Responses of riparian cottonwoods to alluvial water table declines
M. L. Scott, P.B. Shafroth, G.T. Auble
1999, Environmental Management (23) 347-358
Human demands for surface and shallow alluvial groundwater have contributed to the loss, fragmentation, and simplification of riparian ecosystems. Populus species typically dominate riparian ecosystems throughout arid and semiarid regions of North American and efforts to minimize loss of riparian Populus requires an integrated understanding of the role of surface...
A record of hydrocarbon input to San Francisco Bay as traced by biomarker profiles in surface sediment and sediment cores
F. D. Hostettler, W. E. Pereira, K.A. Kvenvolden, A. VanGeen, S. N. Luoma, C. C. Fuller, R. Anima
1999, Marine Chemistry (64) 115-127
San Francisco Bay is one of the world's largest urbanized estuarine systems. Its water and sediment receive organic input from a wide variety of sources; much of this organic material is anthropogenically derived. To document the spatial and historical record of the organic contaminant input, surficial sediment from 17 sites...
The effects of chlorpyrifos on cholinesterase activity and foraging behavior in the dragonfly, Anax junius (Odonata)
S.K. Brewer, G.J. Atchison
1999, Hydrobiologia (394) 201-208
We examined head capsule cholinesterase (ChE) and foraging behavior in nymphs of the dragonfly, Anax junius, exposed for 24 h to 0.2, 0.6 and 1.0 ??g l-1 of the organophosphorus (OP) insecticide, chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate]. The invertebrate community is an important component of the structure and function of wetland...
Time-budgets of Common Murres at a declining and increasing colony in Alaska
Stephani Zador, John F. Piatt
1999, Condor (101) 149-152
We observed Common Murres (Uria aalge) at two breeding sites in lower Cook Inlet, Alaska, to determine whether food availability was reflected in their time-budgets at each colony. Catches of forage fish in nets and relative biomass were greater around a murre colony that has been increasing for the past...
Effects of wind turbines on upland nesting birds in Conservation Reserve Program grasslands
K.L. Leddy, K.F. Higgins, D.E. Naugle
1999, The Wilson Bulletin (111) 100-104
Grassland passerines were surveyed during summer 1995 on the Buffalo Ridge Wind Resource Area in southwestern Minnesota to determine the relative influence of wind turbines on overall densities of upland nesting birds in Conservation Reserve Program (CRP) grasslands. Birds were surveyed along 40 m fixed width transects that were placed...
D/H isotope ratios of kerogen, bitumen, oil, and water in hydrous pyrolysis of source rocks containing kerogen types I, II, IIS, and III
A. Schimmelmann, M. D. Lewan, R. P. Wintsch
1999, Geochimica et Cosmochimica Acta (63) 3751-3766
Immature source rock chips containing different types of kerogen (I, II, IIS, III) were artificially matured in isotopically distinct waters by hydrous pyrolysis and by pyrolysis in supercritical water. Converging isotopic trends of inorganic (water) and organic (kerogen, bitumen, oil) hydrogen with...
Testing earthquake prediction algorithms: Statistically significant advance prediction of the largest earthquakes in the Circum-Pacific, 1992-1997
V.G. Kossobokov, L.L. Romashkova, V. I. Keilis-Borok, J. H. Healy
1999, Physics of the Earth and Planetary Interiors (111) 187-196
Algorithms M8 and MSc (i.e., the Mendocino Scenario) were used in a real-time intermediate-term research prediction of the strongest earthquakes in the Circum-Pacific seismic belt. Predictions are made by M8 first. Then, the areas of alarm are reduced by MSc at the cost that some earthquakes are missed in the...
Grenville age of basement rocks in Cape May NJ well: New evidence for Laurentian crust in U.S. Atlantic Coastal Plain basement Chesapeake terrane
R. E. Sheridan, T.J. Maguire, M.D. Feigenson, L.C. Patino, R.A. Volkert
1999, Journal of Geodynamics (27) 623-633
The Chesapeake terrane of the U.S. mid-Atlantic Coastal Plain basement is bounded on the northwest by the Salisbury positive gravity and magnetic anomaly and extends to the southeast as far as the Atlantic coast. It underlies the Coastal Plain of Virginia, Maryland, Delaware and southern New Jersey. Rubidium/Strontium dating of...
Imager for Mars Pathfinder (IMP) image calibration
R.J. Reid, P. H. Smith, M. Lemmon, R. Tanner, M. Burkland, E. Wegryn, J. Weinberg, R. Marcialis, D.T. Britt, N. Thomas, R. Kramm, A. Dummel, D. Crowe, B.J. Bos, J.F. Bell III, P. Rueffer, F. Gliem, J. R. Johnson, J.N. Maki, Kenneth E. Herkenhoff, Robert B. Singer
1999, Journal of Geophysical Research E: Planets (104) 8907-8925
The Imager for Mars Pathfinder returned over 16,000 high-quality images from the surface of Mars. The camera was well-calibrated in the laboratory, with <5% radiometric uncertainty. The photometric properties of two radiometric targets were also measured with 3% uncertainty. Several data sets acquired during the cruise and on Mars confirm...
Subsurface gas offshore of northern California and its link to submarine geomorphology
J.W. Yun, D.L. Orange, M.E. Field
1999, Marine Geology (154) 357-368
The northern California continental margin contains evidence of abundant subsurface gas and numerous seafloor features that suggest a causative link between gas expulsion and geomorphology. Analyses of seismic reflection, sidescan sonar, and high-resolution multibeam bathymetric data show that the occurrence of subbottom gas and the migration processes beneath the shelf...
Regeneration alternatives for upland white spruce after burning and logging in interior Alaska
R.V. Densmore, G.P. Juday, J.C. Zasada
1999, Canadian Journal of Forest Research (29) 413-423
Site-preparation and regeneration methods for white spruce (Picea glauca (Moench) Voss) were tested near Fairbanks, Alaska, on two upland sites which had been burned in a wildfire and salvage logged. After 5 and 10 years, white spruce regeneration did not differ among the four scarification methods but tended to be...
Comparing global models of terrestrial net primary productivity (NPP): Global pattern and differentiation by major biomes
D. W. Kicklighter, A. Bondeau, A. L. Schloss, J. Kaduk, A. D. McGuire
1999, Global Change Biology (5) 16-24
Annual and seasonal net primary productivity estimates (NPP) of 15 global models across latitudinal zones and biomes are compared. The models simulated NPP for contemporary climate using common, spatially explicit data sets for climate, soil texture, and normalized difference vegetation index (NDVI). Differences among NPP estimates varied over space and...
Late Quaternary slip rate and seismic hazards of the West Klamath Lake fault zone near Crater Lake, Oregon Cascades
C. R. Bacon, M. A. Lanphere, D.E. Champion
1999, Geology (27) 43-46
Crater Lake caldera is at the north end of the Klamath graben, where this N10°W-trending major Basin and Range structure impinges upon the north-south–trending High Cascades volcanic arc. East-facing normal faults, typically 10–15 km long, form the West Klamath Lake fault zone, which bounds the graben on its west side....
Seismic tomography as a tool for measuring stress in mines
Douglas F. Scott, T.J. Williams, D.K. Denton, M.J. Friedel
1999, Mining Engineering (51) 77-80
Spokane Research Center personnel have been investigating the use of seismic tomography to monitor the behavior of a rock mass, detect hazardous ground conditions and assess the mechanical integrity of a rock mass affected by mining. Seismic tomography can be a valuable tool for determining relative stress in deep, >1,220-m...
Accretion in the wake of terrane collision: The Neogene accretionary wedge off Kenai Peninsula, Alaska
J. Fruehn, Roland E. von Huene, M. A. Fisher
1999, Tectonics (18) 263-277
Subduction accretion and repeated terrane collision shaped the Alaskan convergent margin. The Yakutat Terrane is currently colliding with the continental margin below the central Gulf of Alaska. During the Neogene the terrane's western part was subducted after which a sediment wedge accreted along the northeast Aleutian Trench. This wedge incorporates...
ENSO and hydrologic extremes in the western United States
D.R. Cayan, K.T. Redmond, L.G. Riddle
1999, Journal of Climate (12) 2881-2893
Frequency distributions of daily precipitation in winter and daily stream flow from late winter to early summer, at several hundred sites in the western United States, exhibit strong and systematic responses to the two phases of ENSO. Most of the stream flows considered are driven by snowmelt. The Southern Oscillation...
Algal toxins
Lynn H. Creekmore
1999, Report, Field manual of wildlife diseases: General field procedures and diseases of birds
Periodic blooms of algae, including true algae, dinoflagellates, and cyanobacteria or blue-green algae have been reported in marine and freshwater bodies throughout the world. Although many blooms are merely an aesthetic nuisance, some species of algae produce toxins that kill fish, shellfish, humans, livestock and wildlife. Pigmented blooms of toxinproducing...
Status and biology of the Steller's eider in Yakutia, Russia
Andrei G. Degtyarev, S.M. Sleptsov, S.P. Troev, John M. Pearce, Margaret R. Petersen
1999, Casarca (5) 249-262
No abstract available....
Tectonic and regional metamorphic implications of the discovery of Middle Ordovician conodonts in cover rocks east of the Green Mountain massif, Vermont
N. M. Ratcliffe, A. G. Harris, G. J. Walsh
1999, Canadian Journal of Earth Sciences (36) 371-382
Middle Ordovician (late Arenigian - early Caradocian) conodonts were recovered from a dolostone lens in carbonaceous schist 30 m below the base of the Pinney Hollow Formation in the Eastern Cover sequence near West Bridgewater, Vermont. These are the first reported fossils from the metamorphic cover sequence rocks east of...
Methane flux in subalpine wetland and unsaturated soils in the southern Rocky Mountains
K.P. Wickland, Robert G. Striegl, S.K. Schmidt, M.A. Mast
1999, Global Biogeochemical Cycles (13) 101-113
Methane exchange between the atmosphere and subalpine wetland and unsaturated soils was evaluated over a 15-month period during 1995-1996. Four vegetation community types along a moisture gradient (wetland, moist-grassy, moist-mossy, and dry) were included in a 100 m sampling transect situated at 3200 m elevation in Rocky Mountain National Park,...
Voluminous volcanism on early mars revealed in valles marineris
A. S. McEwen, M. C. Malin, M. H. Carr, W.K. Hartmann
1999, Nature (397) 584-586
The relative rates and importance of impact cratering, volcanism, erosion, and the deposition of sediments to the early geological history of Mars are poorly known. That history is recorded in the upper crust of the planet, which is best exposed along the 4,000km-long canyon system called Valles Marineris. Previous studies...
Comparison of post-fire seedling establishment between scrub communities in mediterranean and non-mediterranean climate ecosystems
M.E. Carrington, Jon E. Keeley
1999, Journal of Ecology (87) 1025-1036
I Both fire regimes and the conditions under which fires occur vary widely. Abiotic conditions (such as climate) in combination with fire season, frequency and intensity could influence vegetation responses to fire. A variety of adaptations facilitate post-fire recruitment in mediterranean climate ecosystems, but responses of other communities are less...
Determination of submicrogram-per-liter concentrations of caffeine in surface water and groundwater samples by solid-phase extraction and liquid chromatography
M.R. Burkhardt, P.P. Soliven, S.L. Werner, D.G. Vaught
1999, Journal of AOAC International (82) 161-166
A method for determining submicrogram-per-liter concentrations of caffeine in surface water and groundwater samples has been developed. Caffeine is extracted from a 1 L water sample with a 0.5 g graphitized carbon-based solid-phase cartridge, eluted with methylene chloride-methanol (80 + 20, v/v), and analyzed by liquid chromatography with photodiode-array detection....
General geology and geomorphology of the Mars Pathfinder landing site
A. W. Ward, Lisa R. Gaddis, Randolph L. Kirk, Laurence A. Soderblom, K. L. Tanaka, M.P. Golombek, T. J. Parker, Ronald Greeley, R.O. Kuzmin
1999, Journal of Geophysical Research E: Planets (104) 8555-8571
The Mars Pathfinder (MPF) spacecraft landed on relatively young (late Hesperian-early Amazonian; 3.1-0.7 Ga) plains in Chryse Planitia near the mouth of Ares Vallis. Images returned from the spacecraft reveal a complex landscape of ridges and troughs, large hills and crater rims, rocks and boulders of various sizes and shapes,...
Local tsunamis and distributed slip at the source
E.L. Geist, R. Dmowska
1999, Pure and Applied Geophysics (154) 485-512
Variations in the local tsunami wave field are examined in relation to heterogeneous slip distributions that are characteristic of many shallow subduction zone earthquakes. Assumptions inherent in calculating the coseismic vertical displacement field that defines the initial condition for tsunami propagation are examined. By comparing the seafloor displacement from uniform...
