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在进行山西省1/50万卫片地质解译工作中,发现纵贯汾渭断陷盆地的中段,有一条明显的线性构造影象,它切过了晋中、临汾和运城盆地。由于其走向与汾河在上兰村以下河段的流向基本一致。故称之为“汾河新构造断裂带”。地震勘探资料证实了汾河断裂带的存在及其新构造活动性。山西地震带的震中沿汾河一线分布表明汾河新构造断裂带对山西地震的分布有着举足轻重的作用。 相似文献
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通过浅层高分辨率地震探测 ,结合钻孔资料 ,获得了测线处汾河断裂的准确位置 ,几何结构 ,活动性质、时代和速率等参数 ,并对其动力学属性进行了初步的讨论。地震探测揭露出汾河断裂的西支断层 ,为高角度东倾的斜滑断层 ,切割了第四系下部 ,上断点位于地下约 70m处。据钻孔剖面推断有 2条高角度相向而倾的斜滑断层 ,东支位于汾河东岸 ,断至全新统—上更新统 ,其底界面垂直错距约 8m。断裂北段另一个钻孔剖面表明 ,西支断层切割了全新统—上更新统 ,底界面垂直错距约6m。汾河断裂晚更新世以来的平均垂直滑动速率为 0 0 6~ 0 0 8mm/a ,大震平均重复间隔为 5 0~6 7ka 相似文献
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通过浅层高分辩率地震探测,结合钻孔资料,获得了测线处汾河断裂的准确位置,几何结构,活动性质、时代和速率等参数,并对其动力学属性进行了初步的讨论。地震探测揭露出汾河断裂的西支断层,为高角度东倾的斜滑断层,切割了第四系下部,上断点位于地下约70m处。据钻孔剖面推断有2条高角度相向而倾的斜滑断层,东支位于汾河东岸,断至全新统-上更新统,其底界面垂直错距约8m。断裂北段另一个钻孔剖面表明,西支断层切割了全新统-上更新统,底界面垂直错距约6m。汾河断裂晚更新世以来的平均垂直滑动速率为0.06-0.08mm/a,大震平均重复间隔为5.0-6.7ka。 相似文献
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在山西南部临汾盆地中汾河三条主要支流河岸分别取样进行了~(14)C年龄测定,并用测定结果对地质年代进行了分析. 相似文献
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华北克拉通中西部地区瑞利面波噪声层析成像 总被引:1,自引:0,他引:1
根据2011年在鄂尔多斯地区新架的51套宽频带流动地震台数据,结合区域数字地震台网138个固定台站和2007年华北流动地震台阵连续一年的地震记录,基于背景噪声成像的基本原理与方法得到了华北克拉通中西部地区6~36S的瑞利面波群速度分布图像。6~15s的成像结果很好地对应于上地壳的隆起和塌陷盆地构造;16~30S的成像结果揭示了大同盆地和汾河谷地西侧可能存在中下地壳低速层;30~36S的成像结果反映了华北克拉通地壳东薄西厚的总格局,和断陷盆地下方莫霍面相对隆起的局部特征。 相似文献
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试论1303年山西8级大震的几个问题 总被引:1,自引:0,他引:1
1303年山西汾河中游地区发生的强烈地震,是我国根据现有历史资料所能确定的第一个8级地震。本文根据历史文献和地震考古资料,主要讨论本次大震的历史依据;大震前后山西地震带的地震活动;大震的震害及其评价;宏观震中的可能位置及其命名等问题。经过分析,本次大震宏观震中的可能位置当在霍州城(今霍县城)附近;鉴于目前的认识尚不统一,可将本次大震称之为1303年山西汾河8级地震。同时指出地震史料和地震考古在历史地震研究中具有的重要作用;深入研究这次8级强震取得新的突破,所急待解决的几个关键课题。 相似文献
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Calcareous fens are species‐rich peatlands that are dependent on minerotrophic water sources for wetland functioning, with current conceptual models suggesting the water source is ubiquitously groundwater upwelling. By quantifying the water balance and subsurface water flow paths and fluxes over 3 growing seasons for calcareous fens in 3 different hydrogeomorphic settings (Riparian, Trough, and Basin), we show evidence that challenges this conceptual model. The Riparian Fen received an order of magnitude more water inputs than the Trough or Basin Fens and was dominated by stream recharge inputs and groundwater outputs. Precipitation and evaporation dominated the water balance of the Trough Fen whereas only the Basin Fen received sizeable groundwater inputs. Indeed, subsurface water fluxes were low at all fens due to weak hydraulic gradients and low saturated hydraulic conductivity in some areas of each wetland, though variations in growing season precipitation led to subsurface flow reversals in all 3 fens. Our results demonstrate the importance of understanding landscape position, or hydrogeomorphic setting, on calcareous fen hydrology for improving conservation, management, and restoration efforts of these important ecosystems. 相似文献
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用微小地震在单元体内所累积频次和累积能量资料,分析研究汾渭盆地带中、南段地震活动和现代构造运动的某些特点,并以此为依据,讨论未来中强震活动的趋势。 相似文献
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M. V. Mikhailova 《Water Resources》2011,38(4):438-452
General geographic features of the Thames River, its basin, and mouth area, consisting of the tidal mouth reach of the river,
a large estuary, and an open nearshore zone of the river mouth (the North Sea coastal zone) are discussed. The peculiarities
of river and sea hydrological factors responsible for the regime of the Thames River mouth area are described in detail. Characteristics
of the river water runoff were specified and supplemented by the data on the river inundations in the area of London. Particular
emphasis was placed on variations in the mean sea level in the area of the Thames River mouth as well as on specific features
of tides and storm surges in the area of the sea inlet into the estuary. Main regularities in the estuary evolution during
Holocene and present-day morphological processes in the Thames River mouth area were revealed. 相似文献
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西宁城市活动断裂地表特征初步研究 总被引:13,自引:2,他引:11
在详细的野外地质调查基础上, 通过开挖探槽剖面揭露了断层的基本性质, 初步展示了西宁市北川河东岸断裂、 南川河断裂和湟水河断裂的地表特征。 结合前人的阶地测定年代结果初步判断, 北川河东岸断裂错断相当于湟水河Ⅱ至Ⅲ级阶地, Ⅱ级阶地形成不晚于0.05 Ma, Ⅲ级阶地形成不晚于0.12 Ma, 说明该断裂是晚更新世活动断裂; 南川河断裂错断相当于湟水河Ⅳ、 Ⅴ级阶地, Ⅳ级阶地形成不晚于0.54 Ma, Ⅴ级阶地形成不晚于0.78 Ma, 说明该断裂是早中更新世活动断裂; 湟水河断裂错断其Ⅱ、 Ⅲ级阶地砾石层, 说明该断裂是晚更新世活动断裂。 这些断裂规模小、 活动性弱, 可能为盖层断裂。 相似文献
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The main features of hydrological processes taking place in the mouth area of the Hong Ha River in Vietnam are considered.
The geographic and hydrological conditions in the Hong Ha River basin and in its receiving water body—the Gulf of Tonkin,
South China Sea—are briefly characterized. The main features of the mouth area of the Hong Ha River as a specific geographic
object are identified. The hydrological regime of the delta and the nearshore zone of the Hong Ha River are described in detail.
Water balance of the delta, runoff water levels and delta inundation, water and sediment runoff distributions over delta branches,
and the effect of tides, typhoons, and storm surges on delta regime are considered. Present-day problems of the use and protection
of natural resources at the Hong Ha River mouth are briefly discussed. 相似文献
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在地层剖面中,洪泛沉积物与正常的河道沉积物的沉积学特征非常相似,仅靠沉积学特征很难将两者区分. 为了识别古洪灾事件,因而从环境磁学角度建立两种沉积物的识别标志是非常必要和有意义的. 本文通过对1998年长江黣洲湾溃口扇及其附近的长江现代河漫滩沉积物进行磁组构参数测量和对比分析,并结合长江下游河漫滩沉积物的磁组构参数特征,揭示出长江中游正常河流沉积物与河流溃口沉积物的磁组构参数特征具有明显的不同,并且它们与沉积时的沉积环境有着密切的关系. 因此,对长江中游地区沉积物磁组构参数的测试及磁化率各向异性量值椭球体形态的研究,是目前分辨洪泛沉积物和正常的河道沉积物的一个较有效的方法. 相似文献
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The geographical and hydrological features of the Mekong River basin and the nearshore zone of the South China Sea, which
influence the hydrological regime of the Mekong River mouth, are discussed. Detailed characteristics are provided for the
drainage system of the Mekong River mouth area, water flow distribution among the delta branches, processes of the delta submergence
during floods, as well as propagation of tidal, surge-induced level fluctuations and seawater intrusion into the river. Regularities
of the Holocene evolution of the Mekong River mouth area and recent processes of delta formation are also discussed. 相似文献