老挝国家地震监测台网布局与组网

老挝国家地震监测台网(LEMN)是“一带一路”倡议下中国推进援外地震台网建设的又一重要工程,为了及时总结台网建设经验,从该台网的布局、组网、设备配备、台网链接方式等方面进行详细阐述,为我国未来省域地震监测台网和新时代援外台网的建设积累详实的参考资料。     

老挝国家地震监测台网布局与组网

老挝国家地震监测台网（LEMN）是“一带一路”倡议下中国推进援外地震台网建设的又一重要工程,为了及时总结台网建设经验,从该台网的布局、组网、设备配备、台网链接方式等方面进行详细阐述,为我国未来省域地震监测台网和新时代援外台网的建设积累详实的参考资料。     

宿迁数字测震台网建设效益分析

宿迁市数字测震台网是宿迁市防震减灾"十三五"规划的重点项目,介绍了宿迁数字测震台网的建设内容、台网布局,分析了宿迁测震台网监测能力,以及台网建成后,在宿迁市防震减灾、地震预报研究和保障社会稳定方面发挥的重要作用等。     

中国地震台网观测系统特性分析与资料应用研究

正2000年以来我国地震观测系统得到了迅速的发展,目前已建成了由国家数字地震台网、区域数字地震台网、火山数字地震台网和流动数字地震台网组成的新一代中国数字地震台网。中国地震台网中心每天汇集的数据量达到40GB,可以说,我国地震台网产出的观测数据积累到了一定程度,如此海量的地震波形数据为地震监测与研究提供了丰富的原始资料,     

西藏地震监测台网的建设与发展

回顾西藏自治区地震监测台网发展历程,介绍西藏测震台网、地球物理台网和GNSS台网的建设与发展现状,并对西藏地区测震台网、地球物理台网和GNSS台网的未来发展提出建议,建议进一步优化各类台网布局,提升西藏地区地震监测能力和地球物理参数获取能力,为防震减灾工作和地球科学研究提供高质量观测数据。     

陕西测震台网技术系统

通过测震台网网络技术平台,分析其系统构成及虚拟台网、3G无线传输、远程网络监控等技术在陕西测震台网的应用.该平台的建成,提高了测震台网运行质量及流动测震台网的快速响应能力,实现省、市测震台网观测数据的实时共享,对进一步提升地震部门地震响应能力、完善监测体系,具有重要意义.     

广西数字测震台网建设成果及效益分析

介绍了"十五"广西数字测震台网建设的基本情况,分析了台站布局、观测动态范围和台基环境地噪声水平对台网地震监测能力的影响。实现与邻省台网和地方社会台网的联网与数据共享后,台网监测能力得到进一步提高。以广西数字测震台网投入运行前后记录到的地震情况,阐述了广西数字测震台网技术成果及所取得的社会经济效益。     

对全国地震基本台网的展望与工作设想

随着科学技术的发展与地震监测工作的需要,继全国地震基本台网之后,在我国及各地区又相继建立了一批区域测震台网、流动测震台网、大震速报台网、763长周期台网等。近年来,随着数字技术和计算机技术的飞速发展,又出现了数字地震台网。数字测震观测技术与系统的出现无疑在测震技术与测震观测上是一次巨大的变革与进步,对各类测震台网的     

江西数字测震台网建设效益分析

介绍“十五”江西数字测震台网建设的基本情况,分析台站布局、观测动态范围和台基环境地噪声水平对台网地震监测能力的影响,阐述江西数字测震台网技术成果及所取得的社会经济效益.实现与邻省台网的联网与数据共享后,台网监测能力得到提高.     

区域测震台网监测效能评估方法研究及应用

如何通过评价区域测震台网方式,改善与提高我国区域测震台网监测效能,是当前我们面临的一个新的课题。本文提出的一个省级区域测震台网监测效能评价体系基本思路是,通过建立台网监测效能评价子系统,引入动态统计,指标分析,目标评价,公众评判的综合分析与关联评价方法,探讨我国省级测震台网系统性能与台网运行,维护能力及资料产出、数据服务之间的相互关联。以安徽区域测震台网为例,检验区域台网监测效能评价体系的可行性与实效性。     

Episodic tectonic plate reorganizations driven by mantle convection

Periods of relatively uniform plate motion were interrupted several times throughout the Cenozoic and Mesozoic by rapid plate reorganization events [R. Hey, Geol. Soc. Am. Bull. 88 (1977) 1404-1420; P.A. Rona, E.S. Richardson, Earth Planet. Sci. Lett. 40 (1978) 1-11; D.C. Engebretson, A. Cox, R.G. Gordon, Geol. Soc. Am. Spec. Pap. 206 (1985); R.G. Gordon, D.M. Jurdy, J. Geophys. Res. 91 (1986) 12389-12406; D.A. Clague, G.B. Dalrymple, US Geol. Surv. Prof. Pap. 1350 (1987) 5-54; J.M. Stock, P. Molnar, Nature 325 (1987) 495-499; C. Lithgow-Bertelloni, M.A. Richards, Geophys. Res. Lett. 22 (1995) 1317-1320; M.A. Richards, C. Lithgow-Bertelloni, Earth Planet. Sci. Lett. 137 (1996) 19-27; C. Lithgow-Bertelloni, M.A. Richards, Rev. Geophys. 36 (1998) 27-78]. It has been proposed that changes in plate boundary forces are responsible for these events [M.A. Richards, C. Lithgow-Bertelloni, Earth Planet. Sci. Lett. 137 (1996) 19-27; C. Lithgow-Bertelloni, M.A. Richards, Rev. Geophys. 36 (1998) 27-78]. We present an alternative hypothesis: convection-driven plate motions are intrinsically unstable due to a buoyant instability that develops as a result of the influence of plates on an internally heated mantle. This instability, which has not been described before, is responsible for episodic reorganizations of plate motion. Numerical mantle convection experiments demonstrate that high-Rayleigh number convection with internal heating and surface plates is sufficient to induce plate reorganization events, changes in plate boundary forces, or plate geometry, are not required.     

BOOK REVIEW

Book review in this article
Handbuch der Physik/Encyclopedia of Physics, Ed.: S. Flügge
The Aurora. By S.-I. Akasofu, S. Chapman and A. B. Meinel.
Time-Variations of Cosmic Rays. By S. E. Forbush.
Magnetic Properties of Rocks and Minerals. By T. Nagata.     

Comment on “A note on the free-surface effect on the topographicaily induced vorticity field in a homogeneous flow” by lee-or merkine

Abstract

MASS LOSS AND EVOLUTION OF O-TYPE STARS. I.A.U. Symposium No. 83. Edited by P. S. Conti and C. W. H. de Loore. Reidel, Dordrecht. (ISBN 90-277-0989-0 pbk) 1979. Price U.S. $31.50.

A MATHEMATICAL INTRODUCTION TO FLUID MECHANICS by A. J. Chorin &; J. E. Marsden, 205 pages, paperback, Springer Verlag. (ISBN 0-387-90406-9 and ISBN 3-540-90406-9) 1979. Price: DM 29—US $16.00.     

Curvelet阈值迭代法地震随机噪声压制(英文)

本文将近些年发展起来的多尺度分析技术——Curvelet变换与求解优化反演问题的阈值迭代法相结合,研究了基于Curvelet变换的阈值迭代法在地震数据随机噪声衰减中的应用。充分利用了Curvelet变换对地震数据表示的稀疏性,提出将地震数据随机噪声压制问题转化为基于Curvelet稀疏变换的L1范数最优化问题,并采用前人提出的阈值迭代法求解。通过与常规的中值滤波、FX反褶积和小波阈值法去噪方法对比,理论合成数据和实际数据试算表明,Curvelet阈值迭代法去噪法具有优势,该法不仅能够获得较高的信噪比,而且对有效信号的损失较小。为充分利甩Curvelet的多尺度、多方向特性,提出了在Curvelet阈值迭代法去噪结果的基础上再进行方向控制,进一步提高了数据信噪比。     

Global seismicity of 2003: centroid–moment-tensor solutions for 1087 earthquakes

Centroid–moment-tensor (CMT) solutions are presented for 1087 earthquakes that occurred during 2003. The solutions are obtained using the method of Dziewonski et al. [Dziewonski, A.M., Chou, T.-A., Woodward, J.H., 1981. Determination of earthquake source parameters from waveform data for studies of global and regional seismicity. J. Geophys. Res. 86, 2825–2852] and applying corrections for aspherical Earth structure as represented by the whole-mantle shear-velocity model SH8/U4L8 of Dziewonski and Woodward [Dziewonski, A.M., Woodward, R.L., 1992. Acoustic imaging at the planetary scale. In: Emert, H., Harjes, H.-P. (Eds.), Acoustical Imaging, vol. 19. Plenum Press, New York, pp. 785–797]. The model of inelastic attenuation of Durek and Ekström [Durek, J.J., Ekström, G., 1996. A radial model of inelasticity consistent with long-period surface wave attenuation. Bull. Seism. Soc. Am. 86, 144–158] is used to predict the decay of the waveforms. The focal mechanisms of the largest, or otherwise significant, earthquakes of 2003 are reviewed.     

High attenuation and the low-velocity zone

Both elastic and anelastic properties of the earth simultaneously play an important role in the high-attenuation, low-velocity zone (H.A.L.V.Z.), in the upper mantle, where the drop of velocity appears to be correlated with high attenuation. Internal friction studies and experiments suggest the possibility of relaxation mechanisms occurring within the H.A.L.V.Z. and clearly it is important to compare assumptions of relaxation processes with seismic data and investigate the consequences of such a model. A variety of physical explanations of the H.A.L.V.Z. are discussed and it is concluded that three mechanisms could produce the H.A.L.V.Z., namely partial melting, viscous grain-boundary effects and dislocation-impurity interactions. Only more experiments and more data on the Q-structure of the H.A.L.V.Z. would allow us to decide which is the most probable of these mechanisms.     

震源断层的长度与错动幅度之间关系的讨论

震源断层的长度和错动幅度是震源参数中两个重要的量,寻找它们在震前的指标对地震预报具有要重的意义。这两个量的比值代表了地下断层错动的协调性,因此有助于了解震源环境。本文通过对中国、日本、美国三地区的大震断层资料的处理,得到了震源断层的长度与错动幅度之间近似地存在着线性关系的结论,震源断层的错动幅度是其长度的10~(-5)数量级。另外,本文根据地震过程中震源断层的长度与错动幅度之间的协调关系,讨论了1976年唐山地震前的断层蠕滑问题,以及郯庐断裂带上几百公里的水平错距是否可能的问题。     

相关分析法在研究电离层不均匀結构中的应用

本文詳細地介紹了武汉采用的交点相关法和十点相关法的理論基础和具体計算方法,并与Philtips和spcncer的相关法（PS法）及Yerg的六点相关法进行了比較。正如理論上所預期到的,武汉的实驗表明:交点法提供的参量最多,也最精确可靠,但計算量与PS法的差不多;十点法提供的参量与交点法的一样多,精确性不此PS法的低,然而計算量比PS法的少得多,与六点法的差不多。文中还討論了利用时移图上曲直线,以进一步提高十点法的精确性,以及在相关分析中采用結构函数和后效函数,以进一步簡化計算的可能性。本文还初步討論了各种相关分析法的誤差間題;并提出了相关函数值在时空上的預报方法,以及根据相关函数的預报值与实測值的对此等,判别在記录分析中有无反常現象,和甄別所求出的参量值是否可疑的方法。最后还特別指出了电离层混乱运动变化速度出現虛数值的可能性,并介紹了消除这种虛数值的方法。     

Cainozoic history of southern New Zealand: An accord between geological observations and plate-tectonic predictions

Sea-floor spreading data from the Southwest Pacific have recently been used to predict the Cainozoic geological history along the Indo-Australian/Pacific plate boundary. Geologic and sedimentologic data pertaining to this plate boundary where it crosses southern New Zealand, as the Alpine Fault, are summarised and discussed. It is concluded that there is a close accord between the plate-tectonic predictions and South Island Cainozoic geological history. In particular, (1) no Cainozoic plate boundary traversed the New Zealand region prior to 38 m.y. B.P. (late Eocene); (2) transcurrent movement on the Alpine Fault took place largely between ca. 30 m.y. B.P. (middle Oligocene) and ca. 10 m.y. B.P. (late Miocene); and (3) the period 10 m.y. B.P. to present corresponds to a phase of oblique compression, continental collision, and mountain building along the Alpine Fault sector of the plate boundary. There is a close correlation between the sites and histories of Cainozoic sedimentation and this tectonic timetable.     

Book reviews

Abstract

EDDIES IN MARINE SCIENCE (Edited by A. R. Robinson) Springer-Verlag, 1983, 268 figures, 625 pages. Price: DM 120 (U.S. $49.60). ISBN 3-540-12253-2

THE SOLAR GRANULATION, by R. J. Bray, R. E. Loughhead, and C. J. Durrant, 2nd Ed., Cambridge University Press 1984. xvi + 245 pp. Price: £27.50, $54.50, ISBN 0-521-24714-4.

ASTROPHYSICAL JETS. Proceedings of an International Workshop held in Torino, Italy. October 7–9, 1982. Edited by A. Ferrari and A. G. Pacholczyk, D. Reidel Publishing Company, 1983. xvi + 327 pp. Dfl. 110.00 (US. $48.00). ISBN 90-277-1627-7.

INTERNAL KINEMATICS AND DYNAMICS OF GALAXIES. IAU Symposium No. 100. Edited by E. Athanassoula. D. Reidel Publishing Company, xiv + 432 pp. 1983. Price: Dfl. 115 (U.S. $49.50) ISBN 90-277-1546-7

HANDBOOK OF PLASMA PHYSICS—BASIC PLASMA PHYSICS 1. Edited by A. A. Galeev and R. N. Sudan. North-Holland Publishing Company 1983. 730 pages. Price: US. $180.75 (Dfl. 425.00). ISBN 0-444-86427-x.

NUMERICAL METHODS FOR FLUID DYNAMICS. Edited by K. W. Morton, xiv + 517 pp, Price $55.50 (£30). ISBN 0-12-508360-2.

MAGNETIC FIELDS IN ASTROPHYSICS, By Ya. B. Zeldovich, A. A. Ruzmaikin and D. D. Sokoloff. Gordon and Breach Science Publishers, xvi + 365 pp. 1984. Price $60.00. ISBN 0-677-05530-7 (Vol. 3 in “The Fluid Mechanics of Astrophysics and Geophysics” ISSN 0260 4353).