Earth Sciences Commons^™

Vertical Variation In Groundwater Chemistry Inferred From Fluid Specific-Conductance Well Logging Of The Snake River Plain Basalt Aquifer, Idaho National Engineering Laboratory, Southeastern Idaho, Spencer H. Wood, William Bennecke

Geosciences Faculty Publications and Presentations

Well logging of electrical fluid specific conductance (C_s) shows that permeable zones yielding ground water to intrawell flows and the water columns in some wells at INEL have highly different chemistry, with as much as a two-fold variation in C_s). This suggests that dedicated pump sampling of ground water in the aquifer may not be representative of the chemistry of the waste plumes migrating southwest of the nuclear facilities. Natural background C_s in basalt-aquifer ground water of this part of the Snake River Plain aquifer is less than 325µS/cm (microSiemans/cm), and total dissolved solids in …

A Versatile Shotgun Source For Engineering And Groundwater Seismic Surveys, John R. Pelton

CGISS Publications and Presentations

We describe an electrical seismic gun that is capable of firing 8-gauge blank black powder shells in a water-filled borehole under relatively high hydrostatic pressures. The new seismic gun is a modified version of the electrical shotgun source for engineering seismic surveys introduced by Pullan and MacAulay (1987). Our modifications seal the firing circuit and 8-gauge shell against water entry so underwater detonation will occur reliably at depths to at least 80 m (0.9 MPa atmospheric pressure). Source energy is controlled by varying the size of the black powder load in the shell from 50 grains to 500 grains (10 …

Idaho Earthquakes Of 1905, 1913, And 1916: Intensity, Location, And Magnitude Inferred From Newspaper Accounts, Lynda Koll Harpham

Boise State University Theses and Dissertations

The purpose of this project is to better understand the epicentral location, magnitude, and effects of three southern Idaho earthquakes which occurred in 1905, 1913, and 1916. The three earthquakes are of considerable interest to seismologists owing to their reported proximity to large power dams, multistory buildings, and the nuclear facilities at Idaho National Engineering Laboratory (INEL) in south-central Idaho. structures were built in previous years without assessment of the potential for earthquake damage. Therefore, an understanding of these three earthquakes is important for future development, and for the reevaluation of potential earthquake hazard and adequacy of building codes.

The …

An Electrically Detonated Downhole Seismic Gun, James C. Parker, John R. Pelton, Martin E. Dougherty

CGISS Publications and Presentations

An electrically detonated downhole seismic gun (EDG) that will fire blank 8-guage shells underwater has been constructed and tested to 80m depth (hydrostatic pressures of 130 psi or 8.9 x 10⁵ Pa). Although other engineering seismic guns which fire blank or projectile sources are available, they are for near-surface shots and are not meant to be used for downhold seismic surveys in water-filled boreholes. The EDG was designed primarily for checkshot surveys (well travel-time surveys) and high-quality reflection/refraction tests, but potential applications include shallow vertical seismic profiling and borehole to borehole or borehole to surface tomography, as well as …

Chronology Of Late Pleistocene And Holocene Volcanics, Long Valley And Mono Basin Geothermal Areas, Eastern California, Spencer H. Wood

Geosciences Faculty Publications and Presentations

Hydration-rind ages based on hydration-rind thicknesses of obsidian and an assumed hydration rate of 5 microns²/1000 yrs have been determined for the 26 exposed Mono domes and coulees. Hydration-rind thickness data give good estimates of relative age differences between the domes, but determination of absolute ages will depend upon calibration to radiometric ages.

The first extrusion of highly differentiated, sparsely porphyritic rhyolite occurred an estimated 32,000 to 40,000 yrs ago and consists of a small dome at the northwest end of the contiguous chain. The next major extrusive event occurred about 24,000 yrs ago and is represented by …

Proximal Air-Fall Deposits Of Eruptions Between May 24 And August 7, 1980 -- Stratigraphy And Field Sedimentology. U.S. Department Of The Interior, Geological Survey, Richard B. Waitt Jr., Vicki L. Hansen, Andrei M. Sarna-Wojcicki, Spencer H. Wood

Geosciences Faculty Publications and Presentations

During each of the magmatic eruptions of Mount St. Helens on May 25, June 12, and August 7, a vertical eruptive column rose intermittently to altitudes of 12-15 km, from which pumice, lithic fragments, and crystals settled downwind in lobes that generally become thinner and finer away from the volcano. Each ejecta lobe is asymmetric according to several criteria, including (1) the axes of maximum thickness and of maximum pumice size are not midway between the two margins of the lobe, (2) the axis of maximum pumice size does not correspond to the axis of thickness, and (3) the median …

Areal Distribution, Thickness, Mass, Volume, And Grain Size Of Air-Fall Ash From The Six Major Eruptions Of 1980, Andrei M. Sarna-Wojcicki, Susan Shipley, Richard B. Waitt Jr., Daniel Dzurisin, Spencer H. Wood

Geosciences Faculty Publications and Presentations

The airborne-ash plume front from the Mount St. Helens eruption of May 18 advanced rapidly to the northeast at an average velocity of about 250 km/hr during the first 13 min after eruption. It then traveled to the east-northeast within a high-velocity wind layer at altitudes of 10-13 km at an average velocity of about 100 km/hr over the first 1,000 km. Beyond about 60 km, the thickest ash fall was east of the volcano in Washington, northern Idaho, and western Montana. A distal thickness maximum near Ritzville, Wash., is due to a combination of factors: (1) crude sorting within …