Skip to main content
U.S. flag

An official website of the United States government

Articles

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.

Filter Total Items: 77855

Towards a holistic sulfate-water-O2 triple oxygen isotope systematics Towards a holistic sulfate-water-O2 triple oxygen isotope systematics

Triple oxygen isotope (∆17O with δ18O) signals of H2O and O2 found in sulfate of oxidative weathering origin offer promising constraints on modern and ancient weathering, hydrology, atmospheric gas concentrations, and bioproductivity. However, interpretations of the sulfate-water-O2 system rely on assuming fixed oxygen-isotope fractionations between sulfate and water, which...
Authors
Bryan Alan Killingsworth, Pierre Cartigny, Justin A. Hayles, Christophe Thomazo, Pierre Sansjofre, Virgil Pasquier, Stefan V. Lalonde, Pascal Philippot

Changing impacts of Alaska-Aleutian subduction zone tsunamis in California under future sea-level rise Changing impacts of Alaska-Aleutian subduction zone tsunamis in California under future sea-level rise

The amplification of coastal hazards such as distant-source tsunamis under future relative sea-level rise (RSLR) is poorly constrained. In southern California, the Alaska-Aleutian subduction zone has been identified as an earthquake source region of particular concern for a worst-case scenario distant-source tsunami. Here, we explore how RSLR over the next century will influence future...
Authors
Tina Dura, Andra Garner, Robert Weiss, Robert E. Kopp, Simon E. Engelhart, Robert C. Witter, Richard W. Briggs, Charles Mueller, Alan Nelson, Benjamin P. Horton

What determines the effectiveness of Pinyon-Juniper clearing treatments? Evidence from the remote sensing archive and counter-factual scenarios What determines the effectiveness of Pinyon-Juniper clearing treatments? Evidence from the remote sensing archive and counter-factual scenarios

In the intermountain western US, expansion of Pinyon (Pinus edulis) and Juniper (Juniperus spp.) woodlands (PJ) into grasslands and shrublands is a pervasive phenomenon, and an example of the global trend towards enhanced woody growth in drylands. Due to the perceived impacts of these expansions on ecosystem services related to biodiversity, hydrology, soil stability, fire prevention...
Authors
Stephen E. Fick, Travis W. Nauman, Colby C. Brungard, Michael C. Duniway

Seismotectonic analysis of the 2019–2020 Puerto Rico sequence: The value of absolute earthquake relocations in improved interpretations of active tectonics Seismotectonic analysis of the 2019–2020 Puerto Rico sequence: The value of absolute earthquake relocations in improved interpretations of active tectonics

We present a new catalog of calibrated earthquake relocations from the 2019–2020 Puerto Rico earthquake sequence related to the 7 January 2020 Mw 6.4 earthquake that occurred offshore of southwest Puerto Rico at a depth of 15.9 km. Utilizing these relocated earthquakes and associated moment tensor solutions, we can delineate several distinct fault systems that were activated during the...
Authors
C.W. Cromwell, K.P. Furlong, E.A. Bergman, Harley M. Benz, William L. Yeck, M. Herman

Quantifying the influence of different biocrust community states and their responses to warming temperatures on soil biogeochemistry in field and mesocosm studies Quantifying the influence of different biocrust community states and their responses to warming temperatures on soil biogeochemistry in field and mesocosm studies

Biocrusts influence soil biogeochemistry by fixing carbon (C) and nitrogen (N) and through leachate inputs to soils. Functional rates can vary among biocrust community states and in response to edaphic properties, heterotrophic microbial activity, and global change. Using soils and biocrusts from the Colorado Plateau, Utah, USA, we aimed to quantify the influence of early-successional...
Authors
Scott Ferrrenberg, Colin L Tucker, Robin H. Reibold, Armin J. Howell, Sasha C. Reed

Stock composition of the historical New York Bight Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) intercept fishery revealed through microsatellite analysis of archived spines Stock composition of the historical New York Bight Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) intercept fishery revealed through microsatellite analysis of archived spines

A targeted commercial fishery for Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus once operated in the New York Bight, where it was assumed that most harvested Atlantic Sturgeon were natal to the Hudson River population. However, more recent evidence suggests that the fishery may have been targeting a mixed-stock aggregation, in which case harvested Atlantic Sturgeon could have been...
Authors
Shannon L. White, Robin L. Johnson, Barbara A. Lubinski, Michael S. Eackles, David H. Secor, David C. Kazyak

Current distribution and abundance of Kohala forest birds in Hawai‘i Current distribution and abundance of Kohala forest birds in Hawai‘i

The Kohala volcano is home to the most spatially isolated population of Hawaiian forest birds on Hawai‘i Island and contains one of the few native bird populations in the state that has not been monitored since the original Hawai‘i Forest Bird Survey (HFBS) in 1979. We surveyed 143 stations across 13 transects in Pu‘u ‘O ‘Umi Natural Area Reserve on Kohala from February through April...
Authors
Keith Burnett, Richard J. Camp, Patrick J. Hart

Empirically validated drought vulnerability mapping in the mixed conifer forests of the Sierra Nevada Empirically validated drought vulnerability mapping in the mixed conifer forests of the Sierra Nevada

Severe droughts are predicted to become more frequent in the future, and the consequences of such droughts on forests can be dramatic, resulting in massive tree mortality, rapid change in forest structure and composition, and substantially increased risk of catastrophic fire. Forest managers have tools at their disposal to try to mitigate these effects but are often faced with limited...
Authors
Adrian Das, Michele R Slaton, Jeffrey Mallory, Gregory P. Asner, Roberta E. Martin, Paul Hardwick

Complex demographic responses to contrasting climate drivers lead to divergent population trends across the range of a threatened alpine plant Complex demographic responses to contrasting climate drivers lead to divergent population trends across the range of a threatened alpine plant

Alpine plants are likely to be particularly vulnerable to climate change because of their restricted distributions and sensitivity to rapid environmental shifts occurring in high-elevation ecosystems. The well-studied Haleakalā silversword (‘āhinahina, Argyroxiphium sandwicense subsp. macrocephalum) already exhibits substantial climate-associated population decline, and offers the...
Authors
Lucas Berio Fortini, Paul Krushelnycky, Donald Drake, Forest Starr, Kim Starr, Charles G. Chimera

Convergence of undulatory swimming kinematics across a diversity of fishes Convergence of undulatory swimming kinematics across a diversity of fishes

Fishes exhibit an astounding diversity of locomotor behaviors from classic swimming with their body and fins to jumping, flying, walking, and burrowing. Fishes that use their body and caudal fin (BCF) during undulatory swimming have been traditionally divided into modes based on the length of the propulsive body wave and the ratio of head:tail oscillation amplitude: anguilliform...
Authors
V. di Santo, E. Goerig, D Wainwright, O. Akanyeti, J.C. Liao, Theodore R. Castro-Santos, G.V. Lauder

Thermal conditions predict intraspecific variation in senescence rate in frogs and toads Thermal conditions predict intraspecific variation in senescence rate in frogs and toads

Variation in temperature is known to influence mortality patterns in ectotherms. Even though a few experimental studies on model organisms have reported a positive relationship between temperature and actuarial senescence (i.e., the increase in mortality risk with age), how variation in climate influences the senescence rate across the range of a species is still poorly understood in...
Authors
Hugo Cayuela, Jean-Francois Lemaitre, Erin L. Muths, Rebecca M. McCaffery, Thierry Fretey, Bernard Le Garff, Benedikt R. Schmidt, Kurt Grossenbacher, Omar Lenzi, Blake R. Hossack, Lisa A Eby, Brad A. Lambert, Johan Elmberg, Juha Merila, Jerome MW Gippet, Jean-Michel Gaillard, David S. Pilliod

Capacity of two Sierra Nevada rivers for reintroduction of anadromous salmonids: Insights from a high-resolution view Capacity of two Sierra Nevada rivers for reintroduction of anadromous salmonids: Insights from a high-resolution view

Historically, anadromous steelhead Oncorhynchus mykiss and spring-run Chinook Salmon O. tshawytscha used high-elevation rivers in the Sierra Nevada of California but were extirpated in the 20th century by construction of impassable dams. Plans to reintroduce the fish by opening migratory passage across the dams and reservoirs can only succeed if upstream habitats have the capacity to...
Authors
David A. Boughton, Lee R. Harrison, Sara N. John, Rosealea M. Bond, Colin L. Nicol, Carl J. Legleiter, Ryan T. Richardson
Was this page helpful?