新疆泥火山群地震前兆异常实时监测与预报的研究

基于网络技术的视频监控服务,实现了对新疆北天山地区3个泥火山点的实时监测,可在线实时查看泥火山活动情况,分析预报人员依据泥火山活动图像可开展地震预测研究。新疆艾其沟泥火山网络视频监控服务系统扑捉到了2次6级地震前火山液面明显的宏观异常变化现象,这说明基于宽带网络技术的网络视频监控服务,可实现互联网用户使用客户端远程软件连接服务器,实现在线实时查看泥火山活动情况的监控画面,并依据泥火山群地震观测网,捕捉泥火山群地震前兆异常。     

四川盆地及邻区下寒武统龙王庙组颗粒滩沉积特征与空间分布

通过对区域地质调查剖面资料和钻井资料的研究,结合对部分野外剖面与钻井岩心的系统观察和取样分析,发现四川盆地及邻区下寒武统龙王庙组的颗粒滩主要由颗粒石灰岩(白云岩)和晶粒白云岩构成;颗粒滩以未暴露浅滩为主,发育向上变浅和向上变深2类垂向序列。川中古隆起和黔中古隆起北部地区的颗粒滩的横向规模大、层位稳定性和连续性最好,其余地区颗粒滩多表现为点滩且规模较小。研究区龙王庙期总体上为西浅东深,西南缘、西北缘和北缘为古陆环抱,盆内呈“一隆两坳”的古地理格局。颗粒岩在古地貌高地具有广覆式“五线一带”的平面分布样式。川中古隆起、黔中古隆起北部地区是颗粒滩发育最有利的地区,东北部和东南部的水下岛链区是优质颗粒滩带发育的潜在区。古隆起发育演化对颗粒滩和有利储集相带具有明显的控制效应,次一级海平面升降变化影响滩体的垂向叠置样式和横向连续性。     

基于点稳定系数法的斜坡稳定性分析

基于莫尔-库伦强度理论构架,界定了点稳定系数的概念,并推导其计算公式。利用Geostudio软件建立了均质斜坡模型及计算其应力分布,并在此基础上结合MATLAB软件计算斜坡模型中各点的点稳定系数,勾绘出斜坡体内不同稳定度区域,探析了斜坡稳定性,并与传统极限平衡法进行了对比。对比结果表明:对直立斜坡,两种方法的计算结果均为不稳定,但点稳定性系数法勾绘出坡脚及坡脚底部存在两处不稳定区域;对60°斜坡,点稳定系数法的计算结果表明坡脚处存在潜在不稳定区域,而极限平衡法的计算结果表明坡体处于稳定状态;对45°斜坡,两种方法的计算结果均为稳定,计算结果一致。进一步分析得到结论:点稳定系数法不需要假设或指定某一形状滑面进行斜坡稳定性评价,且可考虑应力集中对坡体稳定性的影响;极限平衡法以稳定系数表达计算结果,而点稳定系数法以不稳定区域表达计算结果。在分析了应力和岩土体力学参数因素对点稳定系数法计算结果的敏感性后发现:相对于极限平衡法,岩土体力学参数对点稳定系数法影响更为敏感,存在黏聚力界限点和内摩擦角界限点,且对均质斜坡破坏形式(局部滑动变形破坏或整体压缩变形破坏)起着非常重要的作用。     

山东省地震局数字科技信息平台建设与服务

从山东省地震局数字信息服务的沿革、数字科技信息网的建设、及对数字化信息资源建设与服务的再认识等方面,展示了山东省地震局数字科技信息服务平台。该平台突出防震减灾和地区特色,整合信息资源,建立了更加完备的数字化信息网站,全面提升了山东省地震局数字科技信息的服务水平,以全新的服务模式实现了全方位、多层次的数字化信息管理服务。     

底板导水裂隙带中含承压水裂隙的力学特性

华北煤田煤系地层的底部为含水丰富的奥陶系灰岩,该层灰岩与地表水系和煤系地层含水层存在着密切的水力联系。许多大型突水是采掘空间与含水层之间形成突水通道引起的。因此,分析开采工过程中底板岩体中含承压水裂隙的断裂力学特性具有重要意义。本文采用作者提出的数值方法分析了含高压水裂隙在开采过程中的断裂力学特性。假设裂隙面上作用着均匀水压力,考虑地应力的影响,采用断裂力学的叠加原理,分析了采煤工作面推进过程中含承压水裂隙的断裂力学特性,讨论了开采过程中底板承压水导升。结果表明:在工作面推进过程中,位于底板岩层且与含承压水岩层连通的裂隙,会在承压水水压力和扰动应力的共同作用下,产生破坏,导水裂隙带的高度会增加;这就增加了底板突水的危险性。     

三维成矿预测多源地学空间数据库建设——以宁芜盆地钟姑矿田为例

大数据是海量、高增长率和多样化的信息资产,是未来找矿靶区预测的不可或缺的技术。大数据-三维成矿预测研究面临机遇与挑战,其涉及的地学大数据除了数据来源众多、比例尺不同、数据量大、非结构化管理、时效性强、空间数据与非空间数据协同管理等复杂特点外,还必须具有适应进行三维建模及空间分析的数据结构。本文分析了地学空间大数据的特点,对多源地学综合信息的管理需求进行研究,参考国家及行业标准,建立了可满足三维成矿预测需求的多源地学空间数据库模型,并依据实际划分为勘查控制钻孔地质数据库、空间属性数据库和地球物理数据库,各数据库可在多源地学空间索引库的支持下协同工作。本文以大数据应用的典型实例--钟姑矿田作为研究对象,系统收集了矿田内勘查成果资料,建立了钟姑矿田多源地学空间数据库,并在此基础上进行了控矿要素的有效提取,可进一步支持三维成矿预测。研究结果表明,本文提出的多源地学空间数据库可有效管理地学空间大数据,是大数据-三维成矿预测的重要解决方案,是进行三维成矿预测的重要数据支持。     

Formation of chlorite rims and the impact of pore-lining chlorite on reservoir quality: a case study from Shiqianfeng sandstones in upper Permian of Dongpu Depression,Bohai Bay Basin,eastern China

The source material, precursor and formation processes of chlorite rims, and impact of pore-lining chlorite on reservoir quality of the Shiqianfeng sandstones, Dongpu Depression, Bohai Bay Basin, China, are studied using an integrated approach, including core observation, point-count analysis of thin-sections, scanning electron microscopy, electron microprobe analysis and cathode luminescence. The petrographic analysis shows that chlorite rims consist of grain-coating chlorite, poorly crystalline pore-lining chlorite and euhedral-crystallised pore-lining chlorite. The chemical composition shows that pore-lining chlorite is mainly Fe-rich with an average of 0.785 for Fe/(Fe+Mg) ratio. Petrographic analysis shows a large amount of volcanic dust (3.0～16.0 vol%, average of 7.93 vol%) in Shiqianfeng sandstones, which determines the formation of poorly crystalline pore-lining chlorite. Transformation of volcanic dust to smectite rims started with shallow burial depth at an early diagenetic stage, followed by in situ alteration of the smectite rims to poorly crystalline chlorite rims. Euhedral-crystallised chlorite mainly develops in sandstones with high porosity, high permeability and open flow systems. Pore-lining chlorite can inhibit quartz overgrowth but cannot effectively prevent pore-filling of authigenic quartz, carbonate and kaolinite cements, and therefore cannot prevent porosity destruction. However, the occurrence of pore-lining chlorite is a barometer of good reservoir quality and intense hydrodynamic conditions.     

Flash flood vulnerability assessment for small catchments with a material flow approach

Destructions resulted from natural hazards like earthquake, landslide, or flood in the urban roads and lifelines introduce their negative effects including the psychological damage to citizens as well as decreased urban functions that usually last for a long time. Thus, a quick and efficient recovery of infrastructures, lifelines, and service-providing facilities along with reducing reconstruction costs and time are essential. This paper proposed an approach that consists of four models for forming an algorithm in order to quantitating and integrating of the criteria that have decisive influence in the recovery of urban roadways after a natural disaster. Meanwhile, to aggregate and conclude the data that are collected by means of presented functions and formulations, we applied fuzzy VIKOR technique as a compromise ranking method. The model outputs a priority list showing the revival of which urban paths stands in higher priority for recovery operation after a natural disaster. Results show that not only the model is able to precisely quantize the selected criteria and provide an action plan for post-event recovery prioritization, but also it offers an appropriate order of transportation roads priority for recovery operations. Finally, the results from the recovery model application to a roadway system in Tehran area are provided.     

Modeling coastal tsunami hazard from submarine mass failures: effect of slide rheology,experimental validation,and case studies off the US East Coast

Natural Hazards - We perform numerical simulations to assess how coastal tsunami hazard from submarine mass failures (SMFs) is affected by slide kinematics and rheology. Two types of two-layer SMF...     

Effects of river damming on biogenic silica turnover: implications for biogeochemical carbon and nutrient cycles

Rivers link terrestrial ecosystems and marine ecosystems, and they transport large amounts of substances into oceans each year, including several forms of silicon (Si), carbon (C), and other nutrients. However, river damming affects the water flow and biogeochemical cycles of Si, C, and other nutrients through biogeochemical interacting processes. In this review, we first summarize the current understanding of the effects of river damming on the processes of biogeochemical Si cycle, especially the source, composition, and recycling process of biogenic silica (BSi). Then, we introduce dam impacts on the cycles of C and some other nutrients. Dissolved silicon in rivers is mainly released from phytolith dissolution and silicate weathering. BSi in suspended matter or sediments in most rivers mainly consists of phytoliths and mainly originates from soil erosion. However, diatom growth and deposition in many reservoirs formed by river interception may significantly increase the contribution of diatom Si to total BSi, and thus significantly influence the biogeochemical Si, C, and nutrient cycles. Yet the turnover of phytoliths and diatoms in different rivers formed by river damming is still poorly quantified. Thus, they should be further investigated to enhance our understanding about the effects of river damming on global biogeochemical Si, C and nutrient cycles.