On September 5,2022,an earthquake of magnitude MS6.8 occurred in Luding County,Sichuan Province.This earthquake occurred at the key part of the southeast-clockwise extrusion of material on the eastern margin of the Qinghai Plateau,the Y-shaped confluence of the Xianshuihe,Longmenshan and Anninghe fault zones.In this study,the three-dimensional dynamic crustal density changes in the earthquake area are obtained by the typical gravity change data from 2019 to 2022 before the earthquake and gravity inversion by growing bodies.The results indicate that gravity changes presented an obvious four-quadrant and gradient belt distribution in the Luding area before the earthquake.The three-dimensional density horizontal slices show that small density changes occurred at the epicenter in the mid-to-upper crust between 2019.9-2020.9 and 2019.9-2021.9.At the same time,the surrounding areas exhibited a positive and negative quadrant distribution.These observations indicate that the source region was likely in a stable locked state,with locking-in shear forces oriented in the NW and NE di-rections.From 2021.9 to 2022.8,the epicentral region showed negative density changes,indicating that the source region was in the expansion stage,approaching a near-seismic state.The three-dimensional density vertical slices reveal a southeastward migration of positive and negative densities near the epicenter and on the western of the Xianshuihe Fault Zone,indicating that the material is flowing out to the southeast.The observed local negative density changes at the epicenter along the Longmenshan Fault Zone are likely associated with the NE-oriented extensional stress shown by the seismic source mech-anism.The above results can provide a basis for interpreting pre-earthquake gravity and density changes,thereby contributing to the advancement of earthquake precursor theory.

The gravity inversion results of three-dimensional density interface are often not unique,which brings some difficulties to further scientific research.The classical particle swarm optimization algorithm has a higher global extremum search ability,faster inversion speed in computing highdimensional nonlinear inversion problems,and the final solution is independent of the initial model compared with traditional inversion density interface algorithms such as L-M,Tikhonov regularization,Gauss-Newton method,etc.However,in classical particle swarm optimization,the initial model setting and parameter selection are not perfect.Therefore,this paper further enhances the algorithm based on the classical particle swarm optimization algorithm,referring to the previous optimization ideas.The test results of various models show that the optimized particle swarm optimization algorithm has a stable ability to search for the optimal global solution,and the depth error is smaller.In addition,if we adopt parallel computing,the inversion speed can be effectively improved.We obtained the Indosinian density interface depth model of the Changning area by inversion using multiple measured high-density gravity profile data based on the improved algorithm.The overall scope of the survey area is small and diamond-shaped,including the complete Changning-Shuanghe anticline and some surrounding synclines.The inversion results show that the Indosinian density interface generally presents the characteristics of uplift in the middle and depressions around it,and the depth range is 0.3～3.3km,which is basically consistent with the inversion results of the drilling data and previous gravity data,and the details are more prominent.It can better express its structural characteristics.The depression degree of the interface on the right side is significantly larger than that on the left side.The uplift part corresponds to the Changning-Shuanghe complex large anticline,and the depth varies from 0.3km to 1.9km.The core of the anticline is exposed to the surface by uplifting and erosion of the tectonic movement.The inversion result provides essential information for studying the seismotectonic environment and is also a vital reference for studying the multi-layer density interface model.Density interface fluctuation is the product and sign of a specific area under the action of multistage tectonic movement,which plays an essential role in studying basin basement,regional structure,and deep structural fluctuation.It provides critical information for the analysis of the origin of earthquakes.Therefore,we analyzed the structural characteristics of this area and its relationship with earthquakes combined with the undulating morphology of the Indosinian surface.Earthquakes in the Changning area are concentrated on the north and south sides of the large anticline.The seismic distribution pattern and focal parameters on both sides are obviously different.The main reason for this phenomenon is that there are significant differences in the causes of earthquakes.The Indosinian surface in the north wing of the anticline is steeper than that in the south wing.The location of the strip distributed shallow earthquakes in the north wing is highly related to the fluctuation of the Indosinian surface,and they mainly occur at the places where the Indosinian surface fluctuates violently.The local density changes drastically,and the earthquakes’occurrence is greatly affected by hidden faults.The clumped distributed shallow earthquakes in the south wing occur at locations where there is an apparent depression on the Indosinian surface,which may be caused by shale gas exploitation,and the earthquakes are more affected by local stress changes.Deep earthquakes may be closely related to the revival of basement faults.There may still be seismic risk in the northeast wing of the large anticline in the future.In general,the optimized particle swarm algorithm has achieved good results in both model testing and practical applications.In order to further improve the accuracy of the inversion results,we will focus on improving the applicability of the algorithm in various situations and the ways of adding multiple constraint information.More detailed geophysical research should be carried out in this area,which will help to better understand its crustal structure,earthquake mechanism,geological structure,and the development of earthquake prevention and disaster reduction.

The Tangshan M(S)7. 8 earthquake in 1976 was located at the transitional part between the Yanshan fold and the North China Plain. The research on the existing crustal structure in the earthquake area is still not fine enough, and there are some controversies in the understanding of its seismogenic tectonic conditions. Combining the high-resolution Bouguer gravity anomaly data in Tangshan earthquake area with the latest global gravity field model WGM2012, based on wavelet multi-scale signal separation technology and spatial domain iterative inversion algorithm, the Moho surface fluctuation and the inner crust density disturbance distribution images in the earthquake area are obtained. The results show that the Tangshan earthquake area is located on the east side of Taiyuan-Yanqing Buge gravity anomaly gradient belt (that is, the middle part of the famous gravity gradient belt in eastern China) and the Moho steep belt, its isoline curves from NNE to NE, and the Moho depth is between 32 similar to 37 km. The epicenter of Tangshan is located in the transition between Moho steep belt and uplift area. The internal density distribution of the crust in the earthquake area presents the characteristics of high in the south and low in the north, and the scattered high-density bodies in the shallow part gradually aggregate with increasing depth. The former reflects the difference of tectonic movement between the North China Plain and Yanshan fold, while the latter reflects that the shallow high-density bodies mainly originate from deep upper mantle magmatism. From the density structure profile of the vertical and parallel Tangshan fault, it can be found that the Tangshan fault runs through the Moho surface, and its deep (about >7 km) pre-existing fracture surface is gradually opened by the intrusion of upper mantle magma under the action of horizontal tension and uplift compression of Moho surface, and the magma expands more and more as it goes up. The relatively uniform shallow part (within a depth of about 7 km) may be due to the continuous deposition of new strata and diagenesis on the surface, which prevents magma from invading, thus forming a locking area where stress and strain are easy to accumulate at the top of high-density body. This may be an important reason why the Tangshan earthquake occurred on the top of the high-density body and showed the characteristics of flower-like rupture in the shallow. Combining with the existing achievements, the seismogenic model of the Tangshan earthquake by the combined action of magmatic upwelling and faults is put forward from the point of view of material migration movement, and at the same time, it provides new evidence for the seismic sounding speculation of the seismogenic structural conditions of the Tangshan earthquake.

介绍了 2021年中国大陆构造环境监测网络(简称陆态网络)绝对重力比对观测的工作情况.基于各观测单位提交的数据,采用加权最小二乘平差方法,进行了统一的处理和分析,获得了各比测点位的标准参考值和各观测仪器的等效度.比测结果表明:8台绝对重力仪的等效度在-6.1～3.0 μGal之间,标准差RMS为2.8 μGal,基于归一化偏差进行判断,可见所有参加此次比测的仪器都是等效的,均可满足陆态网络项目要求.

针对中国大陆重力站主要装备的gPhone相对重力仪(约62套)由于缺乏标定,限制其高精度重力数据的科学应用的问题,收集了中国大陆12站同址FG5绝对重力观测与同时段gPhone观测的资料,提出了基于DDW-NHi全球潮汐模型约束的FG5绝对比测标定gPhone重力仪的方法,并与gPhone重力仪出厂格值法、理论固体潮标定法进行比较,讨论未来绝对重力标定的策略.研究结果表明:利用同址绝对观测时长26-64h资料标定gPhone重力仪,格值系数的相对误差为±0.001 3～±0.003 8;标定后各站重力残余振幅≤1×10-8m/s2,达到gPhone重力仪标称精度,优于出厂格值和理论固体潮标定结果;标定后经固体潮、气压负荷潮改正的重力残差振幅与中国大陆海潮负荷规律相符.

Based on the first-hand data obtained from the field survey in terms of geology, landforms, earthquake ruins, this paper focuses on the activity behavior of the Sagaing fault, as well as the damaged buildings and seismic surface rupture zone generated by the 2012 earthquake. The Sagaing fault striking nearly NS is an active large-scale dextral strike-slip fault, with a horizontal slip rate of 18~20 mm/a. Many strong earthquakes more than M 7 have occurred along the Sagaing fault zone historically, and so far, there are still ruins of the earthquakes, such as the 1839 Innwa, Mandalay, M 8 earthquake, the 1930 Bago M 7.3 earthquake and the 1930 Phyu M 7.3 earthquake. The 2012 Thabeikkjin M 7.0 earthquake caused serious damage to pagodas, civil and other buildings, forming an at least 45 km-long seismic surface rupture with bank collapses, landslides, seismic faults and so on. The epicenter intensity of the earthquake is estimated to be IX. Under the dextral strike slip of the fault, the ground fissures show a trend of regular left-step en echelon, and the included angle with the strike of the Sagaing fault is generally 20°~30°; The large-scale ground fissures mostly show a "S" type. The regular left-step en echelon trend of ground fissures and the faulted ground features indicate that the seismic surface fracture are obviously characterized by dextral strike slip. The horizontal dextral displacements caused by the 2012 earthquake are generally between 40~90 cm, and the maximum reaches 102 cm. The surface rupture characteristics and the results of focal mechanism solutions show that the event is caused by the dextral strike-slip of the Sagaing fault.

长期的重力变化和地壳形变观测是研究地下物质运动的重要手段.基于武汉九峰地震台2013-2020年的绝对重力和全球卫星导航系统(global navigation satellite system,GNSS)观测数据,计算了长期的重力与地壳垂直形变的变化趋势,并以1年、2年和3年的时间间隔分段,进行线性趋势拟合,分别获得不同时间段的绝对重力年变化率、地壳垂直形变速率以及对应的比值.研究结果表明,武汉九峰地震台长期的重力年变化率为0.479 9μGal/a,地壳垂直形变速率为-1.2 mm/a,两者的比值为-0.399 9 μGal/mm,与理论值存在一定的偏差,可能与该区域的地下水活动有关.将不同时间段的重力变化与地壳垂直形变的数据展布在一张图中,发现数据点离散分布在不同区域,由此可初步判断地下物质运动过程,为区域动力学机制解释提供参考.

在Qt平台上,基于QSSP软件,利用C++进行地震破裂过程反演方法研究.采用按阶段反演的方法,第1阶段反演采用热浴算法进行全局搜索,先按断层区域的构造背景等初始条件对参数范围进行划取,在该范围内随机给定一组初始值开始迭代,使波形初步拟合避开局部最优解;第2阶段反演使用拟牛顿法进行快速收敛,提高波形拟合程度,迭代至目标函数小于误差条件时停止,输出满足误差条件的待解模型参数.为避免模型参数出现病态问题,使用拉普拉斯方程建立平滑矩阵并引入平滑因子对断层模型进行平滑约束.使用棋盘模型验证该方法的稳定性和可靠性.最后,将全国13个台站的重力数据积分后对2013-04-20芦山7.0级地震的破裂过程进行反演,并与其他研究结论进行对比分析.

Numerous geophysical studies have revealed the lithospheric structure of the Qiangtang and the Songpan-Ganzi terranes in the eastern Tibetan Plateau. However, crust–mantle evolution and crustal response to the Indian lithospheric subduction are still controversial. Answering these questions requires additional information regarding crustal structure. In this study, the 2-D normalized full gradient (NFG) of the Bouguer gravity anomaly was used to investigate anomalous sources and interpret the crustal structure underneath the Qiangtang and Songpan-Ganzi terranes. The NFG-derived structures with low-order harmonic numbers (N = 33 and N = 43) showed that an anomalous source beneath the southern Qiangtang terrane had a characteristic northeastward-dipping shape, suggesting the northeastward motion of the crustal material induced by underthrusting Indian lithospheric mantle. The NFG images with harmonic number N = 53 showed a large-scale anomalous source in the lower crust of the transformational zone from the Qiangtang terrane to the Songpan-Ganzi terrane, consistent with thickening crust and resistance of lower crustal flow. The anomalous source demonstrated by the NFG results with harmonic number N = 71, located in the upper crust underneath the Ganzi-Yushu fault, suggested a seismogenic body of the 2010 MW6.9 Yushu event.

The uneven lateral distribution of lithospheric mass profoundly affects the tectonic stress styles and tectonic deformation of the Tibetan Plateau and its surrounding areas. According to the definition of gravitational potential energy (GPE) , the initial model of GPE in the Tibetan Plateau and its surroundings is calculated using Crust 1.0 model data set. Then we constrain the mantle density data by the two kinds of isostasy adjustment models which are Airy isostasy and Pratt isostasy respectively. Through the above steps, three reasonable lithospheric GPE models which are uncompensated, compensated by Airy isostasy and Pratt isostasy in the Tibetan Plateau and its surrounding areas are established. Comparing with uncompensated GPE model, both isostasy compensation models change little of GPE values. The distribution characteristics of GPE from three models are very close, which show that the distribution of GPE is positively correlated with surface topography. There is a high GPE area within the plateau, whereas the GPE around the plateau is relatively low. The variation ranges of GPE of the three models are respectively 1420. 24 similar to 1579. 99 MPa, 1413. 22 similar to 533. 80 MPa and 1415. 00 similar to 1552. 15 MPa. The deviatoric stress field arising from GPE differences in the plateau and its surroundings is solved by the finite element method. The results show that areas with high GPE are in deviatoric tension and those with low GPE are compressional deviatoric stresses. Magnitudes of deviatoric stress associated with GPE differences are in the range of 10 similar to 30 MPa. We compare deviatoric stresses arising from GPE differences with GNSS strain rates. And results show, in areas with large lateral variations of GPE, such as Qaidam basin and south-central Sichuan-Yunnan block which are within the plateau, and northwestern Tarim block, western Ordos block, northwestern South China block and northern Indian plate which are around the plateau, the deviatoric stress field inferred from GPE differences and GNSS strain field are highly correlated because they have same style of tension and compression and directions of main axis from them agree well. These results suggest the driving force of plate motion affects its tectonic deformation in the form of GPE in the northern and eastern marginal regions of the Tibetan Plateau far away from the Eurasian plate boundary, while in the Himalayas, GPE difference acts in the opposite direction to the Indian plate subduction.

Sichuan-Yunnan and its adjacent area are the main places where the eastward material flow from the Tibet Plateau escapes and spins to SE-SSE with active geological formations and frequent seismic activity. The study of the crustal structure and material transport characteristics of this region is important to reveal the mechanism of earthquake occurrence here. It can also deepen the understanding of the tectonic activity mechanism of the southeastern margin of the Tibet Plateau. This paper summarizes recent achievements and important advances in the study of regional Bouguer gravity anomaly and crustal density structure in Sichuan-Yunnan and its adjacent areas. (1) Bouguer gravity anomaly information of eight gravity profiles was obtained by using gravity and GNSS positioning techniques, and the basic framework of crustal density structure of the southeastern margin of the Qinghai-Tibet Plateau and its adjacent areas was constructed by using gravity inversion techniques constrained by various geophysical observations. (2) New gravitational evidence of clockwise rotation of the Sichuan-Yunnan rhomboid massif was found through the separation and extraction of gravity signals by wavelet decomposition and normalized gradient. (3) Through the scientific research of the Yushu MS7.1, Lushan MS7.0 and Ludian MS6.5 earthquakes, we have deepened our understanding of the seismogenic tectonic environment in the southeastern margin of the Tibet Plateau. There are significant differences in density distribution on sides of the left-slip shear fault zone (Ganzi-Yushu, Xianshuihe and Xiaojiang) and the large thrust nappe structure (Longmen Shan), both of which are regional seismicity-controlled faults. The seismicity of the Ludian earthquake zone may be related to the eastward migration of the Xiaojiang fault zone. The nappe characteristics and detachment structure of the Longmenshan fault zone may be an important factor in the occurrence of the Lushan earthquake at the Houshan fault.

为评估全球潮汐模型在我国潮汐改正中的适用性,本文首先对10个重力站2016—2018年的观测数据进行了精度评定,而后基于均方根、和方根、纬度依赖关系以及重力残差等指标对7个全球潮汐模型进行了精度评定.结果表明:10个重力站的一些评价指标达到甚至超越了早期超导重力仪,例如M2波潮汐因子的中误差普遍小于0.00070,其中最高精度约为0.00014,5个主要潮波的稳定度均≤0.0015.在10个观测模型和7个全球潮汐模型中,DDW-NHi和M2001模型考虑了地球扁率的影响,基于这两个模型计算的和方根较其它模型所得的和方根均小,约为0.288×10-8 m/s2.基于最高精度的乌什站数据对Molodensky,DDW-NHi,M2001与观测模型的改正精度的对比显示,DDW-NHi模型改正计算的重力残差(±0.4×10-8—±1.0×10-8 m/s2)不及观测模型(±0.1×10-8—±0.5×10-8 m/s2),但依然优于M2001模型(±0.7×10-8—±1.4×10-8 m/s2),且DDW-NHi模型改正获得的残差比传统的Molodensky模型所得残差(±0.5×10-8—±1.5×10-8 m/s2)小1×10-8—2×10-8 m/s2.

潮汐变化空间分布可用于地球不同位置受外力响应及地球形状、地表变形的相关研究.受观测技术、仪器数量和观测精度等制约,中国大陆重力潮汐观测直到21世纪初才得到较大改善和发展.利用2015-2017年中国大陆运行较好的51个重力站潮汐观测数据,采用国际标准潮汐处理方法和软件,分析计算了中国大陆主要潮波潮汐因子的空间分布,同时,结合1′×1′的全球地形模型(ETOPO1)和全球重力场模型(WGM2012)讨论了中国大陆东西和南北向2个潮汐剖面的构造物理特征.研究结果表明:①90％以上重力站M2波潮汐因子中误差优于0.001,这已和20世纪80～90年代的超导重力仪的观测精度相当;沿海台站的O1和K1波潮汐因子大于其他地区,经Nao99b和Nao99jb海潮模型检验认为是海潮负荷引起的.②沿狮泉河—玉树—松潘—黄梅—上海佘山的东西向M2波潮汐剖面显示,当海拔高程差异超过4500m、布格重力异常差异600×10-5m/s2时,重力站间M2波潮汐因子差异可达2％,且和高程呈正相关特征.③沿孟连—西昌—银川—乌加河的南北向M2波潮汐剖面站间潮汐因子差异为1.0％～1.5％.④重力站潮汐因子和高程的相关性分析表明,内陆站M2、O1波相关系数超过40％具有正相关特征.上述结果可为中国大陆地壳结构横向不均匀性和动力变形响应研究提供参考.

Previous studies show that the calculated loading effects from global ocean tide models do not match actual measurements of gravity attraction and loading effects in Southeast Asia. In this paper, taking advantage of a unique network of gravity tidal stations all over the Chinese mainland, we compare the observed and modeled tidal loading effects on the basis of the most recent global ocean tide models. The results show that the average efficiencies of the ocean tidal loading correction for O1, K1, M2 are 77%, 73% and 59%, respectively. The loading correction efficiencies using recent ocean tidal models are better than the 40 years old Schwiderskis model at coastal stations, but relative worse at stations far from ocean.

地震的孕育发生过程伴随着构造运动、物质迁移和密度变化,将引起地球重力场变化,流动重力重复观测有可能捕捉到与地震孕育有关的前兆信息,从而为中短期地震预测提供重要依据.基于南北地震带2017-2020年的流动重力观测资料,获得了甘东南地区的区域重力场时空变化图像,分析了区域重力场动态变化及其与2019年甘肃夏河Ms 5.7地震发生的关系.结果 表明:①震前测区重力异常变化等值线与临潭—宕昌断裂走向基本一致,且在震中附近出现四象限分布特征,夏河Ms5.7地震发生在重力高梯度带和四象限中心附近;②地震前后区域重力场经历了"区域性重力异常—四象限分布特征—反向变化发震"的时空演化过程;③九寨沟地震的发生可能引起附近断层区域应力场的调整,从而加速了夏河地震的发生;④区域重力场时变与临潭—宕昌断裂在空间上有较好的对应,综合分析可认为该次地震的发震断裂为临潭—宕昌断裂.

对中国大陆7次强震前出现的典型重力场变化图像(梯度带和四象限)及其量化参数进行总结.结果表明,目前采用的地震预测指标具有一定的不确定性,与测网观测时段、测点空间分布、变化幅值空间差异等具有密切关系;芦山地震前潮汐因子异常空间范围是流动重力典型变化范围的近10倍,可能与连续重力观测站的精度比流动重力联测高1个数量级有关.基于闭锁剪力模式提出利用典型重力变化图像进行地震数值预测的方法,强震前在孕震源存在的双力偶闭锁剪力的持续作用下,走滑型力偶会在地表引起四象限重力变化,倾滑型力偶会在地表引起二象限(梯度带)重力变化.预测回溯算例实验结果初步表明,该方法对走滑型和倾滑型地震的震级预测较为有效,同时可给出未来地震的地点和类型.

文中基于矩形位错理论及USGS发布的断层模型,结合研究区地壳—上地幔平均波速分层结构,模拟计算了弹性-黏弹分层半空间中2021年玛多MS7.4地震产生的同震及震后地表形变和重力变化.经分析发现,同震形变和重力变化显示发震断层具有左旋走滑兼正断错动的综合特征,其变化主要发生于断层在地表投影周边50km的范围内,向断层两侧快速衰减,向E最大水平位移量>1000mm,向N最大位移量达570mm,垂直位移近750mm,重力变化达150μGal;远震区(与断层的距离>150km)的水平位移量值一般<10mm,向外衰减较慢;而垂直位移和重力变化图像呈现一定的负相关,呈蝴蝶状的正负四象限对称分布,向外衰减的速率明显强于水平形变,变化量值一般<2mm和<1μGal.震后效应随时间的推移逐步显现并持续增强,其图像变化形态与同震类似,表现出明显的继承性增强趋势;震后黏弹性松弛效应的影响范围远大于同震,震后400a间其影响量值在近场区一般≤同震的2倍,但远场区均>3倍;震后400a间黏弹性松弛对水平位移、垂直位移和重力变化的影响可达100mm、130mm和30μGal;同震效应的极值区域主要集中在断层两侧,且离断层越近量值越大,而震后黏弹性松弛效应的极值区分布于离断层两侧约50km处,两者并不重合;震后水平位移主要表现为持续单调增强,而垂直位移和重力震后的变化则相对复杂:近场区在震后5a内呈现相对同震的继承性增强,随后反向调整,而远场区则相反,先反向调整,后呈继承性增强;水平位移在100a后基本稳定不变,而黏弹性松弛效应对垂直位移和重力变化的影响会持续到震后300a.与GNSS实测结果对比后发现,两者在运动方向和量级大小上基本一致,远场符合更好,这可能与断层模型的分辨率有关.文中研究可为利用实际形变和重力资料解释此次地震的孕震过程研究提供理论依据.

Multidisciplinary research shows the Red river fault zone’s (RRFZ) present movement and deformation state has complex segmentation feature. In order to further reveal its deep deformation mode, firstly, we extract tectonic movement gravity change information from mobile gravity measurement data by remove water storage varation and Vertical movement gravity effect; Secondly, together crust density interfaces model with gravity change information, then we can get the NMRFZ’s deformation mode of deep crust, which causes gravity variation.The average effect with a 50km radius is calculated for the recent gravity change rate in the Sichuan-Yunnan region, then the background rate field and the residual gravity change rate field are obtained. The trend of -0.66μGal/yr gravity-low-speed change in Sichuan-Yunnan region indicates that there is an inheritance between the gravity field and the uplifting background of the southeastern Tibetan Plateau. The crustal uplift is an important reason for the negative surface gravity changes, but it is mainly related to the deep tectonic environment. There are local positive change zones in the block boundary area, with obvious lateral extrusion and deep mass accumulation. It reflects that under the dynamic environment of the eastward flow of the Tibetan Plateau, the crust of north and middle-south section of the RRFZ are extruded and the underground mass become densification which make the surface gravity raising. The positive gravity changes in up-middle crust are more obvious than lower crust and Moho in Sichuan-Yunnan area. The RRFZ also exhibits a strong demarcation feature as a plate boundary, and the northern segment is the dividing line of gravity positive and negative changes area, while the middle-southern segment and its two sides also showed a wide range of positive change trends, with deep mass continue accumulation.The results of crustal deep deformation show that both the upper and the lower crust are obviously demarcated along the 101.5°E boundary, with the west side of the southwest Yunnan descending (moho: -0.05m/yr, upper-middle crust: -0.03m/yr) and east side of Sichuan-Yunnan block rising (moho ： 0.05m/yr，upper-middle crust： 0.02m/yr), which shows that the control effects in depth of the Kangdian crustal axis. The deformation rate of the deep crust in the RRFZ is the largest, the middle-south is next and the south the smallest. Gradual zone between the middle-south segment of the RRFZ and the Chuxiong-Jianshui fault zone shows strong activity and difference in the upper middle crust.

基于形变与密度变化耦合运动理论,利用时变场内重力垂直梯度的计算方法,采用直立长方体模型,根据青藏高原平均降升速率,模拟计算在艾黎地壳均衡模式下,地表形变所引起重力及其垂直梯度的变化.结果显示,在山体抬升过程中,伴随着地表的隆升,重力值亦逐渐减小,导致其减小的原因为介质体密度减小与测点的高度增加.伴随着山体最高点抬升了 5 cm,在最高点处重力变化为-14 μGal,对应的重力梯度约为-2.6 E.重力垂直梯度与静态场重力梯度存在一定的差异,其原因为在重力梯度场中加入了时间效应.

地球重力场及其地学应用是地球科学领域的重要内容之一,在国家基础测绘、灾害监测、资源勘探、地表圈层耦合作用和航空航天等方面等都具有不可替代的重要作用.近年来,随着重力场观测技术的不断革新,重力测量以及相应的理论、方法及应用的发展迅速,取得了丰硕的研究成果.2020年中国地球科学联合学术年会重力场专题报告(包括42个口头报告和10个张贴报告)就是这些成果的集中展示.基于年会重力场专题报告内容,综述了我国近年来在地球重力场及其地学应用方面的最新研究进展.