Secondary hydroeruptions in pyroclastic-flow deposits: Examples from Mount St. Helens
T.C. Moyer, D. A. Swanson
1987, Journal of Volcanology and Geothermal Research (32) 299-319
Secondary hydroeruptions occur in pyroclastic-flow deposits when water or ice is trapped beneath hot pyroclastic debris and rapidly heated to steam. These eruptions display various styles of activity including fumarolic degassing, tephra fountaining, and explosive cratering. The deposits, which occupy the layer 3 stratigraphic position on the top of pyroclastic-flow...
Field guide to sedimentary structures in the Navajo and Entrada sandstones in southern Utah and northern Arizona
David M. Rubin, Ralph E. Hunter
1987, Conference Paper, Field-trip guidebook, 100th annual meeting, The Geological Society of America, Phoenix, Arizona, October 26-29, 1987
This field-trip guide describes the common sedimentary structures that occur in eolian sands. The outcrops that are described occur in the Navajo and Entrada Sandstones between the areas of Page, Arizona and St. George, Utah (figure I), but the sedimentary structures of these two sandstones are typical of most eolian...
Hydrogeologic reconnaissance of the Beowawe Geysers geothermal area, Nevada
F. H. Olmsted, F. E. Rush
1987, Geothermics (16) 27-46
The Beowawe Geysers in north-central Nevada are the discharge from a hydrothermal-convection system in a region of high heat flow. The site of thermal-fluid upflow (at about 18 kg/s before drilling and well testing) appears to be related to the intersection...
“Magnifying-Glass” Azimuthal Map Projections
John P. Snyder
1987, American Cartographer (14) 61-68
For maps focusing on a region of interest, but including surrounding areas to provide a setting, new azimuthal projections have been developed with a 'magnifying-glass' effect. On two such projections, inside a circle bounding the region of interest is a standard Azimuthal Equidistant or Lambert Azimuthal Equal-Area projection. Between this...
EMBANKMENT-DAM BREACH PARAMETERS.
David C. Froehlich
1987, Conference Paper
The study used data from 43 embankment-dam failures to develop equations that predict breach formation model parameters. These data include the failure mode, embankment characteristics, reservoir conditions at the time of failure, geometry of the final breach, and the time taken to form the breach. Regression equations were developed to...
Langrangian model of nitrogen kinetics in the Chattahoochee River
H.E. Jobson
1987, Journal of Environmental Engineering (113) 223-242
A Lagrangian reference frame is used to solve the convection‐dispersion equation and interpret water‐quality data obtained from the Chattahoochee River. The model was calibrated using unsteady concentrations of organic nitrogen, ammonia, and nitrite plus nitrate obtained during June 1977 and verified using data obtained during August 1976. Reaction kinetics of...
Liquid carbon dioxide of magmatic origin and its role in volcanic eruptions
A.R. Chivas, I. Barnes, William C. Evans, J.E. Lupton, J.O. Stone
1987, Nature (326) 587-589
Natural liquid carbon dioxide is produced commercially from a 2.5-km-deep well near the 4,500-yr-old maar volcano, Mount Gambier, South Australia. The carbon dioxide has accumulated in a dome that is located on the extension of a linear chain of volcanic activity. A magmatic origin for the...
Stable isotope compositions of fossil mollusks from southern California: Evidence for a cool last interglacial ocean.
D.R. Muhs, T.K. Kyser
1987, Geology (15) 119-122
Stable isotope compositions have been determined for modern mullusks and fossil mollusks collected from uplifted marine terraces at three localities in southern California. By using a paleoclimatic model that decouples the temperature and ice-volume signals in ocean water, ocean-water temperatures off southern California...
Natural-field and very low-frequency tipper profile interpretation of contacts
Victor F. Labson, Alex Becker
1987, Geophysics (52) 1697-1707
Anomalous vertical magnetic field (tipper) profiles acquired using natural or very low-frequency (VLF) radio transmitter sources can be interpreted simply and rapidly for a number of geologic settings. The relations between computed numerical models, and outcropping dipping and buried vertical contacts are presented here in a series of interpretation charts....
One hundred years of earthquake recording at the University of California
B. A. Bolt
1987, Earthquakes & Volcanoes (USGS) (19) 88-92
Seismology is a relatively new science, so there is special reason to celebrate the first permanent earthquake observatories in America, set up by the University of California 100 years ago. The best seismographs then available arrived from England in 1887 and were installed at Lick Observatory on Mt.Hamilton and at the...
Earthquakes and groundwater
J.D. Bredehoeft, F. S. Riley, E.A. Roeloffs
1987, Earthquakes & Volcanoes (USGS) (19) 138-146
As part of the U.S Geological Survey prediction experiment at Parkfield along the San Andreas fault in California, a network of water wells is being monitored. this network consists of wells that are situated at seven sites that were drilled by Geological Survey for the express prupose of monitoring water...
Aquatic ecoregions of the conterminous United States
J.M. Omernick
1987, Report
Ecoregions are based on perceived patterns of a combination of causal and integrative factors including land use, land surface form, potential natural vegetation, and soils (Omernik, 1987). This is a copy of the ecoregion coverage of Omernik (1987) with some item names modified. This is NOT the most recent...
Charles F. Richter: A personal tribute
Clarence R. Allen
1987, Earthquakes & Volcanoes (USGS) (19) 146-149
With the death of Charles Richter in 1985, the seismological community lost a renowned colleague, and many of us lost a close friend and advisor. Charles was born on a farm in Ohio in 1900, received his A.B. from Stanford in 1920, and his Ph.D. from Caltech in 1928. Virtually...
Volcanic processes in the solar system
M. H. Carr
1987, Earthquakes & Volcanoes (USGS) (19) 128-137
Eruptions of ammonia, water, and sulfur. These have become some of the concerns of planetary volcanologists as they try to understand volcanic processes on other planetary bodies. As exploration of the Solar System has continues, we have been confronted with more and more exotic forms of volcanism and have come...
A visit to Stromboli, lighthouse of the Mediterranean
F. M. Bullard
1987, Earthquakes & Volcanoes (USGS) (19) 199-204
About daybreak of the next morning, the perfect cone-shaped outline of Stromboli appeared on the horizon. No "red" glare could be seen, but a prominent column of white vapor was rising from the crater, and at infrequent emitted. As the boat steamed around the edge of Stromboli, the big "scar'...
Gulf trough: The Atlantic connection
Peter Popenoe, Vernon J. Henry, Faisal M. Idris
1987, Geology (15) 327-332
Analyses of seismic reflection profiles and stratigraphic data indicate a continuation of the Gulf trough trend across eastern South Carolina and offshore between Cape Fear and Cape Hatteras, North Carolina. Seismic profiles show a linear northeast-trending zone of nondeposition and erosion and areas...
Quaternary silicic pyroclastic deposits of Atitlán Caldera, Guatemala
William I. Rose Jr., Christopher G. Newhall, Theodore J. Bornhorst, Stephen Self
1987, Journal of Volcanology and Geothermal Research (33) 57-80
Atitlán caldera has been the site of several silicic eruptions within the last 150,000 years, following a period of basalt/andesite volcanism. The silicic volcanism began with 5–10 km3 of rhyodacites, erupted as plinian fall and pyroclastic flows, about 126,000 yr. B.P. At 85,000 yr. B.P. 270–280 km3 of compositionally distinct rhyolite was...
Sulfur and lead isotope studies of stratiform Zn-Pb-Ag deposits, Anvil Range, Yukon: Basinal brine exhalation and anoxic bottom-water mixing (Canada)
Wayne C. Shanks III, L. G. Woodruff, G.A. Jilson, D.S. Jennings, J.S. Modene, B.D. Ryan
1987, Economic Geology (82) 600-634
Five stratiform Zn-Pb-Ag deposits are known in Early Cambrian metapelitic rocks along a curvilinear trend in the Anvil Range, central Yukon. The Anvil Range deposits occur along the southwestern boundary of the Selwyn basin in the stratigraphic transition zone between metapelites of the Mt. Mye unit and calcareous phyllites of...
36Cl: A tracer in groundwater in the aquia formation of Southern Maryland
C.B. Purdy, A.C. Mignerey, G.R. Helz, D.D. Drummond, P.W. Kubik, D. Elmore, T. Hemmick
1987, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms (29) 372-375
The Aquia Formation (Paleocene) of Southern Maryland, a marine unit consisting predominantly of quartz sands, but containing 20-40% glauconite, represents one of the many productive, heavily pumped aquifers of the Southeastern Coastal Plain. An unusually high 36Cl activity ( ~ 15 ?? modem water) measured in an outcrop sample is...
Seismic stratigraphy and facies of continental slope and rise seaward of Baltimore Canyon Trough
John S. Schlee, K. Hinz
1987, American Association of Petroleum Geologists Bulletin (71) 1046-1067
As part of a survey of the United States continental rise seaward of the northern Baltimore Canyon Trough, four major depositional sequences were mapped on a grid of 2,350 km of multichannel seismic reflection profiles. The sequences, which range in age from Jurassic (?) to Quaternary, record a gradual sedimentary...
Subsidence, crustal structure, and thermal evolution of Georges Bank basin
B. Ann Swift, D. S. Sawyer, J. A. Grow, Kim D. Klitgord
1987, American Association of Petroleum Geologists Bulletin (71) 702-718
A geophysical study of Georges Bank basin defines a deep crustal structure that is interpreted in terms of the basin's tectonic and thermal history. Gravity models along three basin cross sections delineate two zones of crustal thinning at the basement hinge zone and oceanic crustal margins. These two zones bound...
Geologic map of the Handies Peak quadrangle, San Juan, Hinsdale and Ouray Counties, Colorado
Robert G. Luedke, Wilbur S. Burbank
1987, Geologic Quadrangle 1595
No abstract available....
Earthquakes, May-June 1987
W. J. Person
1987, Earthquakes & Volcanoes (USGS) (19) 110-112
There were no major earthquakes (7.0-7.9) during this reporting period but earthquake related deaths were reported in Italy, Iran, and the Philippine Islands. In the United States a moderate earthquake occurred in southern Illinois and caused some damage. ...
Yield and dynamics of destabilized chub (Coregonus spp.) populations in Lakes Michigan and Huron, 1950-84
Edward H. Brown Jr., Ray L. Argyle, N. Robert Payne, Mark E. Holey
1987, Canadian Journal of Fisheries and Aquatic Sciences (44) 371-383
Deepwater ciscoes (Coregonus spp.) or 'chubs' of Lake Michigan far surpassed those of Lake Huron in yield, population density, and resilience following severe depletion in the 1960s and 1970s, when the bloater (C. hoyi) composed more than 90% of the stocks. The population decline of bloaters in recent decades was...
Thermal and dissolved oxygen characteristics of a South Carolina cooling reservoir
James L. Oliver, Patrick L. Hudson
1987, Water Resources Bulletin (23) 257-269
Temperature and dissolved oxygen concentrations were measured monthly from January 1971 to December 1982 at 1-m depth intervals at 13 stations in Keowee Reservoir in order to characterize spatial and temporal changes associated with operation of the Oconee Nuclear Station. The reservoir water column was i to 4°C warmer in...
