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G.M. Robinson

Publications and source records attributed to G.M. Robinson.

4 recordsLinked to original sources

Notes on earth fissures in southern Arizona

This report describes earth fissures at six sites in southern Arizona. These notes are preliminary to a more extensive study and detailed analysis being prepared by hydrologists in the Water Resources Division. Earth fissures were first recorded in Arizona in 1927, and have been noticed with increasing frequency since 1949. Fissures at Black Canyon, Bowie, Chandler Heights, Luke Air Force Base, Picacho, and Sells are discussed and illustrated with photographs.

Circular↗

A formula for computing transmissibility causing maximum possible drawdown due to pumping

By modifying the Theis nonequilibrium formula a relation is found in which the maximum possible drawdown is expressed in terms of a unique value for the aquifer coefficient of transmissibility. The relation is valid for any specified period and rate of pumping, for a given aquifer coefficient of storage, and for ,any desired radial distance from the center of pumping.

Water Supply Paper↗

Radio-tracer techniques for the study of flow in saturated porous materials

An experiment was conducted by the U.S. Geological Survey to determine the feasibility of using a radioactive substance as a tracer in the study of microscopic flow in a saturated porous solid. A radioactive tracer was chosen in preference to dye or other chemical in order to eliminate effects of the tracer itself on the flow system such as those relating to density, viscosity and surface tension. The porous solid was artificial “sandstone” composed of uniform fine grains of sand bonded together with an epoxy adhesive. The sides of the block thus made were sealed with an epoxy coating compound to insure water-tightness. Because of the chemical inertness of the block it was possible to use radioactive phosphorus (P 32 ). Ion-exchange equilibrium was created between the block and nonradioactive phosphoric acid. Then a tracer tagged with P 32 was injected into the block in the desired geometric configuration, in this case, a line source. After equilibrium in isotopic exchange was reached between the block and the line source, the block was rinsed, drained and sawn into slices. It was found that a quantitative analysis of the flow system may be made by assaying the dissected block.

International Journal of Applied Radiation and Iso↗