Satellite detection of IR precursors using bi-angular advanced along-track scanning radiometer data: a case study of Yushu earthquake

The paper has developed and proposed a synthesis analysis method based on the robust satellite data analysis technique(RST) to detect seismic anomalies within the bi-angular advanced along-track scanning radiometer(AATSR) gridded brightness temperature(BT)data based on spatial/temporal continuity analysis. The proposed methods have been applied to analyze the Yushu(Qinghai, China) earthquake occurred on 14 th April 2010,and a full AATSR data-set of 8 years data from March2003 to May 2010 with longitude from 91°E to 101°E and latitude from 28°N to 38°N has been analyzed. Combining with the tectonic explanation of spatial and temporal continuity of the abnormal phenomena, the analyzed results indicate that the infrared radiation anomalies detected by the AATSR BT data with nadir view appear and enhance gradually along with the development and occurring of the earthquake, especially along the Ganzi-Yushu fault, Nu River fault and Jiali-Chayu fault; more infrared anomalies along the earthquake fault zone(Lancangjiang fault and Ning Karma Monastery-Deqin fault) are detected using the proposed synthesis analysis method, which can also characterize the activity of seismic faults more precisely.     

Air‐stream temperature correlation in forested and urban headwater streams in the Southern Appalachians

Air temperature can be an effective predictor of stream temperature. However, little work has been done in studying urban impacts on air‐stream relationships in groundwater‐fed headwater streams in mountainous watersheds. We applied wavelet coherence analysis to two 13‐month continuous (1 hr interval) stream and air temperature datasets collected at Boone Creek, an urban stream, and Winkler Creek, a forest stream, in northwestern North Carolina. The main advantage of a wavelet coherence analysis approach is the ability to analyse non‐stationary dynamics for the temporal covariance between air and stream temperature over time and at multiple temporal scales (e.g. hours, days, weeks and months). The coherence is both time and scale‐dependent. Our research indicated that air temperature generally co‐varied with stream temperature at time scales greater than 0.5 day. The correlation was poor during the winter at the scales of 1 to 64 days and summer at the scales of 1.5 to 4 days, respectively. The empirical models that relate air temperature to stream temperature failed at these scales and during these periods. Finally, urbanization altered the air‐stream temperature correlation at intermediate time scales ranging from 2 to 12 days. The correlation at the urban creek increased at the 12‐day scale, whereas it decreased at scales of 2 to 7 days as compared with the forested stream, which is probably due to heated surface runoff during summer thunderstorms or leaking stormwater or wastewater collection systems. Our results provide insights into air‐stream temperature relationships over both time and scale domains. Identifying controls over time and scales are needed to predict water temperature to understand the future impacts that interacting climate and land use changes will have on aquatic ecosystem in river networks. Copyright © 2014 John Wiley & Sons, Ltd.     

Clay record of climate change since the mid‐Pleistocene in Jiujiang,south China

To obtain a better understanding of climate change in south China in the Quaternary, a clay mineralogical study was undertaken on the red earth profile at Jiujiang, using X‐ray diffraction (XRD) and particle‐size distribution analysis methods. The XRD results showed that the clay minerals of the Jiujiang red earth were mainly mixed‐layer illite–smectite (I/S), illite, kaolinite and vermiculite, with trace amounts of mixed‐layer kaolinite–smectite (K/S). Changes in clay mineral composition displayed a trend of three‐stage evolution. The higher mixed‐layer I/S clays and kaolinite contents in the lower portion suggest extremely warm and humid climates over the period c. 700 to c. 350 ka ago. A gradual decrease in I/S clays and kaolinite reveals a gradual climate change from warm/humid to cool/dry during the period c. 350 to c. 130 ka ago. The higher illite and vermiculite contents indicate a relatively cool and dry climate during the period since c. 130 ka ago. The particle‐size distribution pattern of the upper section was similar to that of the Xiashu loess, while that of the middle to lower section was similar to those of fluvially reworked red earth. A rapid increase in the abundance of large grain‐size components at 2.6 m depth indicates an intensification of the winter monsoon and a cool and dry climate during the period, in good agreement with results from the clay mineral composition and homogeneous structure. The red earth sequences in south China could probably be used to test the response of tropical to subtropical regions to global climate changes.     

(Pre-) historic changes in natural and anthropogenic heavy metals deposition inferred from two contrasting Swiss Alpine lakes

Continuous high-resolution sedimentary record of heavy metals (chromium (Cr), copper (Cu), lead (Pb), zinc (Zn), manganese (Mn), and mercury (Hg)), from lakes Lucerne and Meidsee (Switzerland), provides pollutant deposition history from two contrasting Alpine environments over the last millennia. The distribution of conservative elements (thorium (Th), scandium (Sc) and titanium (Ti)) shows that in absence of human disturbances, the trace element input is primarily controlled by weathering processes (i.e., runoff and erosion). Nonetheless, the enrichment factor (EF) of Pb and Hg (that are measured by independent methods), and the Pb isotopic composition of sediments from the remote lake Meidsee (which are proportionally more enriched in anthropogenic heavy metals), likely detect early mining activities during the Bronze Age. Meanwhile, the deposition of trace elements remains close to the range of natural variations until the strong impact of Roman activities on atmospheric metal emissions. Both sites display simultaneous increases in anthropogenic trace metal deposition during the Greek and Roman Empires (ca 300 BC to AD 400), the Late Middle Ages (ca AD 1400), and the Early Modern Europe (after ca AD 1600). However, the greatest increases in anthropogenic metal pollution are evidenced after the industrial revolution of ca AD 1850, at low and high altitudes. During the twentieth century, industrial releases multiplied by ca 10 times heavy metal fluxes to hydrological systems located on both sides of the Alps. During the last decades, the recent growing contribution of low radiogenic Pb further highlights the contribution of industrial sources with respect to wood and coal burning emissions.     

密云司马台-雾灵山沟域经济区泥石流分布及防治措施

＂沟域经济＂是北京近年来探索出来的一种新的山区发展模式。密云山清水秀,风景优美,有良好的旅游基础。对密云司马台-雾灵山沟域经济发展区泥石流地质灾害调查,查明了泥石流发育分布特征,提出其防治措施,为沟域经济发展规划建设提供科学依据。     

武昌地区街道尘埃磁学特征及其对环境污染的指示意义

对在武昌地区4个功能区域(青山、洪山、东湖风景区、东湖开发区)主要交通街道收集的尘埃样品进行详细的环境磁学测量,包括质量磁化率、频率磁化率、等温剩磁退磁系数以及典型样品的磁滞回线参数等。研究结果表明:尘埃样品中剩磁载体均以亚铁磁性矿物为主,样品中的磁性颗粒呈现低矫顽力的磁铁矿特征,软磁性的磁性矿物是样品剩余磁性的主要载体。尘埃样品χ、SIRM的区域分布特征受区域周围工业、车流量及道路状况等多种环境因素的影响,在4个功能区域中存在明显的磁性差异:青山工业区污染较重,东湖开发区、洪山、东湖风景区次之;硬剩磁(HIRM)的分布可能指示了道路交通来源的磁颗粒特征,东湖开发区和青山工业区由于行驶的货车和重型车辆较多,表现出硬剩磁量值较高。与其他城市(兰州、西安、南京、徐州等)相比,整个武昌地区街道尘埃样品的磁性含量仍较高,说明在城市环境方面还有待于进一步改善和保护。     

川中雷口坡组四~3亚段地震相分析——应用波形分类技术研究沉积相的实例

在工区面积大、钻井少的情况下开展地震相研究,可以有效绘出沉积相展布图。对四川盆地中部雷口坡组四3亚段利用GS1和YS104两口井进行地震地质标定,建立了膏盐湖、白云岩坪及颗粒滩等几种不同沉积微相的地震响应模式。膏盐湖相表现为强振幅、高连续的地震响应,而颗粒滩及白云岩坪主要表现为中振幅、低连续的地震响应特征。在地质标定基础上,对全区利用波形分类技术开展地震相研究,恢复了古沉积环境,获得了颗粒滩相及白云岩坪的展布图,这些分布区是有利储层的发育区。龙岗—营山—南充—蓬溪一带处于颗粒滩、白云岩坪有利相带,且处于雷四3亚段地层剥蚀线附近,受岩溶改造强烈,储层较为发育,是川中地区的重要勘探对象。     

珠江口盆地流花油田新近系生物礁灰岩储层特征及成因分析

南海珠江口盆地东沙隆起流花油田新近系灰岩储层为典型的台地边缘生物礁储层。岩石类型包括皮壳状珊瑚藻黏结灰岩、缠绕状珊瑚藻-珊瑚骨架灰岩、泥晶有孔虫-珊瑚藻颗粒灰岩、亮晶有孔虫-珊瑚藻颗粒灰岩、含红藻石灰岩、泥晶珊瑚颗粒灰岩、生屑泥晶灰岩7类。孔缝类型丰富,包括泥晶基质溶孔、粒间溶孔、藻架溶孔、粒内溶孔、铸模孔、体腔孔、晶间微孔7类孔隙及溶蚀缝、珊瑚藻皮壳间隙缝、似缝合线溶蚀缝、构造缝4类裂缝。划分了孔洞-网状裂缝型、孔隙型、裂缝-孔洞型、致密裂缝型4种储集类型。皮壳状珊瑚藻灰岩属于孔洞-网状裂缝型储层,泥晶颗粒灰岩、含红藻石灰岩和红藻石灰岩属于孔隙型,珊瑚骨架灰岩属于裂缝-孔洞型,亮晶生屑灰岩和胶结作用较强的皮壳状藻灰岩属于致密裂缝型。沉积微相和成岩作用控制了不同储集类型的分布,生物礁形成过程中的多期暴露对沉积微相和储集空间有重要影响。沉积-成岩演化过程划分为早期成礁与早期暴露、晚期成礁与次级暴露、埋藏压实与泥岩再造水改造阶段、两期成藏与地下水溶蚀4个阶段。根据沉积-成岩演化分析,预测了研究区储集类型空间分布。     

矿物中4He同位素提取和含量测定研究

(U-Th)/He定年是一种有效的低温热年代学定年技术,现已被广泛应用于地质研究的各个领域,而矿物中4He同位素的有效提取和含量准确测定是该技术的关键。磷灰石和锆石是(U-Th)/He定年最常用的矿物,其4He提取条件及铀钍含量测定方法都较为成熟;而其他矿物(如磁铁矿、橄榄石、针铁矿、石榴子石等)的研究则相对较少。文章介绍了当前国内外(U-Th)/He研究中采用的4He同位素提取方法———真空炉加热法和激光加热法,激光加热法因具有低4He背景值和耗时短的优点而成为主要的提取方法。以磷灰石样品测试为例,介绍了成都地质矿产研究所建立的采用激光加热法和四极杆质谱提取4He同位素及其含量测量过程、含量计算和校正方法。指出未来(U-Th)/He测试技术除继续改进现有分析方法外,应加强对更多不同矿物的测试研究。     

Environmental geochemistry of an active Hg mine in Xunyang,Shaanxi Province,China

The Xunyang Hg mine (XMM) situated in Shaanxi Province is an active Hg mine in China. Gaseous elemental Hg (GEM) concentrations in ambient air were determined to evaluate its distribution pattern as a consequence of the active mining and retorting in the region. Total Hg (HgT) and methylmercury (MeHg) concentrations in riparian soil, sediment and rice grain samples (polished) as well as Hg speciation in surface water samples were measured to show local dispersion of Hg contamination. As expected, elevated concentrations of GEM were found, ranging from 7.4 to 410 ng m⁻³. High concentrations of HgT and MeHg were also obtained in riparian soils, ranged from 5.4 to 120 mg kg⁻¹ and 1.2 to 11 μg kg⁻¹, respectively. Concentrations of HgT and MeHg in sediment samples varied widely from 0.048 to 1600 mg kg⁻¹ and 1.0 to 39 μg kg⁻¹, respectively. Surface water samples showed elevated HgT concentrations, ranging from 6.2 to 23,500 ng L⁻¹, but low MeHg concentrations, ranging from 0.022 to 3.7 ng L⁻¹. Rice samples exhibited high concentrations of 50–200 μg kg⁻¹ in HgT and of 8.2–80 μg kg⁻¹ in MeHg. The spatial distribution patterns of Hg speciation in the local environmental compartments suggest that the XMM is the source of Hg contaminations in the study area.