Reports
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 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.
Filter Total Items: 84733
Hawaiian hoary bat (Lasiurus cinereus semotus) acoustic monitoring at Hawaii Army National Guard (HIARNG) installations statewide Hawaiian hoary bat (Lasiurus cinereus semotus) acoustic monitoring at Hawaii Army National Guard (HIARNG) installations statewide
Acoustic sampling for occurrence of the endangered Hawaiian hoary bat (Lasiurus cinereus semotus) was conducted at 18 “long-term” acoustic monitoring stations on 12 Hawai‘i Army National Guard (HIARNG) installations across the islands of Hawai‘i, Maui, Moloka‘i, O‘ahu, and Kaua‘i between 2012 and 2018. Bats were confirmed as present at 10 of these installations: Kealakekua Armory...
Authors
Kristina Montoya-Aiona, Corinna Pinzari, Robert W. Peck, Kevin W. Brinck, Frank J Bonaccorso
Assessing the spawning movement and habitat needs of riverine Neosho Smallmouth Bass Assessing the spawning movement and habitat needs of riverine Neosho Smallmouth Bass
Stream fishes are vulnerable to a variety of natural and anthropogenic stressors. Information on fish movements and habitat use is essential to conserve and manage populations, particularly at the edges of distributions and novel habitats. The Neosho Smallmouth Bass Micropterus dolomieu velox is endemic to the southwestern Ozark Highlands ecoregion, where the riverscape is highly...
Authors
Shannon K. Brewer, Andrew Miller
Potential duration of aftershocks of the 2020 southwestern Puerto Rico earthquake Potential duration of aftershocks of the 2020 southwestern Puerto Rico earthquake
Abstract Aftershocks (earthquakes clustered spatially and chronologically near the occurrence of a causative earthquake) are ongoing in southwestern Puerto Rico after a series of earthquakes, which include a magnitude 6.4 earthquake that occurred near Barrio Indios, Guayanilla, on January 7, 2020, and affected the surrounding area. This report estimates the expected duration of these...
Authors
Nicholas van der Elst, Jeanne L. Hardebeck, Andrew J. Michael
Forecasting future beach width- A case study along the Florida Atlantic coast Forecasting future beach width- A case study along the Florida Atlantic coast
Historical cross-shore positions of the shoreline and dune base were used as inputs for a Kalman filter algorithm to forecast the positions of these features in the year 2028. The beach width was also computed as the cross-shore distance between the forecasted 2028 shoreline and dune-base positions. While it does not evaluate the suitability of a nesting beach or identify optimal nesting...
Authors
Joseph W. Long, Rachel E. Henderson, David M. Thompson
Catalogue of polar bear (Ursus maritimus) maternal den locations in the Beaufort and Chukchi Seas and nearby areas, 1910–2018 Catalogue of polar bear (Ursus maritimus) maternal den locations in the Beaufort and Chukchi Seas and nearby areas, 1910–2018
This report presents data on the approximate locations and methods of discovery of 530 polar bear (Ursus maritimus) maternal dens observed in the Beaufort and Chukchi Seas and neighboring areas from 1910 to 2018, and archived partly by the U.S. Geological Survey, Alaska Science Center, and partly by the U.S. Fish and Wildlife Service, Marine Mammals Management, in Anchorage, Alaska. A...
Authors
George M. Durner, Steven C. Amstrup, Todd C. Atwood, David C. Douglas, Anthony S. Fischbach, Jay W. Olson, Karyn D. Rode, Ryan H. Wilson
Final Alabama Barrier Island restoration assessment report, appendix A: Data management plan Final Alabama Barrier Island restoration assessment report, appendix A: Data management plan
The Alabama Barrier Island Restoration Assessment project focused exclusively on Dauphin Island, a significant barrier island along the northern Gulf of Mexico. This restoration feasibility study effort required data collection and analysis of many data types (e.g., hydro, sediment, currents, etc.) through the project’s life cycle to assess restoration measures and their effects on the
Authors
Christina B. Hunnicutt, Craig Conzelmann
Assessment of undiscovered oil and gas resources in the Central North Slope of Alaska, 2020 Assessment of undiscovered oil and gas resources in the Central North Slope of Alaska, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 3.6 billion barrels of oil and 8.9 trillion cubic feet of natural gas (associated and nonassociated) in conventional accumulations in Mississippian through Paleogene strata in the central North Slope of Alaska.
Authors
David W. Houseknecht, Katherine J. Whidden, Christopher D. Connors, Richard O. Lease, Christopher J. Schenk, Tracey J. Mercier, William A. Rouse, Palma J. Botterell, Rebecca A. Smith, Margaret M. Sanders, William H. Craddock, Christina A. DeVera, Christopher P. Garrity, Marc L. Buursink, C. Ozgen Karacan, Samuel J. Heller, Thomas E. Moore, Julie A. Dumoulin, Marilyn E. Tennyson, Katherine L. French, Cheryl A. Woodall, Ronald M. Drake, Kristen R. Marra, Thomas M. Finn, Scott A. Kinney, Chilisa M. Shorten
Seafloor change around the Mississippi barrier islands, 1920 to 2016—The influence of storm effects on inlet and island morphodynamics Seafloor change around the Mississippi barrier islands, 1920 to 2016—The influence of storm effects on inlet and island morphodynamics
The Mississippi Barrier Islands in the northern Gulf of Mexico experienced high rates of spatial change over recorded history. Wave-induced sediment transport induced island migration, landward retreat, and inlet evolution. These processes can be measured using repeat bathymetric surveys to analyze elevation change over time. This study analyzes digital elevation models created from...
Authors
James Flocks, Noreen A. Buster, Owen T. Brenner
Precipitation, temperature, groundwater-level elevation, streamflow, and potential flood storage trends within the Brazos, Colorado, Big Cypress, Guadalupe, Neches, Sulphur, and Trinity River basins in Texas through 2017 Precipitation, temperature, groundwater-level elevation, streamflow, and potential flood storage trends within the Brazos, Colorado, Big Cypress, Guadalupe, Neches, Sulphur, and Trinity River basins in Texas through 2017
The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (USACE), analyzed streamflow trends and streamflow-related variables through 2017 in seven important water-supply basins to provide information that can help water managers with the USACE and river authorities make future water management decisions. The primary purpose of this report is to document...
Authors
Glenn R. Harwell, Jeremy McDowell, Cathina Gunn-Rosas, Brett Garrett
Seepage investigation of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above El Paso, Texas, 2018 Seepage investigation of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above El Paso, Texas, 2018
Seepage investigations were conducted periodically by the U.S. Geological Survey (USGS) from 1988 to 1998 and from 2006 to 2015 along a 64-mile reach of the Rio Grande as part of the Mesilla Basin monitoring program. Past studies were conducted during no-flow or low-flow periods. In 2018, a seepage investigation was conducted during April 3–4 along a 62.4-mile study reach, from below...
Authors
Grady P. Ball, Andrew J. Robertson, Karen Medina Morales
Kelp forest monitoring at Naval Base Ventura County, San Nicolas Island, California: Fall 2017 and Spring 2018, Fourth Annual Report Kelp forest monitoring at Naval Base Ventura County, San Nicolas Island, California: Fall 2017 and Spring 2018, Fourth Annual Report
To assess and track changes to the rocky subtidal communities surrounding San Nicolas Island, the U.S. Navy entered into an agreement with the U.S. Geological Survey (USGS) in 2014 to conduct an ecological monitoring program at several sites around the island. Four permanent sites—Nav Fac 100, West End, Dutch Harbor, and Daytona 100—were established. The sites were based on ones that had...
Authors
Michael C. Kenner, Joseph A. Tomoleoni
Distribution and abundance of Least Bell’s Vireos (Vireo bellii pusillus) and Southwestern Willow Flycatchers (Empidonax traillii extimus) on the Middle San Luis Rey River, San Diego County, southern California—2019 data summary Distribution and abundance of Least Bell’s Vireos (Vireo bellii pusillus) and Southwestern Willow Flycatchers (Empidonax traillii extimus) on the Middle San Luis Rey River, San Diego County, southern California—2019 data summary
We surveyed for Least Bell’s Vireos (Vireo bellii pusillus; vireo) along the San Luis Rey River, between College Boulevard in Oceanside and Interstate 15 in Fallbrook, California (middle San Luis Rey River), in 2019, and we surveyed and conducted nest monitoring for Southwestern Willow Flycatchers (Empidonax traillii extimus; flycatcher) in a survey area where breeding had historically...
Authors
Lisa D. Allen, Barbara E. Kus