首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
地震应急流动观测系统的组建与应用   总被引:1,自引:0,他引:1  
针对大地震发生之后,对地震现场开展的应急流动观测工作进行归纳和总结,根据相关规程对地震现场流动观测系统的组建给出方法和建议,以便提高应急流动观测的科学性和时效性,提高整体观测效能,并分析了地震应急流动观测系统在监测效能、数据产出、预测预报等科研工作中的重要应用。  相似文献   

3.
利用2014-2015年南天山地区45个测点的2期流动地磁资料,分析喀什及邻近区域相邻两期岩石圈磁场的动态变化特征,同时,利用2014-2016年170个测点的4期流动重力资料,分析不同时间尺度的重力场动态变化信息。研究表明:皮山6.5级地震的发生对皮山一带的地磁矢量分布特征影响较大,总磁场强度、磁偏角和磁倾角均有变化;无论是半年尺度还是一年尺度的重力变化图像都显示乌恰一直处于重力变化的高梯度带;综合多手段的观测资料对震情形势的判定更为准确。  相似文献   

4.
邢台5.4级地震前的流动重力和地磁异常初步研究   总被引:1,自引:0,他引:1  
根据测值空间变化等值线和时序变化曲线,分析了2002年邢台5.4级地震前流动重力和流动地磁异常的动态演化。两种异常震前表现出如下特征:①流动重力、流动地磁观测资料均有较为明显的前兆异常反应;②地震发生在重力变化的“0”等值线附近;③流动地磁部分点位测值呈现趋势性异常,震前全部点位观测值整体上升,形成完整的高值异常区。  相似文献   

5.
全球地幔垂直流动速度研究   总被引:5,自引:0,他引:5       下载免费PDF全文
用高分辨率地震体波速度成像以及相关的地球物理资料,计算地幔垂直流动形式及流动速度,得到全球地幔流垂直运动模式.从全球尺度来看,地幔流基本可划分为以下几个区域:欧亚大陆—澳大利亚、北美洲—南美洲为两个大规模下降流区域,西印度洋—非洲及大西洋、中南太平洋及东太平洋为两个大规模地幔上升流区域.地幔上升流起源于核幔边界,主要表现在地幔中部和上地幔下部.地幔垂直流动速度约每年1~4cm.地幔流动对地表板块运动、海洋中脊和中隆、俯冲带和碰撞带的分布起着控制作用.地幔上升流与地表现代热点有密切关系.从东亚尺度看,地幔流大体分为三个区域:东亚边缘裂谷系和西太平洋边缘海为上升流、西伯利亚地幔深度表现为物质下降流、青藏高原—缅甸—印度尼西亚特提斯俯冲带地幔下降流,这三个区域地幔流动与地表的西太平洋构造域、亚洲构造域和特提斯构造域相吻合.勾勒出南海地区构造特征:从上到下的大体结构是上部呈“工"字型、中间为圆柱型、底部呈盾形的地幔上升流.  相似文献   

6.
根据地震流动观测实践经验,归纳总结了地震流动观测在提升地震监测能力,开展地震科学研究方面的作用和意义。着重介绍根据不同地区日照情况和设备功耗水平,确定流动地震台站关键设备参数的方法;针对流动观测特点设计制作地震流动观测防护装置、专用底座和集成装置;通过开展软土场地和水泥地面对比观测,分析两种观测环境下背景噪声特点,为改进和发展地震流动观测实用技术拓宽思路。   相似文献   

7.
大陆板内塑性流动波与地震迁移(一)   总被引:11,自引:7,他引:4       下载免费PDF全文
王绳祖  张宗淳 《地震地质》1994,16(4):289-297
大陆岩石圈下层的网络状塑性流动,通过能量的远距离传递,控制着板内地震的空间分布,而脉动式塑性流动波的传播决定了地震的迁移。根据地震时、空分布特征的分析结果,以喜马拉雅碰撞带为驱动边界的中东亚网络系统主要存在着两种塑性流动波,波速的沿网带分量分别约为1~7km/a和12~45km/a,边界起波的时间间隔平均为93.7a和10.8a,分别称之为“百年波”和“十年波”。塑性流动波的波峰带为地震的发生提供必要的能量背景条件  相似文献   

8.
以2014年11月22日四川康定发生6.3级地震后开展应急流动观测为例,描述了在应急流动观测组网中,如何应对震区高原环境,完成4个流动台选址架台、快速组网、运维保障;并通过对流动台址地动噪声功率谱密度分析计算,获得的台基达Ⅱ或Ⅲ级环境地动噪声水平,余震微小震检测能力与定位精度得到极大改善。流动台网运行期间,提高了震区监测台站覆盖面,记录到了大量余震微小震,加密台站对震区定位精度提升了量级,震源深度、震级更加准确。结果表明:一旦大震发生后,及时组织开展应急流动观测是必要的,而完成好一次大震后快速有效的应急流动监测,必须综合考虑震区地域环境、人员配备、预案选择、通信条件、设备可靠诸多因素与运维保障,采用固定与流动台联合组网方式,应急流动发挥效益最佳。  相似文献   

9.
利用波形对比分析与多台到时对比的方法找出了流动台站记录的地震波形常规分析中存在的问题,提高了流动台资料的利用率。  相似文献   

10.
牟剑英  张清  向巍  符衡 《华南地震》2021,41(3):141-147
大震或有感地震发生后,迅速组织开展地震现场流动监测是地震监测应急的一项重要内容.回顾广西测震流动观测的发展历程,介绍广西数字应急测震流动台网的技术构成、管理和考评、启动和终止,最后结合实际介绍了测震流动观测在广西中强地震、显著震群、水库加密观测及科研项目中的应用.  相似文献   

11.
12.
The determination of the coefficient of viscosity of eruptive products gives useful elements to the knowledge of possible variations of composition and physical conditions of the magmas.  相似文献   

13.
14.
Geomagnetism and Aeronomy - The magnetic evolution of the active region of the Sun at the level of the photosphere has been studied. Magnetic synoptic maps of the 2007 Kitt Peak Observatory were...  相似文献   

15.
Until recently, the existing data prevented the geophysicists from accurately dating the Bysy-Yuryakh stratum, which outcrops in the middle reach of the Kotuy River, constraining the time of its formation to a wide interval from the end of the Late Cambrian to the beginning of the Silurian. The obtained paleomagnetic data unambiguously correlate the Bysy-Yuryakh stratum to the Nyaian regional stage and constrain its formation, at least a considerable part of it, by the Tremadocian. This result perfectly agrees with the data on the Bysy-Yuryakh conodonts studied in this work and yields a spectacular example of the successful application of paleomagnetic studies in solving important tasks of stratigraphy and, correspondingly, petroleum geology. Within the Bysy-Yuryakh stratum, we revealed a large normal-polarity interval corresponding to the long (>1 Ma) period when the geomagnetic reversals were absent. This result, in combination with the data for the Tremadocian and Middle–Upper Cambrian sequences of the other regions, indicates that (1) the rate of occurrence of the geomagnetic reversals on the eve of the Ordovician Moyero superchron of reversed polarity was at most one reversal per Ma; (2) the superchron does not switch on instantaneously but is preceded by a certain gradual change in the operation conditions of the dynamo mechanism which, inter alia, manifests itself by the reduction of the frequency of geomagnetic reversals with the approach of the superchron. This finding supports the views according to which a process preparing the establishment of the superchrons takes place at the core–mantle boundary.  相似文献   

16.
Summary The results of two different methods of the determination of the non-linearity of the gravimeter scale are compared; the economy is discussed as well.  相似文献   

17.
Atmospheric temperature and humidity fields as well as information on other meteorological parameters are nowadays retrieved from radiance measurements recorded by operational meteorological satellites. Up to now, the inversion procedures used only take into account crude information on the topography of the Earth’s surface. However, the applied radiative transfer codes have to consider the Earth’s surface as the lower boundary of the atmospheric model and, therefore, need a more precise mean elevation and a classification of the roughness of the Earth’s surface. The influence of the topography of the Earth surface on retrieved temperature profiles is studied by using a physico-statistical inversion method. An objective analysis is made of the more precise mean elevation and derivation of roughness parameters using a new high-resolution digital elevation model (DEM) with a resolution of 500 m×500 m. By means of a geomorphological process and a newly developed topography rejection test, areas with a high surface roughness are localized and singled out. The influence of topography on the retrieved temperature profiles is illustrated by case studies. Changes are found predominantly in areas with a high variation of topography. Using the new high-resolution DEM and the topography rejection test, the geographical position of the calculated temperature profiles tends to be shifted towards areas with a small vertical variation of topography. The mean elevation determined by the new elevation model better characterizes the area observed. Hence, the temperature profiles can be calculated down to lower atmospheric levels. Furthermore, a guess profile better describing the atmospheric situation is selected by the more precise elevation. In addition, the temperature profiles obtained near the coast are improved considerably by the more precise determination of the surface property ‘sea’ and ‘land,’ respectively. Integration of an independent physical information such as topography leads, on average, to a slight improvement of the results of the physico-statistical inversion procedure. In some cases, however, significant improvements have been achieved regarding the desired accuracy of temperature profiles of the order of 1 K. In future, the spatial resolution of new high-resolution sounding instrumentation on the next generation of operational meteorological satellites will be increased. To exploit the resolving power of this new instrumentation, the different variation of the topography of the Earth surface, especially in regions with a high variation of topography, can be taken into account more precisely by using a high-resolution DEM.  相似文献   

18.
Summary A simple model is proposed suitable for studying the effect of the ground layer of the atmosphere, polluted by aerosol, on the albedo. This model is founded on solving the equation of transfer of radiative energy. The numerical results are discussed, particular attention being paid to the analysis of errors due to neglecting the multiple reflection of solar radiation on the aerosol particles. A method which would also include the multiple reflection is proposed, and the conditions under which the presence of the aerosol is responsible for an increase or decrease of the solar radiation balance on the Earth's surface, are analysed.  相似文献   

19.
Резюме Дается вывод формул для вычислений длины хорды, длины и азимутов нормаляных сечений и длины геодезической линии эллипсоида. Применяются тригонометрические функции данных величин и постоянные принятого ргфгргнц-эллипсоида, что является целесообразным при использовании вычислителQjных машин, особенно автоматов. Рабочие формулы рекомендуются в форме (8–11).

Dedicated to Professor František Fiala on His 85th Birthday

Address: Veveři 95, Brno.  相似文献   

20.
Summary The maintenance of the axisymmetric component of the flow in the atmosphere is investigated by means of a steady-state, quasi-geostrophic formulation of the meteorological equations. It is shown that the meridional variations in the time-averaged axisymmetric variables can be expressed as the sum of three contributions, one being due to the eddy heat transport, another to the eddy momentum transport, and a third to the convective-radiative equilibrium temperature which enters the problem through the specification of a Newtonian form of diabatic heating. The contributions by the large scale eddies are evaluated through the use of observed values for the eddy heat and momentum transports.The contributions from each of the three forcing mechanisms to the temperature and zonal wind fields are invstigated individually and found to be of about equal importance. The sum of the three contributions are also presented for the temperature, the zonal wind, the stream function associated with the mean meridional circulation and the corresponding vertical motion. Although the results fail to reproduce the main observed features of the lower stratosphere, they are found to be in good agreement with observations in the middle latitude troposphere. At any pressure level, for example, the computed mean zonal wind has a jet-like profile and the axis of the jet is found to slope to the south with height, as observed in the atmosphere.Based in part on a thesis submitted by the first author as partial fulfillment of the requirements for the Ph.D. degree at the University of Michigan. — Publication No. 194 from the Department of Meteorology and Oceanography, The University of Michigan.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号