Coastal geomorphology of arctic Alaska
Peter W. Barnes, Stuart E. Rawlinson, Erk Reimnitz
1988, Technical Council on Cold Regions Engineering Monograph 3-30
The treeless, tundra-plain of northern Alaska merges with the Arctic Ocean along a coastal area characterized by low tundra bluffs, and sparse coastal and delta dunes. Coastal engineering projects that aggrade or degrade permafrost will alter the geomorphology and rates of coastal processes by changing coastal stability. Similarly, projects that...
Mineral resources of the Turtle Mountains Wilderness Study Area, San Bernardino County, California
Keith A. Howard, Jane E. Nielson, Robert W. Simpson, Richard W. Hazlett, Henry V. Alminas, John K. Nakata, John R. McDonnell Jr.
1988, Bulletin 1713-B
At the request of the U.S. Bureau of Land Management, approximately 105,200 acres of the Turtle Mountains Wilderness Study Area (CDCA-307) were evaluated for mineral resources (known) and resource potential (undiscovered). In this report, the area studied is referred to as "the wilderness study area" or simply "the study area";...
Comprehensive method of characteristics models for flow simulation
Chintu Lai
1988, Journal of Hydraulic Engineering (114) 1074-1097
The use of the specified time interval (STI) numerical schemes has been popular in applying the method of characteristics (MOC) to unsteady open‐channel flow problems. Studies and analyses of several variants of the STI schemes have led to the derivation of a new scheme, referred to herein as the multimode...
Applying the population/area model for planning of large mammal translocations
C. Schonewald-Cox, R.J. Baker, J.W. Bayless
L. Nielsen, R.D. Brown Jr., editor(s)
1988, Translocation of Wild Animals. 52-63
No abstract available at this time...
The information content of high-frequency seismograms and the near-surface geologic structure of "hard rock" recording sites
E. Cranswick
1988, Pure and Applied Geophysics PAGEOPH (128) 333-363
Due to hardware developments in the last decade, the high-frequency end of the frequency band of seismic waves analyzed for source mechanisms has been extended into the audio-frequency range (>20 Hz). In principle, the short wavelengths corresponding to these frequencies can provide information about the details of seismic sources, but...
A simulation model of coal mining effects on cottonwood tree Growth in the Powder River Basin of Wyoming
K. McEachern
1988, Report
No abstract available at this time...
Uranium-series age estimates and paleoclimatic significance of Pleistocene tufas from the Lahontan basin, California and Nevada
Y. Lao, L. Benson
1988, Quaternary Research (30) 165-176
An extended chronology of Lahontan basin lake levels based on uranium-series age estimates correlates with the global ice-volume record. Lake highstands occur at or shortly after times of maximum ice-sheet size. Moderate size lakes occur when the global ice volume is about 80% of its maximum. The data indicate that...
U.S. Geological Survey deep seismic reflection profile across the Gulf of Maine
Deborah R. Hutchinson, Kim D. Klitgord, Myung W. Lee, Anne M. Trehu
1988, Geological Society of America Bulletin (100) 172-184
Deep seismic reflection and magnetic data suggest that the Gulf of Maine is underlain by four crustal blocks of differing reflection and magnetic character. Two of these blocks, the Gulf of Maine fault zone and adjacent central plutonic zone, can be correlated with Avalonian rocks in southern New England and...
History of significant earthquakes in the Parkfield area
W. H. Bakun
1988, Earthquakes & Volcanoes (USGS) (20) 45-51
Seismicity on the San Andreas fault near Parkfield occurs in a tectonic section that differs markedly from neighboring sections along the San Andreas to the northwest and to the southeast. Northwest of the Parkfield section, small shocks (magnitudes of less than 4) do occur frequently, but San Andreas movement occurs...
Extracting topographic structure from digital elevation data for geographic information-system analysis
Susan K. Jenson, Julia O. Domingue
1988, Photogrammetric Engineering and Remote Sensing (54) 1593-1600
Software tools have been developed at the U.S. Geological Survey's EROS Data Center to extract topographic structure and to delineate watersheds and overland flow paths from digital elevation models. The tools are specialpurpose FORTRAN programs interfaced with general-purpose raster and vector spatial analysis and relational data base management packages. The first...
Hydraulic conductivity of a sandy soil at low water content after compaction by various methods
John R. Nimmo, Katherine C. Akstin
1988, Soil Science Society of America Journal (52) 303-310
To investigate the degree to which compaction of a sandy soil influences its unsaturated hydraulic conductivity K, samples of Oakley sand (now in the Delhi series; mixed, thermic, Typic Xeropsamments) were packed to various densities and K was measured by the steady-state centrifuge method. The air-dry, machine packing was followed...
Simulation of three lahars in the Mount St Helens area, Washington using a one-dimensional, unsteady-state streamflow model
Antonius Laenen, R. P. Hansen
1988, Water-Resources Investigations Report 88-4004
A one-dimensional, unsteady-state, open-channel model was used to analytically reproduce three lahar events. Factors contributing to the success of the modeling were: (1) the lahars were confined to a channel, (2) channel roughness was defined by field information, and (3) the volume of the flow remained relatively unchanged for the...
General solutions For viscoplastic debris flow
Cheng-lung Chen
1988, Journal of Hydraulic Engineering (114) 259-282
Theoretical velocity profile and theoretical pressure and concentration distributions for (steady) uniform debris flow in wide channels are derived from a generalized viscoplastic fluid (GVF) model without imposing R. A. Bagnold's assumption of constant grain concentration. Good agreement between the theoretical velocity profile and the experimental data of Japanese scientists...
Crustal contributions to arc magmatism in the Andes of Central Chile
W. Hildreth, S. Moorbath
1988, Contributions to Mineralogy and Petrology (98) 455-489
Fifteen andesite-dacite stratovolcanoes on the volcanic front of a single segment of the Andean arc show along-arc changes in isotopic and elemental ratios that demonstrate large crustal contributions to magma genesis. All 15 centers lie 90 km above the Benioff zone and 280??20 km from the trench axis. Rate and...
Compositional evolution of the zoned calcalkaline magma chamber of Mount Mazama, Crater Lake, Oregon
C. R. Bacon, T. H. Druitt
1988, Contributions to Mineralogy and Petrology (98) 224-256
The climactic eruption of Mount Mazama has long been recognized as a classic example of rapid eruption of a substantial fraction of a zoned magma body. Increased knowledge of eruptive history and new chemical analyses of ∼350 wholerock and glass samples of the climactic ejecta, preclimactic rhyodacite flows and...
Detection of tannins in modern and fossil barks and in plant residues by high-resolution solid-state 13C nuclear magnetic resonance
M. A. Wilson, Patrick G. Hatcher
1988, Organic Geochemistry (12) 539-546
Bark samples isolated from brown coal deposits in Victoria, Australia, and buried wood from Rhizophora mangle have been studies by high-resolution solid-state nuclear magnetic resonance (NMR) techniques. Dipolar dephasing 13C NMR appears to be a useful method of detecting the presence of tannins in geochemical samples including barks, buried woods, peats and leaf...
Mineral and whole-rock compositions of seawater-dominated hydrothermal alteration at the Arctic volcanogenic massive sulfide prospect, Alaska
J.M. Schmidt
1988, Economic Geology (83) 822-842
The Arctic volcanogenic massive sulfide prospect, located in the Ambler mineral district of northwestern Alaska, includes three types of hydrothermally altered rocks overlying, underlying, and interlayered with semimassive sulfide mineralization. Hydrothermal alteration of wall rocks and deposition of sulfide and gangue minerals were contemporaneous with Late Devonian or Early Mississippian...
Predicting tidal currents in San Francisco Bay using a spectral model
Jon R. Burau, Ralph T. Cheng
1988, Conference Paper
This paper describes the formulation of a spectral (or frequency based) model which solves the linearized shallow water equations. To account for highly variable basin bathymetry, spectral solutions are obtained using the finite element method which allows the strategic placement of the computation points in the specific areas of interest...
Aftershock patterns and main shock faulting
C. Mendoza, S.H. Hartzell
1988, Bulletin of the Seismological Society of America (78) 1438-1449
We have compared aftershock patterns following several moderate to large earthquakes with the corresponding distributions of coseismic slip obtained from previous analyses of the recorded strong ground motion and teleseismic waveforms. Well-located aftershock hypocenters are projected onto the main shock fault plane, and their positions are examined relative to the...
Forecast model for great earthquakes at the Nankai Trough subduction zone
W.D. Stuart
1988, Pure and Applied Geophysics PAGEOPH (126) 619-641
An earthquake instability model is formulated for recurring great earthquakes at the Nankai Trough subduction zone in southwest Japan. The model is quasistatic, two-dimensional, and has a displacement and velocity dependent constitutive law applied at the fault plane. A constant rate of fault slip at depth represents forcing due to...
Age and petrology of alkalic postshield and rejuvenated-stage lava from Kauai, Hawaii
D.A. Clague, G. B. Dalrymple
1988, Contributions to Mineralogy and Petrology (99) 202-218
At the top of the Waimea Canyon Basalt on the island of Kauai, rare flows of alkalic postshield-stage hawaiite and mugearite overlie tholeiitic flows of the shield stage. These postshield-stage flows are 3.92 Ma and provide a younger limit for the age of the tholeiitic shield stage. The younger Koloa...
Two-dimensional Lagrangian simulation of suspended sediment
David H. Schoellhamer
1988, Journal of Hydraulic Engineering (114) 1192-1209
A two‐dimensional laterally averaged model for suspended sediment transport in steady gradually varied flow that is based on the Lagrangian reference frame is presented. The layered Lagrangian transport model (LLTM) for suspended sediment performs laterally averaged Lagrangian calculations with steady or unsteady upstream boundary concentration. The elevations of nearly horizontal...
Anomalous shear wave attenuation in the shallow crust beneath the Coso volcanic region, California
C. Sanders, P. Ho-Liu, D. Rinn, Kanamori Hiroo
1988, Journal of Geophysical Research Solid Earth (93) 3321-3338
We use seismograms of local earthquakes to image relative shear wave attenuation structure in the shallow crust beneath the region containing the Coso volcanic-geothermal area of eastern California. SV and P wave amplitudes were measured from vertical component seismograms of earthquakes that occurred in the Cososouthem Sierra Nevada region from July 1983 to August...
Using laser micro mass spectrometry with the LAMMA-1000 instrument for monitoring relative elemental concentrations in vitrinite
J.J. Morelli, D.M. Hercules, P.C. Lyons, C.A. Palmer, J.D. Fletcher
1988, Mikrochimica Acta (96) 105-118
The variation in relative elemental concentrations among a series of coal macerals belonging to the vitrinite maceral group was determined using laser micro mass spectrometry (LAMMS). Variations in Ba, Cr, Ga, Sr, Ti, and V concentrations among the coals were determined using the LAMM A-1000 instrument. LAMMS analysis is not...
Pb, Sr, and Nd isotopic compositions of a suite of Late Archean, igneous rocks, eastern Beartooth Mountains: Implications for crust-mantle evolution
J. L. Wooden, P.A. Mueller
1988, Earth and Planetary Science Letters (87) 59-72
A series of compositionally diverse, Late Archean rocks (2.74–2.79 Ga old) from the eastern Beartooth Mountains, Montana and Wyoming, U.S.A., have the same initial Pb, Sr, and Nd isotopic ratios. Lead and Sr initial ratios are higher and Nd initial ratios...
