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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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Development of a companion questionnaire for “Did You Feel It?”: Assessing response in earthquakes where an earthquake early warning may have been received Development of a companion questionnaire for “Did You Feel It?”: Assessing response in earthquakes where an earthquake early warning may have been received

Earthquake early warning (EEW) systems are relatively new technologies having first emerged as regional systems in the 1990s. Japan was the first nation to develop and implement a nationwide system in October 2007, and in the United States, ShakeAlert® became available on the entire length of the US West Coast in May 2021. Assessing how EEW is perceived and utilized by alert recipients...
Authors
James D. Goltz, David J. Wald, Sara K. McBride, Robert Michael deGroot, Jolie Breeden, Ann Bostrom

Modeling the spatial and temporal dynamics of land-based polar bear denning in Alaska Modeling the spatial and temporal dynamics of land-based polar bear denning in Alaska

Although polar bears (Ursus maritimus) of the Southern Beaufort Sea (SBS) subpopulation have commonly created maternal dens on sea ice in the past, maternal dens on land have become increasingly prevalent as sea ice declines. This trend creates conditions for increased human–bear interactions associated with local communities and industrial activity. Maternal denning is a vulnerable...
Authors
Vijay P. Patil, George M. Durner, David C. Douglas, Todd C. Atwood

Can lava flow like water? Assessing applications of critical flow theory to channelized basaltic lava flows Can lava flow like water? Assessing applications of critical flow theory to channelized basaltic lava flows

Flowing lava and water have dramatically different physical properties but can form similar hydraulic structures, including undular hydraulic jumps, or standing wave trains. In water flows, undular hydraulic jumps are evidence of critical flow (Froude number ∼1) and open-channel hydraulic theory provides a powerful tool for estimating flow depth and velocity. Monitoring these parameters...
Authors
Hannah R. Dietterich, Gordon E. Grant, Becky Fasth, J. J. Major, Katharine V. Cashman

Effects of formaldehyde (Parasite-S®) on biofilter nitrification from a cold- and a warm freshwater RAS Effects of formaldehyde (Parasite-S®) on biofilter nitrification from a cold- and a warm freshwater RAS

The effect of Parasite-S® (an aqueous formaldehyde solution) on the nitrification processes of biofilters was evaluated in two recirculating aquaculture systems (RASs). Rearing tanks in the warmwater RAS contained yellow perch (Perca flavescens) and grass carp (Ctenopharyngodon idella) with an initial weight of 166.8 kg and a mean density of 39.5 kg/m3. Rearing tanks in the coldwater RAS...
Authors
Kim T. Fredricks, Susan M. Schleis, Justin R. Smerud, Mark P. Gaikowski, Richard A. Erickson, Jillian Lee Hebert, Gregory J. Fischer, Kendall Holmes, Christopher F Hartleb

Wildfire influences individual growth and breeding dispersal, but not survival and recruitment in a montane amphibian Wildfire influences individual growth and breeding dispersal, but not survival and recruitment in a montane amphibian

Global wildfire regimes are changing rapidly, with widespread increases in the size, frequency, duration, and severity of wildfires. Whereas the effects of wildfire on ecological state variables such as occupancy, abundance, and species diversity are relatively well documented, changes in population vital rates (e.g., survival, recruitment) and individual responses (e.g., growth...
Authors
Gabriel M. Barrile, Anna D. Chalfoun, Wendy A. Estes-Zumpf, Annika W. Walters

The influence of submerged coastal structures on nearshore flows and wave runup The influence of submerged coastal structures on nearshore flows and wave runup

Engineered and natural submerged coastal structures (e.g., submerged breakwaters and reefs) modify incident wave fields and thus can alter hydrodynamic processes adjacent to coastlines. Although submerged structures are generally assumed to promote beach protection by dissipating waves offshore and creating sheltered conditions in their lee, their interaction with waves can result in...
Authors
Renan F. da Silva, Jeff Hansen, Dirk P. Rijnsdorp, Ryan Lowe, Mark L. Buckley

Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars

The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater’s sedimentary delta, finding the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Fe...
Authors
K.A. Farley, K.M. Stack, D.L. Shuster, B.H.N. Horgan, J. A. Hurowitz, J. D. Tarnas, J.I. Simon, V.Z. Sun, E.L. Scheller, K.R. Moore, S.M. McLennan, P.M. Vasconcelos, R. C. Wiens, A.H. Treiman, Lisa E. Mayhew, O. Beyssac, T.V. Kizovski, N. J. Tosca, K.H. Williford, L.S. Crumpler, L.W. Beegle, J.F. Bell, B.L. Ehlmann, Y. Liu, J.N. Maki, M. E. Schmidt, A.C. Allwood, H.E.F. Amundsen, R. Ghartia, Tanja Bosak, A.J. Brown, B. C. Clark, A. Cousin, O. Forni, Travis S.J. Gabriel, Y. Goreva, S. Gupta, S.-E. Hamran, C.D.K. Herd, Keyron Hickman-Lewis, J.R. Johnson, L.C. Kah, P. B. Kelemen, K.B. Kinch, L. Mandon, N. Mangold, C. Quantun-Nataf, M.S. Rice, P.S. Russell, S. Sharma, S. Siljestroem, A. Steele, R. Sullivan, M. Wadhwa, Ben P. Weiss, A.J. Williams, B.V. Wogsland, P.A. Willis, T.A. Acosta-Maeda, B. Peck, K. Benzerara, S. Bernard, A.S. Burton, E. L. Cardarelli, B. Chide, Elise Clavé, E. A. Cloutis, A.D. Czaja, Vinciane Debaille, E. Dehouck, A.G. Fairen, D.T. Flannery, S.Z. Fleron, T. Fouchet, J. Frydenvang, B.J. Garczynski, E.F. Gibbons, E.M. Hausrath, A.G. Hayes, J. Henneke, J.L. Jorgensen, E.M. Kelly, J. Lasue, Stéphane Le Mouélic, J. M. Madariaga, S. Maurice, M. Merusi, P. #NAME? Meslin, S.M. Milkovich, C.C. Million, R.C. Moeller, J.I. Nunez, A.M. Ollila, G. Paar, D.A. Paige, D.A.K. Pedersen, P. Pilleri, C. Pilorget, P.C. Pinet, J.W. Rice Jr., C. Royer, V. Sautter, M. Schulte, M. A. Sephton, S.K. Sharma, S.F. Sholes, N. Spanovich, M. St. Clair, C.D. Tate, K. Uckert, S.J. VanBommel, A.G. Yanchilina, M. #NAME? Zorzano

Methods for robust estimates of tree biomass from pollen accumulation rates: Quantifying paleoecological reconstruction uncertainty Methods for robust estimates of tree biomass from pollen accumulation rates: Quantifying paleoecological reconstruction uncertainty

Pollen accumulation rates (PAR, grains cm–2 year–1) have been shown to be a reliable but methodologically complex bioproxy for quantitative reconstruction of past tree abundance. In a prior study, we found that the PARs of major tree taxa – Pseudotsuga, Pinus, Notholithocarpus, and the pollen group TC (Taxaceae and Cupressaceae families) – were robust and precise estimators of...
Authors
Clarke Alexandra Knight, John J. Battles, M. Jane Bunting, Marie Rhondelle Champagne, James A. Wanket, David Wahl

Range-wide sources of variation in reproductive rates of northern spotted owls Range-wide sources of variation in reproductive rates of northern spotted owls

We conducted a range-wide investigation of the dynamics of site level reproductive rate of northern spotted owls using survey data from 11 study areas across the sub-species geographic range collected during 1993–2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed...
Authors
Jeremy T. Rockweit, Julianna M Jenkins, James E. Hines, James D. Nichols, Katie M. Dugger, Alan B. Franklin, Peter C. Carlson, William L. Kendall, Damon B. Lesmeister, Christopher McCafferty, Steven H. Ackers, L. Steven Andrews, Larissa Bailey, Jesse Burgher, Kenneth P. Burnham, Tara E. Chestnut, Mary M Conner, Raymond J. Davis, Krista E. Dilione, Eric D. Forsman, Elizabeth M. Glenn, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, David W Lamphear, Trent L. McDonald, Janice A Reid, Carl J. Schwarz, David C. Simon, Stan G Sovern, James K. Swingle, David Wiens, Heather Wise, Charles B. Yackulic

Incorporating streambank wells in stream mass loading studies to more effectively identify sources of solutes in stream water Incorporating streambank wells in stream mass loading studies to more effectively identify sources of solutes in stream water

Stream synoptic sampling studies that include flow estimates derived from the stream tracer dilution method are now commonly performed to identify sources and processes controlling solute transport to streams. However, a limitation of this mass-loading approach is its inability to identify the side of the stream on which a source is located in the common case where loading is largely...
Authors
Andrew H. Manning, Robert L. Runkel, Jean M. Morrison, Richard B. Wanty, Katherine Walton-Day
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