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261.
上海地震台阵的地震定位方法 总被引:5,自引:0,他引:5
详细介绍了上海地震台阵数据处理软件系统中的地震定位方法,用台阵的聚束方法得到地震的方位角和视慢度,根据统计得到的视慢度-震中距表推算震中距。并结合了地震台网的定位方法,由单台记录的各类主要震相从J-B走时表得到震中距,然后进行地震定位。该定位方法可对近震、远震进行定位处理,并由深震相得到震源深度。 相似文献
262.
新疆数字地震前兆台网的数据传输功能分析 总被引:1,自引:0,他引:1
为了进一步提高地震前兆数据的传输效率和准确性 ,实现前兆数据采集和管理的自动化 ,对新疆地震局数字化地震前兆台网中心的功能、数据采集原理、数据传输特征进行了分析 ,认为数字化观测技术为地震前兆数据的采集、传输提供了一种高效、可靠的手段 相似文献
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In this study, observed seismic attributes from shot gather 11 of the SAREX experiment are used to derive a preliminary velocity and attenuation model for the northern end of the profile in southern Alberta. Shot gather 11 was selected because of its prominent Pn arrivals and good signal to noise ratio. The 2-D Gaussian beam method was used to perform the modeling of the seismic attributes including travel times, peak envelope amplitudes and pulse instantaneous frequencies for selected phases. The preliminary model was obtained from the seismic attributes from shot gather 11 starting from prior tomographic results. The amplitudes and instantaneous frequencies were used to constrain the velocity and attenuation structure, with the amplitudes being more sensitive to the velocity gradients and the instantaneous frequencies more sensitive to the attenuation structure. The resulting velocity model has a velocity discontinuity between the upper and lower crust, and lower velocity gradients in the upper and lower crust compared to earlier studies. The attenuation model has Q
p
-1 values between 0.011 and 0.004 in the upper crust, 0.0019 in the lower crust and a laterally variable Q
p
-1 in the upper mantle. The Q
p
-1 values are similar to those found in Archean terranes from other studies. Although the results from a single gather are non-unique, the initial model derived here provides a self-consistent starting point for a more complete seismic attribute inversion for the velocity and attenuation structure. 相似文献
267.
Gil A. J. Rodríguez-Caderot G. Lacy M. C. Ruiz A. M. Sanz de Galdeano C. Alfaro P. 《Studia Geophysica et Geodaetica》2002,46(3):395-410
The Granada Basin (Central Betic Cordillera), one of the most seismically active areas of the Iberian Peninsula, is currently subjected to NW-SE compression and NE-SW extension. The present day extension is accommodated by normal faults with various orientations but particularly with a NW-SE strike. At the surface, these active NW-SE normal faults are mainly concentrated on the NE part of the Basin. In this part we have selected a 15-km long segment where several active normal faults crop out. Using the marine Tortonian rocks as a reference, we have calculated a minimum extensional rate of 0.15-0.30 mm/year. The observed block rotation, the listric geometry of faults at depth and the distribution of seismicity over the whole Basin, indicate that this rate is a minimum value. In the framework of an interdisciplinary research project a non-permanent GPS-network has been established in the central sector of Betic Cordillera to monitor the crustal deformations. The first two observation campaigns were done in 1999 and 2000. 相似文献
268.
Seismic structural control using semi-active tuned mass dampers 总被引:8,自引:1,他引:8
This paper focuses on how to determine the instantaneous damping of the semi-active tuned mass damper (SATMD) with continuously
variable damping. An off-and-towards-equilibrium (OTE) algorithm is employed to examine the control performance of the structure/SATMD
system by considering the damping as an assumptive control action. The damping modification of the SATMD is carried out according
to the proposed OTE algorithm, which is formulated based on analysis of the structural movement under external excitations,
and the measured responses of the structure at every time instant. As examples two numerical simulations of a five-storey
and a ten-storey shear structures with a SATMD on the roof are conducted. The effectiveness on vibration reduction of MDOF
systems subjected to seismic excitations is discussed. Analysis results show that the behavior of the structure with a SATMD
is significantly improved and the feasibility of applying the OTE algorithm to the structural control design of SATMD is also
verified. 相似文献
269.
B.C. Papazachos A.S. Savvaidis C.B. Papazachos G.F. Karakaisis 《Journal of Seismology》2002,6(2):237-245
On the basis of growing evidence thatstrong earthquakes are preceded by a periodof accelerating seismicity of moderatemagnitude earthquakes, an attempt is madeto search for such seismicity pattern in NWAegean area. Accelerating seismic crustaldeformation has been identified in the areaof southern Albanides mountain range(border region between Greece, formerYugoslavia and Albania). Based on certainproperties of this activity and on itssimilarity with accelerating seismicdeformation observed before a strongearthquake which occurred in the sameregion on 26 May 1960 (M = 6.5), we canconclude that a similar earthquake may begenerated in the same region during thenext few years. This conclusion is inagreement with independent results whichhave been derived on the basis of the timepredictable model. 相似文献
270.
珠江三角洲地区一体化交通运输网络发展构想 总被引:4,自引:0,他引:4
从区域经济一体化角度分析了珠江三角洲经济区交通运输的现状、问题和发展趋势,提出了建设一体化交通运输网络的基本思路和总体构想。认为珠三角交通运输设施虽然种类齐全且发展迅速,但还存在数量、质量、结构、布局等方面与区域经济一体化和未来发展趋势不相适应的问题;为了促进区域经济一体化,交通运输应从被动适应变为主动发展并引导城镇体系和生产力布局,从注重设施数量变为强调设施质量并向高速高效型发展;应该分4个层次建设3个枢纽和3大组团并与大运量快速干线相连接,构建区域一体化的交通运输网络。 相似文献