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991.
2015年9月16日22时54分(当地时间)智利中部近岸发生Mw8.3级地震,震源深度25 km。同时,强震的破裂区长200 km,宽100 km,随之产生了中等强度的越洋海啸。海啸影响了智利沿岸近700 km的区域,局部地区监测到近5 m的海啸波幅和超过13 m的海啸爬坡高度。太平洋区域的40多个海啸浮标及200多个近岸潮位观测站详细记录了此次海啸的越洋传播过程,为详细研究此次海啸近场及远场传播及演化规律提供了珍贵的数据。本文选择有限断层模型和自适应网格海啸数值模型建立了既可以兼顾越洋海啸的计算效率又可以实现近场海啸精细化模拟的高分辨率海啸模型。模拟对比分析了海啸的越洋传播特征,结果表明采用所建立的模型可以较好地再现远场及近场海啸特征,特别是对近场海啸的模拟结果非常理想。表明有限断层可以较好地约束近场、特别是局部区域的破裂特征,可为海啸预警提供更加精确的震源信息,结合高分辨率的海啸数值预报模式实现海啸传播特征的精细化预报。本文结合观测数据与数值模拟结果初步分析了海啸波的频散特征及其对模型结果的影响。同时对观测中典型的海啸波特征进行的简要的总结。谱分析结果表明海啸波的能量主要分布在10~50 min周期域内。这些波特征提取是现行海啸预警信息中未涉及,但又十分重要的预警参数。进一步对这些波动特征的详细研究将为海啸预警信息及预警产品的完善提供技术支撑。  相似文献   
992.
利用近年来水深地形数据和2010年全潮水文观测资料分析了丹东港海域在填海工程建设前后的冲淤变化特征,并阐述了冲淤变化的成因,以对该类型海域海洋工程的选址和海洋环境保护等提供科学依据。研究结果表明,研究区海底在工程建设前除靠近大东作业区的岬角处冲刷较大外,其他海域整体冲淤厚度小于0.2 m/a。工程建设后海底冲淤格局发生重新分布,主要表现在工程南侧普遍冲刷和东侧航道内及西南侧海域的淤积。利用刘家驹公式计算了工程建设前后的航道回淤强度,计算结果表明:工程后A点年均淤积厚度减小了0.09 m,B、C点年均淤积厚度分别增加了0.02、0.19 m。Mike21数值模拟结果显示,工程建设改变了原来的流场,造成研究区冲刷悬浮的泥沙在潮流的作用下重新搬运与沉积,同时波浪场也因工程的影响下蚀海底的能力增强。  相似文献   
993.
Due to the powerful anisotropy of the physical properties of volcanic reservoirs, their component minerals and pore configuration are very complex, rendering fluid identification very difficult. This paper first computed the cementation exponent, which was based on triple porosity model, then used the varied matrix density and matrix neutron to compute the porosity, and finally combined with resistivity well log, and a P 1/2 probability distribution curve was built. The fluid properties were predicted from the shape of the P 1/2 probability distribution curve. Good results were achieved when these methods were used in the volcanic reservoir of the Wangfu fault depression, which indicated that these methods can be used in the fluid property identification of volcanic reservoirs and can also be referred to for other lithology reservoirs.  相似文献   
994.
Calcium isotopic compositions of sixteen Ca‐bearing USGS geological reference materials including igneous and sedimentary rocks are reported. Calcium isotopic compositions were determined in two laboratories (GPMR, State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan; and CIG, Centre for Isotope Geochemistry, University of California, Berkeley) using the 42Ca‐48Ca double‐spike technique by thermal ionisation mass spectrometry. As opposed to common cation exchange resin, a micro‐column filled with Ca‐selective resin (DGA resin) was used in order to achieve high recovery (> 96%) and efficient separation of Ca from the sample matrix. The intermediate measurement precision was evaluated at 0.14‰ (2s) for δ44/40CaSRM915a at GPMR, based on replicate measurements of pure Ca reference material NIST SRM 915a, NIST SRM 915b and seawater. Overall, the measurement uncertainties in both laboratories were better than 0.15‰ at the 2s level. Result validation was carried out for all available data sets. The Ca isotopic compositions of USGS reference materials are not only in agreement between GPMR and CIG, but also in agreement with previously published data within quoted uncertainties. The comprehensive data set reported in this study serves as a reference for both quality assurance and interlaboratory comparison of high precision Ca isotopic study.  相似文献   
995.
长白山仙人桥温泉是我国著名的矿泉水疗养旅游胜地,阐明其成因模式对于温泉区的进一步开发和热水资源的可持续利用具有一定的指导意义。笔者采用地质学、水文地质学和地球物理学结合的方法对其进行了系统研究。结果表明,该区属中低温对流型地热系统,地热成因模式为断裂岩溶复合型。热储层主要为古生界寒武系和奥陶系灰岩,灰岩本身的孔渗条件较差,但后期发育的构造裂缝和溶蚀裂缝却极大地改善了热储层的储集性能;盖层主要为中生界侏罗系安山岩和安山质火山碎屑岩,封闭性较好。长白山一带的大气降水沿侧向断裂和溶蚀裂缝渗入热储层中成为地下水;然后经正常大地热流加热成为地热水,热储温度为89~118℃,循环深度为2 853~3 820m;最终地热水在区内NE向与NW向断裂交汇处富集并沿导水断裂上涌形成温泉。因此,该区断裂交汇和岩溶发育的部位是地热勘探的有利部位。该结论为该区类似地热资源的勘探提供了理论依据。  相似文献   
996.
The release of mercury from intertidal sediment to atmosphere was studied based on the simulated experiment. The experiment samples were collected from the Haibo Estuary (S1) and the Licun Estuary (S2) of the Jiaozhou Bay in China,which are seriously polluted with mercury. The results show that the mercury in sediment releases rapidly to atmosphere under solar radiation. After 8 hours of solar radiation,mercury concentrations decrease from 5.62 μg/g and 2.92 μg/g to 2.34 μg/g and 1.39 μg/g in S1 and S2 sediments respectively in summer,and decrease from 5.62 μg/g and 2.92 μg/g to 4.58 μg/g and 2.13 μg/g respectively in winter. The mercury species in the sediment change markedly under solar radiation. The concentrations of mercury bound to organic matter decrease significantly from 2.73 μg/g to 0.31 μg/g in S1 and from 2.07 μg/g to 0.31 μg/g in S2,and the released mercury mainly comes from mercury bound to organic matter. Mercury flux shows distinguishing characteristic of diurnal change,and it increases rapidly in the morning with the rising of solar radiation intensity,but decreases in the afternoon. The mercury flux increases with sediment temperature and solar radiation intensity. The rapid release of mercury in intertidal sediment plays an important role in the regional mercury cycle.  相似文献   
997.
According to palaeoclimatic and modern instrumental data, numerous studies have indicated that the Arctic climate has undergone a significant warming during the past 100 years, and this may lead to significant impact on the fragile lake ecosystem. In this study, we collected a lake sediment core from the Ny-(A)lesund of Svalbard and determined the concentrations of four pigments including chlorophyll derivatives, total carotenoids, oscillaxanthin and myxoxanthophyll in the sediments. Combined with other physical and chemical proxies such as calcium carbonate, total organic carbon, biogenic silicon etc., we have reconstructed the historical changes of lacustrine primary productivity in Ny-(A)lesund, especially for the past 100 years. The results showed that during the period of Little Ice Age (LIA), the climate was unfavorable for the growth of the lake algae, and thus the lacustrine productivity declined. This result was supported by the relatively low contents of pigment and biogenic silica in the sediments. In contrast, the contents of total organic carbon (TOC) and sediment pigments increased significantly in the upper 5 cm (~1890AD), reflecting the rapid growth of the lake algae, thus the great increase of lacustrine primary productivity, corresponding to the warming climate after LIA. However, the biogenic silica in the upper sediments still had a relatively low level, and this might be related to the growth competition with other algae species. Over the past 100 years, the ratio of Osc/Myx in the sediments decreased continuously, indicative of durative increase of myxoxanthophyll in blue-green algal pigments, and this might imply that the human activity had enhanced the nutrition level of the lake in the Arctic region.  相似文献   
998.
??????8.0????????????????????????????????????λ??????????????η????????ν??????????????????8.0??????GPS??InSAR????α??????????????????????????????????????????1?????????????????GPS??InSAR??????????α????????????97.27%;2??????????????????????????????????????0??20 km??????????????λ???????????????????????????????????????????0??20 km???????????????????10 m????????10??15 km?????????????6.5 m??3??????????????????????????????????????????????????????????103??????????????????????121????????????????????138??????????????????????????105??4?????????????????8.7??10 20 Nm???????Mw7.9??  相似文献   
999.
???????????????????????????о????????????????????????????????????????Kalman??????????????÷??????????????????Kalman????????????????????????????????????????и????????????3???????????????顢???Kalman??????????????????????????????????????????Kalman??????????????????????????????  相似文献   
1000.
地电阻率观测各类干扰源的分析与研究   总被引:2,自引:1,他引:1  
地电阻率观测是我国地震前兆监测的重要手段之一,目前已积累了大量的观测资料和强震震例。但随着农村经济的发展和城市现代化轨道交通设施的建设,使得部分地电台站观测环境发生较大变化,导致地电阻率前兆观测资料受到较强的干扰。本文通过对国内现有地电阻率观测资料的分析、干扰源的调研,研究了各类干扰产生的原因及识别方法。并根据已有的研究成果,对地电阻率观测抑制干扰的技术和方法及数据使用与处理提出了相应的建议。  相似文献   
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