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...
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...
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...
Physical aspects of Hurricane Hugo in Puerto Rico
F.N. Scatena, Matthew C. Larsen
1991, Biotropica (23) 317-323
On 18 September 1989 the western part ofHurricane Hugo crossed eastern Puerto Rico and the Luquillo Experimental Forest (LEF). Storm-facing slopes on the northeastern part of the island that were within 15 km of the eye and received greater than 200 mm of rain were most affected by the storm....
Unified theory on power laws for flow resistance
Cheng-lung Chen
1991, Journal of Hydraulic Engineering (117) 371-389
Two general power formulas, one for hydraulically smooth flows and the other for fully rough flows, are derived in a rational way from the widely accepted logarithmic formulas for the velocity profile and the Darcy‐Weisbach friction factor. A regression analysis based on the method of least squares is used to...
Evidence of strong earthquake shaking in the lower Wabash Valley from prehistoric liquefaction features
S. F. Obermeier, N.R. Bleuer, C.A. Munson, P.J. Munson, W.S. Martin, K.M. McWilliams, D.A. Tabaczynski, J. K. Odum, M. Rubin, Donald L. Eggert
1991, Science (251) 1061-1063
Earthquake-induced liquefaction features in Holocene sediments provide evidence of strong prehistoric shaking, magnitude mb 6.2 to 6.7, in the Wabash Valley bordering Indiana and Illinois. The source of the one or more earthquakes responsible was almost certainly in or near the Wabash Valley. The largest event is interpreted to have occurred between...
User's guide to the wetland creation/restoration data base, version 2
Lee Miller, Gregor T. Auble, Keith Schneller-McDonald
1991, Book
Wetland creation or restoration projects are frequently proposed as mitigation for unavoidable wetland losses, as components of wetland enhancement programs, and as tools to accomplish specific objectives such as waterfowl production or flood control. There is considerable controversy concerning the effectiveness of such projects as well as the most appropriate...
Evaluation of unsaturated zone air permeability through pneumatic tests
Arthur L. Baehr, Marc F. Hult
1991, Water Resources Research (27) 2605-2617
Predicting the steady state distribution of air pressure in the unsaturated zone resulting from a pneumatic test provides a method for determining air-phase permeability. This technique is analogous to the inverse problem of well hydraulics; however, air flow is more complicated than ground water flow because of air compressibility, the...
Effects of roadside habitat and fox density on a snow track survey for foxes in Ohio
Thomas R. Stanley, Jonathan Bart
1991, Ohio Journal of Science (91) 186-187
Many methods have been used to survey red fox (Vulpes vulpes) and gray fox (Urocyon dnereoargenteus) populations. However, none has proven entirely satisfactory, and wild foxes remain one of the most difficult economically important wildlife species to monitor. In this study we evaluated the reliability of a snow track survey...
Weights and hematology of wild black bears during hibernation
Glenn D. DelGiudice, Lynn L. Rogers, Arthur W. Allen, U.S. Seal
1991, Journal of Wildlife Diseases (27) 637-642
We compared weights and hematological profiles of adult (>3-yr-old) female black bears (Ursus americanus) during hibernation (after 8 January). We handled 28 bears one to four times (total of 47) over 4 yr of varying mast and berry production. Mean weight of lactating...
The Reaction Titanite+Kyanite=Anorthite+Rutile and Titanite-Rutile Barometry in Eclogites
C.F. Manning, S.R. Bohlen
1991, Contributions to Mineralogy and Petrology (109) 1-9
Titanite and rutile are a common mineral pair in eclogites, and many equilibria involving these phases are potentially useful in estimating pressures of metamorphism. We have reversed one such reaction, {Mathematical expression} using a piston-cylinder apparatus. Titanite+kyanite is the high-pressure assemblage and our results locate the equilibrium between 15.5 15.9,...
Seed germination and life history syndromes in the California chaparral
Jon E. Keeley
1991, Botanical Review (57) 81-116
Syndromes are life history responses that are correlated to environmental regimes and are shared by a group of species (Stebbins, 1974). In the California chaparral there are two syndromes contrasted by the timing of seedling recruitment relative to wildfires. One syndrome, here called the fire-recruiter or refractory seed syndrome, includes...
Sources of dissolved and particulate organic material in Loch Vale Watershed, Rocky Mountain National Park, Colorado, USA
Jill Baron, Diane M. McKnight, A. Scott Denning
1991, Biogeochemistry (15) 89-110
The sources of both dissolved organic carbon (DOC) and particulate organic carbon (POC) to an alpine (Sky Pond) and a subalpine lake (The Loch) in Rocky Mountain National Park were explored for four years. The importance of both autochthonous and allochthonous sources of organic matter differ, not only between alpine...
An exact solution of solute transport by one-dimensional random velocity fields
V.D. Cvetkovic, G. Dagan, A.M. Shapiro
1991, Stochastic Hydrology and Hydraulics (5) 45-54
The problem of one-dimensional transport of passive solute by a random steady velocity field is investigated. This problem is representative of solute movement in porous media, for example, in vertical flow through a horizontally stratified formation of variable porosity with a constant flux at the soil surface. Relating moments of...
Fossil and active fumaroles in the 1912 eruptive deposits, Valley of ten thousand smokes, Alaska
T. E. C. Keith
1991, Journal of Volcanology and Geothermal Research (45) 227-254
Fumaroles in the ash-flow sheet emplaced during the 1912 eruption of Novarupta were intensely active throughout the Valley of Ten Thousand Smokes (VTTS) when first studied in 1917. Fumarole temperatures recorded in 1919 were as hot as 645??C. Influx of surface waters into the hot ash-flow sheet provided the fluid...
Late Laramide thrust-related and evaporite-domed anticlines in the southern Piceance Basin, northeastern Colorado Plateau
M. A. Grout, G. A. Abrams, R. L. Tang, T. J. Hainsworth, E.R. Verbeek
1991, American Association of Petroleum Geologists Bulletin (75) 205-218
New seismic and gravity data across the hydrocarbon-producing Divide Creek and Wolf Creek anticlines in the southern Piceance basin reveal contrasting styles of deformation within two widely separated time frames. Seismic data indicate that prebasin Paleozoic deformation resulted in block faulting of the Precambrian crystalline basement rocks and overlying Cambrian...
Application of ground-penetrating-radar methods in hydrogeologic studies
Milan Beres Jr., F.P. Haeni
1991, Ground Water (29) 375-386
A ground-penetrating-radar system was used to study selected stratified-drift deposits in Connecticut. Ground-penetrating radar is a surface-geophysical method that depends on the emission, transmission, reflection, and reception of an electromagnetic pulse and can produce continuous high-resolution profiles of the subsurface rapidly and efficiently. Traverse locations on land included a well...
Subalkaline andesite from Valu Fa Ridge, a back-arc spreading center in southern Lau Basin: petrogenesis, comparative chemistry, and tectonic implications
T.L. Vallier, G.A. Jenner, F.A. Frey, J.B. Gill, A. S. Davis, A.M. Volpe, J.W. Hawkins, J.D. Morris, Peter A. Cawood, J. L. Morton, D.W. Scholl, M. Rautenschlein, W.M. White, Ross W. Williams, A.J. Stevenson, L. D. White
1991, Chemical Geology (91) 227-256
Tholeiitic andesite was dredged from two sites on Valu Fa Ridge (VFR), a back-arc spreading center in Lau Basin. Valu Fa Ridge, at least 200 km long, is located 40-50 km west of the active Tofua Volcanic Arc (TVA) axis and lies about 150 km above the subducted oceanic plate....
Seismicity and shear strain in the southern Great Basin of Nevada and California
J. Gomberg
1991, Journal of Geophysical Research (96) 16383-16399
This study examines the relationship between the distribution of small earthquakes (ML≤4.3) and mechanisms of strain accumulation and relaxation in an area with long repeat times between large events, the Southern Great Basin Seismic Network (SGBSN) region. The Great Basin is a unique continental extensional...
A review of the regional geophysics of the Arizona Transition Zone
J. D. Hendricks, J. B. Plescia
1991, Journal of Geophysical Research (96) 12351-12373
A review of existing geophysical information and new data presented in this special section indicate that major changes in crustal properties between the Basin and Range and Colorado Plateau occur in, or directly adjacent to, the region defined as the Arizona Transition Zone. Although this region...
Soil chronosequence studies in temperate to subtropical, low-latitude, low-relief terrain with data from the eastern United States
H. W. Markewich, M.J. Pavich
1991, Geoderma (51) 213-239
The Coastal Plain of the eastern United States is a low-latitude, low-altitude, low-relief terrain composed primarily of gently dipping marine and marginal-marine sediments that range in age from Cretaceous to Quaternary. Population density of the area is moderate, and most of the population is concentrated along the coast. Inland of...
Statistical analyses of soil properties on a quaternary terrace sequence in the upper sava river valley, Slovenia, Yugoslavia
N. Vidic, M. Pavich, F. Lobnik
1991, Geoderma (51) 189-211
Alpine glaciations, climatic changes and tectonic movements have created a Quaternary sequence of gravely carbonate sediments in the upper Sava River Valley, Slovenia, Yugoslavia. The names for terraces, assigned in this model, Günz, Mindel, Riss and Würm in order of decreasing age, are used as morphostratigraphic terms. Soil chronosequence on...
Isotopic and chemical constraints on the petrogenesis of Blackburn Hills volcanic field, western Alaska
E. J. Moll-Stalcup, Joseph G. Arth
1991, Geochimica et Cosmochimica Acta (55) 3753-3776
The Blackburn Hills volcanic field is one of several Late Cretaceous and early Tertiary (75–50 Ma) volcanic fields in western Alaska that comprise a vast magmatic province extending from the Arctic Circle to Bristol Bay. It consists of andesite flows, rhyolite domes, a central granodiorite to quartz monzonite pluton, and...
A comparison of Sr-Nd-Pb isotopes in young and old continental lithospheric mantle: Patagonia and eastern China
R. E. Zartman, K. Futa, Z. C. Peng
1991, Australian Journal of Earth Sciences (38) 545-557
It is commonly accepted that beneath the continental crust lies a keel of lithospheric mantle, which extends 50–200 kilometres downward to a transition zone into the asthenosphere. The chemical and physical properties of this reservoir are best known through studies of the basalts and xenoliths that provide samples of the...
Volcanic eruptions; energy and size
S. de la Cruz-Reyna
1991, Earthquakes & Volcanoes (USGS) (22) 140-141
The Earth is a dynamic planet. Many different processes are continuously developing, creating a delicate balance between the energy stored and generated in its interior and the heat lost into space. The heat in continuously transferred through complex self-regulating convection mechanisms on a planetary scale. The distribution of terrestrial heat...
