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Reports

Browse more than 82,000 reports authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.

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2023 PyLith Hackathon report

The 3rd Pylith Hackathon was held June 12–17, 2023, at the Colorado School of Mines in Golden, Colorado with funding from the Computational Infrastructure for Geodynamics (CIG). The hackathon involved 17 participants working on 5 different projects to implement new features and create new examples for the PyLith crustal deformation modeling software. The projects included (1) spontaneous rupture u
Authors
Brad T. Aagaard

Hydrologic framework and characterization of the Little Colorado River alluvial aquifer near Leupp, Arizona

The Little Colorado River alluvial aquifer near Leupp, Arizona, was investigated as a possible source of irrigation water for the Leupp and Birdsprings Chapters of the Navajo Nation. The physical, chemical, and hydraulic characteristics of the alluvial aquifer were studied using geophysical surveys, installation of observation wells, water-level measurements, chemical analyses, groundwater pumping
Authors
Jon P. Mason, Jeffrey R. Kennedy, Jamie P. Macy, Bruce Gungle

Nearshore ecosystems in the Gulf of Alaska

Nearshore ecosystem monitoring in western Prince William Sound, Kenai Fjords National Park, Kachemak Bay, and Katmai National Park and Preserve has been conducted as a single Nearshore Component of the Gulf Watch Alaska program over the past five years (2017-2021). This program builds on the previous five years and continues, in many cases, decades of preceding research and monitoring. During the
Authors
Heather A. Coletti, Daniel Esler, Brenda Ballachey, Jim Bodkin, George G. Esslinger, Kimberly A. Kloecker, Daniel Monson, Brian H. Robinson, Sarah Beth Traiger, Katrin Iken, Brenda Konar, Tom Dean, Mandy Lindeberg, Ben Weitzman

Least Bell's Vireos and Southwestern Willow Flycatchers at the San Luis Rey Flood Risk Management Project Area in San Diego County, California—Breeding activities and habitat use—2022 annual report

Executive SummaryWe completed four protocol surveys for Least Bell’s Vireos (Vireo bellii pusillus; vireo) during the breeding season, supplemented by weekly territory monitoring visits. We identified a total of 133 territorial male vireos; 114 were confirmed as paired, and 3 were confirmed as single males. For the remaining 16 territories, we were unable to confirm breeding status. Two transient
Authors
Alexandra Houston, Lisa D. Allen, Shannon M. Mendia, Barbara E. Kus

U.S. Geological Survey Rocky Mountain Region 2022 science exchange, showcasing interdisciplinary and state-of-the-art USGS science

IntroductionThe Rocky Mountains and the Colorado River Basin in the Western United States represent complex, interconnected systems that sustain a number of species, including tens of millions of humans. These systems face several challenges, including worsening drought, altered wildfire regimes, climate change, and the spread of invasive species. These factors can exacerbate one another, further
Authors
Dana E. Peterson, Katherine L. French, Jeannette H. Oden, Patrick J. Anderson, Timothy N. Titus, Katharine G. Dahm, Jessica M. Driscoll, William J. Andrews

Integrated rangeland fire management strategy actionable science plan completion assessment— Climate and weather topic, 2015–20

Loss and degradation of sagebrush (Artemisia spp.) rangelands due to an accelerated invasive annual grass-wildfire cycle and other stressors are significant management, conservation, and economic issues in the western U.S. These sagebrush rangelands comprise a unique biome spanning 11 states, support over 350 wildlife species, and provide important ecosystem services that include stabilizing the e
Authors
Christopher R. Anthony, Matthew J Holloran, Mark A. Ricca, Steven E. Hanser, Sue L. Phillips, Paul Steblein, Lief A. Wiechman

Application of surrogate technology to predict real-time metallic-contaminant concentrations and loads in the Clark Fork near Grant-Kohrs Ranch National Historic Site, Montana, water years 2019–20

Grant-Kohrs Ranch National Historic Site (GRKO) in southwestern Montana commemorates the frontier cattle era and its formative role in shaping the culture and history of the Western United States. The ranch was designated a national historic landmark in 1960 and a unit of the National Park Service (NPS) by Congress in 1972. The GRKO is unique because of its proximity to large-scale extraction, mil
Authors
Christopher A. Ellison, Steven K. Sando, Tom E. Cleasby

Least Bell’s Vireo (Vireo bellii pusillus) and Southwestern Willow Flycatcher (Empidonax traillii extimus) surveys in the Sepulveda Dam Basin, Los Angeles County, California—2022 data summary

Executive SummaryWe surveyed for Least Bell’s Vireos (Vireo bellii pusillus; vireo) and Southwestern Willow Flycatchers (Empidonax traillii extimus; flycatcher) along Bull Creek, Haskell Creek, and the Los Angeles River (Sepulveda Dam project area) in Los Angeles County, California, in 2022. Four vireo surveys were completed from April 26 to July 14, and three flycatcher surveys were completed fro
Authors
Ryan E. Pottinger, Barbara E. Kus

U.S. Geological Survey Colorado Water Science Center postcard

The U.S. Geological Survey Colorado Water Science Center provides timely, high-quality science information on Colorado’s water resources to help planners, managers, and others to make the decisions necessary for the use of these limited and shared resources throughout the State. 
Authors
Jeannette H. Oden

Ecological effects of pinyon-juniper removal in the Western United States—A synthesis of scientific research, January 2014–March 2021

Executive SummaryIncreasing density of pinyon (Pinus spp.) and juniper (Juniperus spp.) woodlands (hereinafter “pinyon-juniper”), as well as expansion of these woodlands into adjacent shrublands and grasslands, has altered ecosystem function and wildlife habitat across large areas of the interior western United States. Although there are many natural and human-caused drivers of woodland infilling
Authors
Douglas J. Shinneman, Susan K. McIlroy, Sharon A Poessel, Rosemary L. Downing, Tracey N. Johnson, Aaron C. Young, Todd E. Katzner

Simulation of future streamflow and irrigation demand based on climate and urban growth projections in the Cape Fear and Pee Dee River Basins, North Carolina and South Carolina, 2055–65

Water resources in the coastal region of North Carolina and South Carolina (Coastal Carolinas) are currently under stress from competing ecological and societal needs. Projected changes in climate and population are expected to place even more stress on water resources in the region. The Coastal Carolinas Focus Area Study was initiated by the U.S. Geological Survey Water Availability and Use Scien
Authors
Laura N. Gurley, Ana María García, Cassandra A. Pfeifle, Georgina M. Sanchez

Age-0 sablefish size and growth indices from seabird diets at Middleton Island, Gulf of Alaska

Sablefish (Anoplopoma fimbria) is a commercially valuable groundfish species in Alaska, with the population assessed annually by the National Oceanic and Atmospheric Administration Alaska Fisheries Science Center. Sablefish recruit into the commercially fished population at 2 years old and are poorly sampled by most surveys before that age. However, information on the abundance, distribution, and
Authors
Mayumi L. Arimitsu, Scott A. Hatch