lossy atmosphere. But also under these conditions, the low frequency absorption part of the spectrum is observable.     

雹云的3参数概率判别法

根据山东省雷达回波资料,天气和灾情实况,统计了回波顶高Ｈｍ强回波区顶高Ｈｚ回波强度Ｚ与降雹概率的关系,给出单,双参数判别雹云的指标,提出用３参数降雹条件概率法判别雹云,指出了３参数识别指标对降雹的预示作用,这对强对流天气的短期预报具有一定的实用价值。     

强降水雷达回波参数特征

利用７１３型测雷达资料,对江西强降水回波参数特征进行统计,分析结果表明：强降水与回波顶高、回波强度、水平尺度及地形等有关,为强降水天气预测提供了依据．