Sampling design for groundwater solute transport: Tests of methods and analysis of Cape Cod tracer test data
Debra S. Knopman, Clifford I. Voss, Stephen P. Garabedian
1991, Water Resources Research (27) 925-949
Tests of a one-dimensional sampling design methodology on measurements of bromide concentration collected during the natural gradient tracer test conducted by the U.S. Geological Survey on Cape Cod, Massachusetts, demonstrate its efficacy for field studies of solute transport in groundwater and the utility of one-dimensional analysis. The methodology was applied...
Extent of reaction in open systems with multiple heterogeneous reactions
John C. Friedly
1991, American Institute of Chemical Engineers (37) 687-693
The familiar batch concept of extent of reaction is reexamined for systems of reactions occurring in open systems. Because species concentrations change as a result of transport processes as well as reactions in open systems, the extent of reaction has been less useful in practice in...
Prospects for eruption prediction in near real-time
B. Voight, Reinold R. Cornelius
1991, Nature (350) 695-698
The 'materials science' method for eruption prediction1–3 arises from the application of a general law governing the failure of materials: Ω⊙−α Ω¨ − A = 0, where A and α are empirical constants, and Ω is an observable quantity such as ground deformation, seismicity or gas emission. This law leads to the idea of the...
A whale of a new species
Katharine Ralls, Robert L. Brownell Jr.
1991, Nature (350)
No abstract available....
Xerus rutilus
T. J. O'Shea
1991, Mammalian Species (370) 1-5
No abstract available....
Platyrrhinus helleri
C.S. Ferrell, Don E. Wilson
1991, Mammalian Species (373) 1-5
No abstract available....
Impact craters on Venus: Initial analysis from Magellan
R.J. Phillips, R. E. Arvidson, J. M. Boyce, D.B. Campbell, J. E. Guest, Gerald G. Schaber, Laurence A. Soderblom
1991, Science (252) 288-297
Magellan radar images of 15 percent of the planet show 135 craters of probable impact origin. Craters more than 15 km across tend to contain central peaks, multiple central peaks, and peak rings. Many craters smaller than 15 km exhibit multiple floors or appear in clusters; these phenomena are attributed...
Mantle phase changes and deep-earthquake faulting in subducting lithosphere
Stephen H. Kirby, W.B. Durham, L.A. Stern
1991, Science (252) 216-225
Inclined zones of earthquakes are the primary expression of lithosphere subduction. A distinct deep population of subduction-zone earthquakes occurs at depths of 350 to 690 kilometers. At those depths ordinary brittle fracture and frictional sliding, the faulting processes of shallow earthquakes, are not expected. A fresh understanding of these deep...
Magellan: Radar performance and data products
G.H. Pettengill, P.G. Ford, W.T.K. Johnson, R.K. Raney, Laurence A. Soderblom
1991, Science (252) 260-265
The Magellan Venus orbiter carries only one scientific instrument: a 12.6-centimeter wavelength radar system shared among three data-taking modes. The synthetic-aperture mode images radar echoes from the Venus surface at a resolution of between 120 and 300 meters, depending on spacecraft altitude. In the altimetric mode, relative height measurement accuracies...
Venus volcanism: Initial analysis from Magellan data
J.W. Head, D.B. Campbell, C. Elachi, J. E. Guest, D.P. Mckenzie, R.S. Saunders, Gerald G. Schaber, Gerald Schubert
1991, Science (252) 276-288
Magellan images confirm that volcanism is widespread and has been fundamentally important in the formation and evolution of the crust of Venus. High-resolution imaging data reveal evidence for intrusion (dike formation and cryptodomes) and extrusion (a wide range of lava flows). Also observed are thousands of small shield volcanoes, larger...
Basin and range crustal and upper mantle structure, northwest to central Nevada
Rufus D. Catchings, Walter D. Mooney
1991, Journal of Geophysical Research B: Solid Earth (96) 6247-6267
We present an interpretation of the crustal and uppermost mantle structure of the Basin and Range of northwestern Nevada based on seismic refraction/wide‐angle reflection, near‐vertical reflection, and gravity data. In comparison to most previous estimates, we find that the crust is somewhat thicker (32–36 km versus 22–30...
Strain measurements and the potential for a great subduction earthquake off the coast of Washington
J.C. Savage, M. Lisowski
1991, Science (252) 101-103
Geodetic measurements of deformation in northwestern Washington indicate that strain is accumulating at a rate close to that predicted by a model of the Cascadia subduction zone in which the plate interface underlying the continental slope and outer continental shelf is currently locked but the remainder of the interface slips...
Microbial reduction of uranium
Derek R. Lovley, Elizabeth J.P. Phillips, Y.A. Gorby, E. R. Landa
1991, Nature (350) 413-416
Reduction of the soluble, oxidized form of uranium, U(VI), to insoluble U(IV) is an important mechanism for the immobilization of uranium in aquatic sediments and for the formation of some uranium ores1–10. U(VI) reduction has generally been regarded as an abiological reaction in which sulphide, molecular hydrogen or organic compounds...
U–Pb geochronology of Late Cretaceous and early Tertiary plutons in the northern Coast Mountains batholith
G.E. Gehrels, W. C. McClelland, S.D. Sampson, Patchett P. Jonathan, David A. Brew
1991, Canadian Journal of Earth Sciences (28) 899-911
U–Pb geochronologic studies demonstrate that steeply dipping, sheetlike tonalitic plutons along the western margin of the northern Coast Mountains batholith were emplaced between ~83 and ~57 (perhaps ~55) Ma. Less elongate tonalitic–granodioritic bodies in central portions of the batholith yield ages of 59–58 Ma, coeval with younger phases of the tonalitic...
A model of volcanic dome-hosted precious metal deposits in Bolivia
Charles G. Cunningham, J. McNamee, J.P. Vasquez, G. E. Ericksen
1991, Economic Geology (86) 415-421
No abstract available. ...
Aquatic habitat measurement and valuation: imputing social benefits to instream flow levels
Aaron J. Douglas, Richard L. Johnson
1991, Journal of Environmental Management (32) 267-280
Instream flow conflicts have been analysed from the perspectives offered by policy oriented applied (physical) science, theories of conflict resolution and negotiation strategy, and psychological analyses of the behavior patterns of the bargaining parties. Economics also offers some useful insights in analysing conflict resolution within the context of these water...
Single-station decomposition of seismograms for subevent time histories
Massimo Di Bona, John Boatwright
1991, Geophysical Journal International (105) 103-117
We have adapted an iterative least-squares inversion with positivity constraints to the problem of deconvolving the recordings of a small earthquake from the recordings of a large composite earthquake. The inversion uses an F test to minimize the number of non-zero amplitudes or subevents in the solution set, by requiring each added...
Population trends from the American woodcock singing-ground survey, 1970-88
John R. Sauer, James B. Bortner
1991, Journal of Wildlife Management (55) 300-312
Population trend analysis of American woodcook (Scolopax minor) using data from a singing-ground survey indicates population declines throughout the breeding range of the species between 1970 and 1988. In the eastern United States and Canada, this decline has been quite consistent throughout the period, but in the central portion of...
Diurnal photosynthesis cycle in CAM and non-CAM seasonal pool aquatic macrophytes
Jon E. Keeley, Darren R. Sandquist
1991, Ecology (72) 716-727
Seasonal pools undergo marked diurnal changes in pH, free carbon dioxide, and oxygen levels. Previous studies showed that Isoetes howellii utilized crassulacean acid metabolism (CAM) photosynthesis as a means of assimilating carbon at night when ambient carbon dioxide levels are high. However, much of the pool flora is not CAM....
Effect of hunting on annual survival of grey ducks in New Zealand
Richard J. Barker, James E. Hines, James D. Nichols
1991, Journal of Wildlife Management (55) 260-265
We used band recovery data from grey ducks (Anas superciliosa) banded in New Zealand between 1957 and 1974 to test 2 null hypotheses: (1) hunting mortality is completely additive to natural sources of mortality, and (2) hunting mortality is completely compensated by changes in natural mortality. We modeled annual survival...
Density cycles in an island population of deer mice, Peromyscus maniculatus
Charles A. Drost, Gary M. Fellers
1991, Oikos (60) 351-364
We report on eight years of data for a population of deer mice (Peromyscus maniculatus) on Santa Barbara Island, California which reaches exceptionally high densities and fluctuates markedly in an apparent three- to four-year cycle. The cyclic increase follows winters with high rainfall, and the decline may be similarly associated...
Comment on the treatment of residual water content in “A consistent set of parametric models for the two-phase flow of immiscible fluids in the subsurface” by L. Luckner et al.
John R. Nimmo
1991, Water Resources Research (27) 661-662
Luckner et al. [1989] (hereinafter LVN) present a clear summary and generalization of popular formulations used for convenient representation of porous media fluid flow characteristics, including water content (θ) related to suction (h) and hydraulic conductivity (K) related to θ or h. One essential but problematic element in the LVN...
Home range and movements of juvenile Puerto Rican parrots
Gerald D. Lindsey, Wayne J. Arendt, Jan Kalina, Grey W. Pendleton
1991, Journal of Wildlife Management (55) 318-322
We studied home range and movements of 15 radio-marked, juvenile Puerto Rican parrots (Amazona vittata) fledging from wild nests during summer and fall, 1985-87. When juvenile parrots remained in the nest valley, home ranges during 1986 (x̄ = 32 ± 10 [SE] ha, n = 4) were larger (P...
In vivo and in vitro transfer of trout spleen sections for early analysis of the immune response
D. P. Anderson, O. W. Dixon, E. F. Lizzio
1991, Fish and Shellfish Pathology (1) 99-105
To determine the earliest time after in vivo immunisation that the spleen could be excised and held in vitro to detect an immune response, lake trout (Salvelinus namaycush) were exposed to DNP-Ficoll or Yersinia ruckeri O antigen administered by intraperitoneal injection or by bath. The spleens were excised from the fish at selected times after immunisation,...
Construction effects on sediment for two basins in Puerto Rico
Allen C. Gellis
Shou-Shan Fan, Y.-H. Kuo, editor(s)
1991, Conference Paper, Proceedings of the Fifth Federal Interagency Sedimentation Conference
