Atrazine retention and degradation in the vadose zone at a till plain site in central Indiana
E.R. Bayless
2001, Ground Water (39) 169-180
The vadose zone was examined as an environmental compartment where significant quantities of atrazine and its degradation compounds may be stored and transformed. The vadose zone was targeted because regional studies in the White River Basin indicated a large discrepancy between the mass of atrazine applied to fields and the...
Lethality of sea lamprey attacks on lake trout in relation to location on the body surface
Roger A. Bergstedt, Clifford P. Schneider, Robert O’Gorman
2001, Transactions of the American Fisheries Society (130) 336-340
We compared the locations of healed attack marks of the sea lamprey Petromyzon marinus on live lake trout Salvelinus namaycush with those of unhealed attack marks on dead lake trout to determine if the lethality of a sea lamprey attack was related to attack location. Lake trout were collected from Lake Ontario, live fish...
International collaboration: The cornerstone of satellite land remote sensing in the 21st century
G. Bryan Bailey, Donald T. Lauer, David M. Carneggie
2001, Space Policy (17) 161-169
Satellite land remotely sensed data are used by scientists and resource managers world-wide to study similar multidisciplinary earth science problems. Most of their information requirements can be met by a small number of satellite sensor types. Moderate-resolution resource satellites and low-resolution environmental satellites are the most prominent of these, and...
Vegetation and paleoclimate of the last interglacial period, central Alaska
D.R. Muhs, T. A. Ager, J. E. Beget
2001, Quaternary Science Reviews (20) 41-61
The last interglacial period is thought to be the last time global climate was significantly warmer than present. New stratigraphic studies at Eva Creek, near Fairbanks, Alaska indicate a complex last interglacial record wherein periods of loess deposition alternated with periods of soil formation. The Eva Forest Bed appears to...
Amplitude blanking related to the pore-filling of gas hydrate in sediments
Myung W. Lee, William P. Dillon
2001, Marine Geophysical Research (22) 101-109
Seismic indicators of gas-hydrate-bearing sediments include elevated interval velocities and amplitude reduction of seismic reflections owing to the presence of gas hydrate in the sediment's pore spaces. However, large amplitude blanking with relatively low interval velocities observed at the Blake Ridge has been enigmatic because realistic seismic models were absent...
Early life history of the northern pikeminnow in the lower Columbia River basin
D.M. Gadomski, C.A. Barfoot, J.M. Bayer, T.P. Poe
2001, Transactions of the American Fisheries Society (130) 250-262
The northern pikeminnow Ptychocheilus oregonensis is a large, native cyprinid in the Columbia River basin that has persisted in spite of substantial habitat alterations. During the months of June to September 1993-1996, we investigated the temporal and spatial patterns of northern pikeminnow spawning, along with describing larval drift and characterizing...
Wildfire-related debris-flow initiation processes, Storm King Mountain, Colorado
S.H. Cannon, R. M. Kirkham, M. Parise
2001, Geomorphology (39) 171-188
A torrential rainstorm on September 1, 1994 at the recently burned hillslopes of Storm King Mountain, CO, resulted in the generation of debris flows from every burned drainage basin. Maps (1:5000 scale) of bedrock and surficial materials and of the debris-flow paths, coupled with a 10-m Digital Elevation Model (DEM)...
Late Cenozoic regional collapse due to evaporite flow and Dissolution in the Carbondale Collapse Center, West-Central Colorado
R. M. Kirkham, R. K. Streufert, J. R. Budahn, Michael J. Kunk, W. J. Perry
2001, Mountain Geologist (38) 193-210
Dissolution and flow of Pennsylvanian evaporitic rocks in west-central Colorado created the Carbondale Collapse Center, a 450 mi2 structural depression with about 4,000 ft of vertical collapse during the late Cenozoic. This paper describes evidence of collapse in the lower Roaring Fork River valley. Both the lateral extent and amount...
Droughts, epic droughts and droughty centuries - lessons from a California paleoclimatic record: a PACLIM 2001 meeting report
M. D. Dettinger
2001, Interagency Ecological Program Newsletter (14) 51-53
During the early 1990s (but echoing studies by S.T. Harding at the University of California, from as early as the 1930s), several lines of paleoclimate evidence in and around the Sierra Nevada Range have provided the water community in California with some real horror stories. By studying ancient tree stumps...
Shallow-storage conditions for the rhyolite of the 1912 eruption at Novarupta, Alaska
Michelle L. Coombs, James E. Gardner
2001, Geology (29) 775-778
Recent studies have proposed contrasting models for the plumbing system that fed the 1912 eruption of Novarupta, Alaska. Here, we investigate the conditions under which the rhyolitic part of the erupted magma last resided in the crust prior to eruption. Geothermometry suggests that the rhyolite was held at ∼800-850 °C,...
Subglacial sediments: A regional geological template for iceflow in West Antarctica
M. Studinger, R.E. Bell, D. D. Blankenship, C. A. Finn, R.A. Arko, D. L. Morse, I. Joughin
2001, Geophysical Research Letters (28) 3493-3496
We use aerogeophysical data to estimate the distribution of marine subglacial sediments and fault-bounded sedimentary basins beneath the West Antarctic Ice Sheet (WAIS). We find that significant ice flow occurs exclusively in regions covered by subglacial sediments. The onsets and lateral margins of ice streams coincide with the limit of...
Thermal thickness and evolution of Precambrian lithosphere: A global study
I.M. Artemieva, Walter D. Mooney
2001, Journal of Geophysical Research B: Solid Earth (106) 16387-16414
The thermal thickness of Precambrian lithosphere is modeled and compared with estimates from seismic tomography and xenolith data. We use the steady state thermal conductivity equation with the same geothermal constraints for all of the Precambrian cratons (except Antarctica) to calculate the temperature distribution in the stable...
The roughness of natural terrain: A planetary and remote sensing perspective
Michael K. Shepard, Bruce A. Campbell, Mark H. Bulmer, Lisa R. Gaddis, Tom G. Farr, Jeffrey J. Plaut
2001, Journal of Geophysical Research E: Planets (106) 32777-32795
We examine the various methods and parameters in common use for quantifying and reporting surface topographic "roughness." It is shown that scale-dependent roughness parameters are almost always required, though not widely used. We suggest a method of standardizing the parameters that are computed and reported so that topographic data gathered...
Bird-landscape relations in the Chihuahuan Desert: Coping with uncertainties about predictive models
K.J. Gutzwiller, W.C. Barrow Jr.
2001, Ecological Applications (11) 1517-1532
During the springs of 1995–1997, we studied birds and landscapes in the Chihuahuan Desert along part of the Texas–Mexico border. Our objectives were to assess bird–landscape relations and their interannual consistency and to identify ways to cope with associated uncertainties that undermine confidence in using such relations in conservation decision...
A model for rotation and shape of Asteroid 9969 Braille from ground-based observations and images obtained during the deep space 1 (DS1) flyby
J. Oberst, S. Mottola, Martino M. Di, M. Hicks, B. Buratti, L. Soderblom, N. Thomas
2001, Icarus (153) 16-23
Image data from the DS1 encounter with Asteroid 9969 Braille and data from a coordinated ground-based photometric observing campaign are combined to study the physical properties of this small Mars crosser. From telescope data the object's brightness was found to vary by up to 0.5 mag from night to night,...
Solute transport along preferential flow paths in unsaturated fractures
Grace W. Su, Jil T. Geller, Karsten Pruess, James R. Hunt
2001, Water Resources Research (37) 2481-2491
Laboratory experiments were conducted to study solute transport along preferential flow paths in unsaturated, inclined fractures. Qualitative aspects of solute transport were identified in a miscible dye tracer experiment conducted in a transparent replica of a natural granite fracture. Additional experiments were conducted to measure the breakthrough curves of a...
Crustal structure and tectonics from the Los Angeles basin to the Mojave Desert, southern California
G. S. Fuis, T. Ryberg, N. J. Godfrey, D. A. Okaya, J.M. Murphy
2001, Geology (29) 15-18
A seismic refraction and low-fold reflection survey, known as the Los Angeles Region Seismic Experiment (LARSE), was conducted along a transect (line 1) extending from Seal Beach, California, to the Mojave Desert, crossing the Los Angeles and San Gabriel Valley basins and San Gabriel Mountains. The chief result of this...
Comparisons of ground motions from the 1999 Chi-Chi, earthquake with empirical predictions largely based on data from California
D.M. Boore
2001, Bulletin of the Seismological Society of America (91) 1212-1217
This article has the modest goal of comparing the ground motions recorded during the 1999 Chi-Chi, Taiwan, mainshock with predictions from four empirical-based equations commonly used for western North America; these empirical predictions are largely based on data from California. Comparisons are made for peak acceleration and 5%-damped response spectra...
Distribution of algae in the San Joaquin River, California, in relation to nutrient supply, salinity and other environmental factors
H.V. Leland, L. R. Brown, D. K. Mueller
2001, Freshwater Biology (46) 1139-1167
1. The taxonomic composition and biomass of the phytoplankton and the taxonomic composition of the phytobenthos of the San Joaquin River and its major tributaries were examined in relation to water chemistry, habitat and flow regime. Agricultural drainage and subsurface flow contribute to a complex gradient of salinity and nutrients...
Diapause in copepods (Crustacea) from ephemeral habitats with different hydroperiods in Everglades National Park (Florida, U.S.A.)
M.C. Bruno, W.F. Loftus, J.W. Reid, S.A. Perry
2001, Conference Paper, Hydrobiologia
Water management practices in the Everglades have severely stressed the natural system, particularly by reducing the hydroperiods of much of the region. During the dry season of 1999, we investigated the influence of hydroperiod on the species composition and dormancy patterns of freshwater copepod communities in seasonal wetlands of Everglades...
Juxtaposition of Neoproterozoic units along the Baruda - Tulu Dimtu shear-belt in the East African Orogen of western Ethiopia
A. Braathen, Tor Grenne, M.G. Selassie, T. Worku
2001, Precambrian Research (107) 215-234
Amalgamation of East and West Gondwanaland during the Neoproterozoic East African Orogen is recorded by several shear-belts or 'suture zones', some of which are associated with ultramafic and mafic complexes that have been interpreted as ophiolite fragments. The Baruda shear-belt is a major structure of this type that belongs to...
Recent growth of conifer species of western North America: Assessing spatial patterns of radial growth trends
D. McKenzie, Amy E. Hessl, D. L. Peterson
2001, Canadian Journal of Forest Research (31) 526-538
We explored spatial patterns of low-frequency variability in radial tree growth among western North American conifer species and identified predictors of the variability in these patterns. Using 185 sites from the International Tree-Ring Data Bank, each of which contained 10a??60 raw ring-width series, we rebuilt two chronologies for each site,...
Magmatic gas scrubbing: Implications for volcano monitoring
R.B. Symonds, T.M. Gerlach, M.H. Reed
2001, Journal of Volcanology and Geothermal Research (108) 303-341
Despite the abundance of SO2(g) in magmatic gases, precursory increases in magmatic SO2(g) are not always observed prior to volcanic eruption, probably because many terrestrial volcanoes contain abundant groundwater or surface water that scrubs magmatic gases until a dry pathway to the atmosphere is established. To better understand scrubbing and...
Empirical Green's function analysis of recent moderate events in California
S. E. Hough
2001, Bulletin of the Seismological Society of America (91) 456-467
I use seismic data from portable digital stations and the broadband Terrascope network in southern California to investigate radiated earthquake source spectra and discuss the results in light of previous studies on both static stress drop and apparent stress. Applying the empirical Green's function (EGF) method to two sets of...
High CO2 emissions through porous media: Transport mechanisms and implications for flux measurement and fractionation
William C. Evans, M.L. Sorey, B. M. Kennedy, David A. Stonestrom, J.D. Rogie, D.L. Shuster
2001, Chemical Geology (177) 15-29
Diffuse emissions of CO2 are known to be large around some volcanoes and hydrothermal areas. Accumulation-chamber measurements of CO2 flux are increasingly used to estimate the total magmatic or metamorphic CO2 released from such areas. To assess the performance of accumulation chamber systems at fluxes one...
