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1.
Satellite thermal infrared images contain valuable earthquake precursor information. Past studies concluded that such information appeared only a few days or dozens of days before an earthquake would occur. In our study, though, we observed that the time intervals between the thermal infrared precursor and an earthquake??s occurrence can be up to 10?years. An infrared image can also synchronously indicate the locations of additional future earthquakes with different epicenters within a region. The shape, area, intensity, and movement of thermal infrared anomaly areas are a combination of all the future strong earthquakes within a region. These distant future earthquakes are generally located near the edges, endpoints, or corners of the main structure, fine structures or periphery structures of a thermal infrared anomaly area and play a role in confining the anomaly area. There have not been any exceptions among the strong earthquakes we analyzed, which have included the 2011 Japan M w 9 event, the 2010 Yushu M S 7.1 event, the 2008 Wenchuan M S 8 event, and many other strong events following the 2004 Sumatra M S 9 event. Surprisingly, some of the earthquakes can outline an area of elevated temperature observed many months ago. If we can roughly locate these potential epicenters through the analysis of thermal infrared images and combining the analysis with other information, and then dynamically monitor them, it may be easier to observe the precursor of an earthquake and predict its occurrence.  相似文献   

2.
The preparation process of an impending earthquake may leave fingerprints on the earth??s surface. Elastic strain in rocks, formation of micro-cracks, gas releases and other chemical or physical activities in the earth??s crust before and during earthquakes has been reported to cause rises in temperature, surface latent heat flux (SLHF), upwelling index and chlorophyll-a (Chl-a) concentration on the ground or sea surface. Changes in surface temperature can be monitored with thermal infrared sensors such as NOAA-AVHRR and microwave radiometers like AMSR-E/Aqua. SLHF data and upwelling indices are provided by National Centers for Environmental Prediction (NCEP) Reanalysis Project and Pacific Fisheries Environmental Laboratory, respectively. This study examines behaviors of the above four factors prior to the past three oceanic and coastal earthquakes occurred at the Pacific Ocean (Northern California of June 15, 2005, Central California of September 28, 2004, and December 22, 2003). We were successful in detecting pre-earthquake anomalies prior to all three earthquakes. Our detailed analysis revealed 1?C5?°C rises in surface temperature in epicentral areas. Considerable anomalies in Chl-a concentration, 1?C2?weeks before the day of the main earthquakes, were spotted, which are attributed to the rise in upwelling index. Time series of SLHF showed meaningful rises from 1?month to a fortnight before the earthquake events. One problem in our research was the low resolution of the data which makes the graphs that are generated from NCEP database affected by all sources of anomalies, other than seismic activities, within an about 1.8°?C2.5° (200?km) area.  相似文献   

3.
Long-term conditional probabilities of occurrence of great earthquakes along the Himalaya plate boundary seismic zone have been estimated. The chance of occurrence of at least one great earthquake along this seismic zone over a period of 100 years (beginning the year 1999) is estimated to be about 0.89. The 100-year probability of such an earthquake occurring in the Kashmir seismic gap is about 0.27, in the central seismic gap about 0.52 and in the Assam gap about 0.21. The 25-year probabilities of their occurrence in these gaps are 0.07, 0.17, and 0.05 respectively. These probability estimates may be used profitably to assess the seismic hazard in the Himalaya and the adjoining Ganga plains.  相似文献   

4.
回顾了1994年美国Northridge地震、1995年日本阪神地震、1999年土耳其Kocaeli地震、1999年台湾集集地震、2008年中国汶川地震、2010年智利Maule地震、2010～2011新西兰Darfield地震及余震、2011年东日本地震中大量的、不同类型的液化实例调查与研究,发现这些地震的液化具有以下特点：（1）罕见的特大地震（Mw9.0）使远离震中300～400 km的新近人工填土发生严重的大规模液化;（2）特大地震（Ms8.0、Mw8.8）使远离震中的低烈度Ⅴ～Ⅵ度地区发生严重液化;（3）海岸、河岸附近地区的新近沉积冲积、湖积土,填筑时间不到50年的含细粒、砂砾人工填土,容易发生严重液化;（4）天然的砂砾土层液化发生严重液化;（5）发生了深达20 m的土层液化现象;（6）松散土层液化后可以恢复到震前状态并再次发生液化;（7）高细粒（粒径≤75 ?m）含量≥50%或高黏粒（粒径≤5 ?m）含量≥25%的低-中塑性土严重液化,对介于类砂土与类黏土之间的过渡性态土,有时地表未见液化现象;（8）液化土层的深度较深或厚度较小时,容易出现地面裂缝而无喷砂现象;有较厚的上覆非液化土层时,场地液化不一定伴随地表破坏。液化实例证明,第四系晚更新世Q3地层可以发生严重液化;黏粒含量不是评价细粒土液化可能性的一个可靠指标;低液限、高含水率的细粒土易发生液化,采用塑性指数PI、含水率wc与液限LL之比作为细粒土液化可能性评价的指标是适宜的。综合Boulanger和Idriss、Bray和Sincio、Seed和Cetin等的液化实例调查与室内试验研究成果,建议细粒土液化可能性的评价准则如下：PI ＜12且wc/LL＞0.85的土为易液化土,12＜PI≤20和/wc/LL≥0.80的土为可液化土;PI ＞20或wc/LL＜0.80的土为不液化土。  相似文献   

5.
The earthquake closet: rendering early-warning useful   总被引：1，自引：1，他引：0  
Max Wyss 《Natural Hazards》2012,63(2):761-768
Early-warning of imminently approaching strong shaking that could have fatal consequences is a research field that has made great progress. However, its potential to save lives has a serious Achilles heel: The time for getting to safety is 5 to 10?s only, in those cities that need warnings most. Occupants of the upper floors cannot get out of their buildings and narrow streets are not a safe place in strong earthquakes. The official advice, to crawl under a table, protects from falling objects only, but not from collapsing buildings. Thus, only about 10?% of a city??s population can benefit from early-warnings, unless they have access to an earthquake protection unit that is strong enough to improve their chances of survival and not being injured by factors of 1,000 to 30,000. The purpose of this paper is to generate discussion on how to use early-warning to improve the safety for occupants of buildings exposed to strong earthquake shaking.  相似文献   

6.
This article presents the results of deterministic and probabilistic seismic hazard analyses (DSHA and PSHA) of the city of Hamedan and its neighboring regions. This historical city is one of the developing cities located in the west of Iran. For this reason, the DSHA and PSHA approaches have been used for the assessment of seismic hazards and earthquake risk evaluation. To this purpose, analyses have been carried out considering the historic and instrumented earthquakes, geologic and seismotectonic parameters of the region covering a radius of 100?km, keeping Hamedan as the center. Therefore, in this research, we studied the main faults and fault zones in the study area and calculated the length and distance of faults from the center of Hamedan. In the next step, we measured the maximum credible earthquake (MCE) and peak ground acceleration (PGA) using both DSHA and PSHA approaches and utilized the various equations introduced by different researchers for this purpose. The results of DSHA approach show that the MCE-evaluated value is 7.2 Richter, which might be created by Nahavand fault activities in this region. The PGA value of 0.56?g will be obtained from Keshin fault. The results of PSHA approach show that the MCE-evaluated value is 7.6 Richter for a 0.64 probability in a 50-year period. The PGA value of 0.45?g will be obtained from Keshin fault. Seismic hazard parameters have been evaluated considering the available earthquake data using Gutenberg?CRichter relationship method. The ??a?? and ??b?? parameters were estimated 5.53 and 0.68, respectively.  相似文献   

7.
江苏—南黄海地区城市密集,人口众多,是中国东部经济最发达的地带之一。同时,该地区历史上曾频发中—强以上级别的地震,地震及次生地质灾害是威胁该区经济社会发展的自然灾害之一。该区的地震活动时空特征和发震机制还不清楚。本文通过整理江苏—南黄海地区的历史和仪器记录地震数据,分析了该区地震活动时空分布格局,发现地震活动主要集中于若干条区域活动断裂带,在时间上具有约60年的平静期,目前仍处于地震活跃期。深部构造研究还表明该区域内地震活跃的南部坳陷和勿南沙隆起区均存在显著的地球物理异常,表明地震活动与区域深部构造有关。东部菲律宾海板块的俯冲作用和印度—欧亚大陆碰撞引起的板块边界挤压力和大陆边缘因地形高程差异伴随的重力势能是中国海洋地震的主要驱动力。上述认识不仅加深了对江苏—南黄海地区地震构造环境的理解,同时也能对该区防震减灾公益事业提供科学参考。  相似文献   

8.
Seismogenesis of aftershocks occurring in the Kachchh seismic zone for more than last 10?years is investigated through modeling of fractal dimensions, b-value, seismic velocities, stress inversion, and Coulomb failure stresses, using aftershock data of the 2001 Bhuj earthquake. Three-dimensional mapping of b-values, fractal dimensions, and seismic velocities clearly delineate an area of high b-, D-, and Vp/Vs ratio values at 15?C35?km depth below the main rupture zone (MRZ) of the 2001 mainshock, which is attributed to higher material heterogeneities in the vicinity of the MRZ or deep fluid enrichment due to the release of aqueous fluid/volatile CO2 from the eclogitisation of the olivine-rich lower crustal rocks. We notice that several aftershocks are occurred near the contacts between high (mafic brittle rocks) and low velocity regions while many of the aftershocks including the 2001 Bhuj mainshock are occurred in the zones of low velocity (low dVp, low dVs and large Vp/Vs) in the 15?C35?km depth range, which are inferred to be the fractured rock matrixes filled with aqueous fluid or volatiles containing CO2. Further support for this model comes from the presence of hydrous eclogitic layer at sub-lithospheric depths (34?C42?km). The depth-wise stress inversions using the P- and T-axes data of the focal mechanisms reveal an increase in heterogeneity (i.e., misfit) with an almost N?CS ??1 orientation up to 30?km depth. Then, the misfit decreases to a minimum value in the 30?C40?km depth range, where a 60o rotation in the ??1 orientation is also noticed that can be explained in terms of the fluid enrichment in that particular layer. The modeling of Coulomb failure stress changes (??CFS) considering three tectonic faults [i.e., NWF, GF, and Allah bund fault (ABF)] and the slip distribution of the 2001 mainshock on NWF could successfully explain the occurrences of moderate size events (during 2006?C2008) in terms of increase in positive ??CFS on GF and ABF. In a nutshell, we propose that the fluid-filled mafic intrusives are acting as stress accentuators below the Kachchh seismic zone, which generate crustal earthquakes while the uninterrupted occurrence of aftershocks is triggered by stress transfer and aqueous fluid or volatile CO2 flow mechanisms. Further, our results on the 3-D crustal seismic velocity structure, focal mechanisms, and b-value mapping will form key inputs for understanding wave propagation and earthquake hazard-related risk associated with the Kachchh basin.  相似文献   

9.
Y. Y. Kagan 《Tectonophysics》1997,270(3-4):207-219
This note discusses three interconnected statistical problems concerning the Parkfield sequence of moderate earthquakes and the Parkfield prediction experiment: (a) Is it possible that the quasi-periodic Parkfield sequence of characteristic earthquakes is no uncommon, specific phenomenon (the research hypothesis), but can be explained by a preferential selection from available earthquake catalogs? To this end we formulate the null hypothesis (earthquakes occur according to the Poisson process in time and their size follows the Gutenberg-Richter relation). We test whether the null hypothesis can be rejected as an explanation for the Parkfield sequence. (b) If the null hypothesis cannot be refuted, what is the probability of magnitude m ≥ 6 earthquake occurrence in the Parkfield region? (c) The direct goal of the Parkfield experiment is the registration of precursory phenomena prior to a m6 earthquake. However, in the absence of the characteristic earthquake, can the experiment resolve which of the two competing hypotheses is true in a reasonable time? Statistical analysis is hindered by an insufficiently rigorous definition of the research model and inadequate or ambiguous data. However, we show that the null hypothesis cannot be decisively rejected. The quasi-periodic pattern of intermediate size earthquakes in the Parkfield area is a statistical event likely to occur by chance if it has been preferentially selected from available earthquake catalogs. The observed magnitude-frequency curves for small and intermediate earthquakes in the Parkfield area agree with the theoretical distribution computed on the basis of a modified Gutenberg-Richter law (gamma distribution), using deformation rates for the San Andreas fault. We show that the size distribution of the Parkfield characteristic earthquakes can also be attributed to selection bias. According to the null hypothesis, the yearly probability of a m ≥ 6 earthquake originating in the Parkfield area is less than 1%, signifying that several more decades of observation may be needed before the expected event occurs. By its design, the Parkfield experiment cannot be expected to yield statistically significant conclusions on the validity of the research hypothesis for many decades.  相似文献   

10.
Paper describes triggered seismicity to 200?km distance and for a decade due to the 2001 M w7.7 Bhuj earthquake. The Kachchh region is seismically one of the most active intraplate regions of the World due to the occurrence of two large earthquakes 1819 (M w7.8) and 2001 (M w7.7). Though, it has high hazard but was known to have low seismicity in view of the occurrence of fewer smaller shocks. However, the status seems to have changed after 2001. Besides the strong aftershock activity for over a decade, seismicity has spread to nearby faults in Kachchh peninsula and at several places southward for 200?km distance in Saurashtra peninsula. Beyond the rupture zone of the 2001 Bhuj earthquake, more than 40 mainshocks of M w?~?3?C5 have occurred at 20 different locations, which is unusual. The increased seismicity is inferred to be caused by stress perturbation due to the 2001 Bhuj earthquake by viscoelastic process. In Saurashtra, over and above the viscoelastic stress increase, the transient stress increase by water table rise in monsoons seems to be affecting the timing of mainshocks and associated sequences of earthquakes.  相似文献   

11.
Statistics of ultimate strain are improved by adding new data to the previous ones. The critical value for horizontal strain seems somewhat larger than that for vertical strain, although parameters of a Weibull distribution, which is customarily used for quality-control research and which fits in very well with the present statistics, are calculated for the whole set of data making no distinction between the two subsets because of their scantiness.On the basis of the parameters thus determined and strain rates obtained from geodetic data, probabilities of earthquake occurrence in a few regions in Japan and the U.S. are estimated. Probability of having an earthquake in an area southwest of Tokyo, where we had the 1923 earthquake (magnitude 7.9), at this time amounts to 20%, a value almost the same as that obtained in the previous papers. The probability will reach some 50 and 90% by 2000 and 2050, respectively. In the North Izu district, where an earthquake of magnitude 7.0 occurred in 1930, a shearing crustal motion is going on to an extent for which we have a probability for an earthquake recurring there in these 40 years amounting to 40%. By the end of this century, it will become as high as 85%.Similar estimates of such cumulative probabilities are made for the San Francisco and Fort Tejon regions, where great earthquakes occurred respectively in 1906 and 1857, yielding values of 30 and 80% at present. These probabilities are tentative because of possible errors in evaluating geodetic measurements and uncertainty of the ultimate crustal strain assigned to the San Andreas fault.  相似文献   

12.
Precise zonation of the territory of China has been performed based on the active known faults, type of faulting and seismicity level. One hundred and forty seven seismogenic regions were defined, forming 10 larger seismic areas, and the seismotectonic characteristics in each one of them were investigated in detail. After checking for data accuracy and completeness of the shallow earthquakes (h≤60 km), the regional time and magnitude predictable model was applied and the model parameters were estimated. Based on the model applicability in the studied area, probabilities for the occurrence of strong (M≥6.0) earthquakes during the next 10 years were calculated for each seismogenic region. Statistical tests have been used proving the superiority of the model in comparison with the time independent one, as well as in comparison with the actual earthquake occurrence.  相似文献   

13.
受环太平洋地震带影响,华北平原地区地震频发,尤其是处于中国首都经济圈的京津冀地区的地震事件备受关注。通过对历史文献资料及地震台网记录中的地震事件统计、分析,重建该地区地震事件历史并获取其潜在的空间分布特征及时间规律,对未来地震事件的早期预警具有重要参考意义。分析结果表明,公元前231年至公元2018年期间京津冀地区发生的1044起地震事件中,以有感地震和中强地震为主,小地震、强烈地震以及大地震发生频次较低。地震记录完整性分析结果表明,除小地震外,其他等级地震记录自公元1400年以来基本完整。在空间分布上,京津冀地区历史地震呈“T”字形分布,沿1条北西—南东走向地震带和1条北东—南西走向地震带分布。在时间上,京津冀地区地震事件呈现出阶段性的变化,在公元1480—1680年间以及1950年以来2个时间段内较为活跃,发生频率较高,频谱分析结果进一步表明地震记录存在45年的复发周期。在月际尺度上,地震事件同样存在季节性差异且多发于夏秋季节,同时地震密集区域在年内呈现出自西向东迁移的现象。最后,根据历史地震事件发生的时间规律,在未来一段时间内京津冀地区仍将处于地震活跃期,存在发生强震的风险。  相似文献   

14.
Understanding the source mechanism of earthquakes may be the key to predict earthquakes. The testing of radioactive radiations and reactionary hypothesis of gases before and after quake events can help predict and monitor earthquake occurrence. In this study, the Atmospheric Infrared Sounder (AIRS) and the column ozone (O3) were applied to evaluate the December 26, 2003 earthquake of Bam city in western Iran. The results show that ozone concentration (column density) decreased about 30 DU and or 807?×?10E15/cm2 molecules. Using high-resolution AIRS data for the study area, we were able to discriminate gases that formed and changed before the main shock at least a day before the occurrence of the quake in Bam.  相似文献   

15.
In this paper, we report that the ratio of broadband energy (0.01?C2?Hz) to high-frequency energy (0.3?C2?Hz), E r, estimated from regional seismograms of India, might be a useful parameter in estimating tsunami potential of earthquakes in the Sumatra?CAndaman region. E r is expected to be sensitive to the depth as well as to the source characteristics of an earthquake. Since a shallow and slow earthquake has a greater tsunamigenic potential, E r may be a useful diagnostic parameter. We base our analysis on broadband seismograms of the great earthquakes of Sumatra?CAndaman (2004, M w?~?9.2) and Nias (2005, M w 8.6), 41 of their aftershocks, and the earthquakes of north Sumatra (2010, M w 7.8) and Nicobar (2010, M w 7.4) recorded at VISK, a station located on the east coast of India. In the analysis, we also included the two recent, great strike-slip earthquakes of north Sumatra (2012, M w 8.6, 8.2) recorded at VISK and three south Sumatra earthquakes (2007, M w 8.5; 2007, M w 7.9; 2010, M w 7.8) recorded at PALK, a station in Sri Lanka. We find that E r is a function of depth; shallower earthquakes have higher E r values than the deeper ones. Thus, E r may be indicative of tsunamigenic potential of an earthquake. As M w and E r increase so does the tsunami potential. In addition to the parameter E r, the radiated seismic energy, E s, may be estimated from the regional seismograms in India using empirical Green??s function technique. The technique yields reliable E s for the great Sumatra and Nias earthquakes. E r and E s computed from VISK data, along with M w and focal mechanism, may be useful in estimating tsunami potential along the east coast of India from earthquakes in the Sumatra?CAndaman region in less than ~20?min.  相似文献   

16.
马瑾 《地学前缘》1999,6(4):363-370
讨论活动块体在地震活动中的作用。板缘地震在空间上呈线性分布,而中国大陆地震在空间上呈片状分布。大陆强震往往涉及两个以上方向断层的活动,且强震往往沿块体边界迁移或在其两侧断层上对迁。一些强震前后由中小地震震源机制解反映的Ｐ轴方向往往发生近９０°的转向,这种现象难以用区域应力方向变化来解释,但可从块体活动角度出发,用块体两个边界断层的先后错动来解释。地震前异常的远程效应、震后烈度异常分布图像以及地震序列特点等也显示了活动块体的作用。不同地区由地震活动性推测的块体活动方式有所差别,其原因可能和区域主压应力轴与块体两个边界断层走向的夹角不同有关。据此认为,在分析中国地震活动时要把视角从以活动断层为中心转变为以活动块体为中心  相似文献   

17.
The Elat fault (a segment of the Dead Sea Transform) runs along the southern Arava valley (part of the Dead Sea Rift, Israel) forming a complex fault zone that displays a time-dependent seismic behaviour. Paleoseismic evidence shows that this fault zone has generated at least 15 earthquakes of magnitude larger than M 6 during the late Pleistocene and the Holocene. However, at present the Elat fault is one of the quietest segments of the Dead Sea Transform, lacking even microsesimicity. The last event detected in the southern Arava valley occurred in the Avrona playa and was strong enough to have deformed the playa and to change it from a closed basin with internal drainage into an open basin draining to the south.Paleoseismological, geophysical and archaeological evidences indicate that this event was the historical devastating earthquake, which occurred in 1068 AD in the eastern Mediterranean region. According to the present study this event was strong enough to rupture the surface, reactivate at least two fault branches of the Elat fault and vertically displace the surface and an early Islamic irrigation system by at least 1 m. In addition, the playa area was uplifted between 2.5 and 3 m along the eastern part of the Elat fault shear zone. Such values are compatible with an earthquake magnitude ranging between M 6.6 and 7. Since the average recurrence interval of strong earthquakes during the Holocene along the Elat fault is about 1.2 ± 0.3 ky and the last earthquake occurred more about 1000 years ago, the possibility of a very strong earthquake in this area in the future should be seriously considered in assessing seismic hazards.  相似文献   

18.
断块大地构造与地震活动的构造物理研究   总被引：3，自引：0，他引：3       下载免费PDF全文
马瑾 《地质科学》2009,44(4):1063-1082
断块大地构造理论几乎涉及地震活动的各个方面： 1）地震记录表明不但是强震,大多数6级以上地震也分布在构造块体边界上,构造块体控制了地震分布; 2）地震活动规律体现在块体整体活动中。例如,鄂尔多斯地块周边单个断陷带的地震活跃期与平静期长短不一,无明显规律。但当把鄂尔多斯地块周边作为一个整体,其地震活动在时间上显示了准周期性; 3）地块运动通过周边断层交替活动实现。从断层活动相互作用的时间间隔和错动形式出发可把它分为强震交替活动型（又可分长时间间隔和短时间间隔两类）和强震与弱震或断层蠕动交替活动型。强震交替活动型中时间间隔很短的双震活动较早被发现。强震交替活动型中时间间隔很长的类型虽然不易识别,但是依赖于中国历史地震目录,还是发现鄂尔多斯地块周边山西断陷带与渭河断陷带在历史上的3次交替活动等; 强震与弱震或断层蠕动型的交替活动型很不容易被发现,仅在台网较密,观测条件较好的北京地区观测到。4）利用一些实验结果讨论了交替活动的规律。此外,结合断块大地构造理论对一些地震现象进行了讨论。  相似文献   

19.
The rocky coastline of the Sultanate of Oman between Fins and Sur is decorated by a number of large blocks and boulder accumulations forming ramparts. The blocks occur as individual rocks of up to 40 tons, as imbricated sets and as ??boulder trains.?? Landward, the deposits change into a sand/boulder mixture and distal into sands. The coast is made up of Tertiary folded limestones and beach rock of Quaternary age, both also constitute the megaclasts. The transport distance from the fractured seaward platform of 6?C10?m above mean sea level varies between 20?m and more than 50?m. We found individual blocks of recent corals and overturned blocks with attached oysters and rock pools. Terrestrial laser scanning was used to analyze geomorphologic features as well as for volumetric estimates of the block weights. Tropical cyclones such as Gonu in 2007 or Phet in 2010 are known to have affected Oman??s coastline in the past. The coastal changes during recent cyclones were minor; therefore, we interpret the block deposits as tsunamigenic. However, this interpretation is not unambiguous. The most likely source area for a tsunami is seen in the Makran Subduction Zone situated in the northern Indian Ocean. Here, at least 4?C5 tsunamigenic earthquakes are documented.  相似文献   

20.
The mechanism of earthquake inoculation and the process of earthquake occurrence are very complicated. Additionally, earthquakes do not happen very often, and we lack enough cognition to the earth’s interior structure, activity regularity and other key elements. As a result, research progress about the theory of earthquake precursors has been greatly restricted. Ground gravity observation has become one of the main ways to study earthquake precursor information in many countries and regions. This paper briefly summarized the surface gravity observation technology and observation network in China: the surface gravity measurement instrument developed from Huygens physical pendulum in seventeenth Century to today’s high-precision absolute gravimeter, and its accuracy reached to ±1×10-8 m/s2. China has successively established the National Gravity Network, Digital Earthquake Observation Network of China,the Crustal Movement Observation Network of China Ⅰ and the Crustal Movement Observation Network of China, to provide a public platform for monitoring non tidal gravity change, seismic gravity and tectonic movement. The use of specific examples illustrated the role of gravity observation data in earthquake prediction. The gravity observation data of ground gravity can be used to capture the information of gravity change in the process of strong earthquake inoculation, and to provide an important basis for the long-term prediction of strong earthquakes. The temporal and spatial variation characteristics of the regional gravity field and its relation to strong earthquakes were analyzed: Before the earthquake whose magnitude is higher than MS 5, generally there will be a large amplitude and range of gravity anomaly zones. Strong earthquakes occur mainly in areas where the gravity field changes violently. The dynamic change images of gravity field can clearly reflect the precursory information of large earthquakes during the inoculation and occurrence. Finally, the existing problems of surface gravity technology in earthquake precursor observation were put forward and the use of gravity measurement data in earthquake prediction research was prospected.  相似文献   

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