Conference Papers

Numerical methods based on unstructured grids, with irregular cells, usually require discrete shape functions to approximate the distribution of quantities across cells. For control-volume mixed finite-element methods, vector shape functions are used to approximate the distribution of velocities across cells and vector test functions are used to minimize the error associated with the...

Coral reefs are threatened worldwide by stresses ranging from local to global in extent. One of the major challenges in studies of reef decline is understanding how to distinguish between changes resulting from natural, anthropogenic, local, and global environmental perturbations. As such, a conceptual risk-assessment model is developed that includes tiers for natural stresses, global...

The Halekulani Sand Channel and the Makua Shelf off the south shore of Oahu contain at least 1.3 million m3 of sediment that is a possible resource for nourishing degraded sections of Waikiki Beach. A sidescan sonar survey indicates continuous sediment cover within the channel and on the shelf, and samples from the top and bottom of vibracores from the channel and shelf contain from 29%...

In the last two decades alone, the U.S. and large portions of the world have witnessed what can be aptly be described as an explosion of scientific information and technological innovations that has permeated almost every aspect of our lives. Given these trends, it is clear that science and the understanding of science are becoming increasingly more relevant and essential to decision...

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The Western Mineral Resources Team of the U.S. Geological Survey (USGS) has three archives, which hold unpublished or difficult-to-obtain records and literature. The Technical Data Unit in Anchorage, Alaska, holds maps, field notes, and other records of the USGS work in Alaska. The USGS Field Office in Spokane, Washington, houses the more than 5,000 files from Federal government...

The Blake Ridge Diapir is the southernmost of a line of salt diapirs along the Carolina trough. Diapirs cause faulting of the superjacent sediments, creating pathways for migration of fluids and gas to the seafloor. We analyzed reflection seismic data from the Blake Ridge Diapir, which is located in a region with known abundant gas hydrate occurrence. A striking feature in these data is...

The finite-volume Eulerian-Lagrangian localized adjoint method (FVELLAM) is a mass-conservative approach for solving the advection-dispersion equation. The method has been shown to be accurate and efficient for solving advection-dominated problems of solute transport in ground water in 1, 2, and 3 dimensions. Previous implementations of FVELLAM have had difficulty in representing...

Tritium/3He dating has been applied to many problems in groundwater hydrology including, for example, determination of circulation patterns, mean residence times, recharge rates, or bank infiltration. Here, we discuss recent progress in the application of the tritium/3He dating method to sites with complex hydrogeological settings. Specifically, we report on tritium/3He dating at sites...

The U.S. Geological Survey (USGS) advocates the use of standards with geosciences and remotely sensed data and metadata for its own purposes and those of its customers. In activities that range from archiving data to making a product, the incorporation of standards makes these functions repeatable and understandable. More important, when accepted standards are followed, data discovery...

Protecting unionid populations as zebra mussels spread into inland waterways has relied mainly on relocating at-risk animals into aquaculture facilities. While such relocations are the only viable management technique for some populations, facility availability is limited, leaving many unionids facing extirpation. Another management strategy is in-situ protection either by enhancing...