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Xin’gang Luo Wanyin Wang Ying Chen Zhizhao Bai Dingding Wang Tao He Yimi Zhang Ruiyun Ma 《海洋学报(英文版)》2023,42(3):227-242
As one of the main controlling factors of oil and gas accumulation, faults are closely related to the distribution of oil and gas reservoirs. Studying how faults control petroliferous basins is particularly important. In this work, we investigated the plane positions of major faults in the China seas and its adjacent areas using the normalized vertical derivative of the total horizontal derivative (NVDR-THDR) of the Bouguer gravity anomaly, the fusion results of gravity and magnetic anomalies, and the residual Bouguer gravity anomaly. The apparent depths of major faults in the China seas and its adjacent areas were inverted using the Tilt-Euler method based on the Bouguer gravity anomaly. The results show that the strikes of the faults in the China seas and its adjacent areas are mainly NE and NW, followed by EW, and near-SN. Among them, the lengths of most ultra-crustal faults are in the range of 1 000–3 000 km, and their apparent depths lie between 10 km and 40 km. The lengths of crustal faults lie between 300 km and 1 000 km, and their apparent depths are between 0 km and 20 km. According to the plane positions and apparent depths of the faults, we put forward the concept of fault influence factor for the first time. Based on this factor, the key areas for oil and gas exploration were found as follows: the east of South North China Basin in the intracontinental rift basins; the southeast region of East China Sea Shelf Basin, the Taixinan and Qiongdongnan basins in the continental margin rift basins; Zhongjiannan Basin in the strike-slip pull-apart basins; the Liyue, Beikang, and the Nanweixi basins in the rifted continental basins. This work provides valuable insights into oil and gas exploration, mineral resource exploration, and deep geological structure research in the China seas and its adjacent areas. 相似文献
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利用中国-尼日利亚国际合作航次获得的船载重力数据,分析了尼日利亚南部大陆边缘的自由空间重力异常和布格重力异常特征,并通过两条从陆架—陆坡—陆隆一直延伸到深海盆地的重力剖面拟合出地壳密度结构。研究结果表明,地壳厚度总体上从陆架、陆坡至深海平原呈现阶梯状减薄的趋势,东侧的减薄幅度大于西侧,东侧从24 km减小到10 km,西侧从21 km减小到14 km。 相似文献
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THE BOUGUER ANOMALIES AND DEPTHS OF MOHOROVICIC DISCONTINUITY IN THE SOUTH CHINA SEA REGION 总被引：3，自引：0，他引：3
The South China Sea is situated at the continsntal margin of South China. In this region, there are both continental and oceanic crusts. The values of Bouguer gravity anomalies on the continental shelf are low positive or low negative. Because the depth of the Mohorovicic discontinuity in this region is about 26-32 km below sea level, the crust belongs to the continental type. The values of Bouguer gravity anomalies in the deep-sea region are more than 250 mgal and the depth of the Moho-surface is about 10-15 km below sea level, so the crust is of oceanic type. The values of gravity anomalies and depths of the Moho-surface, obtained over the continental (and island) slope, range between those regions mentioned above, so the crust belongs to the transitional type. The continental crust is inferred to be directly in contact with the oceanic crust as a result of a lithospheric fault. 相似文献
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Enderby Land in East Antarctica and its adjacent areas, which are closely related to the Indian Plate in their geological evolution, have become one of the key zones for studies on how the Antarctic continent evolves. Based on the isostasy and flexure theories of the lithosphere and using the CRUST1.0 model as the depth constraint, this paper uses the gravity field model EIGEN-6C4 and topographic data to calculate the isostatic gravity anomalies of Enderby Land and its adjacent areas. Then, the ... 相似文献
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南极布兰斯菲尔德海峡及周边区域是南极大陆火山、地震等新构造活动最活跃的地区,与南设得兰海沟、南设得兰群岛一同构成南极大陆边缘现存唯一的"沟-弧-盆"构造体系。本文基于"雪龙"船第28、第30航次实测数据及两个航次的国际共享资料,利用均衡改正数据处理方法获得布兰斯菲尔德海峡的莫霍面深度及其分布规律,分析深部构造-断裂的区域分布及其重力异常特征等。布兰斯菲尔德海峡内的空间重力异常呈条带状分布,走向总体与地形相近,布格重力异常则由两侧向中间升高,大致在坡折处形成异常场值为100×10-5 m/s2的分界线,在中央次海盆和东部次海盆海山处形成两个异常高值圈闭,异常值最高为150×10-5 m/s2。莫霍面深度以弧后扩张中心为最低值,向南设得兰群岛和南极半岛两个方向递增,深度从12 km递增至陆坡位置的24 km。 相似文献
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J. Gómez-Enri M. A. Srokosz C. P. Gommenginger P. G. Challenor M. P. Milagro-Pérez 《Marine Geodesy》2013,36(3):217-233
An adequate conceptual definition of the geoid is essential for the unambiguous combination of satellite tracking data, satellite al‐timetry, and surface gravity measurements to obtain sea surface topography. The factors influencing the selection of a particular level surface of the earth's gravity field include the purpose(s) for which the geoid is to be used at the 5‐cm level, and the types of data to be used in achieving these objectives. The principal reasons for high precision determinations of the shape of the geoid are: the determination of sea surface topography for applications in oceanography; and the unification of leveling datums with a resolution equivalent to that of first order geodetic leveling. A conceptual definition of the geoid acceptable to oceanographers would be: The geoid for a selected epoch of measurement is that level surface of the earth's gravity field in relation to which the average non‐tidal (or quasi‐stationary) sea surface topography is zero as sampled globally in ocean regions. In the geodetic context, it would be convenient, though not essential, to modify this definition in such a way that the global sea surface topography had zero mean as sampled for evaluations of the geodetic boundary value problem. In either case, a basis exists for unifying all leveling datums serving areas in excess of 106 km2, using either gravity anomaly data for the regions or precise determinations of position at first order bench marks. Unfavorable signal‐to‐noise ratios can pose problems when dealing with datums serving smaller areas. Elevation and gravity data banks must be correctly referenced to leveling datums prior to use in sea surface topography determinations. A recent attempt to upgrade the Australian gravity anomaly data bank indicates that all current data banks of this type are inadequate for the task. It is unlikely that time variations in the radial position of the geoid as conceptually defined above, will exceed ±5 cm per century, provided the rate of earth expansion was less than 1 part in 1010 yr‐l and there is no dramatic change in the present rate of secular change in Mean Sea Level. 相似文献
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Polymetalic sulfide is the main product of sea-floor hydrothermal venting, and has become an important sea-floor mineral resources for its rich in many kinds of precious metal elements. Since 2007, a number of investigations have been carried out by the China Ocean Mineral Resources Research and Development Association(COMRA)cruises(CCCs) along the Southwest Indian Ridge(SWIR). In 2011, the COMRA signed an exploration contract of sea-floor polymetallic sulfides of 10 000 km2 on the SWIR with the International Seabed Authority. Based on the multibeam data and shipborne gravity data obtained in 2010 by the R/V Dayang Yihao during the leg 6 of CCCs21, together with the global satellite surveys, the characteristics of gravity anomalies are analyzed in the Duanqiao hydrothermal field(37°39′S, 50°24′E). The "subarea calibration" terrain-correcting method is employed to calculate the Bouguer gravity anomaly, and the ocean bottom seismometer(OBS) profile is used to constrain the two-dimensional gravity anomaly simulation. The absent Moho in a previous seismic model is also calculated.The results show that the crustal thickness varies between 3 and 10 km along the profile, and the maximum crustal thickness reaches up to 10 km in the Duanqiao hydrothermal field with an average of 7.5 km. It is by far the most thicker crust discovered along the SWIR. The calculated crust thickness at the Longqi hydrothermal field is approximately 3 km, 1 km less than that indicated by seismic models, possibly due to the outcome of an oceanic core complex(OCC). 相似文献
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小波分析与解析延拓方法相结合研究东海深部构造 总被引：3，自引：0，他引：3
东海是环太平洋活动构造带的重要组成部分,是探讨西太平洋边缘及边缘海形成演化的重要窗口。向上延拓主要用来削弱局部异常,突出深部异常,小波分析是重磁场位场分解的有效工具,不仅能提取深部异常,还能更好地将区域异常和局部异常分离。本文利用东海及邻域最新的布格重力异常数据资料,将小波分析与解析延拓方法相结合,分析对比向上延拓20 km的布格重力异常结果与小波分析4阶逼近布格重力异常结果,结合东海及邻域莫霍面的深度,对重力场及莫霍面深度进行初步研究。其中小波4阶逼近结果代表莫霍面形态,小波4阶细节结果代表东海及邻域凹陷凸起形态。 相似文献
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A. G. Gainanov D. A. Gilod A. A. Antipov A. A. Bulychev K. V. Krivosheya 《Oceanology》2006,46(4):526-533
Studies of the deep structure of the earth’s crust, lithosphere, and asthenosphere (tectonosphere) of transition zones from continents to oceans is one of the urgent issues of present-day geology and geophysics. The most important information on the deep structure of such zones is provided by seismic and seismological methods. Meanwhile, a comparison between gravity data and results of seismic studies showed that the gravity anomalies observed in the marginal seas of the Pacific Ocean cannot be explained solely by changes in the thickness and composition of the earth’s crust. In order to estimate the internal structure of the Pacific type of transition zones, the authors performed an analysis of the anomalous gravity field and the field of geoid heights in the Indonesian region, which also included calculations of the values of the gravity field and geoid heights in different reductions (Bouguer, Glenny, and isostatic), their transformations, and compilation of density models of the tectonosphere of the transition zone of this region compatible with the geological and geophysical data available. As a result of these studies, we performed zonation of the Indonesian region with respect to the gravity field and defined particular features of the areas distinguished. Based on the analysis performed, we inferred the existence of differences in the structure of individual zones both in the upper layers of the tectonosphere and in deeper layers. Detailed characteristics of the anomalous gravity fields typical of the objects distinguished are presented. 相似文献
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A set of 103 997 free air gravity anomalies in 6′x 10′ blocks has been compiled covering Europe including the Mediterranean Sea, North Sea, Norwegian Sea, Baltic Sea and parts of the North Atlantic Ocean. Concerning sea areas, this data set is based on a collection of point free air gravity anomalies. Anomalies for land areas have been compiled resp. computed from free air gravity anomaly maps or Bouguer anomaly maps and partly from supplied mean values of convenient small block size. Remaining gaps have been interpolated by means of least squares prediction filtering. The precision of the compiled mean free air gravity anomalies is estimated to ±7 mgal, verified by a comparison of independent gravity anomaly sets. 相似文献
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Jia-Ming Deng Tan K. Wang Ben Jhong Yang Chao-Shing Lee Char-Shine Liu Song-Chuen Chen 《Marine Geophysical Researches》2012,33(4):327-349
During TAiwan Integrated GEodynamics Research of 2009, we investigated data from thirty-seven ocean-bottom seismometers (OBS) and three multi-channel seismic (MCS) profiles across the deformation front in the northernmost South China Sea (SCS) off SW Taiwan. Initial velocity-interface models were built from horizon velocity analysis and pre-stack depth migration of MCS data. Subsequently, we used refracted, head-wave and reflected arrivals from OBS data to forward model and then invert the velocity-interface structures layer-by-layer. Based on OBS velocity models west of the deformation front, possible Mesozoic sedimentary rocks, revealed by large variation of the lateral velocity (3.1–4.8 km/s) and the thickness (5.0–10.0 km), below the rift-onset unconformity and above the continental crust extended southward to the NW limit of the continent–ocean boundary (COB). The interpreted Mesozoic sedimentary rocks NW of the COB and the oceanic layer 2 SE of the COB imaged from OBS and gravity data were incorporated into the overriding wedge below the deformation front because the transitional crust subducted beneath the overriding wedge of the southern Taiwan. East of the deformation front, the thickness of the overriding wedge (1.7–5.0 km/s) from the sea floor to the décollement decreases toward the WSW direction from 20.0 km off SW Taiwan to 8.0 km at the deformation front. In particular, near a turn in the orientation of the deformation front, the crustal thickness (7.0–12.0 km) is abruptly thinner and the free-air (?20 to 10 mGal) and Bouguer (30–50 mGal) gravity anomalies are relatively low due to plate warping from an ongoing transition from subduction to collision. West of the deformation front, intra-crustal interfaces dipping landward were observed owing to subduction of the extended continent toward the deformation front. However, the intra-crustal interface near the turn in the orientation of the deformation front dipping seaward caused by the transition from subduction to collision. SE of the COB, the oceanic crust, with a crustal thickness of about 10.0–17.0 km, was thickened due to late magmatic underplating or partially serpentinized mantle after SCS seafloor spreading. The thick oceanic crust may have subducted beneath the overriding wedge observed from the low anomalies of the free-air (?50 to ?20 mGal) and Bouguer (40–80 mGal) gravities across the deformation front. 相似文献
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翁通爪哇高原、凯尔盖朗高原与沙茨基海隆是全球三大洋底高原, 是大量岩浆喷发到地表的结果, 火山面积分别达1.90×106、1.25×106、0.53×106km2。本文详细分析了该三大洋底高原的地形、剩余地幔布格重力异常(residual mantle Bouguer anomaly, RMBA)与重力反演的相对地壳厚度, 并结合地质与地球化学特征约束进行对比研究。结果显示, 翁通爪哇高原、凯尔盖朗高原与沙茨基海隆分别高出周围海底约4.3、5、4km, 相应的地幔布格重力异常最大变化值分别为250、330、200mGal, 以及相应的相对地壳厚度变化分别为11、13、9km, 表明形成三大洋底高原的岩浆量远远大于正常洋中脊的岩浆量。此外, 三大洋底高原皆形成于洋中脊附近。Nd、Pb、Hf同位素比值分析表明, 翁通爪哇高原的玄武岩组分为洋岛玄武岩; 凯尔盖朗高原大部分类似于洋岛玄武岩, 并含有洋中脊玄武岩组分; 沙茨基海隆的玄武岩组分主要为东太平洋海隆正常洋中脊玄武岩, 却又存在少量位于全球洋岛玄武岩范围内。这些特征揭示了三大洋底高原可能形成于“地幔柱-洋中脊相互作用”。对此本文提出了两种模式: 一为洋中脊被地幔柱拖拽至其上方; 二为洋中脊之下的软流圈受到地幔柱影响, 从而产生超常熔融与超厚地壳。 相似文献
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经过三维重力正演计算，我们从台湾的布格重力异常中求得了深部重力异常，其深度相当于地壳下层。分析对比之后发现，深部重力异常等植线的形态，较好地反映了台湾的现代构造地貌特征。如东部等值线的同步弯曲，犹如错断水系，反映现代板块运动的方向；中部大面积零值和负值线圈闭，反映中央山脉的整体上升；在一些等值线聚合成梯度的地带，又往往是某些深断裂的反映。是否可以这样认为，深部重力异常是地壳深处介质密度沿某一方向的 相似文献
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Pan Jiayi Wang Junqin Wang Yanfeng Zhang Xinmei Yuan Yeli Zheng Quan''an 《海洋学报(英文版)》1999,18(4):523-533
INTRODUCTIONThegeoidistheiargeopotentials~econfidingmostlywiththemeanseasurfaceandisdenotedastheheightrelativetotheidealelliPSes~eoftheearth.Thegeoidundulationsinglobalaceareupto100m.TheunevenstructureOftheearthgivesrisetotheunevenfeatureofthecitysot... 相似文献
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Regional gravity and magnetic studies over the continental margin of the central west coast of India
L. V. Subba Raju K. A. Kamesh Raju V. Subrahmanyam D. Gopala Rao 《Geo-Marine Letters》1990,10(1):31-36
Gravity studies over the continental margin of the central west coast of India show a sediment thickness of 2–3 km on the
shelf associated with deeper horst and graben structures, of 6 km in the shelf margin basin, and about 1 km in the deep sea.
The upward trend in free-air gravity anomaly toward the deep sea region is interpreted as crustal thinning. Model studies
indicate a 25-km-thick crust in the shelf region and a minimum of 18 km in the more offshore region. An abrupt magnetic signature
change suggests differential basement depths in the shelf region. Major faulting in the region is confirmed in water depths
of approximately 100–200 m. 相似文献
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The continental shelf in the Arctic north of Russia consists of a series of epicontinental seas, which are the offshore continuation of potentially oil and gas basins on land. The geology of all these epicontinental seas is poorly known, due to the remoteness, the extreme climatic conditions and the extensive costs associated with seismic exploration. Radar altimeter sensors thus provide an invaluable tool for studying the geological structures off the coast. The unique ERS-1 contribution comes from its high latitude coverage (81.5 deg south to north), and the space and time density of its measurements (168-day repeat-orbit).The gravity anomaly field is derived from the geoid height measurements by computing the deflections of the vertical in the north-south and east-west directions and transforming these deflections into gravity anomalies. The gravimetry reveals interesting features of the basement of the Barents and Kara Seas which have not been chartered in recent, previous compilation maps of sedimentary thickness in the Arctic Ocean (Jackson and Oakey, 1988; Gramberg and Puscharovski, 1989). We obtain no indication of the SE-NW offshore Baikalian trend described by Fichler et al (1997) using ERS-1 gravimetry. Instead, the data indicate the presence of a north-south trending gravity high associated with the maximum sediment thickness within the South Barents Sea and the North Barents Sea Basins. Further geological studies are needed to interpret the gravimetric data, which directly addresses the problem of understanding the gravity signature of deep, old, sedimentary basins. 相似文献
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本文基于中国南极考察第30航次、第32航次所获得的实测重力资料,结合NGDC资料,开展12个航次重力场数据的平差融合工作,全部386个交点平差后标准差减小为±1.53×10−5 m/s2,与卫星重力差值平均值为1.49×10−5 m/s2,均方差为±3.81×10−5 m/s2,并在此基础上采用频率域界面反演法计算莫霍面深度。研究发现,与沉积盆地对应重力异常低值相悖,在罗斯海北部盆地、维多利亚地盆地、中央海槽、东部盆地4个主要盆地腹地却表现为重力异常高值,跨度达100 km以上。莫霍面深度分布整体呈南深北浅之势,范围为10~28 km。伴随着罗斯海西部盆地的多次拉张及岩浆活动,该区域的地壳厚度和莫霍面深度高值和低值相间分布,并表现出越来越大的差异性。综合剖面结果表明,罗斯海重力异常值的长波长变化与莫霍面的起伏呈正相关关系,但是反演的莫霍面深度与区域重力场特征并非完全对应,所以岩浆底侵和地壳侵入仍不足以导致罗斯海盆地的重力异常或盆地几何形状。 相似文献
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Sea gravity measurements were carried out over the East China Sea and its neighbourhood using a ZYZY-type Sea Gravimeter in 1977 and 1979.Maps of the free air gravity anomaly, the Bouguer gravity anomaly, crustal thickness and synthetic gravity across the Ryukyu trench have been compiled. The gravity anomaly distribution and the characteristics of the crustal structure are discussed. 相似文献
20.
台湾海峡及其邻近海域海面温度锋的卫星遥感观测 总被引：4，自引：1，他引：4
使用1989~2001年的NOAA AVHRR图像,研究了我国台湾海峡及其邻近海域的海面温度锋.卫星遥感观测表明,该海域海面温度锋终年存在,锋面沿50~100 m等深线分布,西段呈西南西-东北东走向,东段以舌状向北突出,长约470 km.给出了该海域海面温度锋的多年月平均、季平均和年平均特征值.统计结果显示,锋的平均强度、平均最大强度和平均宽度分别为0.147,0.281℃/km和15.15 km.锋的各种特征存在明显的季节和年际变化.锋的不稳定性普遍存在,沿锋面常形成半环状的锋波,使锋面呈半环状波动分布.锋波形成的时间尺度约为1~7 d,锋的波长约为35~133 km,年平均波长为63 km,波幅为25~70 km.锋面的波动向北东北方向传播,并存在锋面整体向北东北的平移现象. 相似文献