位于预测区边缘附近的地震统计检验问题

对位于地震预测工作所圈定的地震危险区附近的地震的统计检验问题 ,一直是地震预测研究中一个颇有争议的问题。本文以中国地震局全国年度地震趋势会商的情况为例 ,对这一问题进行了探讨。结果表明 ,将所划定的地震危险区适度扩大 ,即将现有的地震危险区范围向外扩大约 0 5° ,可以显著地提高预测地震的“命中率”。但从统计检验的角度说 ,这样做并不能提高实际地震预测的能力 ,亦即并不能使R值有显著的提高。     

The Occurrence of Haze in Malaysia: A Case Study in an Urban Industrial Area

— Klang Valley, a heavily industrialized urban area in Malaysia, has experienced severe haze episodes since the early 1980s. Total Suspended Particulate matter (TSP) is used in studying this phenomenon. Three severe haze episodes during the early 1990s are reviewed; August 1990, October 1991, and August–October 1994. The nature of these episodes, their possible causes, and their major features are discussed. Meteorological conditions associated with these episodes were analyzed. Results of the study indicate that stability and trapping of particles are the main factors affecting the pollution during haze periods. Maximum total suspended matter (TSP) was recorded in October 1991. The August–October 1994 episode was the most persistent and least affected by meteorological variables. Analysis of wind direction data showed that southerly and southwesterly winds coincided with the worst haze periods.     

A Multiscale Application of the Unified Scaling Law for Earthquakes in the Central Mediterranean Area and Alpine Region

We study the parameters A, B, and C of the Unified Scaling Law for Earthquakes (USLE) in the Central Mediterranean area and Alpine region on the basis of a variable space and time scale approach. We make use of regional and local earthquake catalogues. Accordingly, we investigate three different scales: the scale of the Central Mediterranean and Alpine region spanning different geological domains, the scale of the Alps focusing on a single geological entity, and the scale of an active fault system at the junction between the southeastern Alps and the external Dinarides in Northeastern Italy and Western Slovenia. Maps based on the varied time and location scales are compared with each other. The observed temporal variability of the A, B, C coefficients indicates significant changes of seismic activity at the time scales of a few decades. Therefore, it is highly recommended to use all the data available for long-term seismic hazard assessment in conjunction with a real-time monitoring of these characteristics for possible evaluation of time-dependent risk at the intermediate-term scales of a few years. The confirmed fractal nature of earthquakes and their distribution in space implies that the traditional estimations of seismic hazard for cities and urban agglomerations are usually underestimated. The degree of underestimation by traditional methods of seismic risk at a city is illustrated by providing estimates of hazard and related personal hazard, which are oversimplified examples of seismic risk assessment accounting for fractal properties of earthquakes in the major cities of the Central Mediterranean and Alpine region.     

Cs baseline levels in the Mediterranean and Black Sea: A cross-basin survey of the CIESM Mediterranean Mussel Watch programme

The common mussel Mytilus galloprovincialis was selected as unique biomonitor species to implement a regional monitoring programme, the CIESM Mediterranean Mussel Watch (MMW), in the Mediterranean and Black Seas. As of today, and upon standardization of the methodological approach, the MMW Network has been able to quantify ¹³⁷Cs levels in mussels from 60 coastal stations and to produce the first distribution map of this artificial radionuclide at the scale of the entire Mediterranean and Black Seas. While measured ¹³⁷Cs levels were found to be very low (usually <1 Bq kg⁻¹ wet wt) ¹³⁷Cs activity concentrations in the Black Sea and North Aegean Sea were up to two orders of magnitude higher than those in the western Mediterranean Basin. Such effects, far from representing a threat to human populations or the environment, reflect a persistent signature of the Chernobyl fallout in this area.     

137Cs baseline levels in the Mediterranean and Black Sea: A cross-basin survey of the CIESM Mediterranean Mussel Watch programme

The common mussel Mytilus galloprovincialis was selected as unique biomonitor species to implement a regional monitoring programme, the CIESM Mediterranean Mussel Watch (MMW), in the Mediterranean and Black Seas. As of today, and upon standardization of the methodological approach, the MMW Network has been able to quantify ¹³⁷Cs levels in mussels from 60 coastal stations and to produce the first distribution map of this artificial radionuclide at the scale of the entire Mediterranean and Black Seas. While measured ¹³⁷Cs levels were found to be very low (usually <1 Bq kg⁻¹ wet wt) ¹³⁷Cs activity concentrations in the Black Sea and North Aegean Sea were up to two orders of magnitude higher than those in the western Mediterranean Basin. Such effects, far from representing a threat to human populations or the environment, reflect a persistent signature of the Chernobyl fallout in this area.     

The lithosphere in the central-eastern Mediterranean area

The lithosphere beneath the central-eastern Mediterranean area has been investigated by the inversion of the regional dispersion relations derived from analysis of surface waves. It is possible to distinguish several types of crust with average S-wave velocities in the range 3.0–3.8 km/sec, and thicknesses varying from a minimum of about 30 km, which corresponds to the Apennines, Crete and Otranto Channel regions, to a maximum of about 51 km beneath the Ionian Sea, which can be considered as a submerged continent. Associated with these crustal features, large lateral variations have been detected in the lithosphere thickness, which varies from a minimum of about 30 km corresponding to the Tyrrhenian Sea and south of Crete to a maximum of about 130 km corresponding to south-eastern Alps and north-central Greece, while the sub-Moho S-wave velocity varies in the range 4.2–4.8 km/sec. The constraint furnished by our results to the geological-tectonic setting of the investigated area, characterized by the continent continent collision between Africa and Europe, is pointed out.Publication No. 405, P. F. Geodinamica, CNR, Roma, Italy.     

The Y-3 tephra: A Last Glacial stratigraphic marker for the central Mediterranean basin

The paper reviews the existing data on the Y-3 tephra layer, first recognised in the Ionian Sea (Mediterranean basin). The collection and collation of old and new data on distal tephra occurrences in terrestrial, marine and lacustrine successions indicate that the Y-3 layer is dispersed over a wide area of the central Mediterranean basin. The peculiar homogeneous chemical composition of this layer makes its recognition rather straightforward and permits it being distinguished from other stratigraphically adjacent tephras. The best age estimate for the Y-3 layer of ca 30–31 cal ka BP, its peculiar stratigraphic position close to the Marine Isotope Stage 3/2 transition or Heinrich Event 3 onset, as well as its wide dispersion makes this layer an important marker to link and date late Pleistocene terrestrial and marine archives of the central Mediterranean basin.     

Sustainable Yield of a Hydrothermal Area: From Theoretical Concepts to the Practical Approach

Sustainable use of groundwater in the hydrothermal area of Viterbo (Central Italy) was analyzed. In this area, multipurposes utilization of groundwater coexists: several thermal springs and wells supply spas and public pools, cold and fresh water is used for irrigation and drinking-water. Starting from theoretical concepts, a management plan has been developed to ensure groundwater sustainability in response to the increased demand of withdrawal from thermal wells, by integrating previous hydrogeological studies, new investigations and a new finite-difference model. The most stringent constraints considered are: to maintain the quality of thermal and fresh waters, to limit the effects on the hydraulic equilibrium existing between overlapping aquifers, to ensure a significant flow to the natural thermal springs and the quality and flow rate of the spring used for drinking purposes. The practical approach included identification of the maximum pumping rate from the wells of the spas, analysis of the response time of the system under development and drafting of a safeguard and monitoring plan. The case examined takes into account the complexity of the task in defining practical measures for groundwater management on the basis of theoretical concepts of its sustainable use. A participative approach among the different water decision-makers and adaptive management in the use of groundwater resources with different quality represent the key points to overcome conflicts between different users, with the awareness of the ineludible uncertainties of the hydrogeological model.     

辽西北地区农业干旱灾害风险评价与风险区划研究

以辽西北29个农业县（市、区）为研究区域,选取辽西北最主要的玉米作物作为研究对象,从造成农业干旱灾害的致灾因子危险性、承灾体暴露性、脆弱性和抗旱减灾能力4个方面着手,利用自然灾害风险指数法、加权综合评价法和层次分析法,建立了农业干旱灾害风险指数（ADRI）,用以表征农业干旱灾害风险程度;借助GIS技术,绘制辽西北农业干旱灾害风险评价区划图,将风险评价区划图与2006年辽西北受干旱影响粮食减产系数区划图对比,发现两者可以较好的匹配。研究结果可为当地农业干旱灾害预警、保险,以及有关部门的旱灾管理、减灾决策制定提供理论依据和指导。     

A New Approach for Border Detection of the Dumluca (Turkey) Iron Ore Area: Wavelet Cellular Neural Networks

Anomaly analysis is used for various geophysics applications such as determination of geophysical structure's location and border detections. Besides the classical geophysical techniques, artificial intelligence based image processing algorithms have been found attractive for geophysical anomaly analysis. Recently, cellular neural networks (CNN) have been applied to geophysical data and satisfactory results are reported. CNN provides fast and parallel computational capability for geophysical image processing applications due to its filtering structure. The behavior of CNN is defined by two template matrices that are adjusted by a properly supervised learning algorithm. After training stage for geophysical data, Bouguer anomaly maps can be processed and analyzed sequentially. In this paper, CNN learning and processing capability have been improved, combining Wavelet functions and backpropagation learning algorithms. The new architecture is denoted as Wavelet-Cellular Neural networks (Wave-CNN) and it is employed to analyze Bouguer anomaly maps which are important to extract useful information in geophysics. At first, Wave-CNN performance is tested on synthetic geophysical data, which are created by a computer environment. Then, Bouguer anomaly maps of the Dumluca iron ore field have been analyzed and results are reported in comparison to real drilling results.     

河北张北地震区活动断裂的探测与研究

1998年1月10日河北张北6．2级地震是河北省张家口坝上稳定地区的一次罕见的破坏性地震。震区被晚第三纪玄武岩覆盖，地面未发现第四纪活动断裂。为了研究震区地表活动断层，利用电磁波探测技术，以玄武岩底界面深度的变化来分析张北震区活动断裂，为此，在河北张北6．2级地震Ⅷ度区范围进行了3条剖面探测，解释结果表明，震区存在北西向、北东向、北北东向3组第四纪活动断裂，张北6．2级地震发生在3组断裂的交汇区附近。     

煤矿采空塌陷特征与危险性预测研究——以北京西山地区为例

本文主要利用可拓理论及层次分析法进行了西山地区采空塌陷危险性预测研究,并在典型地段利用概率积分法、数值模拟方法进行了采空塌陷预测。主要思路是探讨解决采空塌陷危险性预测、区划中人为干扰的问题,为开展地质灾害预警预报工作提供基础资料。     

三湖坳陷第四系生物气异常识别技术及应用——以诺木洪北地区为例

三湖坳陷的生物气岩性气藏勘探尚处于探索阶段。根据生物气岩性气藏的有利沉积相带,首先进行生物气岩性气藏岩石物理参数分析和含气异常正演模拟,用于指导滩坝砂含气异常的地震反射特征识别;结合构造背景,利用敏感地震属性优选可能的含气区带;最后,在异常区带内,利用频谱分解、时频分析、叠后反演及叠前烃类检测等多手段落实有利目标,形成一套适用于三湖坳陷第四系识别生物气异常的技术。     

青岛大沽河断裂活动性初步研究

大沽河断裂是青岛地区规模较大的一条隐伏断裂,前人对该断裂没有进行过详细的研究。由于缺乏足够的证据,无法确定该断裂的展布和产状,更加无法确定其活动性。本文首先基于地质图布设几条地球物理勘探测线,根据物探结果,选取三处异常点分别布设若干钻孔进行钻探验证。根据钻孔地层结构绘制三个联合地质剖面,剖面揭示有断裂通过,从而在土层中选取四个土样进行年代学测试。研究表明,大沽河断裂通过了地球物理勘探的三处异常点,基本确定了断裂走向;年代学测试结果表明该断裂为早更新世或中更新世早中期断裂,不属于活动断裂;根据统计规律,该断裂不会发生破坏性地震,也不会造成地表破裂,重大建设工程不需要避让该断裂。本研究具有十分重要的意义。     

推进地震预测研究的战略对策问题

在简要分析了地震预测面临的主要科学难点问题的基础上,讨论了推进我国地震预测研究的战略对策,认为地震预测研究需要长期攻关,需要有长期的稳定的支持计划。目前推进地震预测科学进步的障碍点可能在于中期(几年尺度)强地震危险地点的确定,若在这一环节上取得突破,就为最终短临预报的突破奠定了基础,应强调理论创新和观测技术进步;坚持发展地震预测试验场;经验性预测与物理预测结合等。