Conference Papers
Science Quality and Integrity
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.
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Hydroacoustic signatures of Colorado Riverbed sediments in Marble and Grand Canyons using multibeam sonar
Characterizing the large-scale sedimentary make-up of heterogeneous riverbeds (Nelson et al., 2014), which consist of a patchwork of sediment types over small scales (less than one to several tens of meters) (Dietrich and Smith, 1984) requires high resolution measurements of sediment grain size. Capturing such variability with conventional physical (e.g. grabs, cores, and dredges) or underwater ph
Authors
Daniel D. Buscombe, Paul E. Grams, Matthew Kaplinski, Robert B. Tusso, David M. Rubin
Projecting changes in subalpine tree populations with warming across an elevation gradient
No abstract available.
Authors
Matthew J. Germino, Lara Kueppers, Erin Conlisk, Cristina Castanha, Andrew Moyes, Jeremy Smith, Tom Veblen
Using oblique digital photography for alluvial sandbar monitoring and low-cost change detection
The maintenance of alluvial sandbars is a longstanding management interest along the Colorado River in Grand Canyon. Resource managers are interested in both the long-term trend in sandbar condition and the short-term response to management actions, such as intentional controlled floods released from Glen Canyon Dam. Long-term monitoring is accomplished at a range of scales, by a combination of an
Authors
Robert B. Tusso, Daniel D. Buscombe, Paul E. Grams
Mapping surficial minerals at high latitudes: The USGS 2014 imaging spectrometer data collection in Alaska
Passive optical remote sensing of high latitude regions faces many challenges including a short acquisition season and poor illumination due to low solar elevation. Additional complications are encountered in the identification of surface minerals for mineral resource characterization because minerals of interest commonly are exposed on steep terrain, further challenging reflectance retrieval and
Authors
Raymond F. Kokaly, Todd M. Hoefen, Garth Graham, Karen Kelly, Michaela Johnson, Bernard Hubbard, Richard Goldfarb
In situ densimetric measurements as a surrogate for suspended-sediment concentrations in the Rio Puerco, New Mexico
Surrogate measurements of suspended-sediment concentration (SSC) are increasingly used to provide continuous, high-resolution, and demonstrably accurate data at a reasonable cost. Densimetric data, calculated from the difference between two in situ pressure measurements, exploit variations in real-time streamflow densities to infer SSCs. Unlike other suspendedsediment surrogate technologies based
Authors
Jeb E. Brown, John R. Gray, Nancy J. Hornewer
An assessment of the impact of the pet trade on five CITES-Appendix II case studies - Boa constrictor imperator
Boa constrictor is a wide ranging snake species that is common in the pet trade and is currently listed in CITES Appendix II. Hog Island boas, or Cayos Cochinos boas, are a dwarf, insular race of Boa constrictor imperator endemic to the Cayos Cochinos Archipelago, Honduras. Cayos Cochinos boas are prized in the international pet trade for their light pink dorsal coloration, as well as for being mu
Authors
Chad E. Montgomery, Scott M. Boback, Robert N. Reed, Julius A. Frazier
Integrating geophysical and oceanographic data to assess interannual variability in longshore sediment transport
Despite their utility for prediction of coastal behavior and for coastal management, littoral sediment budgets are difficult to quantify over large regions of coastline and over short time scales. In this study, bathymetric change analysis shows differences in the magnitude and spatial location of erosion and accretion over three years; more net accumulation occurred at the littoral end point of t
Authors
Jennifer L. Miselis, Joseph W. Long, P. Soupy Dalyander, James G. Flocks, Noreen A. Buster, Rangley C. Mickey
Long-term monitoring of sandbars on the Colorado River in Grand Canyon using remote sensing
Closure of Glen Canyon Dam in 1963 dramatically changed discharge and sediment supply to the downstream Colorado River in Marble and Grand Canyons. Magnitudes of seasonal flow variation have been suppressed, while daily fluctuations have increased because of hydropower generation. Lake Powell, the upstream reservoir, traps all sediment, leaving the Paria and Little Colorado Rivers as the main supp
Authors
Robert P. Ross, Paul E. Grams
Morphodynamic data assimilation used to understand changing coasts
Morphodynamic data assimilation blends observations with model predictions and comes in many forms, including linear regression, Kalman filter, brute-force parameter estimation, variational assimilation, and Bayesian analysis. Importantly, data assimilation can be used to identify sources of prediction errors that lead to improved fundamental understanding. Overall, models incorporating data assim
Authors
Nathaniel G. Plant, Joseph W. Long
Modeled changes in extreme wave climates of the tropical Pacific over the 21st century: Implications for U.S. and U.S.-Affiliated atoll islands
Wave heights, periods, and directions were forecast for 2081–2100 using output from four coupled atmosphere–ocean global climate models for representative concentration pathway scenarios RCP4.5 and RCP8.5. Global climate model wind fields were used to drive the global WAVEWATCH-III wave model to generate hourly time-series of bulk wave parameters for 25 islands in the mid to western tropical Pacif
Authors
J.B. Shope, Curt D. Storlazzi, Li H. Erikson, C.A. Hegermiller
Simulation of earthquake ground motions in the eastern U.S. using deterministic physics-based and stochastic approaches
No abstract available.
Authors
Sanaz Rezaeian, Stephen H. Hartzell, S. Xiaodan, C. Mendoza
Objective definition of rainfall intensity-duration thresholds for post-fire flash floods and debris flows in the area burned by the Waldo Canyon fire, Colorado, USA
We present an objectively defined rainfall intensity-duration (I-D) threshold for the initiation of flash floods and debris flows for basins recently burned in the 2012 Waldo Canyon fire near Colorado Springs, Colorado, USA. Our results are based on 453 rainfall records which include 8 instances of hazardous flooding and debris flow from 10 July 2012 to 14 August 2013. We objectively defined the t
Authors
Dennis M. Staley, Joseph E. Gartner, Jason W. Kean