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.
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Evaluation of 2-D shear-wave velocity models and VS30at six strong-motion recording stations in southern California using multichannel analysis of surface waves and refraction tomography
To better understand the potential for amplified ground shaking at sites that house critical infrastructure, the U.S. Geological Survey (USGS) evaluated shear-wave velocities (VS) at six strong-motion recording stations in Southern California Edison facilities in southern California. We calculated VS30 (time-averaged shear-wave velocity in the upper 30 meters [m]), which is a parameter used in gro
Authors
Joanne H. Chan, Rufus D. Catchings, Mark R. Goldman, Coyn J. Criley, Robert R. Sickler
Nutrient chemistry in the Elizabeth Lake subwatershed—Effects of onsite wastewater treatment systems on groundwater and lake water quality, Los Angeles County, California
Nutrient (nitrogen [N] and phosphorus [P] chemistry) downgradient from onsite wastewater treatment system (OWTS) was evaluated with a groundwater study in the area surrounding Elizabeth Lake, the largest of three sag lakes within the Santa Clara River watershed of Los Angeles County, California.Elizabeth Lake is listed on the “303 (d) Impaired Waters List” for excess nutrients and is downgradient
Authors
Adelia M McGregor, Joseph L. Domagalski, Krishangi D. Groover, Angela M. Hansen, Anthony A. Brown
Hydrologic study of green infrastructure in poorly drained urbanized soils at RecoveryPark, Detroit, Michigan, 2014–21
Uncontrolled stormwater runoff volume is a legacy stressor on sewer-system capacity that is further compromised by the effects of aging infrastructure. Green stormwater infrastructure (GSI) has been used in a variety of designs and configurations (for example, bioretention) with the goal of increasing evapotranspiration and infiltration in the local water cycle. In practice, GSIs have variable eff
Authors
Ralph J. Haefner, Christopher J. Hoard, William Shuster
Peak streamflow trends in Missouri and their relation to changes in climate, water years 1921–2020
This report characterizes changes in peak streamflow in Missouri and the relation of these changes to climatic variability, and provides a foundation for future studies that can address nonstationarity in peak-streamflow frequency analysis in Missouri. Records of annual peak and daily streamflow at streamgages and gridded monthly climatic data (observed and modeled) were examined across four trend
Authors
Mackenzie K. Marti, David C. Heimann
National shoreline change—Summary statistics for vector shorelines from the early 1900s to the 2010s for Puerto Rico
The U.S. Geological Survey (USGS) maintains a database of historical shoreline positions for the United States coasts derived from historical sources, such as aerial photographs or topographic surveys, and contemporary sources, such as modern orthophotography, light detection and ranging (lidar) point clouds, and digital elevation models. These shorelines are compiled within a geographic informati
Authors
Rachel E. Henderson, Julia L. Heslin, Emily A. Himmelstoss, Maritza Barreto-Orta
Using ground crack and very low frequency measurements to map the location of the June 2007 Father’s Day dike, Kīlauea Volcano
An intrusion into Kīlauea’s upper East Rift Zone during June 17–19, 2007, during the 1983–2018 Pu‘u‘ō‘ō eruption, led to widespread ground cracking and a small (approximately 1,525 cubic meters) eruption on the northeast flank of Kānenuiohamo, a cone about 6 kilometers upslope from Pu‘u‘ō‘ō. Transmitted and induced very low frequency (VLF) magnetic fields were measured with a handheld VLF receiver
Authors
Tim R. Orr, James P. Kauahikaua, Christina Heliker
Modeling the impacts of Glen Canyon Dam operations on Colorado River resources
At the time of this report, the Bureau of Reclamation (Reclamation) is writing two supplemental Environmental Impact Statements (sEIS ) and a new Environmental Impact Statement (EIS) that will analyze the effects of changing water flow out of Glen Canyon Dam (GCD) (U.S. Department of Interior, 2024). These actions have the potential to affect downstream resources, including threatened and endanger
Authors
Charles Yackulic, Lucas Bair, Drew Elliot Eppehimer, Gerard Lewis Salter, Bridget Deemer, Bradley J. Butterfield, Alan Kasprak, Joshua Caster, Helen C. Fairley, Paul Grams, Bryce Anthony Mihalevich, Emily C. Palmquist, Joel B. Sankey
Stony coral tissue loss disease (SCTLD) case definition for wildlife
Diagnostic laboratories receive carcasses and samples for diagnostic evaluation and pathogen/toxin detection. Case definitions bring clarity and consistency to the evaluation process. Their use within and between organizations allows more uniform reporting of diseases and etiologic agents. The intent of a case definition is to provide scientifically based criteria for determining (a) if an individ
Authors
Aine C. Hawthorn, Michelle Dennis, Yasu Kiryu, Jan Landsberg, Ester Peters, Thierry M. Work
Ungulate migrations of the Western United States, volume 4
Broadly distributed across the Western United States, ungulates (hooved mammals) play an important role in ecosystem function by affecting vegetation communities and forming the prey base for large carnivores. Additionally, ungulates provide economic benefits to regional communities through tourism and hunting and hold cultural significance for many Tribal communities. Many ungulates migrate seaso
Authors
Matthew Kauffman, Blake Lowrey, Chloe Beaupre, Scott Bergen, Stefanie Bergh, Kevin Blecha, Samantha Bundick, Hunter Burkett, James W. Cain, Peyton Carl, David Casady, Corey Class, Alyson Courtemanch, Michelle Cowardin, Jennifer Diamond, Katie Dugger, Orrin Duvuvuei, Joanna R. Ennis, Michelle Flenner, Jessica Fort, Gary Fralick, Ian Freeman, Jeff Gagnon, David Garcelon, Kyle Garrison, Emily Gelzer, Evan Greenspan, Valerie Hinojoza-Rood, Pat Hnilicka, Andy Holland, Brian Hudgens, Bart Kroger, Art Lawson, Cody McKee, Jennifer L. McKee, Jerod Merkle, Tony W. Mong, Haley Nelson, Brendan Oates, Marie-Pier Poulin, Craig Reddell, Robert Ritson, Hall Sawyer, Cody Schroeder, Jessie Shapiro, Scott Sprague, Erik Steiner, Alethea Steingisser, Sam Stephens, Blair Stringham, Patrick Ryan Swazo-Hinds, Nicole Tatman, Cody F. Wallace, Don Whittaker, Benjamin Wise, Heiko U. Wittmer, Erin Wood
2021 Volcanic activity in Alaska and the Commonwealth of the Northern Mariana Islands—Summary of events and response of the Alaska Volcano Observatory
In 2021, the Alaska Volcano Observatory responded to eruptions, volcanic unrest or suspected unrest, increased seismicity, and other significant activity at 15 volcanic centers in Alaska and the Commonwealth of the Northern Mariana Islands. Eruptive activity in Alaska consisted of repeated small, ash-producing, phreatomagmatic explosions from Mount Young on Semisopochnoi Island; an explosion at Gr
Authors
Tim R. Orr, Hannah R. Dietterich, David Fee, Társilo Girona, Ronni Grapenthin, Matthew M. Haney, Matthew W. Loewen, John J. Lyons, John A. Power, Hans F. Schwaiger, David J. Schneider, Darren Tan, Liam Toney, Valerie K. Wasser, Christopher F. Waythomas
2020 Volcanic activity in Alaska—Summary of events and response of the Alaska Volcano Observatory
The Alaska Volcano Observatory responded to eruptions, volcanic unrest or suspected unrest, increased seismicity, and other significant activity at nine volcanic centers in Alaska in 2020. The most notable volcanic activity in 2020 was an eruption of Shishaldin Volcano, which produced lava flows, lahars, and ash. Mount Cleveland had one small ash-producing eruption in June but was quiet thereafter
Authors
Tim R. Orr, Cheryl Cameron, Hannah R. Dietterich, Matthew W. Loewen, Taryn Lopez, John J. Lyons, Jenny Nakai, John A. Power, Cheryl Searcy, Gabrielle Tepp, Christopher F. Waythomas