Seismic‐wave attenuation determined from tectonic tremor in multiple subduction zones
Suguru Yabe, Annemarie S. Baltay, Satoshi Ide, Gregory C. Beroza
2014, Bulletin of the Seismological Society of America (104) 2043-2059
Tectonic tremor provides a new source of observations that can be used to constrain the seismic attenuation parameter for ground‐motion prediction and hazard mapping. Traditionally, recorded earthquakes of magnitude ∼3–8 are used to develop ground‐motion prediction equations; however, typical earthquake records may be sparse in areas of high hazard. In...
Residual shear strength variability as a primary control on movement of landslides reactivated by earthquake-induced ground motion: Implications for coastal Oregon, U.S.
William H. Schulz, Gonghui Wang
2014, Journal of Geophysical Research F: Earth Surface (119) 1617-1635
Most large seismogenic landslides are reactivations of preexisting landslides with basal shear zones in the residual strength condition. Residual shear strength often varies during rapid displacement, but the response of residual shear zones to seismic loading is largely unknown. We used a ring shear apparatus to perform simulated seismic loading...
Climate change and plant community composition in national parks of the southwestern US: forecasting regional, long-term effects to meet management needs
Seth M. Munson, Jayne Belnap, Robert H. Webb, J. Andrew Hubbard, M. Hildegard Reiser, Kirsten Gallo
2014, The George Wright Forum (31) 137-148
The National Park Service (NPS) faces tremendous management challenges in the future as climates alter the abundance and distribution of plant species. These challenges will be especially daunting in the southwestern U.S., where large increases in aridity are forecasted. The expected reduction in water availability will negatively affect plant growth...
Modeling vegetation heights from high resolution stereo aerial photography: an application for broad-scale rangeland monitoring
Jeffrey K. Gillan, Jason W. Karl, Michael Duniway, Ahmed Elaksher
2014, Journal of Environmental Management (144) 226-235
Vertical vegetation structure in rangeland ecosystems can be a valuable indicator for assessing rangeland health and monitoring riparian areas, post-fire recovery, available forage for livestock, and wildlife habitat. Federal land management agencies are directed to monitor and manage rangelands at landscapes scales, but traditional field methods for measuring vegetation heights...
Thresholds for protecting Pacific Northwest ecosystems from atmospheric deposition of nitrogen: state of knowledge report
Tonnie Cummings, Tamara Blett, Ellen Porter, Linda Geiser, Rick Graw, Jill McMurray, Steven S. Perakis, Regina Rochefort
2014, Natural Resource Report NPS/PWRO/NRR--2014/823
The National Park Service and U.S. Forest Service manage areas in the states of Idaho, Oregon, and Washington – collectively referred to in this report as the Pacific Northwest - that contain significant natural resources and provide many recreational opportunities. The agencies are mandated to protect the air quality...
Barcodes are a useful tool for labeling and tracking ecological samples
Adam J. Copp, Theodore A. Kennedy, Jeffrey D. Muehlbauer
2014, Bulletin of the Ecological Society of America (95) 293-300
Barcodes are used to label and track just about everything these days. Look around your office, in your medicine cabinet, at the package you just received in the mail, or on the shelves of any shop in town, and you will immediately grasp the ubiquity of their use. Interestingly, railroads...
Importance of biogeomorphic and spatial properties in assessing a tidal salt marsh vulnerability to sea-level rise
Karen M. Thorne, Deborah L. Elliott-Fisk, Glenn D. Wylie, William M. Perry, John Y. Takekawa
2014, Estuaries and Coasts (37) 941-951
We evaluated the biogeomorphic processes of a large (309 ha) tidal salt marsh and examined factors that influence its ability to keep pace with relative sea-level rise (SLR). Detailed elevation data from 1995 and 2008 were compared with digital elevation models (DEMs) to assess marsh surface elevation change during this...
Methylmercury-induced changes in gene transcription associated with neuroendocrine disruption in largemouth bass (Micropterus salmoides)
Catherine A. Richter, Christopher J. Martyniuk, Mandy L. Annis, William G. Brumbaugh, Lia C. Chasar, Nancy D. Denslow, Donald E. Tillitt
2014, General and Comparative Endocrinology (203) 215-224
Methyl-mercury (MeHg) is a potent neuroendocrine disruptor that impairs reproductive processes in fish. The objectives of this study were to (1) characterize transcriptomic changes induced by MeHg exposure in the female largemouth bass (LMB) hypothalamus under controlled laboratory conditions, (2) investigate the health and reproductive impacts of MeHg exposure on...
Deep permeability of the San Andreas Fault from San Andreas Fault Observatory at Depth (SAFOD) core samples
Carolyn A. Morrow, David A. Lockner, Diane E. Moore, Stephen H. Hickman
2014, Journal of Structural Geology (64) 99-114
The San Andreas Fault Observatory at Depth (SAFOD) scientific borehole near Parkfield, California crosses two actively creeping shear zones at a depth of 2.7 km. Core samples retrieved from these active strands consist of a foliated, Mg-clay-rich gouge containing porphyroclasts of serpentinite and sedimentary rock. The adjacent damage zone and...
Reply to Efford on ‘Integrating resource selection information with spatial capture-recapture’
J. Andrew Royle, Richard Chandler, Catherine C. Sun, Angela K. Fuller
2014, Methods in Ecology and Evolution (5) 603-605
1. We proposed (Methods in Ecology and Evolution, 2013, 4) a model for combining telemetry data with spatial capture–recapture (SCR) data that was vigorously criticized by Efford (Methods in Ecology and Evolution, 2014, 000, 000). Efford's main claim was that our encounter probability model was incorrect, and therefore our R...
A shift of thermokarst lakes from carbon sources to sinks during the Holocene epoch
K. M. Walter Anthony, S. A. Zimov, G. Grosse, Miriam C. Jones, P. Anthony, F. S. Chapin III, J. C. Finlay, M. C. Mack, S. Davydov, P. F. Frenzel, S. Frolking
2014, Nature (511) 452-469
Thermokarst lakes formed across vast regions of Siberia and Alaska during the last deglaciation and are thought to be a net source of atmospheric methane and carbon dioxide during the Holocene epoch1,2,3,4. However, the same thermokarst lakes can also sequester carbon5, and it remains uncertain whether carbon uptake by thermokarst...
Previous success and current body condition determine breeding propensity in Lesser Scaup: evidence for the individual heterogeneity hypothesis
Jeffrey M. Warren, Kyle A. Cutting, John Y. Takekawa, Susan E.W. De La Cruz, Tony D. Williams, David N. Koons
2014, The Auk (131) 287-297
The decision to breed influences an individual's current and future reproduction, and the proportion of individuals that breed is an important determinant of population dynamics. Age, experience, individual quality, and environmental conditions have all been demonstrated to influence breeding propensity. To elucidate which of these factors exerts the greatest influence...
Titanium 2013
2014, Mining Engineering (66) 35-35
Titanium is the ninth most abundant element in the earth's crust and can be found in nearly all rocks and sediments. It is a lithophile element with a strong affinity for oxygen and is not found as a pure metal in nature. Titanium was first isolated as a pure metal...
Assessment of tsunami hazard to the U.S. Atlantic margin
Uri S. ten Brink, Jason Chaytor, Eric L. Geist, Daniel S. Brothers, Brian D. Andrews
2014, Marine Geology (353) 31-54
Tsunami hazard is a very low-probability, but potentially high-risk natural hazard, posing unique challenges to scientists and policy makers trying to mitigate its impacts. These challenges are illustrated in this assessment of tsunami hazard to the U.S. Atlantic margin. Seismic activity along the U.S. Atlantic margin in general is low,...
Sediment concentrations, flow conditions, and downstream evolution of two turbidity currents, Monterey Canyon, USA
Jingping Xu, Octavio E. Sequeiros, Marlene A. Noble
2014, Deep-Sea Research Part I: Oceanographic Research Papers (89) 11-34
The capacity of turbidity currents to carry sand and coarser sediment from shallow to deep regions in the submarine environment has attracted the attention of researchers from different disciplines. Yet not only are field measurements of oceanic turbidity currents a rare achievement, but also the data that have been collected...
Editorial for Journal of Hydrology: Regional Studies
Patrick Willems, Okke Batelaan, Denis A. Hughes, Peter W. Swarzenski
2014, Journal of Hydrology: Regional Studies (1) A1-A5
Hydrological regimes and processes show strong regional differences. While some regions are affected by extreme drought and desertification, others are under threat of increased fluvial and/or pluvial floods. Changes to hydrological systems as a consequence of natural variations and human activities are region-specific. Many of these changes have significant interactions...
Pyroclast textural variation as an indicator of eruption column steadiness in andesitic Plinian eruptions at Mt. Ruapehu
Natalia Pardo, Shane J. Cronin, Heather M. Wright, C. Ian Schipper, Ian Smith, Bob Stewart
2014, Bulletin of Volcanology (76)
Between 27 and 11 cal. ka BP, a transition is observed in Plinian eruptions at Mt. Ruapehu, indicating evolution from non-collapsing (steady and oscillatory) eruption columns to partially collapsing columns (both wet and dry). To determine the causes of these variations over this eruptive interval, we examined lapilli fall deposits...
Geologic history of Siletzia, a large igneous province in the Oregon and Washington Coast Range: Correlation to the geomagnetic polarity time scale and implications for a long-lived Yellowstone hotspot
Ray Wells, David Bukry, Richard Friedman, Douglas Pyle, Robert Duncan, Peter J. Haeussler, Joe Wooden
2014, Geosphere (10) 692-719
Siletzia is a basaltic Paleocene and Eocene large igneous province in coastal Oregon, Washington, and southern Vancouver Island that was accreted to North America in the early Eocene. New U-Pb magmatic, detrital zircon, and 40Ar/39Ar ages constrained by detailed field mapping, global nannoplankton zones, and magnetic polarities allow correlation of...
Natural regeneration processes in big sagebrush (Artemisia tridentata)
Daniel R. Schlaepfer, William K. Lauenroth, John B. Bradford
2014, Rangeland Ecology and Management (67) 344-357
Big sagebrush, Artemisia tridentata Nuttall (Asteraceae), is the dominant plant species of large portions of semiarid western North America. However, much of historical big sagebrush vegetation has been removed or modified. Thus, regeneration is recognized as an important component for land management. Limited knowledge about key regeneration processes, however, represents...
Replacement cost valuation of Northern Pintail (Anas acuta) subsistence harvest in Arctic and sub-Arctic North America
Joshua H. Goldstein, Wayne E. Thogmartin, Kenneth J. Bagstad, James A. Dubovsky, Brady J. Mattsson, Darius J. Semmens, Laura López-Hoffman, James E. Diffendorfer
2014, Human Dimensions of Wildlife: An International Journal (19) 347-354
Migratory species provide economically beneficial ecosystem services to people throughout their range, yet often, information is lacking about the magnitude and spatial distribution of these benefits at regional scales. We conducted a case study for Northern Pintails (hereafter pintail) in which we quantified regional and sub-regional economic values of subsistence...
Regional mapping of hydrothermally altered igneous rocks along the Urumieh-Dokhtar, Chagai, and Alborz Belts of western Asia using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and Interactive Data Language (IDL) logical operators: a tool for porphyry copper exploration and assessment
John L. Mars
M. L. Zientek, J. M. Hammarstrom, K. M. Johnson, F. W. Pierce, editor(s)
2014, Scientific Investigations Report 2010-5090-O
Regional maps of phyllic and argillic hydrothermal alteration were compiled using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and logical operator algorithms. The area mapped extends from northwestern Iran to southeastern Pakistan and includes volcanic and magmatic arcs that make up the Urumieh-Dokhtar volcanic belt (UDVB), the Chagai...
Marine and inland fishes of St. Croix, U. S. Virgin Islands: an annotated checklist
William F. Smith-Vaniz, Howard L. Jelks
2014, Zootaxa (3803) 1-120
An historical account is given for the ichthyological research at St. Croix, U. S. Virgin Islands, followed by an annotated list of 544 species of mostly marine shore fishes known or reported from the island to depths of 200 m. Color photographs are included for 103 of these species. Collections...
Age, chemistry, and correlations of Neoproterozoic–Devonian igneous rocks of the Arctic Alaska–Chukotka terrane: An overview with new U-Pb ages
Jeffrey M Amato, John N. Aleinikoff, Vyacheslav V Akinin, William C. McClelland, Jaime Toro
Julie A. Dumoulin, Alison B. Till, editor(s)
2014, Book chapter, Reconstruction of a Late Proterozoic to Devonian continental margin sequence, northern Alaska, its paleogeographic significance, and contained base-metal sulfide deposits
The Arctic Alaska–Chukotka terrane is a microcontinent with an origin exotic to Laurentia. We used a sensitive high-resolution ion microprobe (SHRIMP) to date nine samples of Neoproterozoic rock and five samples of Devonian rock from the Brooks Range and Seward Peninsula of Alaska and from the Chukotka Peninsula of northeastern...
Formation temperatures of thermogenic and biogenic methane
D.A. Stolper, M. Lawson, C.L. Davis, A.A. Ferreira, E. V. Santos Neto, G.S. Ellis, M. D. Lewan, Anna M. Martini, Y. Tang, M. Schoell, A.L. Sessions, J.M. Eiler
2014, Science (344) 1500-1503
Methane is an important greenhouse gas and energy resource generated dominantly by methanogens at low temperatures and through the breakdown of organic molecules at high temperatures. However, methane-formation temperatures in nature are often poorly constrained. We measured formation temperatures of thermogenic and biogenic methane using a “clumped isotope” technique. Thermogenic...
USGS National Wildlife Health Center quarterly mortality report
Anne E. Ballmann, C. LeAnn White, Barbara L. Bodenstein, Jennifer Buckner
2014, Wildlife Disease Association Newsletter 3-5
No abstract available....
