印度洋大地震与海啸灾害综述   总被引：1，自引：0，他引：1  

崔秋文  李建一  董军  赵勇  王禹  纪寿文 《山西地震》2005,(3):42-48

2004年12月26日8时58分,印尼苏门答腊岛附近海域发生M8.7地震（百年以来第5次大地震）,其引发的海啸波及了东南亚和南亚至少10个国家,截至2005年3月5日已造成28万人死亡和重大财产损失.这是自1964年3月以来世界上发生的最强烈地震,此次海啸是1900年以来这一地区发生的最大海啸.叙述了此次地震和海啸的破坏情况以及受灾国的应急救援工作和国际社会的反应.概述了地震海啸灾害及其研究简况.  相似文献   

Influence of the modified global ocean tide model with local tides of East and South China Seas on load gravity in China and its neighbor area     

周江存  孙和平 《地震学报(英文版)》2005,18(3):354-360

Introduction With the development of science and technology, the accuracy of gravity measurement is im-proved. The gravity observation with FG5 gravimeter has reached accuracy of μ magnitude. And the high accurate superconducting gravimeter can detect the tiny signal of 10?2 μ magnitude in frequency domain. With the high-accuracy gravity observation on Earth′s surface, the Earth′s tidal parameters can be determined precisely. And the observations can also be used to invert the struc-ture…  相似文献   

Warming in Arctic intermediate and deep waters around Chukchi Plateau and its adjacent regions in 1999   总被引：3，自引：0，他引：3  

ZHAO Jinping  GAO Guoping & JIAO Yutian . First Institute of Oceanography  State Oceanic Administration  Qingdao  China  . Ocean University of China  Qingdao  China 《中国科学D辑(英文版)》2005,48(8):1312-1320

Warming in the Arctic Intermediate Water (AIW) has been reported in a series of articles in recent years. Prior to 1992, the water temperature of AIW off the Chukchi Continental Slope had never exceeded 0.5℃. Aagaard et al.[1] and Carmack[2] were the first to report that the temperature in AIW in the area in 1993 was close to 1℃, based on the data observed in a Canadian expedition. In 1994, the temperature of AIW around the Chukchi Sea and Mendeleyev Ridge again rose by at least an…  相似文献   

A new two-way nesting technique for ocean modeling based on the smoothed semi-prognostic method     

Jinyu Sheng  Richard J. Greatbatch  Xiaoming Zhai  Liqun Tang 《Ocean Dynamics》2005,55(3-4):162-177

A new two-way nesting technique is presented for a multiple nested-grid ocean modeling system. The new technique uses the smoothed semi-prognostic (SSP) method to exchange information between the different subcomponents of the nested-grid system. Four versions of the new nesting technique are described, together with conventional one-way nesting. The performance of the different nesting techniques is compared, using two independent nested-grid modeling systems, one for the Scotian Shelf of the northwest Atlantic Ocean and the other for the Meso-American Barrier Reef System of the northwestern Caribbean Sea. Nesting using the semi-prognostic method is shown to effectively prevent unrealistic drift of the inner model, while use of the SSP method avoids unnecessary damping of small scales on the inner model grid. Comparison of the annual-mean flow field with the near-surface currents determined by Fratantoni (in J Geophys Res 106:2977–2996, 2001) from observed trajectories of near-surface drifters demonstrates the overall superiority of the nesting technique based on the SSP method.  相似文献   

Splitting Numerical Technique with Application to the High Resolution Simulation of the Indian Ocean Circulation     

G. I. Marchuk  A. S. Rusakov  V. B. Zalesny  N. A. Diansky 《Pure and Applied Geophysics》2005,162(8-9):1407-1429

The aim of this paper is twofold : To present an efficient numerical technique for the simulation of the ocean general circulation (OGC) and to apply it to the simulation of the Indian Ocean dynamics with high spatial resolution. To solve model equations we use the splitting method by physical processes and space coordinates. We select the main parts of the model operator and then perform their numerical treatment independently of one another. We describe the general methodology and some special aspects of this approach. Numerical treatment of the monsoon circulation is performed on the basis of the sigma-coordinate primitive equation model, which was developed at the Institute of Numerical Mathematics (Moscow, Russia). We present and briefly analyze the results of the numerical experiment with high spatial resolution 1/8° along latitude, 1/12° along longitude, and with 21 vertical sigma levels.The work was supported by the Russian Foundation for the Basic Research (03-05-64354, 02-05-64909) and by the Russian Academy of Sciences (10002-251/OMN-03/026-020/240603-807)  相似文献   

Caledonide development offshore–onshore Svalbard based on ocean bottom seismometer, conventional seismic, and potential field data     

Asbjrn Johan Breivik  Rolf Mjelde  Paul Grogan  Hideki Shimamura  Yoshio Murai  Yuichi Nishimura 《Tectonophysics》2005,401(1-2):79-117

The western Barents Sea and the Svalbard archipelago share a common history of Caledonian basement formation and subsequent sedimentary deposition. Rock formations from the period are accessible to field study on Svalbard, but studies of the near offshore areas rely on seismic data and shallowdrilling. Offshore mapping is reliable down to the Permian sequence, but multichannel reflection seismic data do not give a coherent picture of older stratigraphy. A survey of 10 Ocean Bottom Seismometer profiles was collected around Svalbard in 1998. Results show a highly variable thickness of pre-Permian sedimentary strata, and a heterogeneous crystalline crust tied to candidates for continental sutures or major thrust zones. The data shown in this paper establish that the observed gravity in some parts of the platform can be directly related to velocity variations in the crystalline crust, but not necessarily to basement or Moho depth. The results from three new models are incorporated with a previously published profile, to produce depth-to-basement and -Moho maps south of Svalbard. There is a 14 km deep basement located approximately below the gently structured Upper Paleozoic Sørkapp Basin, bordered by a 7 km deep basement high to the west, and 7–9 km depths to the north. Continental Moho-depth range from 28 to 35 km, the thickest crust is found near the island of Hopen, and in a NNW trending narrow crustal root located between 19°E and 20°E, the latter is interpreted as a relic of westward dipping Caledonian continental collision or major thrusting. There is also a basement high on this trend. Across this zone, there is an eastward increase in the V_P, V_P/V_S ratio, and density, indicating a change towards a more mafic average crustal composition. The northward basement/Moho trend projects onto the Billefjorden Fault Zone (BFZ) on Spitsbergen. The eastern side of the BFZ correlates closely with coincident linear positive gravity and magnetic anomalies on western Ny Friesland, apparently originating from an antiform with high-grade metamorphic Caledonian terrane. A double linear magnetic anomaly appears on the BFZ trend south of Spitsbergen, sub-parallel to and located 10–50 km west of the crustal root. Based on this correlation, it is proposed that the suture or major thrust zone seen south of Svalbard correlates to the BFZ. The preservation of the relationship between the crustal suture, the crustal root, and upper mantle reflectivity, challenges the large-offset, post-collision sinistral transcurrent movement on the BFZ and other trends proposed in the literature. In particular, neither the wide-angle seismic data, nor conventional deep seismic reflection data south of Svalbard show clear signs of major lateral offsets, as seen in similar data around the British Isles.  相似文献   

Conrad Deep, Northern Red Sea: Development of an early stage ocean deep within the axial depression     

A. Ehrhardt  C. Hübscher  D. Gajewski 《Tectonophysics》2005,411(1-4):19-40

The northern Red Sea represents a continental rift in its final stage and close to the following stage of seafloor spreading. Ocean deeps within the evaporites of the northern Red Sea seem to accompany this process and are thought to be surface expressions of first seafloor spreading cells. In 1999 during R/V Meteor cruise M44/3 a dense multichannel seismic and hydroacoustic survey was conducted in order to investigate the initial formation process of the Conrad Deep, a young northern Red Sea deep. Three seismic units were differentiated in the uppermost part of the Miocene evaporites and the Plio-Quaternary sediments. A weakness zone within the evaporites, oblique to the main extension direction of the Red Sea, led to a transtension process within the evaporites that opened the deep. Its formation is directly related to the emplacement of magmatic bodies in its vicinity and the focusing of the Red Sea extension to the axial depression. The Conrad Deep is an intra-evaporite basin that cannot be regarded as surficial expression of a basement structure as the low shear strength of the evaporites decouple the sediments from the basement. However, its position and shape in combination with the accompanying geophysical anomalies point to a strong correlation with the Red Sea rifting process.  相似文献   

Changes in the source and transport mechanism of terrigenous input to the Indian sector of Southern Ocean during the late Quaternary and its palaeoceanographic implications     

M. Thamban  S. S. Naik  R. Mohan  A. Rajakumar  N. Basavaiah  Witty D’Souza  Sarita Kerkar  M. M. Subramaniam  M. Sudhakar  P. C. Pandey 《Journal of Earth System Science》2005,114(5):443-452

Changes in the terrigenous sediment source and transport mechanisms during the late Quaternary have been investigated using four sediment cores within the Indian sector of Southern Ocean, using the magnetic susceptibility (MS) and sedimentological records. Sediments deposited during the Holocene and other interglacial periods were characterised by low MS, low sand content, reduced ice-rafted detritus (IRD) input and increased illite possibly transported via hydrographic advection from the south. The glacial intervals are characterised by high MS, high sand content, increased IRD input and reduced illite clays, derived from both local as well as Antarctic sources. Significant reduction in clay fraction and illite content during glacials suggests that the erosive and transporting capabilities of the deep and bottom waters could have reduced compared to the interglacial times. The changes in terrigenous influx to this region were significantly influenced by the rhythmic glacial-interglacial fluctuations in bottom circulation and the position of the Polar Front.  相似文献   

Hydroacoustic signals generated by parked and drifting icebergs in the Southern Indian and Pacific Oceans     

Jacques Talandier  Olivier Hyvernaud  Dominique Reymond  Emile A. Okal 《Geophysical Journal International》2006,165(3):817-834

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The influence of Indian Ocean Dipole (IOD) on biogeochemistry of carbon in the Arabian Sea during 1997–1998     

V. V. S. S. Sarma 《Journal of Earth System Science》2006,115(4):433-450

Data on ocean color chlorophylla (Chl a) obtained using Sea-viewing Wide Field of view Sensor (SeaWiFS), sea surface temperature (SST) by Advanced Very High Resolution Radiometer (AVHRR), and sea surface height (SSH) by TOPEX/POSEIDON were analyzed to examine the influence of Indian Ocean Dipole (IOD) on the physical and biogeochemical processes with special reference to phytoplankton primary production and air-sea fluxes of carbon dioxide in the Arabian Sea. Positive SST anomalies (SSTA) were found in the Arabian Sea (0.4 to 1.8°C) with higher values in the southwestern Arabian Sea that decreased towards north. The SSH anomalies (SSHA) and turbulent kinetic energy anomalies (TKEA) suggest decreased mixing during the IOD compared to the normal period. Chlorophylla displayed significant negative correlations with SSTA and SSHA in the Arabian Sea. Consistently, Chla showed negative anomalies (low Chl a) during the IOD period which could be due to reduced inputs of nutrients. The photic zone integrated primary production decreased by 30% during the IOD period compared to the normal whereas pCO₂ levels were higher (by 10–20μatm). However, sea to air fluxes were lower by 10% during the IOD period due to prevailing weaker winds. Primary production seems to be the key process controlling the surface pCO₂ levels in the Arabian Sea. In future, the influence of IOD on ecosystem structure, export production and bacterial respiration rates are to be probed throughin situ time-series observations.  相似文献