Conference Papers

To develop a better predictive tool for dispersion in rivers over a range of temporal and spatial scales, our group has developed a simple Lagrangian model that is applicable for a wide range of coordinate systems and flow modeling methodologies. The approach allows dispersion computations for a large suite of discretizations, model dimensions (1-, 2-, or 3-dimensional), spatial and temporal discr

This work discusses a current open source implementation of a line similarity assessment workflow to compare elevation-derived drainage lines with the high-resolution National Hydrography Dataset (NHD) surface-water flow network. The process identifies matching and mismatching lines in each dataset to help focus subsequent validation procedures to areas of the NHD that more critically need updates

Geologically diverse landforms around the world show indications of energetic macroscale fracture. These fractures are sometimes displayed dramatically as so-called “A-tents”, whereby relatively thin rock sheets push upwards and fracture, forming tent-like voids beneath the ruptured sheets. The origin and formation of such features has been a topic of considerable interest and analysis for over a

Groundwater systems are dynamic geologic environments in which water continuously flows from recharge areas to discharge areas at streams, springs, wetlands, coastal waters, and wells. Natural, predevelopment conditions within groundwater systems are changed by the introduction of wells and other human stresses that modify existing groundwater levels, flow paths, and hydrologic budgets. Groundwate

Five new seismic hazard classifications for Hartford County, Connecticut (CT), were proposed by New England State Geologists (NESG) in an effort to improve the current USGS Seismic Hazard Map. These classes were derived from mapped surficial materials, but in situ information is required to verify this approach. Therefore, active and passive surface wave techniques were performed at thirty field s

We describe and compare two probabilistic models for task-specific seafloor characterization based on multispectral backscatter. We examine whether generative or discriminative approaches to supervised seafloor characterization do better at harnessing the greatly increased information about seafloor substrate composition that is encoded in the backscattering response across multiple frequencies. A

The five-mile-long Elizabeth Tunnel, which crosses the San Andreas fault (SAF) zone near Lake Hughes, California, is part of the Los Angeles Aqueduct (LAA) that delivers water from Owens Valley to the City of Los Angeles. Geologic characterization of the Elizabeth Tunnel alignment is focused on developing a better understanding of fault displacement hazards at the SAF crossing to support design of

We summarize scientific methods for developing probabilistic seismic hazard assessments from 3-D earthquake ground motion simulations, describe current use of simulated ground motions for engineering applications, and discuss on-going efforts to incorporate these effects in the U.S. national seismic hazard model. The 3-D simulations provide important, additional information about earthquake ground

No abstract available.

We use simulated images to demonstrate a novel technique for mitigating geometric distortions caused by platform motion (“jitter”) as two-dimensional image sensors are exposed and read out line by line (“rolling shutter”). The results indicate that the Europa Imaging System (EIS) on NASA’s Europa Clipper can likely meet its scientific goals requiring 0.1-pixel precision. We are therefore adapting

In 2016 the AEWA European Goose Management International Working Group (EGM IWG) adopted document AEWA/EGM IWG 1.8 (Johnson et al. 2016), which contained initial elements of an Adaptive Harvest Management programme for Taiga Bean Geese. This report addresses a number of limitations with the population model presented in that document, and provides up-to-date population projections for the Central

No abstract available.