Hydrated salt minerals on Europa's surface from the Galileo near-infrared mapping spectrometer (NIMS) investigation
T. B. McCord, G. B. Hansen, D. L. Matson, T. V. Johnson, J.K. Crowley, F. P. Fanale, R. W. Carlson, W. D. Smythe, P. D. Martin, C. A. Hibbitts, J. C. Granahan, A. Ocampo
1999, Journal of Geophysical Research E: Planets (104) 11827-11851
We reported evidence of heavily hydrated salt minerals present over large areas of Europa's surface from analysis of reflectance spectra returned by the Galileo mission near infrared mapping spectrometer (NIMS) [McCord et al., 1997a, b, 1998a, b]. Here we elaborate on this earlier evidence, present spatial distributions of these minerals,...
UCODE, a computer code for universal inverse modeling
E. P. Poeter, M. C. Hill
1999, Computers & Geosciences (25) 457-462
This article presents the US Geological Survey computer program UCODE, which was developed in collaboration with the US Army Corps of Engineers Waterways Experiment Station and the International Ground Water Modeling Center of the Colorado School of Mines. UCODE performs inverse modeling, posed as a parameter-estimation problem, using nonlinear regression....
Nearshore versus offshore copper loading in Lake Superior sediments: Implications for transport and cycling
J.J. Kolak, D.T. Long, W.C. Kerfoot, T.M. Beals, Steven J. Eisenreich
1999, Journal of Great Lakes Research (25) 611-624
A thorough understanding of the fate and transport of metals in Lake Superior is necessary in order to predict the ability of Lake Superior to recover from anthropogenic perturbations (copper mining). Sediment cores were collected from nearshore and offshore sites in...
Historical trends in salinity and substrate in central Florida Bay: A paleoecological reconstruction using modern analogue data
G. L. Brewster-Wingard, S. E. Ishman
1999, Estuaries (22) 369-383
Understanding the natural spatial and temporal variability that exists within an ecosystem is a critical component of efforts to restore systems to their natural state. Analysis of benthic foraminifers and molluscs from modern monitoring sites within Florida Bay allows us to determine what environmental parameters control spatial and temporal variability...
Potential impacts on Colorado Rocky Mountain weather due to land use changes on the adjacent Great Plains
T.N. Chase, R.A. Pielke Sr., T.G.F. Kittel, Jill Baron, T.J. Stohlgren
1999, Journal of Geophysical Research D: Atmospheres (104) 16673-16690
Evidence from both meteorological stations and vegetational successional studies suggests that summer temperatures are decreasing in the mountain-plain system in northeast Colorado, particularly since the early 1980s. These trends are coincident with large changes in regional land cover. Trends in global, Northern Hemisphere and continental surface temperatures over the same...
Tectonics of Atlantic Canada
H. Williams, S.A. Dehler, A.C. Grant, G.N. Oakey
1999, Geoscience Canada (26) 51-70
The tectonic history of Atlantic Canada is summarized according to a model of multiple ocean opening-closing cycles. The modern North Atlantic Ocean is in the opening phase of its cycle. It was preceded by an early Paleozoic lapetus Ocean whose cycle led to formation of the Appalachian Orogen. lapetus was...
A goodness-of-fit test for capture-recapture model Mt under closure
T.R. Stanley, K.P. Burnham
1999, Biometrics (55) 366-375
A new, fully efficient goodness-of-fit test for the time-specific closed-population capture-recapture model Mt is presented. This test is based on the residual distribution of the capture history data given the maximum likelihood parameter estimates under model Mt, is partitioned into informative components, and is based on chi-square statistics. Comparison of this test with...
Antarctic glacial history from numerical models and continental margin sediments
P.F. Barker, P. J. Barrett, A. K. Cooper, P. Huybrechts
1999, Palaeogeography, Palaeoclimatology, Palaeoecology (150) 247-267
The climate record of glacially transported sediments in prograded wedges around the Antarctic outer continental shelf, and their derivatives in continental rise drifts, may be combined to produce an Antarctic ice sheet history, using numerical models of ice sheet response to temperature and sea-level change. Examination of published models suggests...
Applications and issues of GIS as tool for civil engineering modeling
S.B. Miles, C.L. Ho
1999, Journal of Computing in Civil Engineering (13) 144-152
A tool that has proliferated within civil engineering in recent years is geographic information systems (GIS). The goal of a tool is to supplement ability and knowledge that already exists, not to serve as a replacement for that which is lacking. To secure the benefits and avoid misuse of a...
Moment tensor solutions estimated using optimal filter theory: Global seismicity, 1997
S.A. Sipkin, C. G. Bufe, M.D. Zirbes
1999, Physics of the Earth and Planetary Interiors (114) 109-117
Moment tensor solutions, estimated using optimal filter theory, are listed for 218 moderate-to-large size earthquakes that occurred during 1997....
Environmental influences on potential recruitment of pink shrimp, Fatlantopenaeus duorarum, from Florida Bay nursery grounds
Joan A. Browder, V.R. Restrepo, J.K. Rice, M. B. Robblee, Z. Zein-Eldin
1999, Estuaries (22) 484-499
Two modeling approaches were used to explore the basis for variation in recruitment of pink shrimp, Farfantepenaeus duorarum, to the Tortugas fishing grounds. Emphasis was on development and juvenile densities on the nursery grounds. An exploratory simulation modeling exercise demonstrated large year-to-year variations in recruitment contributions to the Tortugas rink...
Chronologic model and transgressive-regressive signatures in the late neocene siliciclastic foundation (long key formation) of the Florida keys
L.A. Guertin, D.F. McNeill
1999, Journal of Sedimentary Research (69) 653-666
Recent drilling of continuous cores in southernmost Florida has documented a thick unit of upper Neogene siliciclastics subjacent to surficial shallow-water Quaternary carbonates exposed on islands of the Florida Keys. The siliciclastics comprise the Long Key Formation and were identified in two cores...
Reassessment of ice-age cooling of the tropical ocean and atmosphere
S. W. Hostetler, A.C. Mix
1999, Nature (399) 673-676
The CLIMAP project's reconstruction of past sea surface temperature inferred limited ice-age cooling in the tropical oceans. This conclusion has been controversial, however, because of the greater cooling indicated by other terrestrial and ocean proxy data. A new faunal sea surface temperature reconstruction, calibrated using the variation of foraminiferal species...
Integration of high-resolution seismic and aeromagnetic data for earthquake hazards evaluations: An example from the Willamette Valley, Oregon
L.M. Liberty, A.M. Trehu, R.J. Blakely, M.E. Dougherty
1999, Bulletin of the Seismological Society of America (89) 1473-1483
Aeromagnetic and high-resolution seismic reflection data were integrated to place constraints on the history of seismic activity and to determine the continuity of the possibly active, yet largely concealed Mount Angel fault in the Willamette Valley, Oregon. Recent seismic activity possibly related to...
General-circulation-model simulations of future snowpack in the western United States
G.J. McCabe, D.M. Wolock
1999, Conference Paper, Journal of the American Water Resources Association
April 1 snowpack accumulations measured at 311 snow courses in the western United States (U.S.) are grouped using a correlation-based cluster analysis. A conceptual snow accumulation and melt model and monthly temperature and precipitation for each cluster are used to estimate cluster-average April 1 snowpack. The conceptual snow model is...
Calcium ion binding to a soil fulvic acid using a donnan potential model
J.A. Marinsky, A. Mathuthu, J.H. Ephraim, M.M. Reddy
1999, Radiochimica Acta (84) 205-211
Calcium ion binding to a soil fulvic acid (Armadale Bh Horizon) was evaluated over a range of calcium ion concentrations, from pH 3.8 to 7.3, using potentiometric titrations and calcium ion electrode measurements. Fulvic acid concentration was constant (100 milligrams per liter) and calcium ion concentration varied up to 8...
The mathematics of movement
Douglas H. Johnson
1999, Prairie Naturalist (31) 125-127
Review of: Quantitative Analysis of Movement: Measuring and Modeling Population Redistribution in Animals and Plants. Peter Turchin. 1998. Sinauer Associates, Sunderland, MA. 306 pages. $38.95 (paper)....
A blood chemistry profile for lake trout
Carol Cotant Edsall
1999, Journal of Aquatic Animal Health (11) 81-86
A blood chemistry profile for lake trout Salvelinus namaycush was developed by establishing baseline ranges for several clinical chemistry tests (glucose, total protein, amylase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatine kinase, calcium, and magnesium). Measurements were made accurately and rapidly with a Kodak Ektachem DT60 Analyzer and the...
Stable isotope, chemical, and mineral compositions of the Middle Proterozoic Lijiaying Mn deposit, Shaanxi Province, China
Hsueh-Wen Yeh, James R. Hein, Jie Ye, Delian Fan
1999, Ore Geology Reviews (15) 55-69
The Lijiaying Mn deposit, located about 250 km southwest of Xian, is a high-quality ore characterized by low P and Fe contents and a mean Mn content of about 23%. The ore deposit occurs in shallow-water marine sedimentary rocks of probable Middle Proterozoic age. Carbonate minerals in the ore deposit...
Sidescan-sonar mapping of benthic trawl marks on the shelf and slope off Eureka, California
A. M. Friedlander, G.W. Boehlert, M.E. Field, J.E. Mason, J.V. Gardner, P. Dartnell
1999, Fishery Bulletin (97) 786-801
The abundance and orientation of trawl marks was quantified over an extensive portion (>2700 km2) of the Eureka, California, outer shelf and slope, an important commercial bottom trawling ground for such high-value species as rockfish, sole, and sablefish. Fishing logbook data indicate that the entire reporting area was trawled about...
Decadal variations in the strength of ENSO teleconnections with precipitation in the western United States
G.J. McCabe, M. D. Dettinger
1999, International Journal of Climatology (19) 1399-1410
Changing patterns of correlations between the historical average June-November Southern Oscillation Index (SOI) and October-March precipitation totals for 84 climate divisions in the western US indicate a large amount of variability in SOI/precipitation relations on decadal time scales. Correlations of western US precipitation with SOI and other indices of tropical...
Deformation across the Alaska-Aleutian Subduction Zone near Kodiak
J.C. Savage, J. L. Svarc, W.H. Prescott
1999, Geophysical Research Letters (26) 2117-2120
The Kodiak-Katmai geodetic array, nine monuments distributed along a profile trending north-northwestward across Kodiak Island and the Alaska Peninsula, was surveyed in 1993, 1995 and 1997 to determine the deformation at the Alaska-Aleutian subduction zone. Velocities on Kodiak island measured relative to the stable North American...
Importance of microscopy in durability studies of solidified and stabilized contaminated soils
I. Klich, L.P. Wilding, L.R. Drees, E. R. Landa
1999, Soil Science Society of America Journal (63) 1274-1283
Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical, thermal, or biological means. Despite the increased use of S/S technologies, little research has been conducted on the weathering and...
Harlequin Duck recovery from the Exxon Valdez oil spill: A population genetics perspective
Richard B. Lanctot, Buddy L. Goatcher, Kim T. Scribner, Sandra L. Talbot, Barbara J. Pierson, Daniel Esler, Denny Zwiefelhofer
1999, The Auk (116) 781-791
Concerns about Harlequin Duck (Histrionicus histrionicus) population recovery following the Exxon Valdez oil spill led biologists to ask whether birds located in different molting and wintering areas belong to genetically distinct and, thus, demographically independent populations. Owing to the lack of direct observations of movements among marine areas, three classes...
Synopsis of strontium isotope variations in groundwater at Aspo, southern Sweden
Z. E. Peterman, B. Wallin
1999, Applied Geochemistry (14) 939-951
Strontium isotope ratios are used to identify end-member ground-water compositions at Aspo in southeastern Sweden where the Hard Rock Laboratory (HRL) has been constructed to evaluate the suitability of crystalline rock for the geologic disposal of nuclear waste. The Hard Rock Laboratory is a decline (tunnel) constructed in 1.8 Ga-old...
