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1.
TherelationbetweentheresponsespectrumandthephasediferencespectrumFENG-XINZHAO(赵凤新)andYU-XIANHU(胡聿贤)InstituteofGeophysics,Sta...  相似文献   

2.
(李鸿吉,秦建业)FocalmechanismandmodernstressfieldalongtheBurmeseArcanditsvicinity¥Hong-JiLIandKin-YipCHEN(InstituteofGeophysics,Sta...  相似文献   

3.
(王椿镛,张先康,林中洋,李学清)CharacteristicofcrustalstructureintheShulufaultbasinanditsvicinity¥Chun-YongWANGI;Xian-KangZHANG;Zhong-YangL...  相似文献   

4.
ExpectedmagnitudeanddistanceofpotentialsourceareaandtheestimatingmethodMeng-TtanGAO(高孟潭)(InstituteofGeophysics,StateSeismolog...  相似文献   

5.
3-D velocity images of the crust and upper mantle of the Tianshan area   总被引:1,自引:0,他引:1  
(胥颐,朱介寿,刘志坚,张华卿,朱燕)3-DvelocityimagesofthecrustanduppermantleoftheTianshanarea¥YiXU;Jie-ShouZHU;Zhi-JianLIU;Hua-QingZHANGandYa...  相似文献   

6.
(赵根模,姚兰予,马淑芹)Thestressfieldvariationcausedbyfaultingandthepredictionforseismicrisk¥Gen-MoZHAO;Lan-YuYAOandShu-QinMA(Seismolog...  相似文献   

7.
ComparisonandanalysisofthestressfieldinthesourceregionofTangshanandLancangearthquakesequencesGui-LingDIAO;(刁桂苓)Li-MinYU;(于利民)...  相似文献   

8.
(金延龙,赵卫明)AnimprovementonthemethodofthepatternrecognitionICHAManditsapplication¥Wei-MingZHAOandYan-LongJIN(SeismologicalBureau...  相似文献   

9.
SimulationoftheactiveandquietperiodsofseismicityZHONG-XMNHUANG(黄忠贤)(InstituteofCrustalDynamics,StateSeismologicalBureau,Beiji...  相似文献   

10.
StudyoftheintensityattenuationlawintheEastChinaPlainandthenorthwestofChina郁曙君Shu-JunYU(InstituteofGeophysics,StateSeismologic...  相似文献   

11.
天山地震带的地壳结构与强震构造环境   总被引:60,自引:9,他引:51       下载免费PDF全文
以中国西北地区的地震层析成像为基础,研究了天山地震带深部结构的基本特征.结果表明,天山地震带的地壳中部为低速的韧性滑脱层,南天山的断裂深度超过莫霍面,北天山的断裂深度一般只到地壳中部;天山莫霍面的深度一般大于50km,壳-幔边界由宽而缓的速度过渡带构成,中强地震主要位于盆山边界地壳中下部位波速变化较大的区域.帕米尔、南天山和塔里木之间存在一个北北东方向的低速带,乌恰和伽师地震分别位于该低速带东、西两侧的梯度带附近.推测帕米尔、南天山和塔里木之间的相对运动是导致低速带内部物质发生形变并在边界附近产生破裂的主要原因,地幔热物质的侵入对该地区的构造活动起到了重要的动力学作用.  相似文献   

12.
Takeshi  Tsuji  Yasuyuki  Nakamura  Hidekazu  Tokuyama  Millard F.  Coffin  Keita  Koda 《Island Arc》2007,16(3):361-373
Abstract   To show the structure of oceanic crust and Moho around the eastern Ogasawara Plateau, we have analyzed industry-standard two-dimensional multichannel seismic reflection data. To obtain improved velocity models, phase information of seismic signals was used for velocity analysis and velocity models for oceanic crust above Moho were determined. We apply this velocity analysis technique to seismic reflection data around the eastern Ogasawara Plateau, with the result of clear images of structures within oceanic crust and Moho. South of the Ogasawara Plateau, Moho deepens proximal to the Plateau. Moho distal to the Plateau is ca 7 km below sea floor (bsf), whereas it is ca 10 km bsf near the Plateau. The characters of oceanic crust and Moho differ significantly north and south of the Plateau. To the north, the structure of oceanic crust is ambiguous, the sea floor is shallower and less smooth, and Moho is discontinuous. To the south, structures within oceanic crust and Moho are imaged clearly, and the sea floor is deeper. A strong Moho reflection south of the Plateau might represent a sharp boundary between layered gabbro and peridotite. However, discontinuous Moho reflections north of the Plateau might represent rough topography because of intensive magmatism or a gradual downward increase in velocity within a thick Moho transition zone. A fracture zone north of the Plateau also appears to separate oceanic crust and Moho of different characters, suggesting vigorous magmatism between the Plateau and the fracture zone, and that the Ogasawara Plateau and the fracture zone influenced the genesis of oceanic crust and upper mantle. Differences in acoustic characteristics to the north and south of the Plateau are apparent in profiles illuminated by seismic attributes.  相似文献   

13.
青藏高原东北缘壳幔过渡带研究   总被引:8,自引:1,他引:8       下载免费PDF全文
利用穿过青藏高原东北缘的两条地震测深剖面提供的PMP波形资料,研究了该区不同构造单元壳幔过渡带的复杂性、频谱特征和速度模型.结果表明, 鄂尔多斯盆地和陵中盆地Moho具有稳定的构造特征,壳幔耦合为简单的一级间断面;海原地震区和巴颜喀拉地块与柴达木地块结合带莫霍面具有明显的活动迹象,壳幔耦合为复杂的高、低速相间的多层壳幔过渡带,总厚度达到20多千米.不同构造单元的莫霍面差异性反映了研究区壳幔耦合层的非均匀特征;海原地震区和玛沁断裂壳幔过渡带的细结构差异, 则反映了两个陆 陆碰撞带不同的深部物质结构与地块之间的相互作用结果.   相似文献   

14.
山西高原北部地壳上地幔地震波速结构与深部构造   总被引:9,自引:4,他引:9       下载免费PDF全文
张建狮  祝治平 《地震地质》1997,19(3):29-226
对自河北文安经山西大同至内蒙古岱海的宽角反射/折射地震剖面资料进行了详细的研究。结果表明,地壳厚度由太行山山前地带的36.0km向山西高原增厚至44.0km。在太行山山前基底断裂、紫荆关断裂的下方和大同盆地的东侧存在着延伸至莫霍面的断裂带;太行山隆起区上地幔顶部的速度偏高,太行山山前地带和大同震区上地壳的下部有强烈的速度反转,大同地震与这里的异常的壳幔构造有关,太行山山前地带存在着发生潜在地震的深部构造条件  相似文献   

15.
环渤海地区的地震层析成像与地壳上地幔结构   总被引:36,自引:8,他引:28       下载免费PDF全文
利用环渤海地区的天然地震P波到时资料,采用纬度和经度方向分别为05°×06°的网格划分,反演了该地区地壳上地幔的三维P波速度结构.初步结果表明,环渤海地区地壳上地幔的速度结构具有明显的横向不均匀性:京津唐地区地壳中上部的速度异常反映了浅表层的地质构造特征,造山带和隆起区对应于高速异常,坳陷区和沉积盆地对应于低速异常;地壳下部出现大规模的低速异常与华北地区广泛存在的高导层相对应,估计与壳内的滑脱层和局部熔融、岩浆活动有关;莫霍面附近的速度异常反映了地壳厚度的变化及壳幔边界附近热状态的差异;上地幔顶部大范围的低速异常可能是上地幔软流层热物质大规模上涌所致.  相似文献   

16.
This paper describes synthetically the seismic activity, deep and shallow structures and rock dynamic features in and near Chaoyang—Yixian region. It is supposed that there is a low velocity layer in middle crust and the three-layered crustal velocities are all lower than that in both sides of the region. There exists uplifts of upper mantle and asthenosphere-low resistance layer. It is also studied the composition of matter of three-layered crust, low velocity layer, upper mantle and asthenosphere. In the end the direct relations between the deep and shallow structure, composition and the seismic activity and new activities of faults in this region are discussed.  相似文献   

17.
Using arrival data of the body waves recorded by seismic stations, we reconstructed the velocity structure of the crust and upper mantle beneath the southeastern edge of the Tibetan Plateau and the northwestern continental margin of the South China Sea through a travel time tomography technique. The result revealed the apparent tectonic variation along the Ailao Shan-Red River fault zone and its adjacent regions. High velocities are observed in the upper and middle crust beneath the Ailao Shan-Red River fault zone and they reflect the character of the fast uplifting and cooling of the metamorphic belt after the ductile shearing of the fault zone, while low velocities in the lower crust and near the Moho imply a relatively active crust-mantle boundary beneath the fault zone. On the west of the fault zone, the large-scale low velocities in the uppermost mantle beneath western Yunnan prove the influence of the mantle heat flow on volcano, hot spring and magma activities, however, the upper mantle on the eas  相似文献   

18.
Introduction The Tengchong volcanic-geothermal area is located on the northeast edge of the collision zone between Indian and Eurasian plates, and belongs to Eurasian volcanic zone (the MediterraneanHimalayanSoutheast Asia volcanic zone). In Tengchong area, the Quaternary volcanic, geothermal and seismic activities are all intensive. These phenomena have been drawing the attention of many geoscientists in the world. Their studies are concerned with geology, geophysics, geochemistry, and cr…  相似文献   

19.
利用我国地震台站记录的瑞利波观测资料,通过适配滤波频时分析技术进行数据处理,获得了穿越我国东南及陆缘地区的瑞利波频散.使用随机反演理论取得了东南大陆及陆缘地带4°×4°网格的纯路径频散数据.在网格反演的基础上使用Harkrider的面波反演程序求得了该区剪切波的三维速度结构.结果表明:1.华南大陆Moho界面埋深为30-40km,并由西向东逐渐减薄,在陆缘与浅海地域为25-28km,具有明显的分区特征.2.上地幔低速层埋深为60-0km,变化幅度较大,这与深部断裂分布及深层过程有关,但NS向剖面上各界面的起伏变化均比EW向剖面平缓.3.东南陆缘是东亚大陆的海陆过渡带,在深部表现为Moho界面埋深和地壳平均速度降低的地带,地幔深部界面的起伏形态充分表明,深浅介质结构和物质耦合的不均匀性.  相似文献   

20.
Introduction At the juncture of Qinghai-Xizang, Ordos and Alxa blocks lies the Qinghai-Xizang plateau, an area with complicated topographic and morphologic features, strong tectonic activities and frequent earthquakes (many large-magnitude earthquakes have taken place), has become a focal area for geoscience study. Many geophysical and geological surveys have been carried out in and around the area, such as deep seismic sounding (DSS), gravimetry, magnetotelluric sounding, magnetic anomaly …  相似文献   

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