Conference Papers

The United States National Hydrography Dataset (NHD) is a database of vector features representing the surface water features for the country. The NHD was originally compiled from hydrographic content on U.S. Geological Survey topographic maps but is being updated with higher quality feature representations through flow-routing techniques that derive hydrography from high-resolution elevation data

No abstract available.

This paper proposes a graph-based meta learning approach to separately predict water quantity and quality variables for river segments in stream networks. Given the heterogeneous water dynamic patterns in large-scale basins, we introduce an additional meta-learning condition based on physical characteristics of stream segments, which allows learning different sets of initial parameters for differe

No abstract available.

Rare earth element (REE) enrichment in the Elk Creek carbonatite, Nebraska USA, is comparable to ore grade enrichment in carbonatite-hosted REE deposits[1]. Petrographic examination of textures documents a complex history of crystallization, brecciation, recrystallization, oxidation, and near surface alteration. Barite (BaSO4) is present in most units, including REE-enriched zones, such that it ma

No abstract available.

We present the eruption sequence for the east flank of Santa Ana volcano, which we divide into the sections above and below the Tierra Blanca Joven (TBJ) formation. The sequence below the TBJ suggests a series of mafic magmatic eruptions that began before 7,800 cal BP and continued until after 5,800 cal BP. These eruptions emplaced tephra-fall and pyroclastic-density-current deposits. The sequence

The Acajutla debris-avalanche deposit is dated to about 40,000 cal BP. The dating is based on two 14C dates on pieces of wood from the debris-avalanche deposit recovered from a core at the Santa Águeda School Center. The debris-avalanche deposit overlies a 1.2-m-thick paleosol and four ash layers. One of these ash layers is geochemically correlated to the Los Chocoyos ash from Atitlán Caldera, wh

Effective water resources management depends on monitoring the volume of water flowing through streams and rivers, but collecting continuous discharge measurements using traditional streamflow gauges is prohibitively expensive. Time-lapse cameras offer a lowcost option for streamflow monitoring, but training models for predicting streamflow directly from images requires streamflow data to use as l

Past and present research on earthquake ground motions along the Atlantic and Gulf Coastal Plains and Mississippi Embayment show significant period-dependent site response that is not presently accounted for in ground motion models. These deviations are strongly correlated with the thickness of Mesozoic and younger syn- and post-rift sediments. With the recent incorporation of deep basin depth mea

No abstract available.

Rationale: Increasing exposure to respirable crystalline silica (RCS) linked to changes in mining production processes has been implicated in the resurgence of severe lung disease in U.S. coal miners. Lung mineralogy can provide insight into particle pathogenesis. However, standard approaches to characterizing in situ particulate matter (PM) by pulmonary pathologists have poor inter-rater comparab