The September 1988 intracaldera avalanche and eruption at Fernandina volcano, Galapagos Islands
W.W. Chadwick Jr., T. De Roy, A. Carrasco
1991, Bulletin of Volcanology (53) 276-286
During 14-16 September 1988, a large intracaldera avalanche and an eruption of basaltic tephra and lava at Fernandina volcano, Galapagos, produced the most profound changes within the caldera since its collapse in 1968. A swarm of eight earthquakes (mb 4.7-5.5) occurred in a 14 h period on 24 February 1988...
One perspective on spatial variability in geologic mapping
H. W. Markewich, S.C. Cooper
1991, Conference Paper, SSSA Special Publication (Soil Science Society of America)
This paper discusses some of the differences between geologic mapping and soil mapping, and how the resultant maps are interpreted. The role of spatial variability in geologic mapping is addressed only indirectly because in geologic mapping there have been few attempts at quantification of spatial differences. This is largely because...
Possible tectonomagnetic effect observed from mid-1989, to mid-1990, in Long Valley Caldera, California
R.J. Mueller, M.J.S. Johnston, J. O. Langbein
1991, Geophysical Research Letters (18) 601-604
Precise measurements of local magnetic fields have been obtained with a differentially connected array of three proton magnetometers in the Long Valley caldera region since 1984. Two magnetometers are located inside the caldera with a third reference magnetometer located 26km southeast of the caldera. After correction...
Determining the mean hydraulic gradient of ground water affected by tidal fluctuations
Michael E. Serfes
1991, Ground Water (29) 549-555
Tidal fluctuations in surface-water bodies produce progressive pressure waves in adjacent aquifers. As these pressure waves propagate inland, ground-water levels and hydraulic gradients continuously fluctuate, creating a situation where a single set of water-level measurements cannot be used to accurately characterize ground-water flow. For example,...
Fractal patterns of fractures in granites
B. Velde, J. Dubois, D. Moore, G. Touchard
1991, Earth and Planetary Science Letters (104) 25-35
Fractal measurements using the Cantor's dust method in a linear one-dimensional analysis mode were made on the fracture patterns revealed on two-dimensional, planar surfaces in four granites. This method allows one to conclude that:(1)|The fracture systems seen on two-dimensional surfaces in granites are consistent with the part of...
Rates of soil development from four soil chronosequences in the southern Great Basin
J.W. Harden, E. M. Taylor, C. Hill, R. K. Mark, L. D. McFadden, M.C. Reheis, J.M. Sowers, S. G. Wells
1991, Quaternary Research (35) 383-399
Four soil chronosequences in the southern Great Basin were examined in order to study and quantify soil development during the Quaternary. Soils of all four areas are developed in gravelly alluvial fans in semiarid climates with 8 to 40 cm mean annual precipitation. Lithologies of alluvium are granite-gneiss at Silver...
Status of the least Bell's vireo at the West San Luis Rey River, San Diego County, California, 1990
B.E. Kus
1991, Report
No abstract available at this time...
Distribution and breeding status of the least Bell's vireo at the San Luis Rey River, San Diego County, California, 1991
B.E. Kus
1991, Report
No abstract available at this time...
Our changing continent
John Stevens Schlee
1991, Report
Effectiveness of fences and culverts for protecting desert tortoises along California Highway 58: final report on study design
W.I. Boarman
1991, Report
No abstract available at this time...
Distribution and breeding status of the least Bell's vireo at the San Luis Rey River, San Diego County, California, 1990
B.E. Kus
1991, Report
No abstract available at this time...
A Lome Prieta experience
Thomas C. Hanks
1991, Earthquakes & Volcanoes (USGS) (22) 124-128
Volcanic-hazards assessments; past, present, and future
D. R. Crandell
1991, Earthquakes & Volcanoes (USGS) (22) 131-132
A new reason to study volcanoes has developed within the last few decades; it is to anticipate the specific kinds and extents of future eruptions and their effects on people and property. Such studies are based chiefly on the eruptive histories of volcanoes and the distribution of past eruptive products....
A reconnaissance study of halogenated organic compounds in catfish from the lower Mississippi river and its major tributaries
T.J. Leiker, C.E. Rostad, C.R. Barnes, W. E. Pereira
1991, Chemosphere (23) 817-829
Blue catfish, (Ictarurus furcatus), black bullhead catfish, (Ictalurus melas), channel catfish (Ictalurus punctatus), and flathead catfish (Pylodictus olivaris), were collected along a 1200 mile river reach of the Mississippi River and its major tributaries. Tissue samples were extracted and analyzed by fused silica capillary gas chromatography/mass spectrometry (GC/MS) to determine...
Volcanologists and the geologic past
D. A. Swanson
1991, Earthquakes & Volcanoes (USGS) (22) 138-139
Were volcanologists to be asked why they study active volcanoes, they would list many reasons: to understand their dynamics, to use them as windows into the earth, to warn of hazards, to provide nearly real-time information on rates of various physical and chemical processes, and many others. Near the bottom...
Advances(?) in mitigating volcano hazards in Latin America
M.L. Hall
1991, Earthquakes & Volcanoes (USGS) (22) 149-150
The 1980's were incredible years for volcanology. As a consequence of the Mount St. Helens and other eruptions, major advances in our understanding of volcanic processes and eruption dynamics were made. the decade also witnessed the greatest death toll caused by volcanism since 1902. Following Mount St. Helens, awareness of...
Brine evolution and mineral deposition in hydrologically open evaporite basins
W. E. Sanford, W.W. Wood
1991, American Journal of Science (291) 687-710
A lumped-parameter, solute mass-balance model is developed to define the role of water outflow from a well-mixed basin. A mass-balance model is analyzed with a geochemical model designed for waters with high ionic strengths. Two typical waters, seawater and a Na-HCO3 ground water, are analyzed to illustrate the control that...
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...
Volcanoes in outer space and inner space
P. Francis
1991, Earthquakes & Volcanoes (USGS) (22) 151-153
AS a teenager, I spent many long, bone-chilling hours studying the Moon and the planets with a rickety, homemade telescope. After 30 years, I still recall the pain and pleasure of creeping illicitly out of the house in the small hours of the morning for the few moments of satisfaction...
The use of mineralogic techniques as relative age indicators for weathering profiles on the Atlantic Coastal Plain, USA
D. R. Soller, J. P. Owens
1991, Geoderma (51) 111-131
Textural, geochemical, and mineralogic study of soils and weathering profiles has led to the practice of applying varioys weathering parameters as relative age indicators. In our studies examined the entire thickness of weathered sediment (i.e., the weathering profile) for evidence of weathering-induced changes in both sand- and clay-sized mineralogy, and...
Late Neogene marine Ostracoda from Tjornes, Iceland
T. M. Cronin
1991, Journal of Paleontology (65) 767-794
On the western side of the Tjörnes Peninsula in northern Iceland exposures of fossiliferous marine sediments, basalts, and glacial tills record the climatic history of this region of the North Atlantic Ocean. Seventy-five marine ostracode species were recovered from the Pliocene Tjörnes sediments and Quaternary sediments known...
Revised age of deglaciation of Lake Emma based on new radiocarbon and macrofossil analyses
S. A. Elias, P. E. Carrara, L.J. Toolin, A.J.T. Jull
1991, Quaternary Research (36) 307-321
Previous radiocarbon ages of detrital moss fragments in basal organic sediments of Lake Emma indicated that extensive deglaciation of the San Juan Mountains occurred prior to 14,900 yr B.P. (Carrara et al., 1984). Paleoecological analyses of insect and plant macrofossils from these basal sediments cast doubt on the reliability of...
The library as a reference tool: online catalogs
M. Stark
1991, The Compass: Earth Science Journal of Sigma Gamma Epsilon (68) 81-86
Online catalogs are computerized listings of materials in a particular library or group of libraries. General characteristics of online catalogs include ability for searching interactively and for locating descriptions of books, maps, and reports on regional or topical geology. Suggestions for searching, evaluating results, modifying searches, and limitations of searching...
Imaging the midcontinent rift beneath Lake Superior using large aperture seismic data
Anne M. Trehu, Patrick Morel-a-l’Huissier, R. Meyer, Z. Hajnal, J. Karl, R.F. Mereu, John L. Sexton, J. Shay, W. K. Chan, D. Epili, T. Jefferson, X. R. Shih, S. Wendling, Bernd Milkereit, A. Green, Deborah R. Hutchinson
1991, Geophysical Research Letters (18) 625-628
We present a detailed velocity model across the 1.1 billion year old Midcontinent Rift System (MRS) in central Lake Superior. The model was derived primarily from onshore-offshore large-aperture seismic and gravity data. High velocities obtained within a highly reflective half-graben that was imaged on coincident seismic reflection data demonstrate the...
Introduction to special section on the California-Arizona crustal transect: Part II
G. B. Haxel, R.W. Simpson, Keith A. Howard
1991, Journal of Geophysical Research (95) 19949-19952
In May 1988, a multidisciplinary conference was held in Flagstaff, Arizona, to synthesize recent research on the crustal structural and evolution of a transect across the southern Cordillera. This transect extends from the southern Colorado Plateau southwestward across the Arizona Transition Zone, through the Basin and Range province in the...
