Recent Process in Near-Space Gravity Wave Analysis Based on Satellite Measurements   总被引：2，自引：0，他引：2  

Xu Kai  Yao Zhigang  Han Zhigang  Zhao Zengliang  Fang Hanxian 《地球科学进展》2017,32(1):66-74

This article focused on the research progress in the gravity wave analysis based on satellite measurements including MODIS, AIRS, AMSU, MLS, DNB, COSMIC,HIRDLS and SOFIE. Besides, a few ground-based observation results and numerical models were briefly introduced and some cases of joint applications of satellite observations with ground-based observations and numerical models in the gravity waves were listed. In general, the satellite remote sensing data play an important role in the study of the characteristics in near-space environment, which can be applied to analyze the scales of gravity waves induced by different sources, correlations between the instabilities and waves as well as their patterns, the impacts in the climate process, wave-wave interactions and wave-flow interactions with other data.  相似文献   

A 3D structural analysis of the Goliat field,Barents Sea,Norway     

《Marine and Petroleum Geology》2017

The Goliat field consists of Middle to Late Triassic reservoirs which exploit an elongate anticline (the Goliat anticline) in the hanging wall of the Troms-Finnmark Fault Complex (TFFC), offshore Norway. The area is affected by a dense network of multiple trending fault populations which historically have inhibited seismic resolution owing to persistent fault shadow. Seismic investigations utilising a multi-azimuth three-dimensional survey (EN0901) allow much crisper delineation of seismic features previously unattainable by vintage single-azimuth surveys. Three dominant fault populations are identified in the area, two of which parallel TFFC segments, the Alke–Goliat (WSW–ENE) and the Goliat–Tornerose (NNE–SSW) segments. The Goliat field is located within a zone of intersection between both segments. A third E–W trending fault population, the Hammerfest Regional population, is likely influenced by the offshore extension of the Trollfjord-Komagelv Fault Complex (TKFZ). A local NW–SE trending fault population, the Goliat Central, affects the Goliat anticline and partitions Alke–Goliat and Goliat–Tornerose subsidiary faults resulting in curvilinear traces. Several cross-cutting relationships between fault populations are observed and may provide fluid compartmentalisation in the reservoirs. Compilation of regional transects and the EN0901 survey provides new insight into the evolution of the Goliat anticline which is underlain by a fault-bound basement terrace that became established in the Late Palaeozoic. The structure is interpreted to have formed due to vertical segmentation of the TFFC and cores the overlying broad anticline. The western limb of the Goliat anticline likely formed by differential compaction, whereas the eastern limb is primarily a result of hanging wall roll-over linked to variable listric to ramp-flat-ramp fault geometry. Rifting took place in the Palaeozoic (Carboniferous to Permian?), and in the Mesozoic, possibly as early as the Late Triassic, with a major event in the Late Jurassic to Early Cretaceous. Minor reactivations continued into the Late Cretaceous, and possibly the Early Cenozoic. Mesozoic syn-kinematic geometries in the hanging wall of the Goliat–Tornerose TFFC segment are consistent with deposition during up section propagation of a blind fault, over which, a monocline was established and later breached. Jogs (abrupt orientation changes) in fault traces, transverse folds (associated with displacement maxima/minima) and vertical fault jogs suggest the TFFC existed as a greater number of segments prior to amalgamation during the Late Triassic to Jurassic. A phase of Barremian inversion created local compression structures above blind extensional faults, and deeper seated buttressing against large faults. Polygonal faults affect the Late Cretaceous to Early Cenozoic successions.  相似文献   

Inversion tectonics in Central Africa Rift System: Evidence from the Heglig Field     

《Marine and Petroleum Geology》2017

The Mesozoic-Cenozoic tectonic history of the Muglad Basin, is dominated by extension and inversion tectonics, but evidence of the inversion tectonics has not been well documented yet. In some other rift basins of CARS and WARS the phase of the inversion tectonics is well documented by several authors.This paper presents a structural study of the Heglig field area located on the eastern flank of the Muglad Basin. Detailed 3D seismic interpretation allows a better understanding of the structural style of the Heglig field. The new structural analysis has shown that the Heglig field has a complex structural framework reflected in the presence of a combination of two structural styles. The extensional structure is influenced by inversion tectonics during the Santonian time that creates four-way dip anticline structure, overprinted by the subsequent extensional movement that creates tilted fault block. The presence of inversion tectonics has supported by different means including seismic reflection, velocity, and source rock maturity data. The authors attributed the trapping of oil in the Lower Bentiu reservoir, that requires a horizontal seal, to the presence of the four-way dip anticline structure created by the inversion tectonics.The current interpretation of the Heglig field 3D seismic data sheds new light on the development and evolution of a key structure in the Muglad Basin. The results help to resolve long-standing discussion concerning hydrocarbon accumulation of the lower part of Bentiu Formation that lacks horizontal sealing.  相似文献   

Post-seismic crustal deformation and strain rate in Bhuj region, western India, after the 2001 January 26 earthquake     

C. D. Reddy  P. S. Sunil 《Geophysical Journal International》2008,172(2):593-606

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Strain accumulation along an oblique plate boundary: the Reykjanes Peninsula, southwest Iceland     

M. Keiding  T. Árnadóttir  E. Sturkell  H. Geirsson  B. Lund 《Geophysical Journal International》2008,172(2):861-872

We use annual GPS observations on the Reykjanes Peninsula (RP) from 2000 to 2006 to generate maps of surface velocities and strain rates across the active plate boundary. We find that the surface deformation on the RP is consistent with oblique plate boundary motion on a regional scale, although considerable temporal and spatial strain rate variations are observed within the plate boundary zone. A small, but consistent increase in eastward velocity is observed at several stations on the southern part of the peninsula, compared to the 1993–1998 time period. The 2000–2006 velocities can be modelled by approximating the plate boundary as a series of vertical dislocations with left-lateral motion and opening. For the RP plate boundary we estimate left-lateral motion  18⁺⁴₋₃ mm yr⁻¹  and opening of  7⁺³₋₂ mm yr⁻¹  below a locking depth of  7⁺¹₋₂ km  . The resulting deep motion of  20⁺⁴₋₃ mm yr⁻¹  in the direction of  N(100⁺⁸₋₆)°E  agrees well with the predicted relative North America–Eurasia rate. We calculate the areal and shear strain rates using velocities from two periods: 1993–1998 and 2000–2006. The deep motion along the plate boundary results in left-lateral shear strain rates, which are perturbed by shallow deformation due to the 1994–1998 inflation and elevated seismicity in the Hengill–Hrómundartindur volcanic system, geothermal fluid extraction at the Svartsengi power plant, and possibly earthquake activity on the central part of the peninsula.  相似文献   

A non-linear geodetic data inversion using ABIC for slip distribution on a fault with an unknown dip angle   总被引：1，自引：0，他引：1  

Yukitoshi Fukahata  Tim J. Wright 《Geophysical Journal International》2008,173(2):353-364

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GRIMM: the GFZ Reference Internal Magnetic Model based on vector satellite and observatory data   总被引：3，自引：0，他引：3  

Vincent Lesur  Ingo Wardinski  Martin Rother  Mioara Mandea 《Geophysical Journal International》2008,173(2):382-394

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Instantaneous deformation from continuous GPS: contributions from quasi-periodic loads   总被引：3，自引：0，他引：3  

Richard A. Bennett 《Geophysical Journal International》2008,174(3):1052-1064

Continuous GPS (CGPS) coordinate time-series are known to experience repeating deformation signals with seasonal and other periods. It is unlikely that these signals represent perfect sinusoids with temporally constant amplitude. We develop an analysis method that accommodates temporal variations in the amplitudes of sinusoidal signals. We apply the method to simulated coordinate time-series to numerically explore the potential consequences of neglecting decadal variation in amplitude of annual motions on the residual-error spectra of CGPS measurements, as well as potential bias in estimates for secular site velocity. We find that secular velocity bias can be appreciable for shorter time-series, and that residual-error time-series of longer duration may contain significant power in a broad band centred on semi-annual frequency if temporal variation in the amplitude of annual motions is not accounted for in the model used to reduce the observations to residuals. It may be difficult to differentiate the bandpass filtered signature of mismodelled loading signals from power-law noise, using residual-error spectra for shorter time-series. We provide an example application to a ∼9-yr coordinate time-series for a CGPS station located in southern California at Carbon Creek Control Structure (CCCS), which is known to experience large amplitude seasonal motions associated with the Santa Ana aquifer system.  相似文献   

海岸效应对近海地区大地电磁测深数据畸变作用研究   总被引：4，自引：3，他引：1  

张帆  魏文博  金胜  叶高峰  景建恩  张乐天  董浩  谢成良  王辉 《地球物理学报》2012,55(12):4023-4035

在近海地区采集的大地电磁测深数据通常受到海岸效应的影响,使得大地电磁测深数据发生畸变,因而很难利用大地电磁测深资料较为可靠地获得地下深部的电性结构.本文通过正演模拟方法,分析和总结海水深度变化和海底地形变化对近海地区大地电磁测深数据的畸变影响.当测区与海岸线的距离小于目标频率的大地电磁场趋肤深度时,高导海洋的存在会严重影响测区内电磁场的分布.由于海岸效应的影响,大地电磁测深视电阻率曲线和相位曲线均会发生不同程度的畸变,在低频部分,这种畸变作用尤为明显.大地电磁测深一维Occam反演方法和二维非线性共轭梯度反演方法,对近海地区浅部地层具有较好的反演效果.随着海水深度的增加和海底地形的复杂变化,两种反演方法均会出现不同程度的假异常,为地质解释工作造成了影响.近渤海地区的实测大地电磁测深数据在低频部分可能受到海岸效应的影响而导致视电阻率曲线的严重畸变.  相似文献   

基于HJ-1数据的木孜塔格峰地区雪深时空变化     

吴红波  贺建桥  郭忠明  毛瑞娟  吴玉伟 《地理研究》2013,32(10):1782-1791

以木孜塔格峰地区为研究区,从不同坡度、坡向的样方内测量雪深和采集光谱,通过分析归一化差分雪盖指数（Normalized Difference Snow Index,NDSI）、反照率、HJ-1卫星的红外波段反射率与雪深的相关关系,建立了适用于HJ-1星的积雪深度反演模型,估算出2012年4月14日-25日木孜塔格峰地区的雪深时空变化,并结合实测数据进行验证。结果表明:反照率反演模型的复相关系数为0.992;通过NDSI阈值区分混合雪盖像元和积雪像元,雪深估测精度可达92.78%。冰川区的反照率、NDSI与海拔的相关系数分别为0.626和0.733,且高海拔带反照率值明显高于低海拔带的反照率值。受西风带降雪的影响,非冰川区的北坡雪深值较大;西坡、南坡次之;东坡最小,且雪深最大值出现在坡度约等于10°处。雪深估测的相对误差随着样地的坡度增大而增加,坡度为15°时相对误差较大。  相似文献