Aftershock slip behavior of the 1989 Loma Prieta, California Earthquake
David H. Oppenheimer
1990, Geophysical Research Letters (17) 1199-1202
An analysis of 745 aftershocks of the M7.1 Loma Prieta earthquake of 17 October, 1989 reveals a wide variety of focal mechansims. At the northwestern end of the aftershock zone earthquakes that apparently occurred off the main rupture plane exhibit mechanisms with predominantly reverse slip on planes nearly parallel to the...
Remagnetization and northward translation of Mesozoic red chert from Cedros Island and the San Benito Islands, Baja California, Mexico
Jonathan T. Hagstrum, R.L. Sedlock
1990, Geological Society of America Bulletin (102) 983-991
Samples for paleomagnetic analysis were collected from red radiolarian ribbon chert in a Franciscan-like subduction complex (Western Baja terrane) exposed along the western margin of the Baja California Peninsula. A 40-m-thick section of chert was sampled on Cedros Island, and a 30-m-thick and two smaller sections of chert were sampled...
New Washakiin primates (Omomyidae) from the Eocene of Wyoming and Colorado, and comments on the evolution of the Washakiini
James G. Honey
1990, Journal of Vertebrate Paleontology (10) 206-221
Two new species of washakiin omomyids occur in deposits of early Bridgerian age. Shoshonius bowni, sp. nov., from the Aycross Formation, Absaroka Range, Wyoming, differs from S. cooperi in having enlarged conules on the upper molars and a second metaconule, features convergent with Washakius insignis. Washakius izetti, sp. nov., from the Green River Formation,...
Snapping turtle (Chelydra serpentina) density and biomass at three pond types in the Maryland coastal plain
S.W. Gotte, R.P. Reynolds, R.W. McDiarmid
1990, Book, Proceedings of the Symposium on Phylogeny of Percomorpha
No abstract available....
Age estimates and uplift rates for late Pleistocene marine terraces: Southern Oregon portion of the Cascadia forearc
Daniel R. Muhs, Harvey M. Kelsey, Joseph F. Whelan, Galan W. McInelly
1990, Journal of Geophysical Research D: Atmospheres (95) 6685-6698
Interest in the Cascadia subduction zone has increased because recent investigations have suggested that slip along plates at certain types of convergent margins is characteristically accompanied by large earthquakes. In addition, other investigations have suggested that convergent margins can be broadly classified by the magnitude of their uplift rates. The...
The Denali fault system and Alaska Range of Alaska: Evidence for underplated Mesozoic flysch from magnetotelluric surveys
W. D. Stanley, Victor F. Labson, Warren J. Nokleberg, Bela Csejtey Jr., M. A. Fisher
1990, GSA Bulletin (102) 160-173
Regional magnetotelluric surveys recently completed across the central and eastern Alaska Range of Alaska provide evidence for large volumes of conductive rocks beneath the core of the range. These conductive rocks may represent a formerly extensive, but now collapsed, Mesozoic flysch basin formed on the leading edge of the Talkeetna...
Proceedings of the First National U.S. Fish and Wildlife Service Geographic Information Systems Workshop, June 4-7, 1990
Frank D’Erchia
1990, Report
No abstract available....
Age determinations and growth rates of Pacific ferromanganese deposits using strontium isotopes
B.L. Ingram, J.R. Hein, G. L. Farmer
1990, Geochimica et Cosmochimica Acta (54) 1709-1721
87Sr86Sr ratios, trace element and REE compositions, and textural characteristics were determined for three hydrogenetic Fe-Mn crusts, one hydrothermal deposit, and two mixed hydrothermalhydrogenetic crusts from the Pacific. The Sr isotope data are compared to the Sr seawater curve for the Cenozoic to determine the ages and growth rates of...
Bear use of cutthroat trout spawning streams in Yellowstone National Park
Daniel P. Reinhart, D.J. Mattson
1990, Bears: Their Biology and Management (8) 343-350
Grizzly bears (Ursus arctos) and black bears (U. americanus) prey on spawning cutthroat trout (Oncorhynchus clarki, formerly known as Salmo clarki) in tributary streams of Yellowstone Lake. These tributary streams were surveyed from 1985 to 1987 to determine the presence and level of trout spawning activity and bear use. Indices...
Metamorphism in the Adirondacks: II. The role of fluids
John W. Valley, Steven R. Bohlen, E.J. Essene, Will Lamb
1990, Journal of Petrology (31) 555-596
Quantitative estimates of metamorphic fluid speciation, stable isotopic analyses, and studies of fluid inclusions all document the local complexity of fluids in the deep crustal rocks exposed in the Adirondack Mountains, NY. Estimates of the activity of H2O in the granulite facies are substantially lower than in the amphibolite...
Pliocene-Pleistocene growth of the Rio Ebro margin, northeast Spain: A prograding-slope model
Michael E. Field, James V. Gardner
1990, Geological Society of America Bulletin (102) 721-733
Pliocene-Pleistocene marine deposits overlying Messinian evaporites off northeast Spain are composed of five distinct seismic facies. These facies are interpreted to represent deposition in five adjacent settings: distal (isolated) basin, basin plain, base of slope,slope, and shelf. Contrary to previous studies, a submarine-fan style of deposition is not evident. Distal-basin...
Tectonic erosion along the Japan and Peru convergent margins
Roland von Huene, S. Lallemand
1990, Geological Society of America Bulletin (102) 704-720
The volume of material removed by subduction erosion can be estimated quantitatively if the position of the volcanic arc, the position of the paleotrench axis, and a paleo-depth reference surface are known. Estimates based on these parameters along the Japan and Peru Trenches indicate rates of erosion comparable to well-known...
Application of the Stefan-Maxwell Equations to determine limitations of Fick's law when modeling organic vapor transport in sand columns
Arthur L. Baehr, Clifford J. Bruell
1990, Water Resources Research (26) 1155-1163
The organic component of the vapor phase of a porous medium contaminated by an immiscible organic liquid can be significant enough to violate the condition of a dilute species diffusing in a bulk phase assumed by Fick's law. The Stefan-Maxwell equations provide a more comprehensive model for quantifying steady state...
Cymbella langii, a new miocene diatom from the Espanola area, Rio Arriba county, New Mexico, U.S.A
Robert McLaughlin, George W. Andrews
1990, Diatom Research (5) 55-61
A distinctive new fossil freshwater diatom species, Cymbella langii McLaughlin & Andrews, is described from a diatomaceous earth deposit in the Chamita Formation of the Santa Fe Group near Espaiiola, central New Mexico. This deposit is dated by K-Ar and mammalian biostratigraphy as Hemphillian or late Miocene in...
Decrease in deformation rate as a possible precursor to the next Parkfield earthquake
M. Wyss, L. Slater, Robert O. Burford
1990, Nature (345) 428-431
Crustal deformations along fault zones are monitored because they show the accumulation and possible premonitory release of strain energy before major earthquakes. On the Parkfield segment of the San Andreas fault the next mainshock (local magnitude ML=5.7) is expected to occur between 1983 and 1993, based on the relatively regular recurrence...
Geophysics at Katmai: Geophysical expedition to Novarupta Volcano, Katmai National Park, Alaska
John C. Eichelberger, S. Ballard, Charles R. Carrigan, A. Goodliffe, W. Hildreth, E.Y. Iwatsubo, P. W. Kasameyer, T. E. C. Keith, Juergen Kienle, J. J. Papike, D. D. Pollard, D.B. Stone, P. C. Wallmann, P.L. Ward, M. Wilt, M. E. Yount
1990, Eos, Transactions, American Geophysical Union (71) 733-736
The great eruption of 1912 in the Aleutian Range of Alaska (Figure 1) is exceptional for both its size and relative simplicity. It was the largest eruption of this century and the largest rhyolitic outburst in almost 20 centuries. The 60-hour, 30-km3 (ejecta volume) eruption produced extensive fallout deposits, an ash-flow...
The effects of water levels on Two Lake Ontario Wetlands
Wolf-Dieter N. Busch, Ronald G. Osborn, Gregor T. Auble
1990, Book, Proceedings of an International Symposium: Wetlands of the Great Lakes: Protection and Restoration Policies; Status of the Science
Lake Ontario's water levels have been regulated since 1959, after the completion of the St. Lawrence River navigation and hydropower development project. The plan used to guide the regulation (1958-D) has been in effect since 1963 (Bryce, 1982). The purpose of the regulation was to prevent extreme...
Flank tectonics of Martian volcanoes
Paul Thomas, Steven W. Squyres, M. H. Carr
1990, Journal of Geophysical Research B: Solid Earth (95) 14345-14355
On the flanks of Olympus Mons is a series of terraces, concentrically distributed around the caldera. Their morphology and location suggest that they could be thrust faults caused by compressional failure of the cone. In an attempt to understand the mechanism of faulting and the possible influences of the interior...
Sample size requirements and analysis of tag recoveries for paired releases of lake trout
Joseph H. Elrod, Anthony Frank
1990, North American Journal of Fisheries Management (10) 196-201
A simple chi-square test can be used to analyze recoveries from a paired-release experiment to determine whether differential survival occurs between two groups of fish. The sample size required for analysis is a function of (1) the proportion of fish stocked, (2) the expected proportion at recovery, (3) the level...
Predatory behavior of grizzly bears feeding on elk calves in Yellowstone National Park
Steven P. French, Marilynn G. French
1990, Bears: Their Biology and Management (8) 335-341
Grizzly bears (Ursus arctos horribilis) were observed preying on elk calves (Cervus elaphus) on 60 occasions in Yellowstone National Park, with 29 confirmed kills. Some bears were deliberate predators and effectively preyed on elk calves for short periods each spring, killing up to 1 calf daily. Primary hunting techniques were...
Fluctuating asymmetry and testing isolation of Montana grizzly bear populations
Harold D. Picton, Daniel A. Palmisciano, Gerald Nelson
1990, Bears: Their Biology and Management (8) 421-424
Fluctuating asymmetry of adult skulls was used to test he genetic isolation of the Yellowstone grizzly bear population from its nearest neighbor. An overall summary statistic was used in addition to 16 other parameters. Tests found the males of the Yellowstone populaion to be more vaiable than those of the...
Search path of a fossorial herbivore, Geomys bursarius, foraging in structurally complex plant communities
Douglas C. Andersen
1990, Journal of Mammalogy (71) 177-187
The influence of habitat patchiness and unpalatable plants on the search path of the plains pocket gopher (Geomys bursarius) was examined in outdoor enclosures. Separate experiments were used to evaluate how individual animals explored (by tunnel excavation) enclosures free of plants except for one or more dense patches of a...
Selenium accumulation and elimination in mallards
Gary Heinz, Grey W. Pendleton, Alexander J. Krynitsky, Lyn G. Gold
1990, Archives of Environmental Contamination and Toxicology (19) 374-379
Selenium accumulation and loss were measured in adult mallards (Anas platyrhynchos) fed selenomethionine during two experiments. In Experiment 1, both sexes were fed a diet containing 10 ppm selenium for 6 weeks, followed by 6 weeks on untreated feed. Selenium accumulation in liver and muscle of females was described by...
On the rupture zone and effects of local geologic conditions on damages and ground motions for the Armenian earthquakes of December 7, 1988
Roger D. Borcherdt, C. Langer, John R. Filson, D.W. Simpson, G. Glassmoyer, M. Andrews, E. Cranswick
1990, Conference Paper, Proceedings of the fourth U.S. National Conference on Earthquake Engineering
No abstract available....
Differences between nipher and slter shielded rain gages at two Colorado deposition monitoring sites
David S. Bigelow, A. Scott Denning
1990, Environmental Science & Technology (24) 758-760
In the last decade the United States and Canada have made significant progress in establishing spatial ad temporal estimates of atmospheric deposition throughout North America. Fundamental to the wet-deposition portion of these estimates is the accurate and precise measurement of precipitation amount. Goodison and others (I-3) have reported on a...
