Far field deformation analysis after the Mw9.0 Tohoku earthquake constrained by cGPS data

This study estimates the far field coseismic deformation of China and its surrounding areas caused by the Mw9.0 Tohoku earthquake of Japan using continuous GPS (cGPS) data and final orbits released by International GNSS Service (IGS). Based on these data, we feature the coseismic offsets of several plates affected by the event. Static far field coseismic offsets greater than 2 mm are detected in a wide area of China, which extends as far as about 3,000 km off the epicenter, consisting of that of the 2010 Maule, Chile earthquake. In northeast China, displacements up to 32.7 mm toward southeast are observed; meanwhile, offsets in North China reach about 5–11 mm toward east. Coseismic jumps of about 2–5 mm are measured in South China toward southeast. The southwest extrusion of the Philippine Sea plate is verified by GPS slip vectors, showing that the Philippine Sea plate is decoupled from the Pacific plate by the earthquake. We also infer that the Amurian plate and the Okhotsk plate couple well according to relatively continuous GPS offsets in these plates. Furthermore, the dense far field cGPS offsets due to the Tohoku event hopefully provide opportunities to model the coseismic slip distribution.     

地震应急指挥协同技术平台设计研究

地震应急指挥协同服务能力是国家地震社会服务能力建设的核心内容,我国的地震应急指挥协同服务能力在研究和建设方面尚处于起步阶段,在未来一段时间将开展地震应急指挥协同技术平台的建设。因此,地震应急指挥协同技术平台的关键构成、设计和实现方式还有许多方面有待进一步研究和探讨。本文根据国家地震社会服务工程的初步设计,对地震应急指挥协同技术平台几个方面的内容进行了初步探讨,在此基础上讨论了其未来进一步发展应进行的工作。     

地震滑坡灾害评估中地震影响因素的联合应用

地震滑坡灾害是一种致灾性极高的地震次生灾害,其中的地震触发因素是导致滑坡发生的重要影响因素．可以表征地震影响因素的参数有多种,但它们代表地震动水平的能力有差异,对灾害评估预测结果有很大影响．因此,本文提出利用层次分析法将多种地震动参数联合应用以弥补不同参数间存在的不足和差异．计算实例表明, 参数联合应用所得评估结果与实际破坏情况最为接近,优于参数单独使用所得评估结果,说明该方法是可行的．文中给出的参数联合应用的方法对于其它地震灾害的评估也有很重要的借鉴意义．      

Statistical analysis of background noise in seismic prospecting

From a conventional viewpoint, seismic‐prospecting background noise is usually regarded as the product of a stationary and Gaussian stochastic process. In this paper, we use statistical methods to investigate the properties of the land‐seismic‐prospecting background noise on stationarity, Gaussianity, power spectral density, and spatial correlation. We use and analyse the passive noise records collected by receiver arrays at different typical geological environments (desert, steppe, and mountainous regions). Differences exist in the statistical properties of the background noise from different geological environments, but we still find some common characteristics. It is shown that the background noise is not strictly stationary and has different stationary properties over different timescales. Most of the noise records appear to be a Gaussian process when examined over a period of about 20 s but are found to be non‐Gaussian when examined over shorter periods of about 1 s. The background noise is a kind of colored noise, and its energy mainly concentrates in the low‐frequency bands. We also find that the spatial correlation of the background noise is weak. The results of this paper provide a scientific understanding about the properties of seismic‐prospecting background noise.     

Climate effects of the GlobeLand30 land cover dataset on the Beijing Climate Center climate model simulations

Land cover is one of the most basic input elements of land surface and climate models. Currently, the direct and indirect effects of land cover data on climate and climate change are receiving increasing attentions. In this study, a high resolution (30 m) global land cover dataset (GlobeLand30) produced by Chinese scientists was, for the first time, used in the Beijing Climate Center Climate System Model (BCC_CSM) to assess the influences of land cover dataset on land surface and climate simulations. A two-step strategy was designed to use the GlobeLand30 data in the model. First, the GlobeLand30 data were merged with other satellite remote sensing and climate datasets to regenerate plant functional type (PFT) data fitted for the BCC_CSM. Second, the up-scaling based on an area-weighted approach was used to aggregate the fine-resolution GlobeLand30 land cover type and area percentage with the coarser model grid resolutions globally. The GlobeLand30-based and the BCC_CSM-based land cover data had generally consistent spatial distribution features, but there were some differences between them. The simulation results of the different land cover type dataset change experiments showed that effects of the new PFT data were larger than those of the new glaciers and water bodies (lakes and wetlands). The maximum value was attained when dataset of all land cover types were changed. The positive bias of precipitation in the mid-high latitude of the northern hemisphere and the negative bias in the Amazon, as well as the negative bias of air temperature in part of the southern hemisphere, were reduced when the GlobeLand30-based data were used in the BCC_CSM atmosphere model. The results suggest that the GlobeLand30 data are suitable for use in the BCC_CSM component models and can improve the performance of the land and atmosphere simulations.     

高分二号卫星影像正射纠正精度分析

本文利用收集到的外业像控、加密控制和地图采集控制资料,对试验区高分二号影像进行了基于RMF模型的数字正射纠正处理,统计分析了高分二号影像数据的无控制定位精度和不同控制方案下的纠正精度,验证了高分二号卫星影像在每景不低于一个控制点的情况下其纠正精度能够满足全地形1∶1万比例尺地形图和山地1∶5000比例尺地形图更新要求。利用数字正射纠正后的高分二号全色和多光谱影像进行配准和融合,配准达到亚像素精度,能够满足影像融合需要。     

基于证据理论的煤层气储层评价方法

针对我国煤层气储层非均质性强,储层评价中存在着储层参数的随机性、模糊性以及数据缺乏等许多不确定性问题,将D-S证据理论引入煤层气储层的评价中,以解决评价过程中的不确性问题。应用D-S证据理论建立了煤层气储层评价模型,提出了具体的证据理论算法,并根据一定的决策规则对沁水盆地南部进行了煤储层评价,并优选出了煤层气开发的最有利区。应用结果表明,该模型较好地解决了评价中的不确定性问题,使评价结果更为可靠和精确。      

Isotopes and sustainability of ground water resources, North China Plain

Ground water in deep confined aquifers is one of the major water resources for agricultural, industrial, and domestic uses in the North China Plain. Detailed information on ground water age and recharge is vital for the proper management of these water resources, and to this end, we used carbon 14 of dissolved inorganic carbon and tritium in water to measure the age and determine the recharge areas of ground water in the North China Plain. These isotopic data suggest that most ground water in the piedmont part of the North China Plain is <40 years old and is recharged locally. In contrast, ground water in the central and littoral portions of the North China Plain is 10,000 to 25,000 years old. The delta18O (deltaD) values of this ground water are 1.7 per thousand (11 per thousand) less than that in the piedmont plain ground water and possibly reflect water recharged during a cooler climate during the last glaciation. The temperature of this recharge, based on delta18O values, ranges from 3.7 degrees C to 8.4 degrees C, compared to 12 degrees C to 13 degrees C of modern recharge water. The isotopic data set combined indicates that ground water in the central and littoral part of the North China Plain is being mined under non-steady state conditions.     

Element geochemistry and cleaning potential of the No. 11 coal seam from Antaibao mining district

It has aroused great attention that the mobilization of potential toxic substance during coal mining, pro- cessing and using has serious negative influence on environment. Clearly, the coal cleaning can be prop-erly applied to removing hazardous elements or re-ducing their concentrations prior to combustion, which also is considered as an economical and effective technique in minimizing some of these problems[1]. Unfortunately, there are fairly few studies on the parti-tioning behavior of trac…     

构造波及其在地震预报中的应用

本文依据构造力源假说,对可能沿软流圈或构造带传播的四种类型的构造波进行了研究。这四种构造波为:广义瑞利型构造波;广义洛夫型构造波;广义构造导波及构造形变波。采用适当的软流圈模型,对这四种波型的频散关系及存在条件作了研究。理论研究结果表明,在软流圈中这四类波型均可能存在。 在理论研究的基础上,按照构造波所反映的地震前兆的周期(时间)长短,又把它们归为三类。第一类称为长周期的构造波,它反映了强震震中以波的形式迁移,这可以用来解释强震沿某些构造带与纬度方向迁移及其幅射状迁移等现象。第二类是中周期的构造波,它反映了地震前兆的三阶段发展变化。第三类为长周期的形变波,它是一种短周期的构造波,反映了短期或临震前兆。