2016年度呼图壁地下天然储气库对周缘微地震活动性的影响

呼图壁储气库是中国目前存储量最大的天然气储气库,位于新疆准噶尔盆地南缘,北天山山前坳陷带内的呼图壁背斜上.储气库靠近百万人口大城市乌鲁木齐,气库的注放气活动对其周缘地震活动的长期影响是事关生产和生活的重要安全问题.本文以呼图壁储气库为中心,在86.5°E—87.5°E,43.5°N—44.5°N的范围内,基于新疆维吾尔自治区地震局在该区域建立的密集流动台阵数据,应用模板匹配滤波技术对2016年全年的波形数据进行搜索识别,检测到遗漏地震事件151个,完善扩充了原有地震目录,使得该区域完备震级由1.1降到约0.7.通过分析新目录中404个地震的时空分布规律,我们发现2016年,即气库建成第三年以后,储气库的气压变化依然会影响周缘地区的地震活动.当储气库的气压增大到超过约22 MPa的阈值后,较小的气压波动也会导致该区域地震活动性明显增强;气压变化对距储气库中心最远约40 km范围内区域的地震活动存在较为明显的影响.     

Cold seep deposits of Beauvoisin (Oxfordian; southeastern France) and Marmorito (Miocene; northern Italy): microbially induced authigenic carbonates

The relation of two well-known ancient carbonate deposits to hydrocarbon seepage was confirmed by this study. Archaea are found to be associated with the formation of Oxfordian seep carbonates from Beauvoisin and with a Miocene limestone from Marmorito ("tube-worm limestone"). Carbonates formed due to a mediation by archaea exhibit extremely positive or extremely negative δ¹³C_carbonate values, respectively. Highly positive values (+15‰) reflect the use of ¹³C-enriched CO₂ produced by methanogenesis. Low δ¹³C values of the Marmorito carbonates (–30‰) indicate the oxidation of seepage-derived hydrocarbons. Likewise, the δ¹³C content of specific tail-to-tail linked isoprenoids, biomarkers for archaea, was found to be strikingly depleted in these samples (as low as –115‰). The isotopic signatures corroborate that archaea were involved in the cycling of seepage-derived organic carbon at the ancient localities. Another Miocene limestone ("Marmorito limestone") shows a strong imprint of methanotrophic bacteria as indicated by δ¹³C values of carbonate as low as –40‰ and biomarker evidence. Epifluorescence microscopy and field-emission scanning electron microscopy revealed that bacterial biofilms were involved in carbonate aggregation. In addition to lucinid bivalves previously reported from both localities, we infer that sponges from Beauvoisin and tube worms from Marmorito depended on chemosynthesis as well. Low δ¹³C values of nodules related to sponge taphonomy (–27‰) indicate that sponges might have been linked to an enhanced hydrocarbon oxidation. Tube worm fossils from Marmorito closely resemble chemosynthetic pogonophoran tube worms from Recent cold seeps and are embedded in isotopically light carbonate (δ¹³C –30‰). Received: 13 October 1998 / Accepted: 5 February 1999     

Groundwater storage change detection from in situ and GRACE-based estimates in major river basins across India

ABSTRACT

India has been the subject of many recent groundwater studies due to the rapid depletion of groundwater in large parts of the country. However, few if any of these studies have examined groundwater storage conditions in all of India’s river basins individually. Herein we assess groundwater storage changes in all 22 of India’s major river basins using in situ data from 3420 observation locations for the period 2003–2014. One-month and 12-month standardized precipitation index measures (SPI-1 and SPI-12) indicate fluctuations in the long-term pattern. The Ganges and Brahmaputra basins experienced long-term decreasing trends in precipitation in both 1961–2014 and the study period, 2003–2014. Indeterminate or increasing precipitation trends occurred in other basins. Satellite-based and in situ groundwater storage time series exhibited similar patterns, with increases in most of the basins. However, diminishing groundwater storage (at rates of >0.4 km³/year) was revealed in the Ganges-Brahmaputra River Basin based on in situ observations, which is particularly important due to its agricultural productivity.     

陆表植被碳汇计量管理平台设计与实现

为了实现陆表植被碳汇量精准计测和森林资源的可持续发展,本文采用C#面向对象高级程序设计语言,利用组件式GIS技术和第三方UI控件进行开发,建立了一套现代化、信息化的管理平台。该平台实现了GIS基础操作、森林基础数表、森林资源二类调查、森林观测数据后处理和森林经营辅助决策五大功能模块,构建了较为系统的陆表植被碳汇计量管理基础业务体系。满足了森林资源管理和经营的需要,实现了对森林资源一体化经营和管理。     

Characteristics and formation causes of Qingdao Cold Water Mass

In this work,the main characteristics of the Qingdao Cold Water Mass were studied by using“the comparison analysis method”based on 1980 temperature,salinity and dissolved oxygen data on the western South Yellow Sea.The formation cause of the water mass was analyzed based on February of 1959 temperature and salinity data for this area and on some other authors’studies.The results showed that the Qingdao Cold Water Mass has growing and vanishing processes：appears in the last ten days of March;has stable pattern in April;is biggest in its area in May;becomes small in its area in June;vanishes in July.It comes from the northem Shandong Coastal Water and is characterized by low temperature and salinity and high disolved oxygen.The mass is formed under the joint effects of anticyclonic circulation and solar radiation.     

Natural Geological Weighing Lysimeters: Calibration Tools for Satellite and Ground Surface Gravity Monitoring of Subsurface Water-Mass Change

Increased accuracy in measuring temporal variations in the Earth's gravity field allow inprinciple the use of gravity observations to deduce subsurface water-mass changes. This canbe with respect to a small area, or as a larger spatial average of water mass change usinggravity observations from low-altitude satellites, such as the forthcoming GRACE mission.At both scales, there is a need to validate gravity-based estimates against field recordings ofactual subsurface water-mass variations. In practice, this could prove difficult because thespatial integral of all water-storage change components can be subject to considerable fieldmeasurement error. An alternative approach to the validation process is proposed by whichsuitable geological formations are utilized as giant weighing devices to directly measure area-integratedwater-mass changes. The existence of such natural geological weighing lysimetersis demonstrated using observations from a replicated experimental site in New Zealand. Sitesof this type could be used to verify water-storage change estimates derived from sensitiveground surface gravity instrumentation. In addition, geological lysimeters could be used tomake local checks on the accuracy of any estimated regional water-mass time series, whichis proposed for satellite calibration. The land area weighed by a geological lysimeter increaseswith formation depth and it is speculated that recordings made at oil well depth may allowdirect monitoring of subsurface water mass changes at the regional scale.     

井地直流电法三维数值模拟中若干问题研究

讨论了地下垂直线源分段计算和场叠加的方法,并实现了在套管上供直流电的三维数值模拟。讨论了大型容量矩阵的压缩存储方式,采用数组和结构体相结合的方法实现容量矩阵的一维链表式压缩存储。在求解超大型稀疏线形方程组时引入不完全Cholesky分解稳定化的双共轭梯度算法(ICBG),通过与均匀半空间垂直线源解析解的对比,证明了该算法是准确可靠的。     

地下水人工调蓄研究进展与问题

通过对国内外地下水调蓄有关资料分析,阐明了地下水库、地下调蓄和人工回灌补给理念之间差异及其关系；阐述了国外地下水人工调蓄研究状况及其发展趋势,回顾了国内地下水人工调蓄发展过程及存在的问题,给出了了地下水调蓄基本原理及其条件；结合我国北方地区水资源面临的危机,提出了急需研究的科学问题。     

澜沧江大朝山水库蓄水前的地震活动本底

分析了大朝山水库蓄水前，水库区域历史中强、强地震背景与1992年来的地震活动格局，及蓄水前9年中库坝区天然地震活动的时、空、强分布，结果表明：大朝山水库区为地震活动水平较低的区域，库坝附近30km以2、3级地震活动为主，库首方向距大坝40km左右的景谷与库尾方向距大坝50km的昌宁、凤庆一带为5级地震活动区，外围100km左右的耿马、澜沧、普洱等地区为6、7级强震活动区；库坝区的地震活动基本符合G—R关系式，b值为0．69，累积应变曲线呈稳定增长趋势，时间分布上出现活跃与平静交替的分布格局。