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1.
以2001—2011年美国NOAA长波辐射数据为背景数据,利用涡度背景场法研究2010年9月3日新西兰南岛M7.1级地震前后卫星长波辐射数据变化特征。结果表明,地震当月在震中西南侧出现显著的长波辐射异常变化,这种变化在全年各月及2001—2011年11年历年同月变化中都是最为显著的,认为其是本次地震的1次映震表现。用同样方法对区内2001—2011年11年间发生6次7.0级以上地震的长波辐射数据进行分析,结果在3次陆地地震发震前都检测到了长波辐射异常变化,而海域地震前则未发现这种现象。检索前人的相关研究结果,发现仅有2次海域地震(2004年12月26日印度尼西亚苏门答腊西北海域8.7级地震和2010年1月12日海地7.0级地震)前有长波辐射异常变化的报道,而根据全球云量分布资料显示,这2个地震所发生的区域是全球洋面云量分布最少的2个区域,而新西兰地震发生的区域位于全球洋面云量分布最多的区域。因此,认为由于水汽和云层对地表红外辐射的强吸收作用,长波辐射捕捉陆地地震红外辐射异常变化更加灵敏,对陆地地震的映震效能要强于海洋地震。 相似文献
2.
1999年岫岩Ms5.4级地震前震、主震、余震应变异常特征的研究 总被引：9，自引：0，他引：9
能否捕捉到临震前兆信息在相当程度上依赖于观测技术的进步。营口地震台连续记录的SW应变监测仪在辽宁岫岩Ms5 .4级地震中获取的资料表明 ,岫岩地震主震前的前震序列在受力加载中发震 ,震后呈现出继续受力加载状态 ;主震后的余震序列呈现出卸载状态下发震 ;在临近地震主破裂时应变方向和幅值的变化尤为明显。(1)岫岩地震序列概述 :1999年 11月 2 9日中国辽宁省岫岩发生了Ms5 .4级地震 ,震中位于 4 0°32′N ,12 1°4 8′E。该地震发生在 1975年海城 7.3级地震余震区东南端的延长线上。 1999年 11月 9日岫岩地区开始出现前震序列 ,震中分… 相似文献
3.
基于集集强震群序列地震特征的地震追踪预测 总被引：1，自引：0，他引：1
分析集集强震群前余震序列的 7年 (1993/ 0 9/ 2 1— 2 0 0 0 / 0 9/ 2 0 )中震级规模在M =3 0以上的地震目录 ,可以找到前震类型、孕震空区特征、孕震条带特征、前震丛集性活动与信号震特征、主震前平静以及余震序列的二次余震等至少 6项清楚的地震序列特征。利用已发展出的年度强震趋势分析步骤的经验 ,佐以依据地震序列特征进一步加以追踪的观念 ,以集集地震序列分析为例 ,试图将地震趋势分析由年的时间尺度 ,追踪到更短的月的时间范围 ;并尝试建立台湾地区西部地震带浅源强震的追踪分析步骤 ,并为以测震学为基础的地震预测提供逼近短临时间尺度的分析方法。 相似文献
4.
2004年12月26日北京时间08时56分，印尼苏门答腊西北海域发生了8．7级地震。震后不到3个月，即2005年3月29日，在原震区东南约200km处又发生了8．5级地震。这次地震是全球百年以来发生的最大地震之一，也是1964年美国阿拉斯加地震后全球发生的最大地震。 相似文献
5.
中国大陆科学钻探主孔流体地球化学异常与远强震的关系 总被引：6，自引：1，他引：6
2001年11月14日发生的昆仑山口西 M_s 8.1级地震和2004年12月26日发生的印度尼西亚苏门答腊 M_s 8.7级地震前后,中国大陆科学钻探(CCSD)主孔流体组成出现明显的异常。两次远强震前后的流体异常幅度很大,并具有相似的演化趋势。异常始于震前2-7天,He、N_2/O_2、He/Ar、N_2/Ar 为负异常,Ar/O_2为正异常。远强震前后流体异常特征与 CCSD附近小震前后流体异常特征具有明显的区别,表明昆仑山口西 M_s 8.1级地震前后和苏门答腊 M_s 8.7级地震前后的 CCSD 主孔流体异常可能与两次远强震相关。认为 CCSD 主孔中的 He、N_2、Ar 是记录远强震的敏感载体,可能记录了震前长周期波传播至 CCSD 主孔时激发的流体变化,反映了震源区的应力变化,也可能反映了区域构造活动乃至地球深部构造活动产生的场兆、源兆信息。 相似文献
6.
7.
本文应用陆远忠等人提出的孕震空区和逼近地震方法 ,分析了台湾及其东部海域所有资料较完整的 6 0级以上的地震。结果表明该区普遍存在孕震空区和逼近地震。在判定是否为孕震空区时 ,采用同样的三个标志。用所得到的数据计算经验公式。最后得出 5点初步结论 相似文献
8.
青藏高原昆仑—汶川地震系列与巴颜喀喇断块的最新活动 总被引：23，自引：1，他引：22
青藏高原是中国最主要的地震活动区之一。最近十多年来,在青藏高原中部连续发生了1997年西藏玛尼Ms7.5级地震、2001年青海昆仑山Ms8.1级地震、2008年3月新疆于田Ms7.3级地震和5月四川汶川Ms8.0级地震及2010年青海玉树Ms7.1级地震,它们相继发生于青藏断块区巴颜喀喇断块四周边界活动断裂带上,是该断块最新活动的结果。发生于断块南北边界断裂上的3次地震都是走滑断裂错动的结果,发生在断块东南端的汶川地震则是挤压逆冲断裂的产物,而西北端的于田地震则呈现出张性特征,它们共同反映青藏断块区巴颜喀喇条状断块向东南方向滑动的最新活动。自1900年以来,青藏断块区和巴颜喀喇断块的强震活动表现出多期活动和区域性转移的特征,20世纪早期Ms7.0级以上强地震活动的主体地区在青藏断块区北部边界构造带,中期转移到高原南部喜马拉雅板块边界构造带和断块区南部断块,最近十多年来则在巴颜喀喇断块及周缘边界断裂上活动。青藏高原这种块体活动和地震活动与澳大利亚-印度板块对亚洲大陆的推挤作用相关,因而,青藏高原和巴颜喀喇断块的强震活动与澳-印板块边界苏门答腊强震活动相对应。目前苏门答腊地区强震活动仍在继续,因此,近期对巴颜喀喇断块及青藏高原南部地区的强震活动和强震危险性仍需加以注意。 相似文献
9.
陆远忠 《地壳构造与地壳应力》2005,(1):1-1
2004年12月26日（北京时间）印尼苏门答腊西北近海发生8．9级地震造成了20多万人的死亡和巨大的财产损失，2005年3月29日（北京时间）印尼苏门答腊西北近海又发生8．6级地震。两次大地震的发生，有可能对全球地震活动格局的变化产生或预示重大影响，两次大地震参数见表1，表2是其断层面解。表中资料均取自美国哈佛大学的网站资料。 相似文献
10.
福建数字地下流体网对远处大震映震能力分析 总被引：1，自引：0，他引：1
本文收集、整理了2004年12月26日印尼苏门答腊西北近海8.7级地震和2005年印尼的8.5级和巴基斯坦的7.8级地震,我省地下流体数字化监测台网观测到的震时和震后效应。测点以永安-晋江断裂为界线,北边多数表现为水位上升,南边多数为下降。初步分析认为,这种现象可能与现代构造应力场有关。 相似文献
11.
The 2004 Mw9.2 Sumatra and 2012 Mw8.6 Wharton Basin (WB) earthquakes provide the unprecedented opportunity to investigate stress transfer from a megathrust earthquake to the subducting plate. Comprehensive analyses of this study revealed that the 2004 earthquake excited widespread seismicity in the WB, especially in regions of calculated stress increase greater than 0.3 bars. The 2004 earthquake stressed all three rupture planes of the 2012 Mw8.6 strike‐slip mainshock and the largest Mw8.2 aftershock with mean values of Coulomb stress between 0.3 and 2.1 bars. For the 77 Mw ≥ 4 regional events since 2012, at least one nodal plane for 95% of the events, and both nodal planes for 72% of the events experienced stress increase due to the 2004 earthquake. Results of the analyses also revealed that the regional stress directions in the WB may have controlled the sub‐fault orientations of the 2012 Mw8.6 strike‐slip earthquake. 相似文献
12.
We investigate repeating aftershocks associated with the great 2004 Sumatra–Andaman (Mw 9.2) and 2005 Nias–Simeulue (Mw 8.6) earthquakes by cross-correlating waveforms recorded by the regional seismographic station PSI and teleseismic stations. We identify 10 and 18 correlated aftershock sequences associated with the great 2004 Sumatra and 2005 Nias earthquakes, respectively. The majority of the correlated aftershock sequences are located near the down-dip end of a large afterslip patch. We determine the precise relative locations of event pairs among these sequences and estimate the source rupture areas. The correlated event pairs identified are appropriately referred to as repeating aftershocks, in that the source rupture areas are comparable and significantly overlap within a sequence. We use the repeating aftershocks to estimate afterslip based on the slip-seismic moment scaling relationship and to infer the temporal decay rate of the recurrence interval. The estimated afterslip resembles that measured from the near-field geodetic data to the first order. The decay rate of repeating aftershocks as a function of lapse time t follows a power-law decay 1/tp with the exponent p in the range 0.8–1.1. Both types of observations indicate that repeating aftershocks are governed by post-seismic afterslip. 相似文献
13.
Can electromagnetic disturbances related to the recent great earthquakes be detected by satellite magnetometers? 总被引：1，自引：0，他引：1
On December 26, 2004 the world's fourth largest earthquake since 1900 and the largest since the 1964 Prince William Sound, Alaska earthquake, occurred off the west coast of northern Sumatra with a magnitude of 9.3. On March 28, 2005 another event of magnitude 8.7 took place in the same region. The December 26, 2004 earthquake has prompted scientists to investigate possible electromagnetic signatures of this event, using ground magnetic observations. Iyemori et al. [Iyemori, T. et al., 2005. Geomagnetic pulsations caused by the Sumatra earthquake on December 26, 2004. Geophys. Res. Lett., 32, L20807, doi:10.1029/2005GL024083.] have suggested that a 3.6 min long geomagnetic pulsation, observed shortly after this event, was generated by the earthquake. They have speculated that a 30 s magnetic pulsation was also caused by the earthquake. Here for the first time, CHAMP satellite magnetic and electron density data are examined to find out if electromagnetic signatures which are possibly related to these recent megathrust earthquakes are observed in satellite magnetic data. We have shown that some specific features are observed after the two earthquakes, with periods of about 16 and 30 s. Our results favor an external source origin for the 30 s pulsation. Moreover, after more than 1 h, CHAMP magnetic data indicate the existence of a feature characterized by the same parameters (duration, amplitude, and frequency content), which could be associated with each earthquake, respectively. Further investigations are required in order to answer the question of whether these signals can be associated with earthquakes and to assign their possible usefulness with respect to earthquake development. 相似文献
14.
Complexity in the earthquake mechanism is manifested in different forms such as fractal distribution, clustering of seismicity, etc., and characterized as critical phenomenon. Occurrences of earthquakes generally represent the state of metastable equilibrium. The Andaman–Sumatra subduction zone is one of the most seismically active corridors (possibly in metastable state) in the world. Recently, the region faced three major earthquakes of magnitude more than 8.5 (M ~ 9.1 on December 26, 2004; M ~ 8.6 on March 28, 2005; M ~ 8.6 on April 11, 2012). Researchers have suggested multiple causes of earthquake generation in this region including the one with possible correlation of tidal stresses with earthquake occurrences. The latter issue, however, has been hotly debated in view of the fact that a small stress generated due to tidal forcing cannot cause such a bigger magnitude earthquake. We study here the impact of tidal forcing on critically generated earthquake phenomena. We examined the statistical behavior of recurrence time interval of earthquakes using the available data for period of about 40 years from 1973 to 2013. We constrain the simple empirical toy model using the concept of catastrophe theory to evaluate the impact of small tidal forcing on the critical state of earthquakes occurrences. In addition to the major role of Helmholtz free energy during the plate motion, our analysis suggests that the stability and critical behavior of the earthquake in Sumatra region could be associated with tidal forcing, however, only for triggering of some of the “Catastrophic–Chaotic” earthquake phenomenon. 相似文献
15.
Complexity in the earthquake mechanism is manifested in different forms such as fractal distribution, clustering of seismicity, etc., and characterized as critical phenomenon. Occurrences of earthquakes generally represent the state of metastable equilibrium. The Andaman–Sumatra subduction zone is one of the most seismically active corridors (possibly in metastable state) in the world. Recently, the region faced three major earthquakes of magnitude more than 8.5 (M ~ 9.1 on December 26, 2004; M ~ 8.6 on March 28, 2005; M ~ 8.6 on April 11, 2012). Researchers have suggested multiple causes of earthquake generation in this region including the one with possible correlation of tidal stresses with earthquake occurrences. The latter issue, however, has been hotly debated in view of the fact that a small stress generated due to tidal forcing cannot cause such a bigger magnitude earthquake. We study here the impact of tidal forcing on critically generated earthquake phenomena. We examined the statistical behavior of recurrence time interval of earthquakes using the available data for period of about 40 years from 1973 to 2013. We constrain the simple empirical toy model using the concept of catastrophe theory to evaluate the impact of small tidal forcing on the critical state of earthquakes occurrences. In addition to the major role of Helmholtz free energy during the plate motion, our analysis suggests that the stability and critical behavior of the earthquake in Sumatra region could be associated with tidal forcing, however, only for triggering of some of the “Catastrophic–Chaotic” earthquake phenomenon.
相似文献16.
Natural Hazards - The Andaman–Nicobar–Sumatra (ANS) region is a very hazardous area on the globe, which has witnessed a megathrust earthquake of Mw 9.2 on 26 December 2004 and several... 相似文献
17.
Diptansu Sengupta Basab Mukhopadhyay Om Prakash Mishra 《Journal of the Geological Society of India》2018,92(6):661-670
The annual b-value fluctuation patterns in Burmese subduction zone and Andaman–Sumatra subduction zone are evaluated from earthquake data (January 1990 to June 2016; Mw ³ 4.3) to identify seismic cycles with sequential dynamic phases as described in the ‘elastic failure model’ of Main et al. (1989). Two seismic cycles have been identified in Andaman–Sumatra subduction zone, one started in 1990 and ended on 2004 with occurrence of great Sumatra earthquake (Mw 9.0) and the other started in 2005 and continuing till date with the phase of crack coalescence and fluid diffusion (3A&B). Similarly, the subduction zone of Burma shows evidence of one incomplete seismic cycle within 1990–2016 and presently undergoing the crack coalescence and fluid diffusion (3A&B) phase. The analysis has prompted to subdivide the area into thirteen smaller seismic blocks (A to M) to analyse area specific seismic trend and vulnerability analysis employing Hurst Statistics. Hurst plots with the dynamic phases of ‘elastic failure model’ of earthquake generation is compared to assess the blocks with high seismic vulnerability. The analysis suggest that north Andaman zone (block G) and north Burma fold belt (block M) are seismically most vulnerable. Moreover, the seismic vulnerability of Tripura fold belt and Bangladesh plain (block K) is equally high. 相似文献
18.
P. Mahesh Amit Bansal B. Kundu J. K. Catherine V. K. Gahalaut 《Journal of the Geological Society of India》2011,77(3):243-251
The recent 10 August 2009 Coco earthquake (Mw 7.5), the largest aftershock of the giant 2004 Sumatra Andaman earthquake, occurred
within the subducting India plate under the Burma plate. The Coco earthquake nucleated near the northwestern edge of the 2004
Sumatra-Andaman earthquake rupture under the unruptured updip segment of the plate boundary interface. The earthquake with
predominant normal motion on approximately north-south to northeast-southwest oriented plane is very similar to the 27 June
2008 Little Andaman earthquake which occurred in the South Andaman region near the trench. We provide the only available estimate
of coseismic offset due to the 2009 Coco earthquake at a survey-mode GPS site in the north Andaman, located about 60 km south
of the Coco earthquake epicentre. The not so large coseismic displacement of about 2 cm in the ESE direction is consistent
with the earthquake focal mechanism and its magnitude. We suggest that, like the 2008 Little Andaman earthquake, this earthquake
too occurred on one of the approximately north-south to northeast-southwest oriented steep planes of the obliquely subducting
90°E ridge which was reactivated in normal motion after subduction, under the favourable influence of coseismic and ongoing
postseismic deformation due to the 2004 Sumatra-Andaman earthquake. Another notable feature of this earthquake is its relatively
low aftershock productivity. We suggest that the earthquake occurred very close to the aseismic region of the Irrawaddy frontal
arc of very low seismicity where pre-existing faults are not so critically stressed and because of which the earthquake could
trigger only a few aftershocks in its immediate vicinity. 相似文献
19.
Natural Hazards - A weak tsunami was induced by the 2016 Mw?=?7.8 Sumatra earthquake, which occurred at 12:49 on March 2, 2016 (UTC). The epicenter was at 5.060°S, 94.170°E at... 相似文献