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Browse more than 65,000 articles 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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Design and functionality analysis of the high-stress permeameter (HSP), a device developed for measuring mechanical and hydraulic properties of gas hydrate-bearing pressure core Design and functionality analysis of the high-stress permeameter (HSP), a device developed for measuring mechanical and hydraulic properties of gas hydrate-bearing pressure core
To characterize sediment compressibility and permeability in the presence of gas hydrate, a naturally occurring combination of water and methane that requires elevated pressure and reduced temperature to remain stable, a high-stress permeameter (HSP) device was developed. The HSP was designed to accept gas hydrate-bearing pressure core specimens in their plastic liner at pressures of 10...
Authors
William F. Waite, Adrian Garcia
Adapting wildfire risk assessment for a Tribal landscape: Mount Baldy and the Fort Apache Reservation in Arizona Adapting wildfire risk assessment for a Tribal landscape: Mount Baldy and the Fort Apache Reservation in Arizona
Context
Authors
Aaron Daniel Russell, Todd J. Hawbaker, Doreen Ethelbah-Gatewood, Lucas Bair, Amanda Renee Carlson, James R. Meldrum, Seth M. Munson
Connecting the dots: Using multiple datasets to monitor the brown bear population in Katmai National Park and Preserve Connecting the dots: Using multiple datasets to monitor the brown bear population in Katmai National Park and Preserve
Monitoring wide-ranging wildlife populations is challenging. Surveys are time consuming, expensive, and observation conditions need to be just right. But confidently assessing the number of animals, and if their numbers are increasing or decreasing is important for park management and ecological understanding. This article describes survey methods and how they can be combined for the...
Authors
Leslie C. Skora, Tammy L. Wilson
Abandonment of the Upper Devonian Greenland Gap Group and Scherr Formation and revision of the Upper Devonian Brallier and Foreknobs Formations in the central Valley and Ridge Province Abandonment of the Upper Devonian Greenland Gap Group and Scherr Formation and revision of the Upper Devonian Brallier and Foreknobs Formations in the central Valley and Ridge Province
This study revises the lithostratigraphic framework of the Upper Devonian interval traditionally assigned to the Greenland Gap Group across the central Appalachian Valley and Ridge Province. The work aims to modernize and standardize lithostratigraphic nomenclature, establish a new reference section and demonstrate how the revised stratigraphy improves edge-matching of 1:24,000 scale...
Authors
Alan D. Pitts, Daniel H. Doctor
An empirical test of maximum depositional age through paired LA-ICP-MS and CA-ID-TIMS detrital zircon analysis with implications for the “Nevadan orogeny” in the Sierra Nevada foothills, California, U.S.A. An empirical test of maximum depositional age through paired LA-ICP-MS and CA-ID-TIMS detrital zircon analysis with implications for the “Nevadan orogeny” in the Sierra Nevada foothills, California, U.S.A.
The interpretation of maximum depositional age (MDA) from U-Pb detrital zircon data acquired via laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) or secondary ion mass spectrometry (SIMS) is now routine; however, to date only a few studies have presented tests of such MDAs by subsequently analyzing a subset of the same detrital zircon grains with the more accurate...
Authors
Todd A. LaMaskin, Scott R. Paterson, James L. Crowley, Christopher S. Holm-Denoma, Jack A. Simmons, Laura S. Pianowski
Report 17—Revisions to the articles of organization and procedure of the Commission on Stratigraphic Nomenclature of the Americas Report 17—Revisions to the articles of organization and procedure of the Commission on Stratigraphic Nomenclature of the Americas
Several revisions to the Articles of Organization and Procedure for the North American Commission on Stratigraphic Nomenclature have been adopted following the 75th, 79th, and 80th annual meetings of the Commission in 2020, 2024 and 2025, respectively. Of these, the most substantial change was revision of Article III regarding membership composition of the Commission and the addition of...
Authors
Lynn T. Dafoe, Robert B. MacNaughton, Marie-Pierre Aubry, Carlton E. Brett, James R. Lehane, Fernando Núñez-Useche, Randall C. Orndorff, Frank Brunton, Lucy E. Edwards, Richard H. Fluegeman, Howard Harper, R. Matthew Joeckel, Norman P. Lasca, B.H. Tew
Hyperspectral retrieval of phytoplankton absorption and community composition from NASA’s PACE-OCI in estuarine–coastal waters using a hybrid framework combining mixture-of-experts and Variational Autoencoder Hyperspectral retrieval of phytoplankton absorption and community composition from NASA’s PACE-OCI in estuarine–coastal waters using a hybrid framework combining mixture-of-experts and Variational Autoencoder
Retrieving the phytoplankton absorption coefficient (aphy; m−1), one of the most spectrally rich inherent optical properties, remains challenging in optically complex coastal waters worldwide. Leveraging NASA's new hyperspectral mission, PACE, we introduce Hyper-MoE-VAE, a deep-learning architecture that integrates a Mixture-of-Experts with a Variational Autoencoder to retrieve high...
Authors
Xingyu Bai, Bingqing Liu, Jiang Li, Yuanheng Xiong, Eurico J. D'Sa, Melissa Millman Baustian, Xiaodong Zhang, Brice K. Grunert, Chisom O. Emeghiebo, Cassie Glasspie, Xu Yuan
Special issue “The 2024 M7.6 Noto Peninsula earthquake and seismic swarm” Special issue “The 2024 M7.6 Noto Peninsula earthquake and seismic swarm”
The 2024 Mw7.5 (MJMA7.6) Noto Peninsula earthquake struck the Noto Peninsula, central Japan on January 1, 2024, causing widespread damage. This Mw7.5 mainshock, together with the prolonged seismic swarm that persisted in the northeastern Noto Peninsula since the end of 2020, of which the largest event was the 2023 MJMA6.5 earthquake, constitutes one of the most significant seismic...
Authors
Yoshihiro Hiramatsu, David R. Shelly, Takuya Nishimura, Junichi Nakajima, Haruko Sekiguchi, Tomoaki Morishita, Hiroshi Ichihara, Aitaro Kato
Mercury cycling across a U.S. semi-arid mountain ecosystem elevation gradient Mercury cycling across a U.S. semi-arid mountain ecosystem elevation gradient
Mountains comprise ∼30% of the Earth's surface, but mercury (Hg) cycling in these regions remains understudied, particularly in the semi-arid western U.S. where strong climatic and ecological gradients in mountainous landscapes influence Hg deposition, retention, and bioaccumulation. In this study, we quantified growing season inputs, storage, and bioaccumulation of Hg along a ∼2,000 m...
Authors
Hannah R. Miller, Sarah E. Janssen, Scott A. Taylor, Jacqueline R. Gerson, Tyler L. McIntosh, Eve-Lyn S. Hinckley
Terrestrial ecosystem response to changing temperature and seasonality in the Paleocene-Eocene Thermal Maximum: Shallow marine records from the Salisbury Embayment, USA Terrestrial ecosystem response to changing temperature and seasonality in the Paleocene-Eocene Thermal Maximum: Shallow marine records from the Salisbury Embayment, USA
The Paleocene-Eocene thermal maximum (PETM, ∼56 Ma) is marked by a massive and rapid rise in atmospheric CO2 and ∼5°C of global warming. It is globally characterized by a negative carbon isotope excursion (CIE), and, at least locally, is preceded by a pre-onset excursion (POE). We present palynological and bioclimatic analyses from stratigraphically expanded marginal marine sediment...
Authors
Debra A. Willard, Mei Nelissen, Appy Sluijs, Henk Brinkhuis, Tammo Reichgelt, Marci M. Robinson, Jean Self-Trail
Extreme precipitation variability and soil texture controls on water-table response Extreme precipitation variability and soil texture controls on water-table response
Extreme precipitation events (EPEs), a key class of hydrometeorological extremes, are intensifying globally under climate change; however, their effects on water-table dynamics across varying soil textures remain poorly understood. To better understand the impacts of EPEs, we conducted one-dimensional modeling to evaluate water-table response time, displacement, recession time, and total...
Authors
Claudia R. Corona, Shemin Ge, Suzanne P. Anderson, Jesse E. Dickinson
Deformed submarine terraces in Puget Sound, Pacific Northwest, indicate only one M >~7.5 earthquake on the Seattle fault zone in the past 11,000 yr Deformed submarine terraces in Puget Sound, Pacific Northwest, indicate only one M >~7.5 earthquake on the Seattle fault zone in the past 11,000 yr
Submerged marine terraces in Puget Sound, deformed across the Seattle fault zone (SFZ), indicate that only one earthquake as large as M~7.5 has occurred in at least the past 11 kyr. Previous paleoseismic studies document a M~7.5 earthquake between 923–4 CE, which uplifted coastal marine terraces by as much as 8 m. We demonstrate that this earthquake was the only such event since ~11 ka...
Authors
Elizabeth J. Davis, Juliet G. Crider, Ralph A. Haugerud, Emily Roland, Ginevra Moore