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1.
将多通道相关分析方法用于宽频带地震仪的自噪声检测,测量分析了Reftek 130、130 B和130 S三种地震数据采集器的自噪声检测结果以及14套Reftek 130 S连接Guralp CMG-3T地震计的自噪声一致性检测结果,同时给出了地震计的三轴正交性估计.结果表明:Reftek数据采集器设置为普通增益时在0.3 Hz以上频段自噪声高于Guralp CMG-3T地震计自噪声,设置为32倍高增益时在测量频段远低于地震计自噪声;测量的多台Guralp CMG-3T地震计自噪声结果在不同频段一致性差异较大,垂直向分量0.3 Hz以下频段可作为一致性比对参考频段,采集配置选择普通增益时0.3~2 Hz频段可作为数据采集器一致性比对参考频段;Guralp CMG-3T地震计三轴正交性误差估计平均在0.5°以内. 相似文献
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随着ChinArray等大型地震观测项目逐渐推进,一些台站不得不安装在软土层等较高背景噪声区域,研究这些区域中不同类型地震仪在不同安装方法之间的背景噪声水平差异,对于提高观测数据质量、选取观测仪器类型、研制地震仪器等问题具有重要意义.本文在北京通州西集地震台,通过一系列比测实验研究了宽频带地震仪在不同安装深度、安装方式以及保温隔离防护方式下的安装效果差异,结果表明：在0.05～1 Hz的海浪脉动噪声频段附近,所有参与比测地震仪的三个分量背景噪声水平均高度一致,符合远场海浪脉动信号的特点;在低于0.05 Hz的低频段范围,背景噪声主要和地震计附近的温度变化及气流扰动环境相关,增加安装深度和采取保温隔离防护措施效果类似,其中垂直向对保温隔离防护措施更为敏感,比如1～2 m深度安装的地震计在妥善进行保温隔离措施后可获得和283 m井下地震计类似噪声水平,水平向由于存在地倾斜噪声,当大幅度增加安装深度时仍可有效降低噪声水平;在高于1 Hz的高频段范围,背景噪声衰减和地下介质岩性相关,软土层地区地下10 m以内随安装深度增加背景噪声水平衰减非常有限.另外,我们还研究了宽频带、短周期、节点式等不同... 相似文献
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新疆数字地震台站观测动态范围和台基噪声的分析 总被引：2，自引：0，他引：2
介绍了新疆数字地震台仪器的配置,对新疆23个数字地震台站台基噪声进行分析计算。台站的观测动态范围,反映了观测仪器本身的性能和台基环境干扰背景的水平,有效动态范围大小反映记录地震信号的最大能力。台站(台网)的监测能力不仅取决于仪器的性能,而且还与台基的噪声背景有关。得出了各地震台台基的脉动噪声的均方根值、观测动态范围、地噪声功率谱。有效观测动态范围的大小与数字地震仪的种类和配置有关。新疆23个数字地震台中的21个台的台基地动噪声在1~20 Hz内符合中国数字测震台网技术规程的要求,而另外2个台,即二宫和石河子数字地震台没有达到规定指标。 相似文献
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研究了2001年11月14日昆仑山MS8.1大地震前新疆地区宽频带地震仪记录到的异常扰动事件.新疆地震台网在发生强震的前三天记录到了强烈的扰动信号.由于新疆地震台距离昆仑山大地震的震中很近,因此该震前扰动的成因备受关注,一直被认为可能是与大地震相关的慢地震事件,可能是大地震的某种前兆现象.本研究扩大了观测异常扰动事件的范围,分析了欧亚大陆187个宽频带地震仪在2001年11月的观测记录,发现这些地震仪在11月10—12日期间都记录到了时频特征类似的强扰动信号,其中最强的扰动信号出现在挪威台站KONO.调查研究发现挪威海域在11月10—12日期间出现了一次超强北极风暴,我们对扰动源位置初步定位后发现大地震前欧亚大陆各台站记录的最大扰动信号主要来源于挪威西南海岸.本文的研究结果确认昆仑山大地震前新疆台网记录到的强烈震前扰动信号不是与大地震相关的慢地震事件,而是挪威海域北极风暴激发的微地震（地脉动）.本文进一步研究表明北极风暴激发的地脉动可显著影响中国大陆的地震和重力观测.在分析中国大陆地震台网记录的强扰动信号时,北极风暴的影响不能忽视. 相似文献
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蒙城地震台地磁偏角日均值自1999年7月起出现了趋势性变化,台站观测人员搜集整理了周边泰安、郑州、佘山、武汉地磁台的三分量数据,应用对比、相关分析等方法,研究了此变化,认为是地磁场的长期变,非地震趋势异常。 相似文献
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流动地震地磁矢量观测是一种获取地震前兆异常的方法,试验研究和观测实例表明,地震孕育引起的地磁场异常变化量级较小,因此在观测、数据处理过程中都要尽可能消除误差提高精度.本文主要从地磁矢量数据日变通化精度方面开展讨论,首先使用反距离加权插值法由泰安、武汉、崇明、杭州4个地磁台观测资料计算出蒙城地磁台相应的虚拟地磁数据,其磁偏角、水平分量、垂直分量三个要素与真实观测值的相关系数分别高达0.9987、0.9946和0.9806,验证了反距离加权插值方法对地磁观测数据空间插值的有效性.其次,选择东部和西部测区分别使用反距离加权插值方法建立各地磁矢量测点位置的虚拟日变台并用其进行通化,实例计算结果表明,该方法可有效提高日变通化精度,对于地磁台站稀疏地区更具实际应用价值. 相似文献
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为探索地震事件对GPS坐标时间序列的长周期影响,对汶川地震前后四川GPS观测网络长约10年的解算成果进行了多参数模型噪声特征分析.基于最大似然估计方法和频谱特性分析,提取了地震前后各测站坐标序列中的噪声分量,使用Λ-统计检验,得出"白噪声+闪烁噪声"模型可以作为四川GPS区域观测网络的最优噪声组合模型,同时,地震事件使得地震前后GPS噪声分量中的白噪声、闪烁噪声、随机游走噪声等发生显著改变,说明传统谱噪声分析中简单地将地震数据拼接在一起并进行统一处理的模式并不可取;使用共模误差分析方法、区域速度场变化趋势等信息对地震前后噪声模型的改变成因进行了初步的物理解析. 相似文献
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基于地脉动噪声计算方法,以呼伦贝尔市地震台网8个台站连续波形资料为基础,对地震观测台网监测能力进行评估,同时开展台网优化和科学布局研究。通过累计的历史噪声数据,用来评估台站观测环境的变迁,及时掌握地震监测能力的变化。该成果将为地震速报、重点地震危险区震情跟踪、强震后现场应急提供科学参考。 相似文献
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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
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Studia Geophysica et Geodaetica - 相似文献
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.
V. E. Pavlov T. Yu. Tolmacheva R. V. Veselovskiy A. V. Latyshev A. M. Fetisova I. V. Bigun 《Izvestiya Physics of the Solid Earth》2017,53(5):702-713
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
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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
17.
Josef Vykutil 《Studia Geophysica et Geodaetica》1968,12(2):217-220
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
Dedicated to Professor František Fiala on His 85th Birthday
Address: Veveři 95, Brno. 相似文献
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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
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Ivanka Jakubcová Věra Marvanová Miloš Pick Antonín Novotný Reviewer Z. Šimon 《Studia Geophysica et Geodaetica》1982,26(2):193-196
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
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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