Learn More
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)
BACKGROUND beta-Alanine (betaA) has been shown to improve performance during cycling. This study was the first to examine the effects of betaA supplementation on the onset of blood lactate accumulation (OBLA) during incremental treadmill running. METHODS Seventeen recreationally-active men (mean +/- SE 24.9 +/- 4.7 yrs, 180.6 +/- 8.9 cm, 79.25 +/- 9.0 kg)(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)
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)
An International Polar Year aerogeophysical investigation of the high interior of East Antarctica reveals widespread freeze-on that drives substantial mass redistribution at the bottom of the ice sheet. Although the surface accumulation of snow remains the primary mechanism for ice sheet growth, beneath Dome A, 24% of the base by area is frozen-on ice. In(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)
We describe the services, architecture and application of the GriPhyN Virtual Data System, a suite of components and services that allow users to describe virtual data products in declarative terms, discover definitions and assemble workflows based on those definitions, and execute the resulting workflows on Grid resources. We show how these(More)