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The mapping method of Wisdom (1982) is generalized to encompass all gravitational n-body problems with a dominant central mass. The method is used to compute the evolution of the outer planets for a billion years, providing independent numerical confirmation of the result of Sussman and Wisdom (1988) that the motion of the planet Pluto is chaotic. The(More)
The forces that drove rock uplift of the low-relief, high-elevation, tectonically stable Colorado Plateau are the subject of long-standing debate. While the adjacent Basin and Range province and Rio Grande rift province underwent Cenozoic shortening followed by extension, the plateau experienced approximately 2 km of rock uplift without significant internal(More)
Petascale simulations are needed to understand the rupture and wave dynamics of the largest earthquakes at shaking frequencies required to engineer safe structures (> 1 Hz). Toward this goal, we have developed a highly scalable, parallel application (AWP-ODC) that has achieved “M8”: a full dynamical simulation of a magnitude-8 earthquake on the(More)
Long-period surface-wave (R(1), G(1)), body-wave (S, SS, SSS), and ScS-reverberation data have been inverted to obtain anisotropic structures along seismic corridors that sample Australia and the western Pacific. These models support the proposal that the Lehmann discontinuity beneath stable continents represents a transition from an anisotropic lithosphere(More)
We apply full 3D tomography (F3DT) to a regional dataset in the Los Angeles area. In F3DT, the starting model as well as the model perturbation is three-dimensional and the sensitivity (Fréchet) kernels are computed using numerical schemes that account for the full physics of 3D wave propagation. F3DT can account for the nonlinearity of structural inverse(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)
Probabilistic forecasting models describe the aleatory variability of natural systems as well as our epistemic uncertainty about how the systems work. Testing a model against observations exposes ontological errors in the representation of a system and its uncertainties. We clarify several conceptual issues regarding the testing of probabilistic forecasting(More)
This paper discusses the process of building an environment where large-scale, complex, scientific analysis can be scheduled onto a heterogeneous collection of computational and storage resources. The example application is the Southern California Earthquake Center (SCEC) CyberShake project, an analysis designed to compute probabilistic seismic hazard(More)