Thomas H Jordan

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[1] The southernmost San Andreas fault has a high probability of rupturing in a large (greater than magnitude 7.5) earthquake sometime during the next few decades. New simulations show that the chain of sedimentary basins between San Bernardino and downtown Los Angeles form an effective waveguide that channels Love waves along the southern edge of the San(More)
The coherence of azimuthal seismic anisotropy, as inferred from shear-wave splitting measurements, decreases with the relative distance between stations. Stochastic models of a two-dimensional vector field defined by a von Karma'n [T. von Karma'n, Progress in the statistical theory of turbulence, J. Mar. Res., 7 (1948) 252–264.] autocorrelation function(More)
A central problem of seismology is the inversion of regional waveform data for models of earthquake sources. In regions such as Southern California, preliminary 3-D earth structure models are already available, and efficient numerical methods have been developed for 3-D anelastic wave-propagation simulations. We describe an automated procedure that utilizes(More)
Theoretical modeling has played an important role in understanding wave propagation in complex media. Finite difference is one of the most used methods to solve Partial Differential Equations numerically, and very often it requires enormous computational time and resources. In this thesis a variable finite difference method is developed, where a finer grid(More)
Phase delays of Rayleigh and Love waves from teleseismic earthquakes recorded during the Southern Africa Seismic Experiment have been inverted for upper-mantle seismic velocities along the propagation paths and beneath the station array. Successful models of subarray structure displayed significant radial anisotropy in the uppermost mantle but no shear-wave(More)
This article reports on a workshop held to explore the potential uses of operational earthquake forecasting (OEF). We discuss the current status of OEF in the United States and elsewhere, the types of products that could be generated, the various potential users and uses of OEF, and the need for carefully crafted communication protocols. Although(More)
Slow earthquakes have been hypothesized to be compound events, i.e. comprised of both an ordinary earthquake and a smooth moment-release transient of longer duration. Low-frequency normal-mode based studies which support the compound event hypothesis have suggested that low-frequency source-spectra of some slow earthquakes require that the slow-component(More)
This thesis addresses the planetary-scale mixing of tracers along isentropic surfaces in the extratropical winter stratosphere. The primary goal is a more fully quantitative understanding of the mixing than is available at present. The general problem of representing eddy mixing in a one-dimensional mean representation of a two-dimensional flow is(More)
A scalable parallel visualization algorithm has been designed to visualize large datasets that are spatially decomposed onto processors of a massively parallel computer. The ParaViz algorithm, which is based on hybrid sort-first/sort-last parallel visualization, employs distributed visibility ordering to implement a scalable hierarchical depth buffer. A(More)
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