On interpolation functions in traveltime tomography     

Masatoshi Miyazawa  Mamoru Kato 《Geophysical Journal International》2004,158(1):169-178

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Short scale heterogeneity in the lowermost mantle: insights from PcP-P and ScS-S data     

Hrvoje Tkal?i?  Barbara Romanowicz 《Earth and Planetary Science Letters》2002,201(1):57-68

We compare lateral variations at the base of the mantle as inferred from a global dataset of PcP-P travel time residuals, measured on broadband records, and existing P and S tomographic velocity models, as well as ScS-S travel time data in some selected regions. In many regions, the PcP-P dataset implies short scale lateral variations that are not resolved by global tomographic models, except under eastern Eurasia, where data and models describe a broad region of fast velocity anomalies across which variations appear to be of thermal origin. In other regions, such as central America and southeastern Africa, correlated short scale lateral variations (several hundred kilometers) are observed in PcP and ScS, implying large but not excessive values for the ratio R=∂ ln V_s/∂ ln V_p (∼2.5). On the other hand, in at least two instances, in the heart of the African Plume and on the edge of the Pacific Plume, variations in P and S velocities appear to be incompatible, implying strong lateral gradients across compositionally different domains, possibly also involving topography on the core-mantle boundary. One should be cautious in estimating R at the base of the mantle from global datasets, as different smoothing and sampling of P and S datasets may result in strong biases and meaningless results.  相似文献   

用地震走时反演长白山天池火山地区的二维地壳结构   总被引：7，自引：2，他引：7  

王夫运  张先康  杨卓欣 《地震学报》2002,24(2):144-152

应用一种同时获得地壳上地幔二维速度结构和界面形态的地震走时反演算法，对在长白山天池火山区L1剖面获得的人工地震折射和宽角反射走时数据进行反演，得到了该剖面的地壳上地幔二维速度结构和构造．结果表明:长白山天池火山口下方中下地壳存在一倒三角状的低速体，壳内反射界面和莫霍面一致呈下凹形态，幅度2～6km不等，形成一个地壳根，推测是长白山天池火山系统．最后将所得结果与SEIS83正演试错模拟结果进行了比较．   相似文献   

Traveltime approximation for a reflected wave in a homogeneous anisotropic elastic layer     

M. Zillmer  B. M. Kashtan 《Geophysical Journal International》2002,151(1):172-183

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Ray-theoretical seismic traveltime inversion: modifications for a two-dimensional radially parametrized Earth     

Andrew R. Gorman 《Geophysical Journal International》2002,151(2):511-516

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Calculation of the seismic first-break time field and its ray path distribution using a minimum traveltime tree algorithm   总被引：13，自引：0，他引：13  

Shunhua Cao  Stewart Greenhalgh 《Geophysical Journal International》1993,114(3):593-600

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3-D velocity structure from simultaneous traveltime inversion of in-line seismic data along intersecting profiles   总被引：1，自引：0，他引：1  

Colin A. Zelt 《Geophysical Journal International》1994,118(3):795-801

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Traveltime tomography in anisotropic media—II. Application   总被引：1，自引：0，他引：1  

R. G. Pratt  C. H. Chapman 《Geophysical Journal International》1992,109(1):20-37

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Seismic-wave traveltimes in random media     

G. Müller  M. Roth  M. Korn 《Geophysical Journal International》1992,110(1):29-41

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Seismic traveltime inversion for 2-D crustal velocity structure   总被引：51，自引：0，他引：51  

C. A. Zelt  R. B. Smith 《Geophysical Journal International》1992,108(1):16-34

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