定量提取固体潮异常信息

虽然中强地震前可能会出现多种前兆,然而找到一个"特定"的异常来预报大地震的发生却极其困难.地震孕育是一个非常复杂的动力学过程,地震的发生是地下介质从失稳到破裂的过程,在这一过程中由于强非线性与动态时变性现象的存在,轻微的扰动就很可能会导致失稳介质的破裂,从而使地震发生的具体时刻变得不可预测.     

样本条件对加卸载响应比计算结果的影响分析

基于随机 Posson 模型和Gutenberg-Richter 关系, 构造在10年尺度内样本量从300到5000的若干组模拟地震数据,计算分析各种样本条件下的加卸载响应比Y 时间进程变化。结果表明,计算样本的震级上限M_t 相对于logN-M 关系中拟合线性外推最大震级M_T 的变化对Y的异常分布有一定影响,其影响随地震样本量从小到大而明显减小。当滑动计算时间窗内地震样本为几十个量级, M_t 取为M_T -1.5(或至2. 0)时,随机出现Y 大于2.0的高值异常分布频度明显降低。而当地震样本量达到上百个以上量级, M_t 取为M_T-0. 0(或0. 5)时, Y大于2.0的高异常值随机出现频度即极低。在实际地震资料的Y计算中若注意Mt 的选取后,其结果的稳定性和异常的可信度将得到显著提高。     

从地理态势分析科索沃战争中的地理环境

给出了地理态势的概念, 初步探讨了地理环境的分析方法, 并从地理态势角度分析了科索沃战争的发生、发展和结局。     

Multi-beam and seismic investigations of the active Haima cold seeps,northwestern South China Sea

To confirm the seabed fluid flow at the Haima cold seeps, an integrated study of multi-beam and seismic data reveals the morphology and fate of four bubble plumes and investigates the detailed subsurface structure of the active seepage area. The shapes of bubble plumes are not constant and influenced by the northeastward bottom currents, but the water depth where these bubble plumes disappear (630–650 m below the sea level) (mbsl) is very close to the upper limit of the gas hydrate stability zone in the water column (620 m below the sea level), as calculated from the CTD data within the study area, supporting the “hydrate skin” hypothesis. Gas chimneys directly below the bottom simulating reflectors, found at most sites, are speculated as essential pathways for both thermogenic gas and biogenic gas migrating from deep formations to the gas hydrate stability zone. The fracture network on the top of the basement uplift may be heavily gas-charged, which accounts for the chimney with several kilometers in diameter (beneath Plumes B and C). The much smaller gas chimney (beneath Plume D) may stem from gas saturated localized strong permeability zone. High-resolution seismic profiles reveal pipe-like structures, characterized by stacked localized amplitude anomalies, just beneath all the plumes, which act as the fluid conduits conveying gas from the gas hydrate-bearing sediments to the seafloor, feeding the gas plumes. The differences between these pipe-like structures indicate the dynamic process of gas seepage, which may be controlled by the build-up and dissipation of pore pressure. The 3D seismic data show high saturated gas hydrates with high RMS amplitude tend to cluster on the periphery of the gas chimney. Understanding the fluid migration and hydrate accumulation pattern of the Haima cold seeps can aid in the further exploration and study on the dynamic gas hydrate system in the South China Sea.     

Dynamic features and driving mechanism of coal consumption for Guangdong province in China

Journal of Geographical Sciences - Guangdong Province, as one of China’s fast-developing regions, an important manufacturing base, and one of the national first round low-carbon pilots, still...     

新疆于田地区背景地震与触发地震活动分析

正新疆于田地区历史上发生过多次6.0级以上地震,北京时间2020年6月26日在此地区再次发生MS 6.4地震。震后,中国地震局地震预测研究所紧急开展地震应急会商,并组织多家单位针对此次地震开展了虚拟科考工作。其中,所发生的地震是否属于其他强震的余震,与历史上已发生的多个强震存在怎样的关系,或者还是属于独立的背景地震活动,     

2021年青海玛多MS7.4地震余震预测及效能检验

1 研究背景 2021年5月22日青海玛多地区发生MS 7.4地震,中国地震局针对此次地震快速组织开展了科学考察工作.根据科考阶段性成果交流形成的统一认识,玛多MS 7.4地震的发震断层为昆仑山口—江错断裂,地表破裂段为该断裂东段,即江错断裂段.为对震后震情形势进一步研判以及为前线科考人员提供"跟踪式"科技支撑,此次科考中对余震趋势评估成为一项重要工作内容.     

A synthetic method for earthquake prediction by multidisciplinary data

China Metropolitan area around Beijing is one of the earthquake test sites in Continental China. Through more than 20 years of hard work, abundant seismic, geological, geophysical and geochemical data have been obtained, and the variation of seismic, geophysical and geochemical parameters was recorded before several strong earthquakes and some moderate earthquakes in this area. In this paper, we chose 19 high qualified observatory parameters in this area to establish a multidisciplinary system for earthquake forecast, including apparent resistivity, ground water level, ground-level, tilt, radon content in groundwater, volumetric strain, Hg content in groundwater, low frequency electric signal. We calculate the synthetic information by a simple algorithm. The procedure is: firstly, we detect the abnormal intervals of the observatory data by some data analysis methods such as filtering, differencing, etc.; secondly, we endow the value of 1 to the abnormal intervals and 0 to other intervals and produce a new time series of data set of the ith parameter; thirdly, we compose the value of the new time series of 19 observatory parameters and obtain the normalized value as called synthetic information. The result shows that there are high correlations between the high synthetic information and the earthquakes with M ≥ 5.0 in this area. The earthquakes almost occurred several days to several months after the peak value of the synthetic information. This synthetic method might be taken for a short-term prediction method for M ≥ 5.0 earthquakes in this area.     

广东省对外直接投资的时空特征及区位因素研究

针对近年来广东省对外直接投资的不断增长，本文基于历年广东省对外直接投资的流量、存量数据，引入重心测度模型，综合分析了广东省对外直接投资的时空特征及投资重心演变，并结合2007-2015年投资东道国国际面板数据运用OLS方法分析了广东省对外直接投资的区位因素。研究表明：（1）广东省投资分布极不平衡，以亚洲为主，重点流入避税地，整体投资重心沿北纬23°西移，投资来源地主要为珠三角地区；（2）广东省对外直接投资的主体、行业、方式等都呈多元化发展趋势，民营企业是投资主体，重点投资第三产业，跨国并购活跃；（3）东道国市场、科技水平、资源丰裕度是影响广东省投资的主要因素，东道国制度因素的影响相对较小，成本和集聚因素的相关性不显著。