The energy radiated by the 26 December 2004 Sumatra-Andaman earthquake estimated from 10-minute P-wave windows
G. L. Choy, J. Boatwright
2007, Bulletin of the Seismological Society of America (97)
The rupture process of the Mw 9.1 Sumatra-Andaman earthquake lasted for approximately 500 sec, nearly twice as long as the teleseismic time windows between the P and PP arrival times generally used to compute radiated energy. In order to measure the P waves radiated by the entire earthquake, we analyze...
The viability of a nonenzymatic reductive citric acid cycle - Kinetics and thermochemistry
D.S. Ross
2007, Origins of Life and Evolution of the Biosphere (37) 61-65
The likelihood of a functioning nonenzymatic reductive citric acid cycle, recently proposed as the precursor to biosynthesis on early Earth, is examined on the basis of the kinetics and thermochemistry of the acetate → pyruvate → oxaloacetate → malate sequence. Using data derived from studies of...
Dominance of organic nitrogen from headwater streams to large rivers across the conterminous United States
D.H. Scott, J. Harvey, R. B. Alexander, G. Schwarz
2007, Global Biogeochemical Cycles (21)
The frequency and magnitude of hypoxic areas in coastal waterbodies are increasing across the globe, partially in response to the increase in nitrogen delivery from the landscape (Diaz, 2001; Rabalais et al., 2002). Although studies of annual total nitrogen and nitrate yields have greatly improved understanding of the contaminant sources...
Diet composition of larval and young-of-year shovelnose sturgeon in the Upper Missouri River
Patrick Braaten, D.B. Fuller, Nathan McClenning
2007, Journal of Applied Ichthyology (23) 516-520
Obtaining food following the transition from endogenous to exogenous feeding and during the first year of life is a critical event that strongly influences growth and survival of young-of-year fishes. For shovelnose sturgeon Scaphirhynchus platorynchus, limited information is available on food habits during the first year of life. The objective of...
Welcome to the National Wetlands Research Center Library: Successful Research Begins @ Your Library
Linda Broussard
2007, Fact Sheet 2007-3033
The National Wetlands Research Center (NWRC) library is part of the U.S. Geological Survey (USGS) and is the only USGS library dedicated to wetland science. The mission of the NWRC library is to support the research and information needs of scientists, managers, and support personnel by providing a specialized, scientific...
A rapid compatibility analysis of potential offshore sand sources for beaches of the Santa Barbara Littoral Cell
Neomi Mustain, G. B. Griggs, P.L. Barnard
2007, Conference Paper, Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
The beaches of the Santa Barbara Littoral Cell, which are narrow as a result of either natural and/or anthropogenic factors, may benefit from nourishment. Sand compatibility is fundamental to beach nourishment success and grain size is the parameter often used to evaluate equivalence. Only after understanding which sand sizes naturally...
Spawning distribution of sockeye salmon in a glacially influenced watershed: The importance of glacial habitats
Daniel B. Young, C.A. Woody
2007, Transactions of the American Fisheries Society (136) 452-459
The spawning distribution of sockeye salmon Oncorhynchus nerka was compared between clear and glacially turbid habitats in Lake Clark, Alaska, with the use of radiotelemetry. Tracking of 241 adult sockeye salmon to 27 spawning locations revealed both essential habitats and the relationship between spawn timing and seasonal turbidity cycles. Sixty-six...
Toward a transport-based analysis of nutrient spiraling and uptake in streams
Robert L. Runkel
2007, Limnology and Oceanography: Methods (5) 50-62
Nutrient addition experiments are designed to study the cycling of nutrients in stream ecosystems where hydrologic and nonhydrologic processes determine nutrient fate. Because of the importance of hydrologic processes in stream ecosystems, a conceptual model known as nutrient spiraling is frequently employed. A central part of the nutrient spiraling approach...
Effects of population increase on cui-ui growth and maturation
G.G. Scoppettone, Peter H. Rissler
2007, Transactions of the American Fisheries Society (136) 331-340
Cui-ui Chasmistes cujus is endemic to Pyramid Lake, Nevada. The cui-ui population declined during much of the 20th century as a result of water diversion and the formation of a shallow and virtually impassable delta at the mouth of the Truckee River, its spawning habitat. The population increased more than...
Hazards from hydrothermally sealed volcanic conduits
B.W. Christenson, Cynthia A. Werner, A.G. Reyes, S. Sherburn, B.J. Scott, C.P. Miller, M.J. Rosenburg, A.W. Hurst, K.A. Britten
2007, Eos, Transactions, American Geophysical Union (88) 53-55
The 17 March 2006 eruption from Raoul Island (Kermadec arc, north of New Zealand) is interpreted as a magmatic‐hydrothermal event triggered by shaking associated with a swarm of local earthquakes. The eruption, which tragically claimed the life of New Zealand Department of Conservation Ranger Mark Kearney, occurred...
Nutrient (N, P) loads and yields at multiple scales and subbasin types in the Yukon River basin, Alaska
M.M. Dornblaser, Robert G. Striegl
2007, Journal of Geophysical Research G: Biogeosciences (112)
Loads and yields of dissolved and particulate nitrogen (N) and phosphorus (P) were measured and modeled at three locations on the Yukon River (YR) and on the Tanana and Porcupine Rivers in Alaska during 2001-2005. Total export of N and P upstream of Yukon Delta averaged 120 Gg N a-1...
Windy Mars: A dynamic planet as seen by the HiRISE camera
Nathan T. Bridges, Paul E. Geissler, Alfred S. McEwen, B.J. Thomson, Frank C. Chuang, Kenneth E. Herkenhoff, Laszlo Kestay, Sara Martinez-Alonso
2007, Geophysical Research Letters (34)
With a dynamic atmosphere and a large supply of particulate material, the surface of Mars is heavily influenced by wind-driven, or aeolian, processes. The High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter (MRO) provides a new view of Martian geology, with the ability to see decimeter-size...
Energy feedbacks of northern high-latitude ecosystems to the climate system due to reduced snow cover during 20th century warming
E.S. Euskirchen, A. V. McGuire, III F.S. Chapin
2007, Global Change Biology (13) 2425-2438
The warming associated with changes in snow cover in northern high-latitude terrestrial regions represents an important energy feedback to the climate system. Here, we simulate snow cover-climate feedbacks (i.e. changes in snow cover on atmospheric heating) across the Pan-arctic over two distinct warming periods during the 20th century, 1910-1940 and...
Growth rate differences between resident native brook trout and non-native brown trout
S.M. Carlson, A.P. Hendry, Benjamin Letcher
2007, Journal of Fish Biology (71) 1430-1447
Between species and across season variation in growth was examined by tagging and recapturing individual brook trout Salvelinus fontinalis and brown trout Salmo trutta across seasons in a small stream (West Brook, Massachusetts, U.S.A.). Detailed information on body size and growth are presented to (1) test whether the two species...
Litterfall production along successional and altitudinal gradients of subtropical monsoon evergreen broadleaved forests in Guangdong, China
G. Zhou, L. Guan, X. Wei, Dongxiao Zhang, Q. Zhang, J. Yan, D. Wen, J. Paul Liu, S. Liu, Z. Huang, G. Kong, J. Mo, Q. Yu
2007, Plant Ecology (188) 77-89
Evaluation of litterfall production is important for understanding nutrient cycling, forest growth, successional pathways, and interactions with environmental variables in forest ecosystems. Litterfall was intensively studied during the period of 1982-2001 in two subtropical monsoon vegetation gradients in the Dinghushan Biosphere Reserve, Guangdong Province, China. The two gradients include: (1)...
Seasonal variation in nutrient retention during inundation of a short-hydroperiod floodplain
G.B. Noe, Cliff R. Hupp
2007, River Research and Applications (23) 1088-1101
Floodplains are generally considered to be important locations for nutrient retention or inorganic-to-organic nutrient conversions in riverine ecosystems. However, little is known about nutrient processing in short-hydroperiod floodplains or seasonal variation in floodplain nutrient retention. Therefore, we quantified the net uptake, release or transformation of nitrogen (N), phosphorus (P) and...
Mass balances of mercury and nitrogen in burned and unburned forested watersheds at Acadia National Park, Maine, USA
S.J. Nelson, K.B. Johnson, J. S. Kahl, T.A. Haines, I.J. Fernandez
2007, Environmental Monitoring and Assessment (126) 69-80
Precipitation and streamwater samples were collected from 16 November 1999 to 17 November 2000 in two watersheds at Acadia National Park, Maine, and analyzed for mercury (Hg) and dissolved inorganic nitrogen (DIN, nitrate plus ammonium). Cadillac Brook watershed burned in a 1947 fire that destroyed vegetation and soil organic matter....
Sandy signs of a tsunami's onshore depth and speed
K. Huntington, J. Bourgeois, G. Gelfenbaum, P. Lynett, B. E. Jaffe, H. Yeh, R. Weiss
2007, Eos, Transactions, American Geophysical Union (88) 577-578
Tsunamis rank among the most devastating and unpredictable natural hazards to affect coastal areas. Just 3 years ago, in December 2004, the Indian Ocean tsunami caused more than 225,000 deaths. Like many extreme events, however, destructive tsunamis strike rarely enough that written records span too little time to quantify tsunami...
Mount St. Helens Petrology Workshop
Michael C. Rowe, John S. Pallister, Anita Grunder
2007, Eos, Transactions, American Geophysical Union (88) 15-15
Following seismic activity in late September 2004, the current eruption of Mount St. Helens began with an explosive steam and ash emission on 1 October 2004, with hot dacite emerging from the crater floor on 11 October 2004. Nearly two years later, with more than 80 million cubic meters of...
A crustal seismic velocity model for the UK, Ireland and surrounding seas
A. Kelly, R.W. England, Peter K.H. Maguire
2007, Geophysical Journal International (171) 1172-1184
A regional model of the 3-D variation in seismic P-wave velocity structure in the crust of NW Europe has been compiled from wide-angle reflection/refraction profiles. Along each 2-D profile a velocity–depth function has been digitised at 5 km intervals. These 1-D velocity functions were mapped into three dimensions using ordinary...
Modeling englacial radar attenuation at Siple Dome, West Antarctica, using ice chemistry and temperature data
J.A. MacGregor, D.P. Winebrenner, H. Conway, K. Matsuoka, P.A. Mayewski, G.D. Clow
2007, Journal of Geophysical Research F: Earth Surface (112)
The radar reflectivity of an ice-sheet bed is a primary measurement for discriminating between thawed and frozen beds. Uncertainty in englacial radar attenuation and its spatial variation introduces corresponding uncertainty in estimates of basal reflectivity. Radar attenuation is proportional to ice conductivity, which depends on the concentrations of acid and...
Sorted bed forms as self-organized patterns: 2. complex forcing scenarios
Giovanni Coco, A. Brad Murray, Malcom O. Green, E. Robert Thieler, T.M. Hume
2007, Journal of Geophysical Research F: Earth Surface (112)
We employ a numerical model to study the development of sorted bed forms under a variety of hydrodynamic and sedimentary conditions. Results indicate that increased variability in wave height decreases the growth rate of the features and can potentially give rise to complicated, a priori unpredictable, behavior. This happens because...
Generation and propagation of nonlinear internal waves in Massachusetts Bay
A. Scotti, Robert C. Beardsley, B. Butman
2007, Journal of Geophysical Research C: Oceans (112)
During the summer, nonlinear internal waves (NLIWs) are commonly observed propagating in Massachusetts Bay. The topography of the area is unique in the sense that the generation area (over Stellwagen Bank) is only 25 km away from the shoaling area, and thus it represents an excellent natural laboratory to study...
Transport and degradation of chlorofluorocarbons (CFCs) in the pyritic Rabis Creek aquifer, Denmark
Klaus Hinsby, Anker Lajer Højberg, Peter Engesgaard, K.H. Jensen, F. D. Larsen, Niel Plummer, Eurybiades Busenberg
2007, Water Resources Research (43)
Vertical profiles of the chlorofluorocarbons CFC‐11, CFC‐12, and CFC‐113 penetrating aerobic and anaerobic parts of a shallow sandy aquifer show that the CFC gases are degraded in the <1 m thick transition zone from aerobic to anaerobic groundwater in a pyritic sand aquifer at Rabis Creek, Denmark. Two‐dimensional solute transport...
Relationships of cadmium, mercury, and selenium with nutrient reserves of female lesser scaup (Aythya affinis) during winter and spring migration
M.J. Anteau, Alan D. Afton, Christine M. Custer, Thomas W. Custer
2007, Environmental Toxicology and Chemistry (26) 515-520
Trace elements may have important effects on body condition of ducks during spring migration, because individuals are experiencing energetically costly events (e.g., migration, nutrient reserve accumulation, pair formation, feather molt, and ovarian follicle development). We examined relationships among hepatic cadmium, mercury, and selenium concentrations (microg/g dry wt) and nutrient reserves...
